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Bridge Engineering Handbook Superstructure Design Wai-Fah Chen, Lian Duan

Segmental Concrete Bridges

Publication details https://www.routledgehandbooks.com/doi/10.1201/b16523-4 Wai-Fah Chen, Lian Duan Published online on: 24 Jan 2014

How to cite :- Wai-Fah Chen, Lian Duan. 24 Jan 2014, Segmental Concrete Bridges from: Bridge Engineering Handbook, Superstructure Design CRC Press Accessed on: 02 Oct 2021 https://www.routledgehandbooks.com/doi/10.1201/b16523-4

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The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The publisher shall not be liable for an loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 while the posttensioning system can be bonded, unbonded tendons, or a combination of both. Bonded Bonded of both. or acombination tendons, unbonded bonded, be can system posttensioning the while methods, or cast-in-place precast/prefabricated by be produced can segments These or substructure. superstructure either system, structural abridge toform tendons posttensioning using segments called members of concrete pieces smaller assembling involves bridges concrete of segmental Construction 3.1 Inc. Brinckerhoff, Parsons Teddy S.Theryo Introduction References 3.9 Durability 3.8 Detailing 3.7 3.6 3.5 3.4 3.3 3.2 3.1 Introduction Construction Stage Analysis Stage Construction Design Longitudinal Design Deck Design Conceptual Methods Construction Material Structural Bridges Concrete Posttensioned of World States United the in Bridges Posttensioned of Problems Durability Design Shear Longitudinal and Bending Transverse Combined Construction during Stability Check Strength Design State Limit •Secondary Effect •Summary Forces of Design •Service Forces •Shear Load Lag •Temperature Effect •Time-Dependent Load Methodology Design Design Layout Approach Design •Structural •Aesthetic System Sections Aspect Span •Span-to-Depth •Proportional Ratios Configuration Launched •Incrementally •Span-by-Span Falsework Construction Construction Cantilever Balanced •Cementitious Steel •Ordinary Grout Reinforcing Steel •Posttensioning •Prestressing •Concrete Systems General ...... • • • • • Durability Problems of Posttensioned Bridges around the the around Bridges Posttensioned of Problems Durability Learned Lessons Forces Design of Summary Strut and Tie Model Tie and Strut Design State Limit Strength • ...... Erection Full-Span Segmental Concrete Concrete Segmental ...... • • Shear and Torsion and Design Shear • Analysis Load Live Check Tension Stress Principal • ...... Envelope Tendon and Layout ...... • New Direction for the Next Generation Generation Next the for Direction New • Erection Tendons Erection ...... • • • Precast Spliced UGirder Spliced Precast Cast-in-Place on Cast-in-Place Conclusions • Service Limit State State Limit Service • Posttensioning Tendon Posttensioning • Bridges • Flexural Flexural • LRFD Live Live LRFD Shear Key Key Shear 3 124 158 148 163 169 115 110 91 97 93 91 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 systems, the segmental bridge construction could not have been realized. not have been could construction bridge segmental the systems, posttensioning Without possible. structures of posttensioned application wide tothe led which wires of practice. standard state-of-the-art current after the World II to War infancy its from construction bridge details. and quantity, material design, the impact also will loads construction cases, most In of structures. type other any unlike ­tendon layouts, and design the outcome of affect greatly will method construction The design. the with proceeding to prior methods, and means construction the todetermine critical it is design, bridge segmental In tendons. or internal of external form the in sheathed, and waxed, or greased, grouted cementitious be could tendons unbonded while tendons, internal grouted of cementitiuos consist typically tendons 92 construction, structural integrity, and durability during its service life. service its during durability and integrity, structural ­construction, during constructability order tomaintain in process of adesign part important an is practice industry standard high and detailing Good completion. tothe design from bridge asegmental of building cess whole pro the during control quality and of workmanship importance on the awareness to build and cost, maintenance minimize structures, the of life service intended the order 3.9to fulfill in Section Specifications. Design LRFD in AASHTO 1989, to edition prior first the since years formany bridges concrete segmental on construction and specifications and guidelines design as served have specifications guide 1999. The 2nd Edition, Bridges, of Segmental Construction and Design for Specifications Guide AASHTO from provisions design bridge segmental adopted LRFD design bridge andconstruction means methods. including design, tofinal conception from design bridge concrete of segmental on acomplete spectrum types). bridge on selecting for more discussions Design 3.4 on Conceptual (see Section valley or deep crossing over river bridge long span for avery as such popular, still is construction bridge segmental cast-in-place circumstances, Under on. so certain and practice, standard local location, length, span project, of the size on the it depends project; bridge every for not suitable is technology However, segmental precast structure. economical overall and portation, of trans ease control, quality better yard, casting the in of segments production mass of construction, company. of the director technical the was Muller where contractor eral a gen Bernard, Campenon by constructed was The bridge France. Paris, in River Seine over the Bridge ­ of the construction for the together them posttensioned and segments between joints along girder. than of girders pieces small transport and tohandle much easier It is of construction. speed improve the and girders of the transportation the order tofacilitate in girder span on asingle site toform together them posttensioned and segments girder precast three assembling York, New upstate in Sheldon Bridge USA, by called bridge single-span of asmall construction to the the ­ against hardened had concrete the after segment cast newly the to applied was Posttensioning segments. stressed and cast previously tothe attached on aform-traveler the ­ and method cantilever balanced the with AG 1951. in constructed was The bridge Widmann & of Dyckerhoff Finsterwalder Dr. Ulrich engineer German pioneered by the was Germany, France. of Paris, east River Marne over the at Luzancy bridges several In 1939, Eugene Freyssinet of France developed a conical wedge posttensioning anchorage system for system anchorage posttensioning wedge aconical developed 1939, of France In Freyssinet Eugene ­ developmentthe segmental of in events/milestones important the someare of The following Aside from design and construction, durability of segmental concrete bridges was discussed in in discussed was bridges concrete of segmental durability construction, and design from Aside 2012) (AASHTO on ­ Specifications Design Bridge LRFD AASHTO the 3.4 to3.8, Sections In students graduate and owners, engineers, to knowledge practicing a practical presents chapter This speed due toits over cast-in-place popularity gained has construction segmental precast then, Since cast match epoxy-coated using girder box segmental precast applied time first for the Muller 1962, In innovation casting match dry-joint the time first for the applied Muller Jean French engineer 1954, In Balduistein, in Bridge Lahn the bridge, segmental cast-in-place long-span development The of a modern ­ segmental prestressed to apply precast first the From 1941 was to1949, Freyssinet provisions are extensively referenced (AASHTO LRFD Sections 4 and 5). AASHTO 5). 4and AASHTO Sections LRFD (AASHTO referenced extensively are Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge previously stressed segments. stressed previously segments were cast were cast segments construction for construction Choisy-le-Roi segmental segmental concrete concrete - - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 plays an ­ an plays also steel reinforcing Ordinary of concrete. shrinkage and creep the tocounteract steel high-strength of the application by concrete prestressed successful first of the use the with credited was Freyssinet of prestress. long-term loss and shrinkage and of creep of understanding due to lack failed structures ­ and steels, ing ­posttensioned general, in which consist structures concrete, of prestress high-strength high-strength to similar are very bridges concrete segmental posttensioned for materials structural basic The 3.2.1 3.2 Bridges Concrete Segmental (anchor head), grout cap, and grout ports as shown in Figure 3.1. Figure in shown as ports (anchor grout and head), cap, grout plate wedge trumpet, plate, abearing comprises system anchorage posttensioning abasic general, In material. and sizes, shapes, different in aredesigned systems anchorage PT The States. United the in industry/market the in found be can systems other and Davis, Schwager BBR, Freyssinet, DSI, VSL, as such systems one of these Any system. aproprietary are bridges posttensioned in systems anchorage PT 3.2.3 order toavoid in honey combing. (SCC) concrete recommended is self-consolidating deviators, and blisters diaphragms, as such bars reinforcing congested highly with members concrete of case In corrosion. from tendons posttensioned the protect and durability improve the will concrete High-performance permeability). (low concrete high-performance with combination in strength high with design amix toselect necessary it may be (55 environment, psi MPa). aggressive 8,000 For an than toor higher equal strength concrete with constructed being are structures concrete prestressed precast and more Therefore, more industry. precast the in nowadays (83 practice acommon is MPa) concrete psi (69 psi 10,000 MPa) to 12,000 producing technology, of concrete advancement the With mations. defor creep long-term minimize to property concrete is a preferred This of elasticity. modulus higher in results concrete higher-strength addition, In structures. concrete prestressed in required is days at 28 psistrength MPa) 5,000 (35 of concrete minimum a Typically, economical. and not efficient is concrete prestressed concrete, high-strength Without section. member tothe forces posttensioning sion of the precompres and members concrete tothe anchorages the around transferred stresses compressive high of because structures posttensioned in required is bridges for posttensioned concrete High-strength 3.2.2 system. protection of corrosion alternative another as tendons sheathed and greased monostrand and wax, grease, petroleum adopted also have countries European the States. United in specified generally are PE ducts smooth tendons, For external (PP) protection. tendon corrosion polypropylene for better (PE) polyethylene or of either made duct plastic tocorrugated US have switched the in owners most 2003 but since duct (internal), metal corrugated grouted used have mostly bridges segmental earlier The structure. of the ­ in structures tendons inclined posttensioned and toconcrete addition in webs, the in capacity shear-carrying tothe contribute also will reinforcement and ordinary spiral; theof form in confinement reinforcement ordinary without properly. tofunction able not be will ture struc concrete prestressed aposttensioned bars, reinforcing ordinary Without materials. structural There are two types of tendons used in segmental bridges, namely bonded and unbonded tendons. tendons. unbonded and bonded namely bridges, segmental in used tendons of types two are There Structural Material Structural General Concrete Posttensioning Systems Posttensioning important role in supplementing concrete and high-strength prestressing steel as the primary primary the as steel prestressing high-strength and concrete supplementing role in important controlling flexural crack width in concrete and contributes in flexural ultimate capacity capacity ultimate flexural in contributes and concrete in width crack flexural controlling ordinary reinforcing steel, including grout in the duct. Earlier, prestressed concrete concrete prestressed Earlier, duct. the in grout including steel, reinforcing ordinary . Ordinary reinforcement also plays an important role in partially prestressed concrete concrete prestressed partially role in important an plays also reinforcement . Ordinary For instance, local zones around the anchorages may crack, may crack, anchorages the around zones local For instance, 93 - - - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 94 two and three-wire strands, oval deformed bars, single wire, and so on. However, only two types of However, on. so types and two only wire, single bars, deformed oval strands, three-wire and two strands, compact strands, nineteen-wire as such bridges posttensioned and for segmental utilized be can that worldwide industry the in types steel prestressing high-strength of forms many are There 3.2.4 wax. and grease petroleum as such material, filler flexible with filled also are tendons external the 3.6). Europe and In 3.5 (see Figures section structural concrete the with are bonded not tendons External grout. cementitious with filled and duct HDPE smooth in bars. or wires, strands, be tendoncould steel (PP).(HDPE) or polypropylene high-strength The polyethylene density high from made be may duct corrugated The plastic 3.4. Figure in shown as grout of cementitious by means concrete structural tothe bonded are and ducts plastic or corrugated ducts two. of the or acombination tendons, external grouted port. grout vertical the through alot simpler be will access inspection the anchorages, new For the requirements. toFDOT similar ages DOTs anchor state PT have adopted other Many 3.3. and 3.2 Figures in shown as systems anchorages PT of newer andgenerations the older between differences the Notice specifications. posttensioning its in cap grout permanent and inspection postgrouting to facilitate trumpet the above located port/vent 3.2 FIGURE 3.1 FIGURE External tendons are typically located outside the perimeter of the concrete section and are housed housed are and section concrete of the perimeter the outside located typically are tendons External metal corrugated in housed are and section concrete structural the inside located are tendons Internal tendons, internal of grouted consisted States United the in built bridges posttensioned general, In grout vertical additional an required (FDOT) of Transportation Department Florida the 2003, In Prestressing Steel Prestressing Basic posttensioning anchorage system. (Courtesy of VSL International.) (Courtesy system. anchorage posttensioning Basic Old generation of PT anchorage system. (Courtesy of DSI.) (Courtesy system. anchorage of PT generation Old Grout po rt Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge Grout ca Ho rizon p We Be tal dge plate/Anchorhead aring plat Tr gr um out po pe t e rt Coupler duc Corrogate t

d - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental 1 past. the in older bridges some in were used wires below. shown as Parallel States, United the in used commonly are steel prestressing 3.5 FIGURE 3.4 FIGURE 3.3 FIGURE (ty Internal tendons

p.) .

Material Properties: Material recommended to use low relaxation for segmental bridges. for segmental low relaxation touse recommended Uncoated seven-wire stress-relieved for prestressed concrete conforming to ASTM A416-90. toASTM It is conforming concrete for prestressed stress-relieved Uncoated seven-wire b. a. c. Yield strength ( Yield strength Apparent modulus of elasticity: 28,500 KSI (197,000 KSI Mpa) 28,500 of elasticity: modulus Apparent ( strength tensile Ultimate Internal tendon. Internal New generation of PT anchorage system. (Courtesy of DSI.) (Courtesy system. anchorage of PT generation New External tendon. External Blister (ty f py ): 243 KSI (1,674 KSI ): 243 Mpa) Diaphrag Diaphrag p.) m f m pu ): 270 (1,860 KSI Mpa) tendon (ty Tr Devi tendon (ty Tr ansverse ansverse Deta ator (ty Ex te il A rnal t p.) p.) p.) endons Grout Grout ca D gr Ve etail Sect out po rt ical ion A- A gr Ho p out po rt Concrete rizon A metal duct duct orcorr Cor ta rt l ru duc Smo Grout ga Stran t te oth pla d pl ugat d as stic tic ed 95 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 96 Deformed and plain billet-steel bars for concrete reinforcement conforming to ASTM A615. toASTM conforming reinforcement for concrete bars billet-steel plain and Deformed 3.2.6 andaccepted. referenced widely are specifications PTI specifications, grout own have their owners most Although methods. and criteria test and acceptance mixture. grout the for used is water potable Clean is optional. sand but sands, fine contains grout Some pumpability. and inhabitation, corrosion entrainment, water, air reduce control, control, bleed improveset isto grout in admixtures The role of fume. cement, or silica slag 120 Grade ash, Ffly Class Cand Class be could additives Mineral Type used. cement is II application, of hydration heat release For slower C150/C150M for mixture. grout toASTM used be Type Ior according Type can cements II concrete. surrounding its and steel prestressing bond between agood toforming addition in steel, ing of prestress protection corrosion primary the as serves grout tendons, posttensioning water. bonded In and aggregates, admixtures, additives, mineral cement, of Portland of amixture consists Grout material 3.2.5 3.6 FIGURE Material properties: Material the including grout, type of each for required properties material the specified also specifications The grout: of types four 2012 listed Edition, 2nd Specifications, Grouting (PTI) Institute Posttensioning Modulus of elasticity: 29,000 KSI (200,000 Mpa) (200,000 KSI 29,000 of elasticity: Modulus (400 Mpa) KSI 60 Yield strength: • • • • 2. Uncoated high-strength steel bar for prestressed concrete according to ASTM A722-90. toASTM according concrete for prestressed bar steel Uncoated high-strength Material Properties: Material bridges. Type (deformed) touse II for segmental It bar recommended is Class D: Engineered grout. Engineered D: Class environments. or aggressive nonaggressive for either Prepackaged C: Class salts. deicing and environment, marine cycle, wet/dry as such exposure Aggressive B: Class outdoor. or nonaggressive indoor as such exposure Nonaggressive A: Class b. a. c.

Ordinary Reinforcing Steel Cementitious Grout Yield strength ( Yield strength Modulus of elasticity: 30,000 KSI (207,000 KSI Mpa) 30,000 of elasticity: Modulus ( strength tensile Ultimate External tendons atdeviator. tendons External Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge f py ): 120 KSI (828): KSI 120 Mpa) f pu ): (1,035 150 KSI Mpa) - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 port, especially one in which the projection is great in relation to the depth, so that the upper part is in in is part upper the that so depth, tothe relation in great is projection the which one in especially port, sup a vertical from projecting member “A is: Webster’s structural from rigid of Dictionary “cantilever” 3.7. Figure in shown Definition as construction staged using support, temporary without structure, lever canti a to point form afixed from outward tobuild used of construction amethod is Free cantilevering 3.3.1 3.3 environment. corrosive extremely the in located elements for structural Bridges Concrete Segmental (Petroski, Henry. 1995). Henry. (Petroski, Tibet and India between Bhutan, in girder span drop-in the with members cantilever timber using century seventeenth the in constructed 3.9, was in Figure shown The Bridge, century. Wandipore fourth tothe dates which bridge, cantilever recorded earliest the is Japan, Nikko, in located Shogun’s Bridge 3.8. Figure in shown as method” construction cantilever “balanced termed it is step, same “bracket.” is of “cantilever” meaning compression.” in Another lower part the and tension 3.8 FIGURE 3.7 FIGURE Some owners have specified solid stainless steel reinforcing bars conforming to ASTM A955/A955M ASTM to conforming bars reinforcing steel stainless solid have specified owners Some It is believed that the idea of cantilevering in bridge construction originated in the ancient Orient. Orient. ancient the in originated construction bridge in of cantilevering idea the that It believed is at the erected and structure asingle as attached are structures cantilever free opposing two When

Fi

Construction Methods Construction xe Balanced Cantilever Construction d po in Cantilevering construction method. Cantilevering Balanced cantilever construction method. construction cantilever Balanced t Fo rm tr av eler L Fo rm tra C L veler Pier L Fo rm tr av eler

97 - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 98 balanced cantilever bridges are especially suitable for construction of long spans over deep valleys and and valleys over deep of long spans for construction suitable especially are bridges cantilever balanced 3.12). world (see the Figure across bridges Cast-in-place of long-span for construction popularity gained segmental concrete bridge construction. of 203.65 1950–1951, length span after a World has 3.11). II and ends Figure bothWar (see at fixed is bridge The in Germany in at Balduinstein Bridge Lahn of the construction with method cantilever balanced the using bridge concrete toacast-in-place posttensioning applied successfully AG (DSI International) Widmann & Dyckerhoff firm the of Finsterwalder Dr.Ulrich required. reinforcing and heavy deflection due toexcessive not successful was concrete for reinforced method 1930. However,in cantilevering the ft223 of a (68 construction the with time first for the River. Lawrence Saint over the 3.10) Bridge (Figure Quebec the and England in Bridge of Forth Firth of the construction with century nineteenth end of the by the method vering FIGURE 3.10 FIGURE 3.9 FIGURE After successful completion of the Lahn Bridge, the system was improved over the years and has has and improvedthe years over was system the Bridge, Lahn the completion of successful After place took bridges concrete reinforced cast-in-place to method cantilevering the of The application cantile the using erected were successfully trusses steel industry, construction bridge steel the In ft m (62.0 Wandipore Bridge (From Petroski, H., H., (From Petroski, Bridge Wandipore Firth of Forth Bridge in the United Kingdom under construction. under Kingdom United the in Bridge of Forth Firth ). This bridge is considered the pioneer of modern long-span balanced cantilever cantilever balanced long-span the pioneer of modern considered is bridge ). This Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge Engineers of Dream of Engineers m ) span bridge across the Rio de Peixe in Brazil Brazil in Peixe de Rio the across bridge ) span ; Alfred A. Knopf, Inc., New York, New Inc., 1995.) Knopf, A. ; Alfred - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental States in 1974. in States (115.8 m) of 270 ftspans five m) (82.3 (518.2 m) long including cantilever tips. both of elevation as as well misalignment horizontal correct to used be also can attachments These 3.15). pour Figure (see closure the movement during toprevent differential tips cantilever to both attached are backs strong steel and a form-traveler Typically segment. pour a closure with structure acontinuous tomake connected are tips 3.14).(see cantilever adjacent Figure two the At mid-span, mid-span toward moving form-travelers using time same at piers the pier or multiple asingle from built be can bridge the point, 3.13. starting Figure From in this shown apier-table as called pier is over the segment starter The overcolumn. a pier constructed first is segment a starter construction, cantilever balanced cast-in-place In concrete. toprecast comparison slow in considered be on site can increment every tocast taken time the For instance, construction. for superstructure required time the is system the of drawback The only prohibitive. or cost not possible is supports temporary placing where rivers FIGURE 3.12 FIGURE 3.11 FIGURE California’s Pine Valley Creek Bridge rises 450 ft 450 (137.2floor, is rises and Bridge Creek Valley 1700valley Pine the above m) California’s ft + 270 ft (82.3 m) and was the first cast-in-place segmental concrete bridge built in theUnited in built bridge concrete segmental cast-in-place first the 270 ft was and m) (82.3 Lahn Bridge. (Courtesy of VSL International.) (Courtesy Bridge. Lahn Vietnam Veterans Memorial Bridge, VA. Bridge, Memorial Veterans Vietnam + 340 ft 340 (103.6 m) + 450 ft 450 (137.2 m) + 380ft 0 8 3 99 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 100 FIGURE 3.15 FIGURE 3.14 FIGURE 3.13 FIGURE Segment placement supported by form-travelers. supported placement Segment Pier table of a cast-in-place balanced cantilever construction. cantilever balanced of acast-in-place table Pier Strong back across a closure pour. aclosure across back Strong Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 ture erection, less creep and shrinkage effect, and better quality control when casting segment in the in segment casting when control quality better and effect, shrinkage and creep less erection, ture of superstruc speed the are construction over cast-in-place bridge segmental of precast advantages Some Muller. M. by Jean designed and contractor Bernard Campenon by the constructed was bridge 1962–1964. in joint The epoxy cast match using constructed bridge cantilever balanced precast modern first the was France in Paris 1950–1951, near in River Seine Germany over the Choisy-le-Roi Bridge accomplished. 16been has ft longer than form-travelers with cantilevering cases, special one. In anew ing order without bereused often can and market, the in widely available are 16 tion, form-travelers segment ft addi In construction. during loads out-of-balance large producing due tolonger segments recommended 10 from to16than 16 ft longer ft (4.9 are not 4.9 ranging m) (3 to lengths m).Segment lengths segment typical Bridges Concrete Segmental equipment: following the ­accomplished with be can erection segment project, of the size the and site condition on the 3.18. Figure Depending in shown as weight segment order the toreduce in segments two into pier segment the tosplit common is Therefore, it in place. segment the and place tolift equipmentcapacity erection the it impacts since t(712 (534 60 to80 toabout weight KN), KN) segment the tolimit It important is transportation. and 10 in ft cast match (3 are m) to handling 12 ft segments of Typically,ease the (3.65 for segments m) long site for project placement. tothe todelivery one prior month on site at stored least are segments cast The pre facilities. testing 3.17), site (see material and storage Figure segment offices, ment transporter, seg facilities, curing towers, survey plant, 3.16), concrete (see jigs, Figure bar cells reinforcing ­casting structure. economical and overall equipments, erection selecting in flexibility ­segments, the of transporting ease condition, of weather independent system, curing better yard, casting the in production mass are construction segmental of precast advantages Other method. construction place cast-in- of the schedule slow to overcome construction invented the was construction segmental Precast France. in River Marne over the Bridge of Luzancy construction the with 1944 in Freyssinet by Eugene pioneered was pieces segment precast posttensioning using construction bridge fact, In yard. ­casting FIGURE 3.16 FIGURE After successful construction of the first modern cast-in-place balanced cantilever (Lahn Bridge) in (Lahn cantilever balanced cast-in-place modern first the of construction successful After with pier table the from symmetrically placed are segments construction, bridge cantilever classical In Precast segmental construction requires a casting yard to accommodate construction materials, materials, construction toaccommodate yard acasting requires construction segmental Precast 2. 4. 3. 1. Overhead launching gantry (Figure 3.19) (Figure gantry launching Overhead Beam and winch and Beam 3.20) (Figure lifter Segment crane based Ground Casting yard. 101 - - - - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 102 FIGURE 3.19 FIGURE 3.18 FIGURE 3.17 FIGURE Segments storage site. storage Segments Split precast pier segment. pier precast Split Segment erection with overhead launching gantry. launching overhead with erection Segment Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental against the adjacent segment after epoxy glue is applied at the match-cast joint between segments. segments. between joint match-cast the at is glueapplied epoxy after segment adjacent the against bars posttensioned with posttensioned temporarily is segment Each whole span. for the segments the by ­ segments of precast for erection meant typically is method construction Span-by-span 3.3.3 3.21. in Figure depicted is false-work on cast-in-place The intensive. labor and slow is relatively false-work on construction Cast-in-place complete. is posttensioning after is removed false-work temporary The conditions. soil good and length, span tomedium short columns, short relatively complex geometry, with forsuperstructure suitable is construction of type This tion. construc segmental cast-in-place as considered be could Therefore, it stages/segments. in structure the toconstruct common It also is bridge. of the length entire for the ground on the directly ­supported on false-work superstructure abridge building is method construction on false-work Cast-in-place 3.3.2 3.21 FIGURE 3.20 FIGURE

Cast-in-Place on Falsework Cast-in-Place Span-by-Span Construction Span-by-Span Cast-in-place on falsework. on Cast-in-place Segment erection with segment lifter. segment with erection Segment posttensioning posttensioning 103 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 case of underslung gantry, support brackets are needed at the columns to support the gantry. the tosupport columns at the needed are brackets support gantry, of underslung case the In gantry. 3.24) or (see underslung Figure gantry launching overhead an using done be either can erection segment 3.23). (see piers span-by-span Figure the The between in required are deviators dons, ten external For the diaphragms. at tendons the longitudinal the by splicing upspans, to ten structure a continuous as designed be also can construction bridge Span-by-span tendons. internal and external ­ The joint. dry using still are countries some although concern, durability in resulted deck the from leaking due to­ States United the in no longer is joint allowed dry with However, segmental ­dry-joint. precast called is of joint type This joints. at the applied have no epoxy bridges span-by-span earlier of the Some 104 3.23 FIGURE 3.22 FIGURE permanent tendons typically consist of external tendons entirely (Figure 3.22) or a­ (Figure entirely tendons of external consist typically tendons permanent External tendons inside a box girder. abox inside tendons External Typical deviator. Typical Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge

combination of combination water water - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental features. of interesting set own have their bridges launched Incrementally site. for solution aparticular economical most the todetermine alternative construction for each evaluated bridge. below the area the disturbing without toabutment abutment from piers over the be done can superstructure the of launching the that is method construction this of advantage The ment. other abut the at position final its reaches segment first the until repeated are sequences construction The forward. launched be to ready then are segments first and second The together. segments two the to­ stressed is posttensioning then and segment first the against cast is segment Anew ­forward. or pulled pushed either being by launched is segment first the lowered is and form Subsequently, the ­ the end nearest segment tothe attached nose asteel-launching with posttensioned and cast segment is (15) 50 about is first segment The Typically, 3.25. each ft to 80 Figure (25 in in length. m) shown as abutments, one of the behind located form casting on astationary segments short ­successive America. North in few applications seen has method construction but world, the the around built have been bridges launched incrementally concrete posttensioned Many Germany. in hold method apatent for and the bridges, launched incrementally concrete posttensioned many have designed they then, Since bridges. development of both the with were credited Baur Willi partner his and Leonhardt Dr. Professor Fritz Austria. Kufstein, in Bridge Inn 1965 at the in structed con was bridge launched incrementally concrete prestressed modern first the that, after Soon 1962. in America, Venezuela, South in Caroni Rio over the bridge concrete of a reinforced construction the to was applied bridge launched incrementally concrete first The structures. for concrete case not the is which compressionand well, tension both handle can material steel the since is notsurprising This years. many for erection bridge steel for used been has method construction bridge launching incremental The 3.3.4 3.24 FIGURE Some advantages of incrementally launched bridge are as follows: as are bridge launched of incrementally advantages Some carefully are disadvantages and advantages the of aproject, phase design conceptual the During in constructed is bridge The simple. is very bridge launched incrementally the of idea basic The 2. 1. Allows for the ability to cast segments during inclement weather and through the winter by winter the through and weather inclement during segments tocast ability for the Allows Requires short casting form of about 100 ft (30 m) long and less heavy equipment. of 100 about ft form heavy (30 and less m) long casting short Requires providing shelter and insulation over the casting form. casting over the insulation and shelter ­providing

Incrementally Launched Span-by-span segment erection using overhead gantry. overhead using erection segment Span-by-span abutment. abutment. connect connect 105 - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 106 Figure 3.29. Figure in shown as device, aspecial using superstructure the by pushing is superstructure the of launching way Another 3.28. Figure in shown as located, is form casting the where abutment the against ­reacting segments. front the moments in bending the to reduce nose of a launching instead used be also can system cable stay and Amast toproper grade. adjusted further be can geometry vertical the support, the reaches girder the When girder. the moments in bending the reduce and nose launching for the support force toprovide toapredetermined loaded are 3.27). jacks The (Figure supports temporary bridge. of the length span longest of the 60%–80% about is length nose The ispreferred. nose stiff sufficiently and Alight together. braced laterally are or trusses girders plate steel of the 3.26). Both (Figure webs the in embedded bars by webs posttensioned girder box concrete end of the leading tothe attached each trusses, steel or two girders plate steel of two sists con nose launching steel The segment. first of the face forward on the attached is nose launching steel guides. lateral and bearings, sliding temporary devices, or pulling pushing jacks, hydraulic 3.25 FIGURE 10. 11. The superstructure can be moved forward, by pulling the superstructure using hydraulic jacks jacks hydraulic using superstructure the by pulling be moved forward, can superstructure The or piers the it reaches jack-up as nose of the facilitate nose of the front at the jacks Hydraulic pier top, a the toreaching prior launching moment during bending cantilever order the toreduce In nose, of a launching consists which equipment, launching require bridges launched Incrementally 4. 6. 8. 5. 3. 9. 7.

Suitable for top–down construction over environmentally sensitive areas. sensitive over environmentally construction for top–down Suitable (average week). per one segment construction fast Relatively Reinforcing bars are continuous across the segment joints. segment the across continuous are bars Reinforcing false-work. no temporary Requires works. repetitive by efficiency Increases segment. toprecast similar control, quality better Provides rivers, valleys, and soft soil conditions. soil soft and valleys, rivers, railways, over construction bridge for suitable and required traffic of maintenance Therefore, no Superstructure erection can be done over the piers without ground-based lifting equipment. equipment. lifting ground-based without piers done be over the can erection Superstructure transportation. and storage no segment Requires Possesses simple geometry control. Casting form. (Courtesy of C2HC Alliance, Australia.) Alliance, of C2HC (Courtesy form. Casting Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental 3.28 FIGURE 3.27 FIGURE 3.26 FIGURE De ad endanchorage Hydraulic jack at launching nose’s tip. (Courtesy of C2HC Alliance, Australia.) Alliance, of C2HC nose’s (Courtesy tip. atlaunching jack Hydraulic Launching nose and segment connection. (Courtesy of C2HC Alliance, Australia.) Alliance, of C2HC (Courtesy connection. segment and nose Launching Bridge pulling device. (Courtesy of VSL International.) (Courtesy device. pulling Bridge Sect B B ion A– Strand cable Pulling de AS Dir ec tion oflaunching Sup vi ce erstr ec ucture tion B–B A A H ydraulic jack 107 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 108 sioned or posttensioned tub girders are posttensioned using draped internal tendons in the web to the in tendons internal draped using posttensioned are girders tub sioned or posttensioned of preten 3.31 long segments 3.32). (see and Figures bridges Several curved horizontally especially bridges, length for medium-span recently popularity gaining have been bridges Ugirder spliced Precast 3.3.6 equipment. erection of the availability the by considering viaduct for the length span optimum the tostudy It important girder. is heavy avery with dealing is method erection of this However, disadvantage of erection. the speed the and girder the to is simpler produce that it are erection span full of advantages The spans. completed the be done over can usually transportation girder The equipment. by one erection handled be ment can place girder and transportation girder The 3.30. Figure in shown as project rail speed for high structure as such viaduct long for a very is ideal erection full-span The segments. short of in instead whole span, 120 up toabout bridges span for short erection by span of span form another is method erection Full-span 3.3.5 3.30 FIGURE 3.29 FIGURE ft m (36 Precast Spliced UGirder Spliced Precast Full-Span Erection Full-Span ). The difference with the span-by-span erection is that the girder is cast in one piece for the in onefor piece cast is girder the that is erection span-by-span the with difference ). The Bridge pushing device. (Courtesy of C2HC Alliance, Australia.) Alliance, of C2HC (Courtesy device. pushing Bridge Full-span girder erection. (Courtesy of DEAL.) (Courtesy erection. girder Full-span Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental range of ft. 150 to 250 range ­ are ments seg The longer segments. using construction bridge of segmental a form also is concept ­construction girder spliced the reality, In continuous. made are girders the until structure the tostabilize locations joint cast-in-place at the provided is support Atemporary transversely. or posttensioned concrete arereinforced diaphragms These locations. splice the at cast typically are diaphragms The ­concrete. a­ form 3.32 FIGURE 3.31 FIGURE continuous multi-span girder from end to end. The joints between the girders are cast-in-place cast-in-place are girders the between joints The end toend. from girder multi-span continuous typically lifted with a ground-based crane. This option is particularly attractive for a span span for a attractive particularly is option This crane. ground-based a with lifted typically Precast spliced U girder bridge during erection. (Courtesy of Summit Engineering Group.) Engineering of Summit (Courtesy erection. during bridge Ugirder spliced Precast Precast U girder supported on temporary false-work. (Courtesy of Summit Engineering Group.) Engineering of Summit (Courtesy false-work. on temporary supported Ugirder Precast

109 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 uneven number of spans from the architectural point of view. Leonhard discussed different approaches approaches different discussed of Leonhard view. point architectural the from of spans number uneven an have to preferable also is It the bridge. the moreeconomical distribution, span the uniform The more segments. the of precasting benefit the order tomaximize in critical is lengths span of the uniformity bridges concrete area). For segmental or mountainous (e.g., valley, over water, land, landscapes and tion condi soil the toknow important It also is required. clearance vertical and horizontal by the dictated much very is waterway over anavigable crossing Abridge bridge. of the site location the considering by first studied closely be should configuration and arrangement span stage, design conceptual the In 3.4.1 3.4 110 than the typical span length ( length span typical the than It preferable tohave an is height. the to consider important is it valley, view. Forshallow oblique an from effect view wall order the toreduce in slender be should pier dimensions lateral the length, span For shorter piers. of the size and shape the also Notice increased. length span the and be reduced should of piers the number Therefore, lengths. span short with piers many toplace practice not it agood is conditions, soil unstable and slope steep and valley For deep respectively). views (a,b c,d and conditions valley shallow and 3.33) valley (See Vshape Figure for deep 3.33 FIGURE

Conceptual Design Conceptual Span Configuration 40 36 m 36 m m Span distribution. (From Leonhardt. F. 1984. F. 1984. (From Leonhardt. distribution. Span L/H 70 40 m 40 m 52 ratio of the opening between two piers, where where piers, two between opening of the ratio m m Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge 40 m 40 m 60% to 80% of typical span length span of typical to80% 60% 58 70 m m L/H 40 m 40 m ratio equal to or greater than 1.5. The end spans should be less be less should 1.5.spans end The than toor greater equal ratio 40 m 40 m 70 m 63 m (d) (b) (a) (c) 40 m 40 m Bridges 70 m 58 40 m m 40 m , The MIT Press, Cambridge, MA, MA, 1984.) Cambridge, Press, MIT , The ) in order to achieve an efficient design. efficient an order toachieve ) in L 40 m is the span length and and length span the is 52 40 m 70 m m 36 40 m 40 m m H is the pier the is - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental require many stages and the structural system is constantly changing from time to time until completion. until totime time from changing constantly is system structural the and stages many require pieces segment the of stitching and erection The of bridges. types conventional or steel concrete ­reinforced as such structures of types other unlike bridges, segmental of nature the is This completed. is bridge the until construction of the tostage stage from changes system statical how the and construction ­during stability the particularly carefully, studied is system structural bridge final The bridge. of the ­system structural the tostudy is step next the stage, toamore advanced progresses design conceptual the As 3.4.4 alternative. preferred on the making decision the in participate also can owners the that so (3D) required is dimensions 3.37 for a3D rendering) (See Figure three in rendering cases, most In alternative. for each cost approximate the and methods, and means construction materials, types, superstructure configurations, span by varying studied are ­alternatives Typically, site. several at aparticular structure proposed of the suitability and compatibility shape and ­ proportional overall the tostudy continues process design conceptual the dimensions, and ­ shape including determined, roughly havebeen the bridge components of structural all After 3.4.3 shows the 3.36 Figure ­preliminary the 3.35 shows Figure design. final and the preliminary in refined continuously is selected depth tial of the basis on the ( ratio depth over Spanlength efficient. and is moreeconomical section depth variable a ft, 250 than larger is length However,span the when utilized. typically is section ft up to250 (75depth For spans m),constant 3.4.2 method. construction the selecting when to consider parameters one of the only is this course, Of span. particular for the suitable is that method construction FIGURE Once the typical span length is selected, use the following chart (Figure 3.34) to determine the kind of kind the 3.34) todetermine (Figure chart following the use selected, is length span typical the Once L

/ Structural System Span-to-Depth Ratios Span-to-Depth Proportional Sections Proportional 3.34 D

) plays an important role in conceptual design. The preliminary section depth is selected selected is depth section The preliminary design. conceptual role in important an ) plays Bridge type 0 0 L Slab/ / 10 tee D Economical span length ranges for typical concrete bridge types. bridge concrete for typical ranges length span Economical ratio for constant depth section of simply supported girder and continuous girder. girder. continuous and girder supported of simply section depth for constant ratio 20 100 30 L I Girder Span by Incremental / span D L 40 launch / ratio rule of thumb to establish the superstructure structural depth. The ini The depth. structural superstructure the toestablish of thumb rule ratio D 50 ratio for a variable-depth girder. for avariable-depth ratio 200 balanced cantilever 60 Precast segment 70 80 300 90 100 110 120 400 130 140 150 500 Cast-in-place segment(Classic) 160 balanced cantilever 170 1801 6007 90 200 2102 00 2202 2302 40 800 50 60 270 900 2802 90 984 ft 300 dimensions dimensions m. exterior exterior 111 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 112 girder. 3.37 FIGURE 3.36 FIGURE 3.35 FIGURE Span over depth ratio for constant-depth bridge girder: (a) simply supported girder; (b) continuous (b) continuous girder; (a) supported simply girder: bridge for constant-depth ratio depth over Span Rendering of Cincinnati Airport Ramp. (Courtesy of Parsons Brinckerhoff, Inc.) Brinckerhoff, of Parsons (Courtesy Ramp. Airport of Cincinnati Rendering Span over depth ratio for variable-depth bridge girder (for span (for span girder bridge for variable-depth ratio depth over Span 07L 0.7– Span/Depth ratio:L/D

– 0.8L 0.8 L Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge L/D D S M S L D = 35to45 = 15to18 Elevation L/d L/d L D = = view M 15to20 (b) (a) 20to25 L D L 0.7 ≥ 250 – 0.8 ' ). L

Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 to avoid excessive long-term deflection due to creep and shrinkage. and creep to due long-term deflection to avoid excessive hinge over the back astrong toprovide necessary it is eliminated, be cannot hinges midspan the reason, for some If hinges. in-span or other midspan eliminated has bridges of segmental generation subsequent (Guyon 1972).The shrinkage and creep to due long-term hinges midspan the at deflection excessive problems to due maintenance suffered had bridges those that discovered later It was bridges. their in bridges. avoided for be segmental should hinges in-span such practically 3.38e–h) (Figure possible, theoretically system. frame portal complicated most to the girder ­supported Bridges Concrete Segmental 3.38 FIGURE Figure 3.38a–l shows some of the structural system possible for segmental bridges from simply simply from bridges for segmental possible system structural shows of some the 3.38a–l Figure The earlier cast-in-place balanced cantilever bridges in Europe had adopted midspan hinges hinges midspan adopted had Europe in bridges cantilever balanced cast-in-place earlier The Possible structural systems. structural Possible (g) (e) Hinge Hinge (b) (a) (d) (c ) Although providing in span hinges is is hinges span in providing Although Hinge (typ.) (h) (f ) Hinge 113 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 114 structural engineers, architects, contractors, and the stakeholders/owners. the and contractors, architects, engineers, structural of planners, collaboration close the involves design bridge A successful durability. and constructability including impact, ship and of concrete shrinkage and long-term creep, loads, temperature loads, wind load, seismic loads, dead live loads, from the bridges, to flow subjected of forces logical the and structure tosub superstructure element from bridge of each functionality the from aesthetics consider engineers Structural angle. different from a aesthetics view engineers structural The 3.42. through 3.39 Figures in shown are of this samples Several location. for aparticular suitable and compatible is bridge of the look the overall that ensure to the shape pier design properly should architect The attractive. inherently already is box girder of the shape the bridges, box girder for segmental Fortunately structures. pleasing aesthetically on importance and more more are placing stakeholders and The owners structure. bridge the selecting in parameters important most one of the become has value Aesthetic structures. guideway rail high-speed and rail light as such structures for transit and interchanges city and urban in also but canyons and over rivers bridges for long span popular not only is construction bridge Segmental 3.4.5 3.39 FIGURE 3.38 FIGURE Aesthetic Aspect Aesthetic ( Continued Segmental bridge concept in an urban area (architect: Scott Danielson). Scott (architect: area urban an in concept bridge Segmental )

Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge Possible structural systems. structural Possible (k) (i )( (l) j) - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental in design to counteract degradation. tocounteract design in considered be also should action freeze–thaw and chemicals De-icing deterioration. and vent cracking to pre effects these given to be should consideration Proper effects. shrinkage and creep and gradients, thermal loads, anddynamic static forces, complexexternal to subjected is girder box of a deck topThe 3.5 3.41 FIGURE 3.40 FIGURE

Deck Design Deck R8.28.02 Sd PB 8.14.02 Segmental bridge concept over a highway (architect: Scott Danielson). Scott (architect: ahighway over concept bridge Segmental Segmental bridge concept in a city (architect: Scott Danielson). Scott (architect: acity in concept bridge Segmental Cu r ve haunc h Highlysculpt Se g, conc . bo ed x 115 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 116 simplified assumption produces reasonable results. reasonable produces assumption ­simplified this model, this for exist conditions boundary different that argued be it could 3.43. While Figure stiffness. totheir relative members slab and webs tothe tion distribu for load allows model frame 2D The properties. cross-sectional varying of these ­interpretation amore representative order toobtain in may analyzed have tobe frames 2D several bridge, of the length the along vary slab bottom web and of the thicknesses the 3.43. If Figure in shown as length, of unit (2D) frame plane atwo-dimensional box as the tomodel practice common it is complex analysis, this of lieu done. In seldom is this systems, tothree-dimensional of prestressing application the particular, in of analysis, type of this complexity tothe Owing needed. is conditions proper boundary with loads all incorporating analysis three-dimensional girder,boxthe a of system final the represent To correctly 3.5.1 mm). (230 of 9in thickness deck aminimum recommends Committee Sections Standard AASHTO-PCI-ASBI around. way other not the states, limit ultimate for checked then and methods elastic using designed be should deck top The prestressed. partially be should deck the at least chemicals, de-icing and action tofreeze–thaw not subjected bridges For overhangs. for even short posttensioned, transversely be top deck the box girders posttensioned for all 1987). Breen that and It recommended is (Posten, Carrasquillo cost cycle low life in results and capacity. for reserved allow and conservative/robust tobe strategy a good always is it bridges, segmental for decks designing when Therefore, bridge. entire the closing to do without impossible almost and not practical is replacement deck superstructures, bridge mental 3.42 FIGURE A typical 2D frame model is assumed to be supported at the lower end of the webs as shown in in shown as lower webs end of at the the supported tobe assumed is model frame 2D A typical mm), (200 of although 8in thickness top deck aminimum toselect practice standard it is general, In durability long-term improves deck of top decks posttensioning transverse that have shown Studies For seg public. traveling tothe inconvenience in results but also costly not only is replacement Deck Design Approach Design Segmental bridge concept for high-speed rail guideway (architect: Scott Danielson). Scott (architect: guideway rail for high-speed concept bridge Segmental Ang ca Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge pital ular Cu ca rv pita ed l Ang ca pita ular l - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental model. 2D 3D tothe forces the resulting obtain to 3.5.1,important is Section it in stated as model, frame 2D toa simplified is model structural the When load. atruck as such deck, tothe applied are loads point multiple complex when more becomes distribution The load slab. of atwo-way behavior structural tothe similar ­longitudinally, as as well transversely deflect will deck the on adeck, applied is load concentrated astatic When 3.5.2 5.14.2). Article (see LRFD stacking segment and equipment, construction lifting, segment as such combinations, load for construction of 1.0. factor 3.43 FIGURE Commonly, there are two ways of handling live load distributions in the transverse direction: transverse the in distributions load live of handling ways two are there Commonly, checked be should design deck the combinations, load state limit strength and toservice addition In aload with combinations load state limit ultimate in included are of forces posttensioning Secondary to limited are not butinclude, design transverse in considered loads design The • • • • • • • • • • 1. In the past, influence surfaces from Pucher or Homberg Charts have been extensively used in boxin used extensively havebeen Charts Pucher or fromHomberg surfaces influence past, the In method is approximate and can be useful for preliminary design. for preliminary useful be can and approximate is method This ratio. depth over midspan depth support the regarding slabs, deck for haunched limitations has method The interpolation. by are approximated supports between moments bending The frame. 2D the to forces external as then applied is end fixed moment only.(FEM) The midspan and end fixed at the length unit moments per bending provide charts dimensionless the plate, selected the of conditions boundary the on Depending soffit. aparabolic with thickness plate depth for some variable and thickness plate depth for constant valid are ­isotropic). charts Some and (homogeneous of plates theory elastic on based are charts These design. transverse girder SH CR PS practice by required not currently TG construction segmental in of cantilevers apart jacking EL PT IM LL DW barrier wall DC Live Load Analysis Live Load

=

=

======Secondary forces from posttensioning from forces Secondary Live load Primary prestressing Primary forces Shrinkage effect of concrete of effect Shrinkage Miscellaneous locked-in force effects resulting from the construction process, including including process, construction the from resulting force effects locked-in Miscellaneous Dynamic load allowance load Dynamic Creep effect of concrete of effect Creep Thermal gradient ( gradient Thermal Dead load of structural components and nonstructural components, such as traffic traffic as such components, nonstructural components and of structural load Dead Dead load of wearing surface or future wearing or future surface of wearing load Dead Simplified two-dimensional plane frame of unit length. unit of frame plane two-dimensional Simplified leng U nit th AASHTO LRFD Design Specifications, but commonly done in standard standard in done commonly but Specifications, Design LRFD AASHTO ± 10°F differential between the inside the between 10°F differential surface and utilities, if any if utilities, and surface and outside of outside box girder) Note: and 117 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 118 To ­ slab. top thin the due to flat in ducts housed usually are tendons These box girder. side of the on each overhang of the face at the anchored and top slab the through tendon passing per strands diameter (13) 0.5- tofour (15 of three or 0.6-in consists mm) typically direction transverse the in Posttensioning 3.5.3 3.6.1.3.3). (see loads Article no lane and design for transverse considered to be 2. method following: the include checked are stresses where 3.45). and points common 3.44 Some (see Figures condition andrecommended. not neglected is effect stiffening edge this quality, future uncertain and barrier of the However, to discontinuities owing longitudinally. load live distribute to further model 3.44 FIGURE Longitudinal axle spacing In the the In using above the locations to corresponding lines influence 3.51 show typical through 3.46 Figures the worst in order to produce placed strategically be configuration load live the that important It very is this into incorporated be could barrier vehicle acontinuous theoretically, that, noted be It should 4'-0" (Tandem) • • • • • efficiently utilize the tendon, it should be suitably profiled for maximum structural efficiency. structural maximum for profiled suitably be tendon, the it should utilize efficiently 14'-0" (Truck) 2. A more accurate method is based on a partial 3D finite element model of the box girder. The term girder.term boxThe the element of model 3D finite on a partial based is method A more accurate Maximum negative moment in the deck overhang where the taper begins taper the where overhang deck moment the in negative Maximum slab bottom and webs the moments in bending positive and negative Maximum webs of the face interior at the top deck moment the in bending negative Maximum webs two between line center moments at the bending negative and positive Maximum overhang of root deck moment at the bending negative Maximum design. for final used be method this that presently, recommended it is available readily are programs element finite general Since truck. of a design wheels rear of and front consisting load a line using erated be gen should lines influence The interest. of section any at be generated can lines influence model, this From effects. three-dimensional to include long enough be will box that of the length a partial as preted “ partial” implies that the entire bridge superstructure need not be modeled; rather it should be inter be it should rather modeled; not be need superstructure bridge entire the that implies ­partial” Posttensioning Tendon Layout Posttensioning AASHTO LRFD Specifications LRFD AASHTO LRFD live load configuration in 3D. configuration load live LRFD to 30'-0" P1 14'-0" P1 Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge P2 P2 axle spacing Transverse P3 6'-0" (AASHTO 2012), only the effect of a design truck truck is tandem) (or design of a 2012), effect (AASHTO the only P3 P2=12.5kips P1=12.5kips 2. Wheelloadsfortandem: P3=16kips P2=16kips P1=4kips 1. Wheelloadsfortruck: Notes: P3=N/A - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental shows one example of the tendon path. of the shows one example 3.52 Figure region. that in bending positive the order to resist in box girder of the centerline the near slab the top of axis the neutral below drops toa level gradually then tendon The webs. moments at the the negative tendonthe resist helps This webs. over the deck of the axis neutral the above to a level 3.46 FIGURE 3.45 FIGURE 1'-0" to barrier Toe of P A typical tendon is generally anchored at mid height of the slab at wing tips and then gradually rises rises gradually then and tips at wing slab of the height at mid anchored generally tendon is A typical 6'-0" P 21'-6" maximum negativemomentatslab PP 6'-0"

Moment per wheel line (kip-ft/ft) Live loadconfigurationfor –16.0 –14.0 –12.0 –10.0 –8.0 –6.0 –4.0 –2.0 21 LRFD live load transverse configurations. transverse load live LRFD Live load influence lines for moment at root of outside wing. of outside forroot moment at lines influence load Live 0.0 2.0 21'-6" maximum positivemomentatslab '-6" bottom slabatinsidefaceofweb –4.0 maximum negativemomentin C L PP Live loadconfigurationfor Live loadconfigurationfor girder Box 6'-0" C L C L girder Live road Box Tandem valuesnoimpact,unfactored HL-93 truckvaluesnoimpact,unfactored 0.0

PP C L 2'-0" 21'-6ʺ 6'-0" P

6'-0" C L Distance fromcenterlineboxgirder(ft) 4.0 P 1'-0" to barrier Toe of (TYP) 8.0 1'-0" barrier Toe of to 12.0 P=125kips 2. Wheelloadsfortandem: P=4or16kips 1. Wheelloadsfortruck: Notes: PP 6'-0" maximum negativemomentatoverhang 16.0 21 21'-6" '-6" maximum negativemomentin top slabatinsidefaceofweb Live loadconfigurationfor Live loadconfigurationfor P 6'-0" C 20.0 P L girder Box C L Wheel loads P C L girder 2'-0" Box 6'-0" P 24. 0 119 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 120 to check stresses. By varying the prestressing force, the combined stresses of service limit states are are states limit of service stresses combined the force, prestressing the varying By stresses. to check spreadsheet in a compiled then are The results loads. live except model, 2D the into incorporated are loads other All software. proprietary using run time-dependent a2D in analyzed then and culations, Specifications AASHTO- in specified States Limit at Service limits stress tothe compared and summarized are top slab the in section predetermined at each stresses compressive and tensile mum maxi The combinations. State Limit Strength and State Limit Service LRFD the using aspreadsheet in be­ may lines influence andlive load 3D analysis frame 2D the from obtained forces design The 3.5.4 prestressing. effective without may be slab of the edges outside near zones not addressed, is spacing ­ maximum If tendon considered. side of the on each point anchorage the from distribution stress 30° on based tendons transverse space to However, anchorages. practice is a good it between effects lag shear limit to4ft to effort an in (1.2 m) restricted typically is tendons of spacing maximum The checks. 3.48 FIGURE 3.47 FIGURE Longitudinally, the tendon spacing is determined using the appropriate service and strength limit state state limit strength and service appropriate the using determined is tendon spacing the Longitudinally, Summary of Design Forces ofDesign Summary

Moment per wheel line (kip-ft/ft) (AASHTO 2012). The prestressing force is usually estimated in preliminary hand cal hand in preliminary estimated usually 2012).is force (AASHTO The prestressing –8.0 –7.0 –6.0 –5.0 –4.0 –3.0 –2.0 –1.0 –1.0 Moment per wheel line (kip-ft/ft) 0.0 1.0 2.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 Live load influence lines for moment at box centerline. box formoment at lines influence load Live Live load influence lines for moment at inside face of web. face inside formoment at lines influence load Live –24.0 –24.0 –20.0 –20.0 Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge –16.0 –16.0 –12.0 –12.0 Distance fromcenterlineboxgirder(ft) Distance fromcenterlineboxgirder(ft) Tandem valuesnoimpact,unfactored HL-93 truckvaluesnoimpact,unfactored Tandem values—noimpact,unfactored HL-93 truckvalues—noimpact,unfactored –8.0 –8.0 –4.0 –4.0 0.0 0.0 4.0 4.0 8.0 8.0 12.0 12.0 16.0 16.0 LRFD Bridge Design Design Bridge LRFD 20.0 20.0 24.0 24.0 combined combined tendon - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental 3.51 FIGURE 3.50 FIGURE 3.49 FIGURE

Moment (kip-ft/ft) –10.0 –15.0 –20.0 –25.0 10.0 –5.0 Moment per wheel line (kip-ft/ft) Moment per wheel line (kip-ft/ft) –8.0 –6.0 –4.0 –2.0 5.0 0.0 –6.0 –5.0 –4.0 –3.0 –2.0 –1.0 0.0 2.0 4.0 –24.0 0.0 1.0 2.0 3.0 4.0 Transverse deck live load moment envelope (unfactored without impact). without (unfactored moment envelope load live deck Transverse Live load influence lines top formomentof at web. lines influence load Live Live load influence lines at outside wing/thickness transition. wing/thickness at outside lines influence load Live –24.0 HL-93 truckonly HL-93 truck&lane 0.0 –20.0 –20.0 –16.0 — –16.0 — 4.0 maximum values minimum values –12.0 –12.0 Distance fromcenterlineboxgirder (ft) Distance fromcenterlineboxgirder(ft) Distance fromcenterlineboxgirder(ft) Tandem values—noimpact,unfactored HL-93 truckvalues—noimpact,unfactored Tandem values—noimpact,unfactored HL-93 truckvalues—noimpact,unfactored –8.0 –8.0 8.0 –4.0 –4.0 Truck only HS25 only 0.0 12.0 0.0 — — maximum values minimum values 4.0 4.0 8.0 16.0 8.0 12.0 12.0 Truck &lane HS25 only 16.0 20.0 16.0 — — minimum values 20.0 maximum values 20.0 24.0 24.0 24.0 121 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 122 current LRFD Specifications for comparison purposes (see Figure 3.53). Figure (see purposes comparison for Specifications LRFD current the and Specifications Standard AASHTO several were computed using stresses service Concrete nents. compo transverse corresponding of the for each capacities bending calculated tothe compared be then the momentcan envelope of values The section. chosen for each determined is values minimum and determined. are segment the in tendons of transverse spacing and size the length, unit tendon per forces selected the Using calculated. FIGURE 3.53 3.52 FIGURE

The LRFD Strength Limit States may be also tabulated in a spreadsheet and an envelope of maximum envelopean maximum of and spreadsheet in a tabulated also be may States Limit Strength LRFD The Stress (psi) (tension is positive)

5 1/2" –1200 –1000 –800 –600 –400 –200 200 400 600 –20.0 0

5 1/2" 3'-3 1/4" T- HS25—min (tension) Std. sp LRFD 3r Typical transverse tendon layout. tendon transverse Typical Concrete service stresses (code comparison) stresses service Concrete Symmetrical about box 5/T –16.0 -10 Prop ec C L d—min (tension) .—min (tension) PI To tendon anchors p ofde 3'-3 1/4"1 Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge Longitudinal –12.0 osed—min (t ck PI –8.0 Distance fromcenterlineof ension) 4" –4.0 0.0 . 1'-6"3 Rmin=50'-0" Minimum tendonradius: Useflatducts Duct size: S=4'-0" Tendon spacing: bo 4.0 x gi rder (f HS25—ma T- Std. sp LRFD 3r 8.0 t) 5/T 4 × 0.6" strandtendon -10 prop PI Bo ec. d—ma ttom ofde —ma x (c 12.0 '-0" 4" omp) osed—max x (c x (c omp) omp) ck 16.0 5 1/2" (c 4 1/2" omp) 20.0 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 load influences aresmall. influences load live where locations at often govern can state limit This gradient. temperature full and load due todead stresses load for service acheck requires LRFD I, State Limit toService addition in Also, load. live nying ­ temperature transverse for 0.5 of factor on a load based is example This basis. on a ­ included be it should if to establish or designer owner it up to the leaving loading, this specify not does specification LRFD current The I. State Limit Service in used box is of the surfaces exterior and interior of 10° Fbetween gradient temperature alinear Also, compression. as well as tension stresses, concrete checking When 3.5.5 Bridges Concrete Segmental In these special cases, both one-way and two-way action shear should be investigated. be should shear action one-way two-way and both cases, special these In them. on placed loads construction havelarge often but can sense, this in similar are decks girder Box bridges. for AASHTO decks of concrete design the in ignored been has behavior shear Traditionally, 3.5.6.2 shear. longitudinal for required reinforcing with manner an appropriate in combined be should This calculated. be should of 50%. reinforcement in increase (203 an to 8in represents mm), which from 12(205) decreased was soffit bottom the in spacing bar transverse the requirement, steel ­minimum the slab bottom the(soffit) design.satisfy To only governs requirement moment. This cracking the below tions. combina load ultimate componentin this include do not Specifications Guide Segmental the addition, In at ultimate. toyield begins reinforcement the if disappear should loads the deformations, restrained of are a result loads these Since instances. 0.0 forof most a recommendation with basis, project-specific example. this in not govern does loading 25% This more self-weight. with load, live ­without State I Limit Strength as same the is IV State Limit Strength design, transverse of the For purposes 3.5.6.1 3.5.6 exceeded construction process. the during are not stresses allowable that ensure to checked be should traffic vehicular and placement to barrier In addition to service limit states under maximum loading, temporary stresses such as those prior prior those as such stresses temporary loading, maximum under states limit toservice addition In Listed below is the ultimate load combination per LRFD: per combination load ultimate the below is Listed bending transverse for required reinforcing steel amount of web the flexure, ultimate under Also, times 1.2 resist to required that to equal reinforcement minimum require specifications LRFD The on a factor a load determining suggest Specifications LRFD factors, load gradient For temperature following: the include example this in used combinations load Service Strength I Strength 3.4.1-2) Equation (LRFD Combination Load Segmental I(Tension &Compression)Service . For these reasons, the temperature gradient was not used in the strength limit state combinations combinations state limit strength the in not used was gradient temperature the reasons, For these

Strength Limit State Design Limit Strength Service Limit State Design Limit Service Flexural Strength Design Check Design Strength Flexural Shear Strength Design Check Design Strength Shear 1. 0D () CD 1. ++ γ+ 0D pp () DC WE CD ++ γ+ L1 only Service Limit State I is checked with a live load factor of 1.0 for factor load alive with checked Iis State Limit Service only WE DW ++ .0 () L1 PT 1. 01 ++ EL .0 1. ++ () 0L PT () .7 50 LI (( ++ LL 1. 0C M1 () IM RS ++ .0 )) ++ () H/ CR .5 ++ CR − SH 1. 0T () SH /0 − G gradient when accompa when gradient .5 () TG project-by-project 123 - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 system throughout construction process. the statical the in changes with associated dates as well as structure, the into incorporated are segments the that times date, casting segment the of function is a analysis Time-dependent effects. time-dependent for structure the toanalyze necessary it is joints, closure cast-in-place through continuous made are vers cantile as erection, during system statical the in tochanges Owing crane. aground-based with method construction cantilever balanced the precast using erected be to assumed is structure The bridge. precast typical for a process design the longitudinal illustrates example design The following 3.6.1 3.6 124 duct should be grouted if no contingency tendons are required. are tendons no contingency if grouted be should duct empty This posttensioning. for contingency toallow cantilever of the segment last on the anchorage an with combined tendons cantilever for the provided was duct empty An needed. if posttensioning gency contin 8% of the approximately provide will out One of 12 tendons. strands for internal required as posttensioning for 5% space contingency toprovide tendons continuity for bottom were used 11 strands 3.56). through 3.54 (see only Figures spans tendon at interior continuity span and bottom one tendon cantilever of one increase an in resulted design final The gradients. ture tempera from resulting stresses tocontrol pour closure the across top slab the in weretendons added continuity eight-strand two experience, of previous basis web. the per On tendons continuity bottom Combinations. Load State Limit LRFD all applicable satisfy to design final the during be modified easily then layoutcan assumed The combinations. live load and dead factor load using effects shrinkage and creep approximate structure final on the based design by preliminary estimated be can tendons continuity Span cantilever. typical of a loading for construction calculations on preliminary based be tendon layout can approximate An 3.6.2 day at 10,000. conditions final and (at end of construction) for initial analyzed and appropriate, as settlement, support and gradient, temperature load, live as such structure on the placed are loads Additional 10,000. day until systems of structural stages various from result that forces locked-in up all to sum structures indeterminate statically in essential It also is occur. to effects time-dependent all toallow 10,000 day time through stepped is structure the modeled, been has construction the After process. construction of the step for each conditions boundary priate appro modeling carefully layout while posttensioning assumed an using performed is analysis stage slab. bottom and the top in lag shear of effects the considering segment for each determined are properties Section temperature. ambient and gate), of hardening, rate aggre (e.g. composition for limestone concrete adjusted be can and section, cross of the dimensions and values. camber correct order toobtain in rerun be should analysis stage-by-stage the available, become dates anderection casting actual when construction, During casting. one after month than earlier erected not to be are Segments cell. casting per week per segment joint one pier/expansion and cell casting per day per segment one typical as assumed is rate production segment the dates, these of estimating For purposes segment. each tocast required time the and cells of casting number assumed of an afunction are dates Casting rate. production segment the and schedule construction of the basis on the established are segments of the dates erection and Casting schedule. ­construction The tendons used are based on a 12-strand system using 0.6 in (15.24 mm) diameter strands. Only Only strands. in 0.6 mm)diameter (15.24 using system on a 12-strand based are used tendons The fiveand tendons cantilever twelve for the need indicates example this for design The preliminary stage-by- A software. proprietary analysis time-dependent into a enteredis information above The humidity environmental of the basis on the established are of concrete properties Time-dependent a reasonable to estimate and of construction sequence assumed an to establish It customary is

Longitudinal Design Design Methodology Design Tendon Layout Envelope and Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge segmental ­segmental - - - - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental ure, and should leave a space of at least 50 ft (15 m) between trucks measured between the rear axle of axle the rear between measured ft 50 trucks of at least leave (15 aspace should and between m) ure, contraflex load uniform of points between only required is truck second by The is reduced 10%. effect total the and added is moments only, For truck negative asecond load. lane distributed ­uniformly a with combined or tandem lane per truck design of asingle (HL-93) load live consists LRFD 3.6.3 2012). (AASHTO Specifications Design Bridge LRFD of5.14.2.3.8 AASHTO Article under covered are anchorages and ducts posttensioning Provisional conditions. unforeseen or for other of deflections for adjustment used be can which box section), (inside tendons the external 3.55 FIGURE 3.54 FIGURE 9ʺ Provisions are also made for future posttensioning by addition of anchorages and deviation points for points deviation and of anchorages by addition posttensioning for future made also are Provisions C L Bo Sy mmetrical ab 1'-6" x 3'-6 1/2" LRFD Live Load LRFD 1'-6" 4'-7"

4 1/2" tendon duc Provisional Sp 1-1/4" readbar(ty 6'-0" out an se Posttensioning tendon locations. tendon Posttensioning Typical section. Typical

1'-3" 6'-7 1/2" ction 6'-10"1 R t 1'-0" = 1'-4" 2.5 1 3/8"di 5 @"1 p)

1 min. '-0" 2'-3 1/2" '-5" 1 10" a. threadbar 8" 0" 1ʹ-7" 4'-11" R 4 @5" = 2'-11" 8" (2) 12'-0"lane 8'-2" 8" 4'-9 1/2"

9" s 2'-0" = 43'-0ʺ 16'-4" 12 ×0.6"dia 24'-0" strand tendonanchor 12 ×0.6"dia 8" 1'-6" 9" strand tendonanchors 12 ×0.6"dia . strandtendo 8'-2" 5 @5" (ty 9" p) . or15×0.5"di

. or15×0.5"di 1'-4 n

8"

17'-11 1/2" " a. 6" (ty a. p) Supp or 10'-0" t se tendon @4'-0"sp 4 ×0.6"di ction 3'-6 1/2" a. strand 1'-6" acing 125

- 9'-0" Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 126 3.56 FIGURE

Bottom span Cantilever tendons Bottom span Cantilever tendons 2'-6" tendons (typ) (typ) tendons (typ) (typ) C L tendons (t contingenc Provisional Abut 6'-3" tendons (ty contingenc Provisional 2'-6" cl po . 1 Typical tendon layout to balanced cantilever bridge construction. bridge cantilever balanced to layout tendon Typical 4 @11'-3" ur (typ yp y osur ) y p) tendons (t T ) op span e tendons (ty T op span Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge yp 8 @12'-0" 200 ) p 2'-6" clo our (ty ' -0" p) 2 ×8-0.6"di 150'-0" p) sur e a. 8 @12'-0" 2 ×8-0.6"di 6 ×22-0.6"di 5'-6" a. C (b L (a) Pier 3 ) a. 5'-6" 5 ×22-.06"di C L Pier 2 tendon fu Provisional ture a. s 8 @12'-0" 200'-0" tendons fu Provisiona ture 8 @12'-0ʺ 2 ×8-0.6"di 200'-0" l po 2'-6" clo

5 × 48-0.6" dia. ur (typ p 2'-6" cl sur our (ty a. 2 ×8-0.6"di ) 5 × 48-0.6" dia. e osur p) e 6 ×22-0.6"di a. a. 4 × 24-0.6" dia. 4 × 24-0.6" dia. 9'-0" Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental FIGURE 3.56 3.56 FIGURE

Bottom span Cantilever tendons 9'-0" Bottom span Cantilever tendons tendons (typ) (typ) tendons (typ) (typ) tendons (t contingenc Provisional tendons contingenc Provisional 2 ×8-0.6 ( Continued po 2 po 2'-6" Closur ' -6 ur ( ur (typ " cl ( ty ty " osur di yp y p p y ) ) a. ) e tendons (ty T ) op span e )

8 @12 200 Typical tendon layout to balanced cantilever bridge construction. bridge cantilever balanced to layout tendon Typical 8 @12'-0ʺ 200'-0" p) ' -0 ' -0 " " 2 ×8-0.6"di a. 5 ' -6 " 6 ×22-0. 6 ×22-0.6"di C L Pier 5 5'-6" " di a. (d C L (c) Pier 4 ) a. 2 ×8-0.6 tendons fu Provisiona ture 8 @12 " di l a. ' -0 tendon fu Provisional " ture 2 po ' 150 -6 s ur ( 8 @12'-0ʺ " cl 200'-0" ' -0 ty tendons To osur " p p span ) e 2 ×8-0.6"di ( ty p ) po 2'-6" Closur

5 × 48 -0.6" dia. 5 × 48-0.6" dia. ur (typ 4 @11 a. ) e ' 5 ×22-0.6 -3 " 6 ' -3 " " di C L a. Abut 2 ' 4 × 24 -0.6" dia. -6 . 6 " 4 × 24-0.6" dia. 127 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 The application of LRFD live loads is shown in Figures 3.57 and 3.58. 3.57 in Figures shown is live loads LRFD of The application 0.85. of factor presence a multiple has and lanes, three on based is example This lanes. three more than for 0.65 and lanes for three to0.85 lane 1.2 for asingle from range factors presence Multiple load. lane example. for this considered not was but specified also is truck Afatigue truck. trailing of the axle front the and truck leading the 128 FIGURE 3.57 R1 R1 C L C A dynamic load allowance (impact) of 33% is added to the design truck, but is not required for design for design not but required is truck, (impact) design of 33% tothe added is allowance load A dynamic L Abut Abut Tr uc . 1L supp at exter Ma . 1 k supp at exter Min. reaction U x. or niform loadp reaction w or of contraflexure ww t 1 ior t 1 ior

Application of LRFD live loads on a continuous structure. on acontinuous loads live of LRFD Application C C L oin Pier 2L Pier 2L t 0.9 w0 ww Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge 0.9*Tr T uc and reaction@pier andem tr or k uc moment @pier moment inspan Ma Ma k x. Min. 50ʹ-0ʺ x. po (15m) negative C sitive C R3 Pier 3L Pier 3L 3 ww 2 0.9*Tr 3 uc k of contraflexure Un .9 w T andem tr iform loadp or uc moment inspan Ma k x. po C sitive C Pier 4L oin Pier 4L t 3 w C C Pier Pier 5L 5L 0.9 w w w C C Abut Abut . 6 . 6 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental Specifications Design Bridge basis. on acase-by-case evaluated be could but designs, all for warranted may be not accuracy additional This steps. intermediate at all conditions statical true toapproximate model construction the in changed be can properties section permits, used where “P/A” the tonot overestimate as so stresses, section, component cross of posttensioning gross full on the based remains area However, cross-sectional the section. of the axis neutral of the location and of inertia more tobe accurate. considered is provision lag shear LRFD the but insignificant, is methods two the between difference The 4.6.2.6.2. Article in shown as Third Edition Specifications, Design the change, to this contrast In regions. support and span between function step to a changed lag provision shear edition, second the However, in flanges. of effective transition linear Edition The 3.6.4 3.58 FIGURE The following shear lag effect calculation is in accordance with article 4.6.2.6 of 4.6.2.6 article with accordance in is calculation effect lag shear The following software the If consideration. under it is time at the system structural of the afunction is lag Shear moment tothe applies lag shear that assumed commonly it is properties, section determining When A. where 3.59)A.1- (see Figure span End P/2 AASHTO Guide Specifications for Design and Construction of Segmental Concrete Bridges, First First Bridges, Concrete Segmental of Construction and Design for Specifications Guide AASHTO

Tr Completed structure Completed b b b P (3.6 m) (3.0 m) (AASHTO 1989a) adopted shear lag provisions of provisions lag 1989a) shear (AASHTO adopted

1 2 uck load Shear Lag Effect Lag Shear L

= 12 f

10 f

= = = ane flange width on each side of web (See Figure 3.60) side of each web Figure on width (See flange

10.37 9.71 PT t t (145 kN P/2 32 k (1.8 m) effective force and force effective 6 f ' Longitudinal and transverse live load configurations. load live transverse and Longitudinal ' t (4.3 mto9m) Tr ) 14 f uck andlaneloads t to30f T ransverse loadcong (1'-0" atde 2'-0" Inty t (145 kN (AASHTO 2012). (AASHTO 32 k (4.3 m) ck overhang) 14 f ) A pical lane

= (AASHTO 2004) adopted shear lag provisions similar to similar provisions lag shear adopted 2004) (AASHTO (35 kN t gross cross section area. section cross gross 8 k uration ) Long (9.3 kN/m) 0.64 k/f itudinal loadcong (55 kN 12 k t Ta ) ndem load (3.6 m) (3.0 m) La 12 f 10 f ne DIN 1075 DIN t t (55 kN 12 k (1.8 m) uration 6 f t ) (German Concrete Code) using a Code) using Concrete (German Ta (110 kN ndem andlaneload Notes 25 k 1. w s 3. ‡edynamicloadallowance 2. D c t 4. Axleswhichdonotcontribute d = 0.64k/f o theextremeforcee‹e hall notbe : onsideration shallb esig ) ynamic loadallowan = AASHTO LRFD Bridge Bridge LRFD AASHTO (110 kN La n laneload. 25 k ne load (1.2 4f t (9.3kN/m)p AASHTO LRFD LRFD AASHTO ) applie m) t s pe (9.3 kN/m) 0.64 k/f r unitlengt d toth DIN 1075 DIN e negl t ce ct under er lane e = ec 33% 129 h te d. , Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 130

3.60 FIGURE 3.59 FIGURE A.2-Inner span (see Figure 3.61) (see Figure span A.2-Inner where l c bmeflange: reduction) (no Effective Obtained l c a b i i

3 ======

= 0.1 0.1 0.1 0.6 0.6 0.8 the largest of largest the 10.37 b b b 7.34 s3e s2e s1e

× ×

× × = = = l l ' End span effective flange width diagram. width flange effective span End Typical box girder section effective flange widths. flange effective section girder box Typical l l ' 8.3 7.34 7.77

b < = = = = s / 0.25 0.25 0.1 0.1 (150 0.1 0.6 0.6 0.1 (150 0.1 b ' and and b ' ' (no reduction) 1 be × × b b b × b 3 2 1 200 1

200 b Ty

, but not exceeding 0.25 0.25 , but not exceeding s b 150 Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge m ' pical se ' ) ) / b b b ' b = '

= 3 2 1

10.37 = ' ratios from LRFD Figure 4.6.2.6.2-2. Figure LRFD from ratios = c

L Abutmen 7.34 9.71 15 = 120 b 20 120 37.5 ac ' ction ' ' 0 ' 10.37 ' 7.34 9.71 " ' b ' be ' ' ' 0.060 0.080 0.086 2 t b b/l 2 0.061 0.081 0.086 i b / l i I = 150'-0'' b × 1.0 0.8 0.8 b s 1.0 0.8 0.8 / l s b / b b b 1.00 1.0 1.0 be 3 b m 1.00 1.0 1.0 m / 3 b / b Supp 7.34 7.77 8.3 b se ' 7.34 7.77 8.3 ' b or se c ' L Pier2 t se ' ' 10.37 7.34 9.71 b ction me ' 10.37 b

7.34 9.71 s b me

' ' ' bm

d0 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental of NCHRP Report 276. Report of NCHRP version an abridged 1989b), (AASHTO is which Bridge Superstructures Concrete in Effects for Thermal Specifications Guide AASHTO the by used that from differs 3.63) that profile Figure (see gradient ture tempera a 3.12.3) adopted (Article Specifications Design Bridge LRFD AASHTO The stresses. resulting todetermine of analysis complex method arather requires which superstructure, of the todepth respect with manner in a nonlinear vary gradients aforementioned The conditions. daytime from unchanged relatively may remain temperatures ground while concrete of deck cooling rapid from results gradient temperature Anegative top deck. the in temperatures higher cause will and surface deck of the heating solar from results gradient temperature Apositive box. of the top tobottom from change temperature as a vertical defined is gradient atemperature to this, contrast In rate. same at the or cooling heating cross-section theentire as defined is superstructure of the change temperature Auniform gradients. temperature as well as change temperature of uniform consist forTemperature superstructures loads 3.6.5 3.62 FIGURE 3.61 FIGURE B.1- Cantilever (see Figure 3.62) (see Figure B.1- Cantilever B.

During construction During b flange: Effective where b b b bmeflange: reduction) (no Effective

s3e s2e s1e Temperature Load

= = = 8.3 7.34 7.77

l i

= Inner span effective flange width diagram. width flange effective span Inner ' Cantilever span effective flange width diagram. width flange effective span Cantilever 1.5 1.5 ' ' (no reduction) bs × l

b b = s1e s3e s2e 1.5 1.5

= = = cc 7.77 7.34 7.28 × 98.75 98.75 b b b ' ' ' b (no reduction) s 3 2 1 = 10.37 148.125 7.34 9.71 b I = ' 0.05 0.07 0.07 200'-0'' b / l I i = 98'-9'' b 1.00 0.75 0.75 s / b 7.34 7.28 7.77 b se ' ' '

bs

bm 131 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 132 where equation: Dischinger’s by mated deformation. to elastic addition (loads) in stress permanent under deformation of concrete loads). aresult is Creep 3.65). Figure (see diminished be to considered are long-term effects when 10,000 day through continue and construction, of the course the during system statical the in due to changes redistribution force in result deformations time-dependent 3.64). (see Nonlinear Figure bridges of segmental design as to referred commonly are steel of prestressing relaxation including of concrete, shrinkage and Creep 3.6.6 deformations. 1.2 for structural and calculations capacity for strength used is of 0.5 A factor states. limit strength in temperature touniform Two assigned are included. is factors load ­temperature design. under are not joint expansion and bearing that assure will factor The 1.2 deformations. structural for and 1.2 stresses, of 1.0 checking when factor aload use temperature for note, uniform Please box. the the top of in pours closure at occurs area an such example, this In aresmall. force load effects live where bridges concrete for segmental controls combination load this general, In included. is gradient temperature the therefore of 100% live load; no has combination load This checked. be shall for service 3.4.1-2) Equation (LRFD combination load only, aspecial design bridge For segmental combinations. load service present in is load live if by 50% reduced may be Temperature gradient ­combinations. 3.63 FIGURE The redistribution of sectional forces due to change in statical system and creep effect can be esti be can effect creep and system statical in change todue forces sectional of The redistribution (applied of stress independent is due to dehydration, of concrete shortening causes which Shrinkage, uniform while combinations, load state limit strength in not included is Temperature gradient load state limit service in included are gradient temperature and temperature uniform Both time-dependent long-term effects long-term time-dependent M M f I

= d Depth of structure = = Final moment 10,000 at day Final Time-Dependent Effect Time-Dependent Moment as constructed at the end of construction at the Moment constructed as Po Vertical temperature gradient profile for segmental bridge (AASHTO LRFD Figure 3.12.3-2). Figure LRFD (AASHTO bridge segmental for profile gradient temperature Vertical sitive ver 8'' A 4ʺ tical temp Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge T 3 erature . These effects are important factors that demand consideration in consideration demand that factors important are effects . These T 2 MM gr fI adient =+ II () MM T – 1 II e −φ 2. g 3. c 1. Notes A F A as T oncrete and radien or negativeverticaltemp 3 phalt overla = = : = Z 1'-0'' for 4' for one 0 orT 4 3 2 1 t, multiplyTby d ≤ < T Te d –0.20forde 5 de 1'-4'' 1 y. mp ≥ (D 38 41 46 54 1'-4'' gr eg erature ee F) s F –0.30forplai s T ck erature 2 (D wi 11 12 14 9 eg th an F) n - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental construction (diagram 312) to day 10,000 (diagram 310). 312) (diagram 10,000 day to (diagram ­construction 303). (diagram false-work 3.65 FIGURE 3.64 FIGURE 303 G 318 CombDC 301 CombTo 312 CombTo 310 CombTo 314 CombTo 315 CombTo 310 CombTo 311 CombTo enl De tal Superimposed final moment (diagram 318), moment (diagram 301) and moment constructed on 301) 318),constructed momentand moment moment (diagram final (diagram Superimposed ad loadofsup Development of time-dependent bending moment due to creep and shrinkage from end of end from shrinkage and creep moment to due bending of time-dependent Development +(C 303 DC R &SH)atda tal cr tal cr tal cr tal cr tal cr tal cr 301 318 ee ee ee ee ee ee p andshrinkageatendofconstr p andshrinkageatda p andshrinkageatda p andshrinkageatda p andshrinkageatda p andshrinkageatda erstr 310 ucture (D y 10,000 312 C only)(e y 2,000 y 1,000 y 500 y 10,000 y 4,000 re ct ed onfalse uction work) (d ay 250) 8800. 6600. 4400. 2200. 0. ‒2200. ‒4400. ‒6600. ‒8800. 54,000. 36,000. 18,000. ‒18,000. ‒36,000. ‒54,000. ‒72,000. 72,000. 0. Bending moment (K-ft) 133 Bending moment (K-ft) Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 strength (GUTS) and not more than 3.5% when stressed to 80% GUTS. to80% 3.5% stressed when (GUTS) not more than and strength tensile ultimate to70% guaranteed stressed initially when 2.5% no more is than 70°F under hours 1000 after loss that relaxation requirement Standard ASTM the meet strands The low-relaxation used. are strands low-relaxation bridges, segmental in loss To of relaxation time. over prevent aperiod excessive 134 day 10,000. code. to code from may differ nations combi load state limit strength in forces secondary of types However, of different ­exception. inclusion systems. indeterminate statically to loads or imposed deformations of applied aresult as generated forces internal are forces Secondary 3.6.7 Mode Code of provisions the using ated 3.66 FIGURE 314 CombTo 290 CombPrestressingse Although Although temperature and length constant under steel prestressing of in tension loss the is relaxation Steel obtain to be rewritten can equation above The All of the above secondary forces are included in service limit state load combinations without without combinations load state limit service in included are forces secondary above of the All follows: as are design bridge segmental in forces secondary recognized Several M ϕ M • • • • •

= cr II Secondary forces due to support settlement due forces tosupport Secondary temperature) gradient and (uniform loads due forces totemperature Secondary effects shrinkage and due forces tocreep Secondary 3.67) and 3.66 (see forces Figures locked-in as such process due forces toconstruction Secondary 3.67) and 3.66 (see Figures posttensioning due forces toprimary Secondary

Creep coefficient Creep = = Secondary Forces Secondary Moment assuming the bridge is constructed on false work on false constructed is bridge the Moment assuming Moment effect due tocreep provisions are commonly used. This design example utilizes the utilizes example design This used. commonly are provisions AASHTO LRFD Bridge Design Specifications Design Bridge LRFD AASHTO tal Superimposed of PT primary moment (292) and secondary moment and locked-in forces (290) forces at locked-in moment and moment (292) secondary and primary of PT Superimposed PT primar condar 290 y momen Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge CEB-FIP Model Code y &lo 292 t cke d-in forcesatda M or or due to creep effects: effects: due tocreep y 10,000 ACI 209 allow creep and shrinkage effects to be evalu be to effects shrinkage and creep allow , for segmental bridge design, the the design, bridge , for segmental M cr

CEB-FIP Model Code 1990 Code Model CEB-FIP = (1−e (1−e − ϕ ) (M ) II

− M 0. 48,000. 26,000. 24,000. 12,000. ‒12,000. ‒24,000. ‒26,000. ‒48,000. CEB-FIP CEB-FIP I ) . - - Bending moment (K-ft) . Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental of 1.0, since live load is not included. For a description of this load case, see LRFD Equation 3.4.1-2. Equation LRFD see case, load of this For adescription not included. is load live of 1.0, since ­ aload receives gradient temperature bridges, tosegmental applying case load For the special data. lieu of project-specific in gradient fortemperature 0.5 of factor a recommends LRFD influence, load live maximum use which III, Iand States Limit For Service applied. be will gradient temperature nonlinear a states, limit three these with combination factor. In load a1.0 live compression with checks State I Limit Service factor, load while live a0.8 using evaluated tobe tension allows III State Limit Service bridges. for segmental case load a special and III, State Limit Service I, State Limit of Service consist These combinations. load for three check astress requires superstructure of the design state limit Service 3.6.9 3.69. and 3.68 Figures in shown as envelopes forces design maximum theof form in are presented forces design all of summary The 3.6.8 of 0.5. factor aload with combinations load state limit strength basis. on aproject-specific considered tobe are forces secondary settlement support while tions, steel. as such of structures types other unlike stages, construction dueforces tomany design final the it modifies since DC, follow should factor EL load end to results. benefit of little serves and complex book-keeping, creates cases load locked-in from cases load dead toseparate back-tracking complete, is process construction the Once force cases. load locked-in and cases load of dead quantities large toaccumulate possible it is process, erection the during stages construction tomany Owing forces. from locked-in distinguished are not loads dead software, bridge segmental most In 1.2 (maximum). and of 0.9 (minimum) (DC) have factor aload loads dead of 1.0, while have factor PS aload and EL both combinations, load state limit For strength editions. previous the in (PS), forces unlike secondary 3.67 FIGURE Uniform-temperature secondary forces, including creep and shrinkage effects, are included in included are effects, shrinkage and creep including forces, secondary Uniform-temperature combina load state limit strength in not included are gradient due forces to temperature Secondary Under 290 CombPrestressingse Service Limit State Design Limit Service Summary of Design Forces ofDesign Summary AASHTO LRFD 6th Edition 6th LRFD AASHTO PT Secondary and locked-in shear forces at day 10,000. atday forces shear locked-in and Secondary PT condar y &lo (2012), the locked-in forces (EL) are separated from prestressing prestressing from (2012), (EL) forces separated locked-in are the cke d-in forcesatda y 10,000 240. 160. 80. ‒80. ‒160. ‒240. ‒320. 320. 0. factor factor

Shear force (kips) 135 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 136 produced by the bottom of the box being warmer than the top. the than warmer box being of the bottom by the produced tension the tocounteract pour closure the box crossing top of the at the were tendons added example, For this box at pier locations. top of the the compression in and pours top of closure the in tension include example for this locations Such zone. tensile precompressed the outside or at locations small are effects load live where at locations control it may indeed present, are of posttensioning amounts 3.69 FIGURE 3.68 FIGURE It is important to note that, although the special load case may not control at locations where large large where may at not locations control case load special the although tonote that, It important is 828 MA 810 MA 809 MA 829 MA 828 MA 840 MA 842 MA 829 MA Maximum shear forces envelop for strength limit state load combinations. load state limit for strength envelop forces shear Maximum Maximum bending moments envelope for strength limit state load combinations. load state limit for strength envelope moments bending Maximum XL Maxi XL Maxi XL Maxi XL Maxi XL Maxen XL HS20-44UL XL HS20-44UL XL Maxen mum forc mum forc mum forc mum forc velop velop Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge T limitstatema T limitstatema e streng e streng es en es en es en es en T = velop velop velop velop 10,000 da th limitst th limitst e ofstreng e ofstreng e ofstreng e ofstreng x EN x EN ys ate (L ate (L V (stdsp V (stdsp th limitst th limitst th limitst th limitst RFD factors) RFD factors) ec ec factors) factors) ate (T ate (T ate (T ate (T (T (T ======(T (T T 350) 350) 10,000) 10,000) 10,000) 10,000) = = = 350 da 10,000) 10,000) ys 75,000. 50,000. 25,000. ‒25,000. ‒50,000. ‒75,000. ‒100,000. 100,000. 0. 3200. 2400. 1600. 800. ‒800. ‒1600. ‒2400. ‒3200. 0.

Shear force (kips) Bending moment (K-ft) Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 be investigated as well. For this example, example, For this well. as investigated be location web interface and top slab the that web, recommended it is of the axis neutral at the required and of value toamaximum stresses tension pal from limited is stress tension principal maximum Typically, the anticipated. may be cracks tension diagonal exceeded, is concrete of the capacity tensile 3.70). (see tension allowable Figure principle the If the Mohr’s todetermine using circle calculated are Stresses checked. be should stresses tension torsion, principal and for shear combinations load state limit at ­ topier adjacent webs support the in developing from cracks tension diagonal order tocontrol In 3.6.10 Bridges Concrete Segmental where 3.72. Figure in seen be can bars posttensioned of vertical toaddition prior ciple stress prin of the Agraph posttensioning. vertical require of segments number asmall only since acceptable more ­ or adding thickness) (web section cross the by modifying addressed be also (see Figure 3.71).could The overstress 1¼ three show that Calculations stress. tension principal the tocontrol used are bars posttensioning ­vertical approximately was stress tension principle maximum the section, critical the at analysis From conditions. web for final tension. in be could fiber extreme the while stresses principal tosatisfy impossible be practically or it would State Limit III Service to similar 0.8 of factor a load has also live load The piers. moment at negative interior the calculating in used as two, than rather one truck, use only should shear to moment load corresponding live HL-93 the and pier locations, at interior occur commonly stresses principle high that noted be It shear. load should live maximum moments for the concurrent mine loading. service 3.70 FIGURE Principal tensile stress check stress tensile Principal the the top of interior at piers the near occurred example this in stresses principal maximum The todeter necessary it is stress, shear and vertical, of longitudinal, afunction is stress principal Since b I Q V

4

=

= = = Moment of inertia about CG of the section of the CG about Moment of inertia Perpendicular web thickness web Perpendicular Vertical shear force shear Vertical First moment of an area with respect to CG of the section of the toCG respect with moment area of an First f c " ′ Principal Tension Stress Check Tension Stress Principal (psi) during construction (Table 4.14.2.3.3-1) for segmental bridges. Although this check is only only is check this (Table Although bridges. 4.14.2.3.3-1) construction for (psi) segmental during diameter bars, are needed in each web to the reduce principle tension to an acceptable value value acceptable toan tension principle reduce web tothe each in needed are bars, diameter Principal stresses and Mohr’s Circle. and stresses Principal longitudinal compressive stress (additional strands). The solution presented was deemed deemed was solution The presented strands). (additional stress compressive longitudinal σ R x 4. 5 v f c ′ ; larger than the previously discussed limit. For this particular example, example, particular For this limit. discussed previously the than ; larger σ σ y y v f 1 = σ R x σ+ xy 2 3. 3. σ 5 5 −+ f f v c c tensio Principa ′ ′ 1 2 tension is used as a­ as used is tension (psi) at service loads (Tables loads 5.9.4.1.2-1 (psi) at service 5.9.4.2.2-1) and = 3 VQ 4v Ib f n c ′ to 2 l () 4 f σ− 1 Shear xy f c ′ (psi). AASHTO LRFD limits the princi the limits (psi). LRFD AASHTO (σ σ y , – 2 v) 2θ (σ maximum ­ maximum v , + f 2 v) Normal allowable value under under value allowable service service 137 - - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 138 where positive is stress compression where 3.72 FIGURE 3.71 FIGURE 1-3/8" dia.threadbar For For f a f Stress (psi) 100 150 200 250 300 350 400 450

= = 50 0 σ= Allowable principal tension principal Allowable Compressive stress at level on web under investigation on at web under level stress Compressive C L 0 y about Box symmetrical 4 1/2" 0

: (at sections where no vertical web posttensioning is present) is web posttensioning no vertical where : (at sections Vertical PT bar in the web. the in bar PT Vertical Principal tension stress at service limit state load combinations along the bridge. the along combinations load state limit atservice stress tension Principal 1-14" dia.threadbar 4'-7" 6'-7 1/2" 150 Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge Principle stresses(psi) 5 @5" 8" 300 10 " 4 @5" Principle stressesatday10,000 v+ Distance alongbridge(ft) aa =× Stressing end 8" ff 2'-0" 450 () Allowable tension(3.5sq.roots) a f 1-14" dia.threadbar 8" 2. 3 1. P Notes: 5 @5" Stress eachbarto75%ofG.U.T.S. segments oneachsideofallpiers. rovide 6–11/4"dia.threadbarspersegmentor –1 1/4"dia.threadbarsperwebforthe‡rsttwo (typ) 9" 600 8" 6" (typ) 1-14" dia.threadbar 750 900

9'-0" Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 imposed result from restrained deformations and should disappear if the reinforcement starts to yield at toyield starts reinforcement the if disappear should and deformations restrained from result imposed loads the gradient, temperature tothe regard With gradient. temperature for of 0.0 the factor a load using recommends LRFD data, specific lieu of project In basis. on aproject-specific determined to be control. not will IV State Limit Strength Hence, component load. dead structural in a25% difference than greater are force load effects of live magnitudes the example, For this may control. IV State Limit Strength large, is load tolive load dead of the However, ratio the considered. where tobe for longerneeds spans that combination load only the Iis State Limit Strength superstructures, with For cases most checked. be must strength flexural of state limit the superstructure, the in satisfied are stresses service Once 3.6.11 Bridges Concrete Segmental where shear. associated its torsion with maximum the ­torsion and associated its with shear maximum the using However, torsion. design to sufficient it is ­maximum and shear maximum the of basis the on design to conservative is Therefore, torsion. it maximum the torsion. and due toshear of reinforcement summation the on based be should webreinforcement transverse final the Therefore, side. other on the other each counteract web and on one side of the additive torsion are and due toshear stresses abox the girder, In 3.6.12.1.1 5.8.3. of Section lieu in applied may be 5.8.6 of Section procedure torsion design and shear bridges, girder with compatible 5.8.3.4.3 5.8.3.4.2. Section Procedure toGeneral alternative an as acceptable it is B5 and moved toAppendix been has procedure The iterative expressions. algebraic noniterative provides AASHTO Currently, parameters. todetermine iteration required contribution capacity shear for concrete procedure general the to2008 Prior design. element of shear important an becomes reinforcement longitudinal the model, truss tothis Owing model. of truss a45° instead truss on variable-angle based is The MCFT calculated. being parameters the to significance physical gives that approach a rational is bridge for segmental Specifications Guide to traditional addition in torsion design and of shear method new 2012) the adopted also Code Design Highway Bridge Ontario the time by first the foradopted was and torsiondesign forshear The 1991)MCFT Mitchell, Canada. in and (Collins Mitchell and Collins by developed was (MCFT) theory compressionfield The modified 3.6.12.1 3.6.12 is required. reinforcement of flexural amount small avery where girder deeper in especially failure, brittle example. this in not considered are settlements support Also, states. limit strength in not considered is gradient temperature the occurrence, to this Owing ultimate. The load factors for support settlement and temperature gradient are not provided by LRFD; they are they LRFD; by are not provided gradient andtemperature settlement forsupport factors The load For shear design, the following basic relationship must be satisfied at each section: each at satisfied be must relationship basic following the design, For shear produces which loading same not the is shear maximum the produces that loading the Normally, specifications LRFD The V n is determined as the lesser of lesser the as determined is Flexural Strength Check Strength Flexural Shear and Torsion and Design Shear AASHTO LRFD AASHTO AASHTO LRFD Shear and Torsion General Design Procedure Design General Torsion and Shear LRFD AASHTO Sections Subjected to Shear Only Shear to Subjected Sections also allows allows also , Article 5.7.3.3.2, require minimum reinforcement in order to prevent flexure order toprevent in flexure reinforcement minimum 5.7.3.3.2, require , Article ACI 318-05 Code in 1991. in The V empirical equations. Unlike previous empirical equations, MCFT MCFT equations, empirical previous Unlike equations. empirical c to be calculated using a simplified procedure as per Section Section per as procedure asimplified using calculated tobe VV and and nc =+ VV un AASHTO LRFD Bridge Design Specifications Design Bridge LRFD AASHTO AASHTO Standard Specification. Standard AASHTO ≤φ VV sp +

AASHTO LRFD AASHTO For segmental box box segmental For ACI (LRFD 5.8.3.3-1) (LRFD and and (AASHTO (AASHTO AASHTO AASHTO Interim, Interim, α and and 139 θ

Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 where where 140 5.8.6 Article Refer toLRFD 3.6.12.2 modified. be also should reinforcing shear of area and reinforcing, longitudinal stress, Shear effects. of these combination the account into taking calculated be should Strain 5.8.3.6. torsion, refer Article and shear to combined subjected For sections 3.6.12.1.3 follows: as expressed is relationship This for sufficiency. checked be must reinforcement longitudinal the of capacity totorsion, the not subjected beam of the section At each steel. longitudinal in tension causes that shear recognition the is theory compression field of modified principles cornerstone ofOne the 3.6.12.1.2 by equation: determined as stresses compressive nal where Tensile strain and The value of value The The nominal shear resistance is the algebraic sum of the contributing components: contributing the of sum algebraic the is resistance shear The nominal equation: using calculated is reinforcement transverse of contribution The ε s α β is the net longitudinal tensile strain in the section at the centroid of the tension reinforcement. reinforcement. tension of the centroid at the section the in strain tensile longitudinal net the is is the angle of inclination of transverse reinforcement and and reinforcement of transverse of inclination angle the is is a factor indicating the ability of diagonally cracked concrete to transmit tension and shear, and tension totransmit concrete cracked of diagonally ability the indicating afactor is

for Segmental Box Girder Bridges Girder Box Segmental for AASHTO Shear and Torsion Design Procedure Procedure Design Torsion and Shear AASHTO Longitudinal Reinforcement Longitudinal Sections Subjected to Combined Shear and Torsion and Shear Combined to Subjected Sections ε β s may be determined by equation: determined may be at a given section is obtained from equation: from obtained is section at agiven Af sy Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge +≥ Af ps ε= s ps V Md s     = uv d M Af Vf v Vf φ vy u cc VV nc f θ= ++ =β nc = + β= d 0. 0. =+ 0. 0. v EA 5 29 0316 ( 25 50 1 NV ss co NV +ε φ +ε uu tc 4. c 750 u 3500 ′ θ+ + VV bd 8 s + vv sp EA    + pp s ot −− ' + φ bd s

u v vv VA V αα s

−− pp p )

si VV

n ps θ sp

is the angle of inclination of diago of inclination angle the is f .5 o

   co t θ    

(LRFD 5.8.3.4.2-4) (LRFD (LRFD 5.8.3.4.2-3) (LRFD (LRFD 5.8.3.4.2-1) (LRFD (LRFD 5.8.3.3-4) (LRFD (LRFD 5.8.3.3-3) (LRFD (LRFD 5.8.3.5-1) (LRFD (LRFD 5.8.3.3-1) (LRFD - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 where where Bridges Concrete Segmental moment: cracking torsional the than where where conditions: following where where The shear provided by concrete section is determined as follows: determined is section concrete by provided shear The to limited is resistance shear the nominal of torsionbe mayneglected, effects the where sections In Torsional effects is investigated in sections where factored torsional moment at the section is greater greater is section the moment at torsional factored where sections in investigated is Torsional effects equation: from determined is reinforcement by transverse provided Shear When torsional effects are considered, the longitudinal and transverse reinforcement must satisfy the satisfy must reinforcement transverse and the longitudinal considered, are effects torsional When moment Torsional cracking A f f b A T T c pc ' e u cr

v o

=

=

= = = = = section resisting shear T K Specified concrete strength concrete Specified Minimum effective shear flow web or flange width to resist torsional stresses stresses (in) torsional resist to width flange flow web or shear effective Minimum Compressive stress in concrete after allowance for all prestress losses at the centroid of cross- centroid of the at losses prestress all for allowance after concrete in stress Compressive Factored torsional moment (kip-ft) torsional Factored Area of transverse reinforcement within a distance adistance within reinforcement of transverse Area n Area enclosed by shear flow path flowpath (in by shear enclosed Area Torsional cracking moment (kip-ft) Torsional cracking is the stress variable parameter expressed by equation: expressed parameter variable stress the is is the nominal torsional resistance of transverse reinforcement calculated as follows: as calculated reinforcement of transverse resistance torsional nominal the is T cr , is given by equation: given , is K TK =+ cr VK Vf cc = = nc 2 1 0. T ) V = 0. n 0632 TT TT s 0. 0632 = 0. uc un = 379 0632 ≥φ 2 ≤φ Af AA f vy ot pc s s r d fA

′

co f f fb ′ bd c

2 ′ ′ v

≤ v s d (in

b 2.

e 0

2 )

(LRFD 5.8.6.5-4)(LRFD (LRFD 5.8.6.5-3)(LRFD (LRFD 5.8.6.5-2)(LRFD (LRFD 5.8.6.3-3)(LRFD (LRFD 5.8.6.3-2)(LRFD (LRFD 5.8.6.4-2)(LRFD (LRFD 5.8.6.3-1)(LRFD (LRFD 5.8.6.4-1)(LRFD 141 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 where 142 where or compression) in is slab moment, bottom tive 3.6.12.2.1.1 3.6.12.2.1 Additionally the section is sized tosatisfy: sized is section the Additionally satisfy: should reinforcement longitudinal The Transverse reinforcement contribution: reinforcement Transverse contribution: Concrete sufficient. is dimension Cross-section Nominal shear resistance: effective shear depth shear effective ϕ p A b dM f h v

c l v

′ ======− 0.90 for shear for 0.90 Perimeter of centerline outermost continuous closed transverse reinforcement (in) reinforcement transverse closed continuous outermost of centerline Perimeter Total additional longitudinal reinforcement required for torsion (in required reinforcement longitudinal Total additional 6k 32 108 Design Examples (Using LRFD Modified Compression Field Theory) Field Compression Modified (Using LRFD Examples Design si in Node Number: 41 (At Critical Shear Section) 41 Shear (At Number: Node Critical , compression strength of concrete of strength compression , , effective web width web , effective 6 −= 17. 1/ 2 93. Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge 4i VV nu n7 => => 4, V n 483 .7 =× 9f    0. bd V t0 v ki 2 u Vf Vf 563 p2    V cc nc VV + V =β s = nc ax u    = A 0. =+ 0. ×× = 2 l 0316 {} V Af 25 Ab = T 2, φ= p vy 2 u oe .9 2 391 = Tp () Af ′ VV d bd nh 108 93. 0    s oy vv v , sp ≤

391 co + ki 44 0. −× ′ + Ultimate moment: moment: Ultimate t p =

bd 474 θ 6, /0 V vv p , .9 483 0. = 72 f c ′ 2, ki

657 p 108 ki , p 2 ) M u = 82 , 091 (LRFD 5.8.6.5-5)(LRFD (LRFD 5.8.6.4-3)(LRFD ki p-ft (nega - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 where Bridges Concrete Segmental tosatisfy: ment needs 3.6.12.2.1.2 Use double #6 bars at 9" centers per web per centers at 9" Use double bars #6 Step 1: Calculate the net longitudinal tensile strain in the section at the centroid of the tension tension of the centroid at the section the in strain tensile longitudinal net the 1:Step Calculate θ β ϕ ϕ steel of concrete contribution Compute the 4: Step of value 3: Compute the Step of value Compute 2: the Step

= = = = reinforcement: angle of inclination of diagonal compressive stresses compressive of diagonal of inclination angle tension totransmit concrete cracked of diagonally ability the indicating factor 0.90 0.95

Longitudinal Reinforcement Longitudinal for flexure; for shear; ε= s == 1, Af M d 929 sy (Table 5.5.4.2.2-1) v 133. (Table 5.5.4.2.2-1) A u s vs θ= VV ++ Af +≥ , = = sn Vf 0. 450 7 sy =− =− Af cc 60 5 29 fd θ β β= =× =β yv ps 2, NV EA : : += ×× ss 0. 0. +ε uu V 391 ps 93. Af co 1 0316 0316 0. 3, VV +ε ps 00007 + /0 500 t 4c cu 4. 750

θ    805 EA .9 =φ ps d M 8 −− pp For sections not subjected to torsion, longitudinal reinforce to torsion, longitudinal not subjected For sections v φ ot VA u s A 4. 1, s 00 =+ v pp + s 53 29. 048 ′ = ×+ = 29 bd 0. − vv 1 1. 24 50 V 63 +× 17 == NV c ° ×× φ 3, 750 sp 67. 1, uu f == 500 in 609 + 2 o 7 0. V 4. 2    = c ×= 08 /f : 8 0. ×= 93. ki φ 253 t 82 in 00007 0. 7. pk −− 41 , 22 00007 79 091 = in 805 .5 17 28 VV , +− = 048 , sp 136 0. , 2, 4. 500 ip 96 29. 53 391 / ki we ki in × 24    p p b co 67. ° /f 67. t t 7 θ 7    ×

189 (LRFD 5.8.3.5-1) (LRFD 143 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 144 where or 3.6.12.2.1.3 M u Transverse reinforcement contribution: reinforcement Transverse contribution: Concrete sufficient are dimensions Cross-section Nominal shear resistance: condition the (5.8.3.5-1)Therefore, satisfied. is dM ϕ b = f v v

c ′ = 20 =− = = 0.90 108 6k 32 , 816 si in Node Number: 29 (At Section 60 Feet from the Face of Diaphragm) of Face the from Feet 60 29 (At Number: Section Node , compression strength of concrete of strength compression , 52 , effective web width web , effective ki −= p-ft .6 V (positive moment, top slab is in compression) in is moment, top slab (positive /2 s = d M 101. v Af φ u vy Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge + = = 7i 0. 13, 7. d VV s 50 v n8 79 nu 82 co 909 NV => => φ , × V uu t 091 4, θ n .4 0. + 882 ki =× = 8f 95    p 0. 20 φ t0 ++ 2 ×× ki 563 −− 0 Vf Vf p1 cc V .4 VV nc =β .5 V ax s    46 nc = VV = u ×× 0. 2, =+ 0. 0. {} sp = 0316 V Af 391 25 90 2 1, 0 φ= .9 p vy ×× 087 = () 101. 108 −× ′ VV 93. d bd    0 9 s v 0. , vv sp co 087 co ki + 4c 51 −× 74 t ′ p t + 5, bd θ = /0 θ vv V ot , .9 0. p 958 , 882 () 72 = 29. 1, − 24 208 ki 108 0c    p ×° ×= ki , effective shear depth; shear , effective 21 ot p 29. , 958 24 ki p Ultimate moment: moment: Ultimate Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 where Bridges Concrete Segmental tosatisfy: forcement needs 3.6.12.2.1.4 Conservatively use double #5 at 18 use Conservatively Minimum reinforcing Step 1: Calculate the net longitudinal tensile strain in the section at the centroid of the tension tension of the centroid at the section the in strain tensile longitudinal net the 1:Step Calculate θ β ϕ ϕ steel of concrete contribution Compute the 4: Step of value 3: Compute the Step of value Compute 2: the Step

= = = = reinforcement: Angle of inclination of diagonal compressive stresses compressive of diagonal of inclination Angle tension totransmit concrete cracked of diagonally ability indicating Factor 0.90 0.95

Longitudinal Reinforcement Longitudinal for flexure; for shear; V ε= s s = = Af 544 M Af d vy − sy (Table 5.5.4.2.2-1) Af v (Table 5.5.4.2.2-1) u 68. vc , ++ d 350 s = +≥ v 2 Af Vf 0. co 0. Af θ= cc sy 5 θ β 0316 =− =× =β ps NV t EA : : θ ss 0. 0. uu += 29 β= ps Vk 0. = 0316 0316 Af " uc 00013 +ε + centers 20 ps 1 φ= 3,    ×× EA

+ε ′ d M ps −− 500 pp b v 4. 750 v . 1, φ For sections not subjected to torsion, longitudinal rein totorsion, longitudinal not subjected For sections VA u 413 4. →ε 8 f pp 087 s + s 86 00 y ′ s 0. bd ×+ A =× s =+ vv s /0 50 v = 60 0. = 29 ×× = NV .9 1 0316 φ sp 0 12 32 ×× 19. 0. uu f +× =≅ 101. 413 + o 750 3, V 1, 1 4.    = c 500 101. 207 ×= : 8 61 7c φ in 20 268 8. 0. 2 ×= −− 71 , /f 48 ip 816 0 0. 6 = ot t .5 = ×= 0 5, 29 28 VV , V +− 4. 12 60 209 118 sp ° 1, , 8 29. 500 ' ×= 087 0 21 ki 0. ki ° ×    248 p p 19. co 19. , 515. t 1 in θ 1    2 × /f 5k

189 t ip (LRFD 5.8.3.5-1) (LRFD 145 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 3.6.12.2.2.1 3.6.12.2.2 146 under it was to insure contribution: Concrete Therefore, the condition condition the (5.8.3.5-1)Therefore, satisfied. is Use double #6 bar at 6 Use double bar #6 contribution: reinforcement Transverse checked was prestressing effective with loads factored under fiber extreme at the Note: Tensile stress ϕ f b f pc v

c

′ = = = = 0.90 for shear for 0.90 32 6k 906 Design Examples (Using AASHTO LRFD Section 5.8.6) Section LRFD (Using AASHTO Examples Design in si ps Node Number: 41 (At Critical Shear Section) 41 Shear (At Number: Node Critical , compression strength of concrete of strength compression , , effective web width web , effective . i at neutral axis neutral at 6 d M v " φ u centers per web per centers Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge f c + ′ VV = = . 0. sn 3, 8. =− =− 50 A 48 396 20 s V 2, NV vs φ c , × = = uu 391 V 816 =× K 0. + s 60 fd ki 20 V VV = y 95 /0    =+ 823 cu p × K 21 .9 =φ φ 102 ++ ×× VK . 01 =+ 1 0632 −− 0 cc A .7 = V v == 1 0. .5 66 ,    = u 0. V 0. 011 0632 − 12 VV 1, = 1. 0632 s 0. 134 63 0. 0. sp V 087 = 76 2, 90 ×× c 0632 0 9 == Af 391 × 1, f in vy 2 −× 6 in 102 pc s 646    2 0. 22 /f =⇒ co d ki 102 /i fb 51 f t 2. n1 = ′ c p ki t ′ θ 62 1, w ≤ p = d , 795 2. 515. 1, .6 0 823 011 1i 2. 50 ki 0 n/ − p ki ki ft p/ p    ×° we co b t2 9 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Bridges Concrete Segmental under it was to insure contribution: Concrete 3.6.12.2.2.2 Check maximum nominal shear resistance: shear nominal maximum Check Ultimate shear resistance: Transverse reinforcement contribution: reinforcement Transverse checked was prestressing effective with loads factored under fiber extreme at the Note: Tensile stress force. shear factored the carry to adequate is section The ϕ b f f pc v c ′

= = = = 0.90 for shear for 0.90 32 6k 533 in si , compression strength of concrete of strength compression , ps Node Number: 29 (At Section 60 Feet from the Face of Diaphragm) of Face the from Feet 60 29 (At Number: Section Node , effective web width web , effective i at neutral axis neutral at 6 φ= f c VV ′ 0. . nu VV 379 sn =− =− V 0. 1, c 9( =× fb 087 1, VV K cv ′ V 20 nc 011 VV n =+ /0 =+ dk K cu =+ v =φ .9 . φ= 1, += =+ VK 1 0632 =× VV 01 cc 1, 011 0. nc = V 1 795 0. VV 379 u 0. sp 0632 , 0. φ+ = +≤ 021 0632 − V 63 0. )2 () 1, 533 1, V p ×× 0632 795 c 087 = == f 63 2 , 6 0 pc 187 525 VV 0. ×× = =⇒ ki sp 103 379 2, fb + f p 2. 2 c ki ′ ki ′ 806 11 p9 ≤ p2 w = 103 d 2. >= 1, fb cv 0 ′ ki 021 3k = 2. p d 0 3, v ip ki 060 , /web p 391 ip ki p 147 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 148 that at least one construction method be designed and shown in the plans. The limits of these loads loads these of limits The plans. the in shown and designed be method one construction at least that practice It common is selected. method construction the with associated design during assumed investigated. tobe need may also structures completed partially other conditions, cantilever tobalanced addition In erection. during imbalance load the tohandle required are supports temporary cases, many In loads. unbalanced the are larger the 3.73).ment (see length, Figure span the The longer period. this during structure of the imbalance load the and of redundancy lower degree due tothe issue design important an becomes therefore, analysis, Stability buckling. and overturning, failure, material against factors safety have ample and state astable in be must foundation and structure the construction, during times At all end. tothe of construction ning begin the from changing constantly are conditions boundary the bridge, of asegmental construction During design. bridge for segmental criteria design one of is the construction during analysis A stability 3.7.1 3.7 A v Minimum reinforcing does not control. However, conservatively use double #5 at 18 use centers in However, not control. does conservatively reinforcing Minimum Minimum reinforcing It is important for the engineer to specify the design plans and the construction loads that were that loads construction the and plans design the to specify engineer for the It important is of a seg erection during check a stability requires that one is example structure cantilever A free force. shear factored the carry to adequate is section The resistance: shear nominal maximum Check Ultimate shear resistance: =

0.

Construction Stage Analysis Stage Construction 413 Stability during Construction during Stability in 2 /f t Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge A A s φ= vs v 0. VV == = = 379 nu V 50 60 fd V s y f == bs 0. y × 93 w fb 9( Vf 103 VV cv ′ sy 1, nc s V =+ 021 dk 50 n d == v =+ 60 φ= 0. ×× =× VV 1, += 16 015 , 0. 20 nc 000 425 021 VV 379 ×× sp 12 +≤ φ+ in V )1 . () 413 22 p 425 = /i = n0 12 0. , 63 301 0 16 VV 0. = 60 ×× sp 379 1, .1 + in ki × 2 446 8i 103 p1 2 /f 103 >= n/ t fb cv ki ′ = ft p = 425 d v 3, , 060 087 ki p ki ip p

- - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental associated stress limit. its and construction during combinations load state 5.14.2.3. Table limit 3.1 Article under shows service the by adopted were 1999). specifications Later, those Bridges Concrete Segmental of Construction and Design for Specifications example. this for loads construction 3.76 3.74 show critical Figures through checked. be also should members the of strengths and loads construction critical by caused stresses The equipment. due toconstruction reactions support approximate including stated, clearly be should schemes construction engineer’s the Additionally, shown. be also should structure on the applied are loads where locations and 3.73 FIGURE The following construction loads should be considered in a stability analysis: stability in a considered be should loads construction The following Article the 7.4 in of covered originally were specifications analysis stability The WS U CLE IE CE CLL DW DIFF DC

= =

lifting, it may be taken as 10% of the lifting load.) lifting as the of 10% taken be may it lifting, (kip). etc. winch, side. other on the ksf 0.005 and cantilever (kip). toone cantilever applied load dead

= = =

Segment unbalanced load (kip). load unbalanced Segment

Dynamic load from equipment; determined according to the type of machinery. (For of machinery. type to the according determined equipment; from load Dynamic = = =

Specialized construction equipment, load from launching gantry, form-traveler, beam and and form-traveler, beam gantry, launching from load equipment, construction Specialized Horizontal wind load on structure in accordance with the provisions of Section 3 (LRFD) (ksf). 3 (LRFD) of Section provisions the with accordance in on structure load wind Horizontal Weight of the supported structure (kip). structure Weight supported of the = Superimposed dead load (kips or klf). (kips load dead Superimposed Longitudinal construction equipment loads (kip). loads equipment construction Longitudinal Distributed construction live load; taken as 0.01 ksf of deck area applied toone side of applied area of deck 0.01 as ksf taken load; live construction Distributed Differential load: applicable only to balanced cantilever construction, taken as 2% of the as 2% of taken construction, cantilever balanced to only applicable load: Differential WUP CLL1 Temporary supporttruss Unbalanced construction load for balanced cantilever construction. cantilever for balanced load construction Unbalanced DC (CLL2 + DIFF.) C L Pier AASHTO LRFD Bridge Design Specifications Design Bridge LRFD AASHTO X1 X2 DC (CE + IE) segment erected Newly , Second Edition Second A + AI AASHTO Guide Guide AASHTO u (AASHTO (AASHTO gradual ­gradual 149 , Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 150 FIGURE 3.75 FIGURE FIGURE 3.74 Case: Case: D

Case: Case: A Construction loads Case A and Case B. Case Aand Case loads Construction Construction loads Case C and Case D. Case Cand Case loads Construction C 0.7 WUP B WUP Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge CLL1 CLL1 98ʹ-9" 98'-9" DC DC CLL1 98'-9" DC 0.7 WS 0.7 WS 86'-9" DC DIFF. (CLL2 (CLL2 CLL2 98ʹ-9" 98'-9" DC DC 98'-9" 98'-9" DC + + DC DIFF.) DIFF.) (CE (CE CE u + Equipment not working + IE) IE) 12'-0" Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 f2 f1 e2 e1 d2 d1 c2 c1 b2 b1 a2 a1 TABLE 3.1 TABLE Segmental Concrete Bridges Concrete Segmental FIGURE 3.76 FIGURE Notes: f: moving equipment e: normal erection 3. d:equipment not working 2. Allowable compressive stress inconcrete where f’c is compressive the strength at of time the application. load 1. OTHER LOADS DC DC DC DC DC DC DC DC DC DC DC DC DC Case: Case:

+ + + + + + + + + + + +

DIFF CLL CLL U U DIFF DIFF DIFF U U DIFF DIFF E F Service Limit State Load Combinations during Construction during Combinations Load State Limit Service + + + +

CLL CLL CLL CLL + +

Construction loads Case E and Case F. Case Eand Case loads Construction + + + + + + (CE (CE

CLL CLL CLL CLL 0.7 0.7 + + + + WS WS (CE (CE (CE (CE = + +

+ + + +

IE) IE) CR +SH +EHEV +TUTG +ESWA ( CE CE ( + + CE CE + + + + CLL1 CLL1 + +

0.7 0.7 IE) IE) IE) IE CLE CLE + +

Load CombinationsLoad + + 98'-9" DC WUP WUP

) 0.7 0.7

IE

IE + + + 86'-9" DC 0.3 WS OTHER LOADS

0.3 WS WS WS + + ) ) 0.3 0.3 +

0.3 0.3 + OTHER LOADS WS WS + + OTHER LOADS WS WS WUP WUP + +

+ + 0.3 0.3

0.3 0.3 + + WE WE

WE WE 0.7 0.7

+ WE WE

OTHER LOADS + OTHER LOADS

+ OTHER LOADS CLL2 CLL2 98'-9" 98'-9" DC DC Tension Stress (ksi) Allowable Flexural 0.22√f 0.19√f 0.22√f 0.19√f 0.22√f 0.19√f 0.22√f 0.19√f 0.22√f 0.19√f 0.22√f 0.19√f (CE (CE u ′ ′ ′ ′ ′ ′ ′ ′ ′ ′ ′ ′ c c c c c c c c c c c c + + Normal erection Moving equipment IE) IE) 12'-0" Allowable Principal Tension Stress (ksi) 0.126√f 0.11√f 0.126√f 0.11√f 0.126√f 0.11√f 0.126√f 0.11√f 0.126√f 0.11√f 0.126√f 0.11√f ′ ′ ′ ′ ′ ′ c c c c c c ′ ′ ′ ′ ′ ′ c c c c c c 151 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 152

FIGURE 3.77 FIGURE Strength limit state load combinations (see Figure 3.77) (see Figure combinations load state limit Strength CR AI A WUP WE WA T SH 1.

= =

For maximum force effects: For maximum added to the dead load as 100% of load A(kip). of 100% load as load dead tothe added perature gradients (TG). gradients perature = = =

Thermal loads; the sum of the effects due to uniform temperature variation (TU) and tem and (TU) variation temperature uniform due to effects the of thesum loads; Thermal Static weight of precast segment being handled (kip). handled being segment of precast weight Static = = Dynamic response due to accidental release of precast segment taken as static load to be tobe load static as taken segment of precast release due toaccidental response Dynamic Shrinkage in accordance with Article 5.14.2.3.6 (LRFD). Article with accordance in Shrinkage Creep effects in accordance with Article 5.14.2.3.6 (LRFD). Article with accordance in effects Creep

Horizontal wind load on equipment taken as 0.1 ksf of exposed surface. of exposed 0.1 as ksf on equipmenttaken load wind Horizontal Water and load = Wind uplift on cantilever taken as 0.005 ksf of deck area applied to one side only. applied area deck ksf of 0.005 as taken cantilever on uplift Wind

Strength limit state construction load combinations. load construction state limit Strength stream 1.1 DC Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge DC 98'-9" 98'-9" Σφ pressure. FD (For maximumforceeects) u (For minimumforceeects) =+ 1. 11 () CD IF FC ++ .3 1.1 DIFF. EA 98'-9" 98'-9" 1.1 DC DC + AI

1.3 CE CE +(A (LRFD 5.14.2.3.4a-1) (LRFD + (A + + AI) AI ) - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Bridges Concrete Segmental where computed. were Table 5.14.2.3.3-1 considered construction. during analysis stability the in Stress Limits for Limits Stress The following construction loads were applied in the stability analysis. stability the in were applied loads construction The following “ combinations The load be will structure cantilever onebalanced only span, typical ft a200 has example design the Since CE 2. 2. 1.

For minimum force effects: For minimum For minimum force effects: For minimum For maximum force effects: For maximum WS, WE and other loads were ignored in this analysis. this in were ignored loads other and WE WS, CE A = =

5 Kip. 5 construction equipment such as stressing jack and stressing platform stressing and jack stressing as equipmentsuch construction =

= static load of typical segment segment of typical load static 5 kip. 5 f c ′ = 6k a si Co ” to“ ∑ : Tensil mp φ= FD u ressi f CL es W ” as specified in the in specified ” as CL 1. A tres up L ∑ ve CE Σφ 11 L 10 =× =× = ×+ 20 =× s0 φ= stress 78 FD 0. 145 kip 145 () =× = += FD u u 005 . IE =+ 005 CD .1 .0 12 =− 90 1k CC ks ks CC ×= 51 sf f4 0. f IF ×= 0. f4 ++ c ′ 50 155 FC == .1 EA f EA 43 c 30 ′ 30 ++ +× .1 =− = = = 5. AASHTO LRFD Bridge Design Specifications Design Bridge LRFD AASHTO 96 145 .3 5k 0. . + . 215 .5 215 43 AI ip AI ki ×= EA kl p 63 0.

kl kl ++ f 465 f f − ks AI ks i i (LRFD 5.14.2.3.4a-2) (LRFD 153

Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 porary posttensioned bars are utilized, the jacking force should be limited to approximately 50% of 50% toapproximately limited be force should jacking the utilized, are bars posttensioned porary However, force. tem reusable if jacking allowable tofull stressed and tendons cantilever permanent of the part as designed be could bars posttensioned the bars, PT erection of permanent case the In segment. erected previously tothe erected being segment the toattach bars nent posttensioning or perma temporary touse bridges segmental cantilever balance precast in practice It common is 3.7.2 combination load 154 bars: sioning control. geometry in error tosystematic lead could which joint, match-cast the across thickness epoxy uneven is to prevent limitation stress the intention of The cured. has epoxy the until joint the across ksi of 0.04 stress average an and of ksi 0.03 stress aminimum toprovide designed be should bars posttensioning follows: as are resin epoxy of the Purposes stressed. are bars sioning bars. of the GUTS FIGURE Although calculations have not been shown in this example, of load cases cases of load example, this in shown have not been calculations Although Essentially, there are two load cases that need to be considered when designing temporary postten temporary designing when considered tobe need that cases load two are there Essentially, temporary the for a Ajoint, Type Specifications LRFD of the 5.14.2.4.2 Article the with accordance In joints. cast match of faces both on applied 1/16thick in is normally epoxy of The application beforepostten segments two between the joint of faces cast match the to is applied resin epoxy The 2. 2. 4. 3. 1. 1. Case 1 plus permanent cantilever tendons. Normally, one or two hours after the open time of the of time the open after hours one or two Normally, tendons. cantilever 1plus permanent Case from water, chlorides and moisture, preventing joint, awater-tight provides epoxy Hardened Dead load of the segment plus construction loads and temporary posttensioning bars, bars, posttensioning temporary and loads plus construction segment of the load Dead out. leaking from tendon duct the in grout cementitious prevents epoxy Hardened more uniformly. stresses shear and stresses compressive helps distribute epoxy Hardened segments. between proper alignment the tofacilitate Lubrication epoxy is completed, the allowable joint stress is zero tension, preferably some compression. some preferably tension, zero is stress joint allowable the completed, is epoxy specifications. LRFD of the 5.14.2.4.2 Article to conform should case load this for stresses joint allowable min). The to 60 ­(approximately 45 epoxy the of time the open during stressed be should bars PT erection The (see Figure 3.78). tendons. the reaching Erection Tendons Erection 3.78

Construction loads during segment erection segment during loads Construction e controls. Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge Pier . (CLL2 A considered e jointbeing + DIFF.) Erection PTbars a to f , strength limit state state limit , strength - - - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 effect) lag shear including section: (use typical Properties Section 3.7.2.1 Bridges Concrete Segmental where example. design this in were selected bars erection Permanent 3.7.2.2 Jacking force: force: Jacking due tofriction: Losses bars. PT dia. in forset anchor 1¼ after forces anchoring Check force: 75% of GUTS Jacking F α μ κ L e α n κ x

pj

======

= Base of the Napierian logarithm Napierian of the Base Length of a prestressing tendon from the jacking end to any point under consideration, (ft) consideration, under point end toany jacking the tendon from of aprestressing Length Wobble (ft coefficient, 0.0002 per ft per 0.0002 Sum of the absolute values of angular change of prestressing steel path from jacking end, (rad) end, jacking from path steel of prestressing change of angular values absolute of the Sum 0.3 12 ft length) (segment friction (1/rad); of Coefficient 0.0 Force in the prestressing steel at jacking, (kip) at jacking, steel prestressing the Force in Design of Erection PT Bars PT Erection of Design Design Assumptions Design P j =× Ma 0. ma 75 Segmen x tt 187. −1 he ) tw P 5 P P u j u u = oi of of of eigh 140. nt 1. 1. 1. 25" =− 375" YS 0" CL tD 625 ff bb += YS ∆= pu dia. =→ tt 148 L dia. FF =→ 20 PF 5. ki dia. IFF1 Ae or 3. == I 6f ba p ×× c ba 4 = A PT 12 ff r0 ba .0 t r1 c 791 pj == 14 = == = r1 () bars .0 ( 1 == 78 70 . 1 2 .8 27 892 − .2 30 = 5 ×× −× .3 e ) .5 5 = ft () 232. = −κ () 1 8f 150 2 8 () 2 141. 150 ft 81 150 () x 150 4 t .4 +µ 2 89 0. 3p 40 α 43 20 ft ks 127. ×= ft 187. lf 3 ×= i

3 237 1 . 155 5k 5k − ki ip 918. ip p 148 96 k ip ki p-ft (LRFD5.9.5.2.2b-1) 155 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 156

3.79 FIGURE 1-3/8" Friction loss is negligible. is loss Friction set Anchor Compute CGS location relative to the top fiber tothe relative location Compute CGS 2 –13/8 4–1¼ Try: GUTS 66% to of equal seating after immediately forces, anchoring Therefore, di a. L C threadba 4 1/2" ab Bo " dia. bottom bars, as shown in Figure 3.79 Figure in shown as bars, bottom dia. out x symmetrical δ 1-1/4" di " Erection PT bars. PT Erection

dia. top bars and top bars dia. = 4'-7" r 1/16 ft 0.0052 in 6'-7 1/2" Loss a. threadba of Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge P i stress =− 807. 140. r 5 @5" ∴= Pb du 84 ∵ i 624 et ∆= o ×= P Pt tto () Pe i 10" oa 8" Y L F op s 1. m ncho = 4 @5" 25 140. 140. 0337 =× =× ∑ 495 (1 40 20 rs P 3) Y 625 625 i ×+ s et = 8" = ki = 0. .6 .6 =ε 807. 124. p ×− 3. −= 5 6 6 E () ×= ×= 65 0337 1 2'-0" s 187. 84 312. 237 375 ft = ki −× 30 5 84 (0 p ki . 140. 8" 0002 , 312. 000 p( ×− 495 (9 66% 29 12 5 @5" 84    ) (typ ki 0. 9" ki 0. ki p 0052 12 G. p 375 ) p U. 8" )    T.S) = 13 6" (typ 1-1/4" di ks i ) a. threadba r

9'-0" Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Bridges Concrete Segmental

PT bars eccentricity eccentricity bars PT b. a. Check joint stresses due to dead loads and PT bars PT and loads due todead stresses joint Check Check stresses at the joint due to dead loads, PT bars and cantilever tendons cantilever and bars PT loads, due joint todead at the stresses Check Tendon 2–12 size: tendons: due tocantilever Stress Tendon 4–12 size: = 3.65−3.4 3.65−3.4 ∅ ∅ 0.6 0.6 Av " " erag strands. (50% PT) less strands. strands. Te f es = b P ndon =− =− =− =− 0.25 ft (below C.G.C.)(below ft 0.25 i f tr f t t =× f f ess b =− =− =− =− =− b 19. 11. 11. f f 0. ∑∑ =− t b =− =− =− =− 0. A ecce 7 = =− 0. =− 27. 52. 406 478 478 1, c 5( ∑∑ P 5( i 0. A 3. 27. 27. 70. 968. ∑∑ 50. −− 98 5k ntricity 0. c 046 P 46 0. A 0. −− − ks i 98 98 38 0. 046 c 134 P 64 3646 1. − sf − 807. f0 96 i S ks 024 ×= + 428 2 24. + + b Pe + =− =− f0 i 141. 0. ks − 1, 24. ks S 84 81 =− )0 )0 52 =− 134 t Pe 1, i0 968. =− S =− i0 0. i . 52 3. b × Pe 134 > 6. M 232. 40 968. > 3646 i S 40 0. , 450 . 232. => b 024 DL 96 968. .0 . . .0 25 012 1823 ks 0. 89 96 3k 3k × 09 ks i .5 89 − ks 96 × 2. si ks i si 141. = 918. i ks 9 2. ks ki i 2.

9 i p 9f 40 96 0. t 04 ks i

(LRFD 5.14.2.4.2) (LRFD 5.14.2.4.2) 157 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 158 There are two types of shear keys in match-cast joints between precast segments: precast between joints match-cast in keys shear of types two are There 3.8.2 added. be could reinforcing additional manner, this in resisted be could that amount the moment applied were toexceed the moment. If applied an counteract would web which the through section toa eccentric be then compression This would the web. of edge extreme the to shifted be would steel. flexural of the to50% steel shear of the or steel, 100% flexural of to100% the steel of shear 50% of adding case worst the touse been has practice standard the reinforcement, flexural and reinforcement shear determined of previously basis the On 3.8.1 3.8 For segments with 4–12 with For segments stresses. of Summation A rational approach can also be used, where the compression strut in an equivalent truss model model truss equivalent an in compression strut the where used, be also can approach A rational Conclusion: 2–12 with For segments • • stresses. joint allowable the satisfy bars PT permanent The proposed Detailing However, alignment shear keys help in preventing local relative vertical displacement on the deck deck on the displacement vertical relative local preventing help in keys shear However, alignment slab. bottom one on the and top slab on the required are keys alignment of three a minimum normally box, For asingle-cell directions. horizontal and vertical in erected being segments cast match- two of the alignment correct the facilitate they rather forces; major shear the transfer to areexpected not keys Alignment flanges. bottom top and the in –Located keys Alignment forces. shear the transferring in considered are keys shear web only keys, shear designing When performance. superior due totheir preferred are keys shear multiple Corrugated box girders. of webs precast of the faces on the –Located Web keys shear Combined Transverse Bending and Longitudinal Shear Longitudinal and Bending Transverse Combined Shear Key Design Shear Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge ∅ ∅ 0.6 0.6 " " tendons tendons ∑ ∑ ∑ ∑ ∑ ∑ ∑ f f f ∑ t t b f b f =− =− t =− f =− f t f b =− b =− 0. 0. 0. =− 0. =− 046 046 134 0. 134 0. 2283 0. 0. 4106 −= −= 146 −= 158 −= 0. 0. 0. 0. 1823 3646 ks 012 024 ks ks ks i0 i0 i0 i0 >− >− > > − − − − .0 0. 0. 0. .0 0. .0 .0 3k 2283 4106 146 3k 158 3k 3k si si si si ks ks ks ks i i i i Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Bridges Concrete Segmental a. FIGURE 3.81 FIGURE 3.80 FIGURE The design of web shear keys should satisfy two design criteria: twodesign satisfy should keys shear of web design The 3.83) (see Figure zones. tendon duct the in located not be should keys alignment and shear Both Shear key design example was illustrated in Figure 3.80 Figure in illustrated was example design key Shear

2. 2. 1. 1. Shear strength design of the shear keys shear of the design strength Shear per As design: strength Shear approxi extends keys of shear depth 5.14.2.4.2-1, total Figure the LRFD per As design: Geometric Geometric consideration (see Figures 3.81 to3.83) (see Figures consideration Geometric necessary to provide more than one alignment shear key. shear one alignment more than toprovide necessary is it wings, cantilevers two or longerwebs between spanning in longerslabs Therefore, joint. cast match on one load side of the due toconcentrated segments precast adjacent two between slab design of shear keys. Use keys. of shear design Specification Design Bridge LRFD AASHTO width key Shear b depth key Shear h Specifications LRFD AASHTO by no longer is joint permitted only. dry joints Note that for dry developed was provision key Edition Second Bridges, of 12.2.21 article with accordance computed in be also could key shear of the strength Alternatively, not exceed should key shear by the carried stress shear of erection, time At the design. key shear the in considered be should stresses 9.20.1.5, shearing reverse 2002), Article 75% web thickness. at least of the and depth 75%mately section of the w

=

= 9ft AASHTO Standard Specifications Standard AASHTO 16 in 16

Details of shear keys. of shear Details Precast segment being erected. being segment Precast AASHTO Guide Specifications for Design and Construction of Segmental Concrete Concrete Segmental of Construction and Design for Specifications Guide AASHTO = = 0.75 0.75 0.75 0.75 Shear failureplane × × (AASHTO 1999). (AASHTO However, the 12'-0" 9ft 16 16 AASHTO Standard Specifications Standard AASHTO = = 12 in 12 6.75 ft 6.75 . AASHTO Standards Specifications, 17th Specifications, Edition Standards AASHTO VV 12'-0" uD , article 9.20.1.5 , article =+ 1. 1 ( does not specify any guideline on the strength strength on the guideline any not specify does 12-0" DC 3 1/2" C DI Er FF ec ) tion PT

1/2" er Segm

1/2" ec , article 9.20.1.5. , article AASHTO Guide Specification Guide AASHTO te ent bars 2 1/2" 2 1/2" d be

2 1/2" in g (AASHTO (AASHTO 2 f c ′ shear shear (psi). (psi). 159 - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 160

FIGURE where 3.82 V Consider one web only, web one Consider

DC

= = VA VV Web shear key detail. key Web shear shear force due to self-weight of one typical segment (kips) segment force due of toself-weight one typical shear 78 78 ck cu =φ =⋅ × 0. 12 12 2. 1. Notes: 5 v As perAASHTOLRFDspeci cationsFig.5.14.2.4.2-1. 1 1/4"≤a≥twicethediameteroftopsizeaggregate. Fr × 0.75b , per key,, per Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge ont face 0.155 0.155 bw D a: , per web, , per d etail w = = 1:2 A 145 kip 145 V u =× 1. 1 DIFF a 145 VV VV uc d d d = nc ×= φ= 2% = 1. 02 of V 162. DC 8k ip

3" 3" 3" Side vi a: d = ew 1:2 a =

1 1/2" 1 1/2" 1 1/2" 0.75 h 3 1/2" 2 1/2" 3 1/2" h Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental in Figures 3.84 through 3.91. through 3.84 Figures in shown are models tie and of strut examples Some by nodes. together tied is and members, tension and compression of consisting members concrete to applied analogy system truss is a tie model and strut The model. tie and strut by the modeled be can foundations topile cap pile pier pier cap, column, bearings, diaphragm, the girder to the box from other.flow The element of tothe forces one structural from forces flow of the studying in used extensively is model tie and strut detailing, and design bridge segmental In 3.8.3 FIGURE Seg where men

t Strut and Tie Model Tie and Strut 3.83 v ϕ A

k = = = allowable shear stress shear allowable 0.9 article 9.14 of AASHTO Standard Specifications 9.14 Standard 0.9 article of AASHTO Sec shear area of one key area shear Bulkhead details. Bulkhead tion A- A A Number

AS spac

(typ 4 1/2 at at

1/2" 1/2" ed

Vp ke male 14 of 6 "

c Varies 2 6 )

" " C

male " Vp ys er C c Seg ke 17 er ke ' men y -8 we ys =× " A 42 t b required k =× vf =× (0 = 3. 2 B B .5 2( 51 1/2 6000 B B ec " 162. () pe (typ c ′ tion B-B 24 rw ps == 8) ) = 3 6506. i) eb ' -0 0. 2i Sy " == 9 mm. ab 4 1/2 n (typ 90. = 6l 2 6. 1/2 1/2 90. " " ) bs 44 5 " 2 1/2

6" 2" 6" ' 44 out C -6 " 17 "

(ty

6. y (t (typ 13. ki L '

-8 5k gi 2 p)

p p) Seg " '' 91 rder ) sa ip men

yk 14 male t 4 spac key ed at s eys 6"

Sec 3" 3" 3" 3" 3" tion C- (ty Alig pical nment ke 1 1/2 C )

1/2 1/2 "

" " 161 3 1/2"2 1/2" 3 1/2" y Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 162 Concrete Bridges; Concrete Bridges; Concrete 3.85 FIGURE 3.84 FIGURE C T +Δ +Δ C T D Transfer of moment from the box girder to the pier column (From Menn, C. 1986. 1986. C. (From Menn, column pier the to girder box the of moment from Transfer Transfer of forces from the diaphragm to a single bearing. (From Menn, C. 1986. 1986. C. (From Menn, bearing. a single to diaphragm the from of forces Transfer Birkhauser-Verlag, Boston, MA, 1986.) MA, Boston, Birkhauser-Verlag, Birkhauser-Verlag, Boston, MA, 1986.) MA, Boston, Birkhauser-Verlag, s Longit Mo C L del Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge ΔM ΔT

Pier udinal se 1M C =Δ =Δ d v 0 T C T v × D ction h o s T C C L T Compressio

Pier ension ho n D s Cros T +Δ s-sect Pl od C T an L ΔT

el Pier T ion v 2 T D h s T h Prestressed Prestressed Prestressed Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental out from the expansion joint diaphragm as a result of severe corrosion of the tendon in the anchorage anchorage the tendon in of the corrosion of severe aresult as diaphragm joint expansion the out from tendon The tendon. pulled end of the north at completely the 57 failed had Span tendon in tensioned apost that revealed bridge of the inspection Further were fractured. strands several and cracked was duct external polyethylene The distress. of state asignificant in found was 28 span tendon in tensioning 2001). (Fib Florida in bridges concrete erected segmentally span-by-span first one tobe of the believed is 1983 and early in constructed was The bridge due tocorrosion. tohave found failed was Keys Florida in Bridge Channel maintenance. minimum requires that system structural durable and economical an as enjoyed popularity its has of bridge type this States, United the in (1949–1950), bridge posttensioned Philadelphia in first Bridge of the Walnut Lane struction con the since acentury, For half states. other in found were voids also grout and ducts polyethylene cracked as such bridges posttensioned of deficiencies Other country. the around engineers bridge and toowners concern agreat become has States United the in bridges concrete of posttensioned durability 2000, to in Florida’s 1999 some in of tendons bridges posttensioning in corrosion of findings the After 3.9.1 3.9 Durability Bridges; Concrete 3.86 FIGURE In August 2000, during a routine inspection of the Mid-Bay Bridge located in Destin, Florida, apost Florida, Destin, in located Mid-Bay Bridge of the inspection aroutine during 2000, August In Niles of the box girder superstructure the in tendons of 1999, external one of the summer the In Durability Problems of Posttensioned Bridges in the United States the in Problems Bridges ofPosttensioned Durability Transfer of moment from the box girder to the box column. (From Menn, C. 1986. 1986. C. (From Menn, column. box the to girder box the of moment from Transfer Birkhauser-Verlag, Boston, MA, 1986.) MA, Boston, Birkhauser-Verlag, C C T T +Δ +Δ +Δ +Δ C C T T C C v v d d o o T T v v C C T T

ho ho ΔT ΔM ΔT ΔM =Δ =Δ =Δ =Δ C C T T × × h h o o Prestressed Prestressed 163 - - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 164 high-level approach columns. approach high-level for the including method, construction segmental precast the 1982 utilized to 1987 in and constructed was bridge The tendons. external superstructure the in found deficiencies including repaired, have been columns approach The high-level 76 contamination. chloride grout and void, grout duct, polyethylene cracked including columns, of the base at the and anchorages the in tendon corrosion severe revealed the ­ of the rest of investigation The bridge. span main of the anchorage cable and superstructure, bridge the columns, approach high-level other all of investigation extensive an triggered finding This (PBQD 2002). 133 northbound column in tendon located vertical external southeast of the of 11 strands ­ the in resulted corrosion severe that discovered it was Florida, Petersburg, St. in Bridge Skyway 2001). (FDOT discovered were voids also grout and ducts polyethylene cracked tendon corrosion, to addition In construction. segmental precast span-by-span using in 1992 constructed was The bridge replacement. that tendons 11 found required was it inspection, and investigation extensive After area. 1986. Menn, C. 3.87 FIGURE In September 2000, during a special inspection of the high level approach columns in the Sunshine Sunshine the in columns approach level high of the inspection aspecial during 2000, September In Prestressed Concrete Bridges; Concrete Prestressed Transfer of torsion moment from the box girder through the diaphragm to bearings. (From bearings. to diaphragm the through girder box the moment from of torsion Transfer V d Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge A w s, h Birkhauser-Verlag, Boston, MA, 1986.) MA, Boston, Birkhauser-Verlag, V d CT C L o

Bo S x S A V w s, d h

S

S columns columns failure failure Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 Segmental Concrete Bridges Concrete Segmental Concrete Bridges; Concrete 1986.) MA, Verlag, Boston, 3.89 FIGURE 3.88 FIGURE Transfer of blister forces to the web. (From Menn, C. 1986. 1986. C. web.(From Menn, the to forces of blister Transfer Radial forces in curved bottom slab. (From Mathivat, J. J. (From Mathivat, slab. bottom curved in forces Radial John Wiley & Sons, New York, New NY, &Sons, 1979.) Wiley John Sec tion A-A p A Sp dditional webreinforcemen an tendons Shear reinforcemen A s f sy ≅0.2 Apf ≅ z/2 A A in thesec Stre py t

ss diaphrag R t The Cantilever Construction of Prestressed Prestressed of Construction Cantilever The Sp C Prestressed Concrete Bridges; Concrete Prestressed L tion Pier an tendon N m 1 s R FF 1 r (radial forces) ust oft Birkhauser- endon R 165 Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 166 on.Pstnindtnosiseto a odce t30lctos hsi esta 1.5% of than is less This locations. at 380 conducted was inspection tendons Posttensioned young. relatively are structures the although corroded, are tendons or not the whether and voids have grout structures Artery Central the if todetermine important It was structures. concrete posttensioned place cast-in- and of segmental numbers considerable are there where Boston in project Artery/Tunnel Central Bridges; Concrete Prestressed Bridges; Concrete Prestressed of Design FIGURE 3.91 FIGURE 3.90 FIGURE The findings of the different bridges in Florida raised concerns about the grouting situation in the in situation grouting the about concerns raised Florida in different bridges the of findings The tendon Bo ttom Diagonal crac A Transfer of forces by opposing blisters. (From Podolny, W., 1982. M. J. Muller, blisters. by opposing of forces Transfer Resal shear effect at a kink in bottom slab. (From Mathivat, J. Mathivat, (From slab. bottom in kink ata effect shear Resal Resultant th Resultant th k Sec Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge John Wiley & Sons, New York, New NY, &Sons, 1979.) Wiley John tion A-A in bo Th ru ru st st rough crac th we John Wiley & Sons, Inc, New York, New Inc, NY, 1982.) &Sons, Wiley John bs Pa To A rt ks p tendon ial long itudinal se distribution inwe due toprestres Diagonal tensio ctio n s n Tr b uss analo The Cantilever Construction of Construction Cantilever The gy C L Pier Construction and Construction Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 tendons in two bridges were discovered. In the late 1980s and early 1990s, about a dozen postten adozen about 1990s, early and 1980s late the In were discovered. bridges two in tendons corroded severely and bridges seven in voids grout were inspected; bridges segmental of nine a sample then 1999). LCPC. and Since TRL, Agency, Setra, Highway (The warning without collapsed y-gwas, States. United the problems in corrosion posttensioned of discovery tothe prior years to30 20 about were discovered Europe problems in of durability Signs 3.9.2 of butvoids strands. no corrosion grout of amounts excessive revealed investigation initial The project. of on tendons the number the total Bridges Concrete Segmental Program, 447 posttensioned concrete bridges bridges concrete posttensioned 447 Program, Inspection Special the from above, mentioned As bridges. concrete posttensioned of its investigation and study extensive an undertaken has that the world in countries the few is one of Kingdom The United 3.9.3 girder box of flanges bottom top and the in tendons internal and dons ten external of replaceable exception the with bridges, of webs posttensioned the in tendons internal on amoratorium placed has Construction and for Transport Ministry Federal German Consequently, Wurzburg-Heilbronn. on motorway over Muckbachtal bridge of the tendon corrosion and Nurenberg, South at the A73 motorway of tendoncorrosion Berlin-Schmargendorf, in flyover junction sion of the in 1976,tendoncorro Dusseldorf in the Heerdter flyover at of the failure for example tendon corrosion, severe by were affected Germany in bridges concrete posttensioned several Task that Group 9.5 reported FIB bridge. not aposttensioned it was although Germany, in failures structure posttensioned tacular spec most one of is the Berlin in Hall of Congress collapse the For instance, bridges. posttensioned their 2001). (Fib bridges posttensioned of grouted on construction new amoratorium placed has Corporation Public Highway the Japan findings, of these aresult As found. were also spalling and cracks, concrete ment corrosion, reinforce tendoncorrosion, as such deficiencies Other voids. grout and grout, imperfect no grout, as such showed grout deficiency have The results 31%investigated tendonsthe bridges. concrete of (Fib 1960 2001). and 1946 between period the in constructed bridges posttensioned of simple-span generation first the including Bridge, Abord d’ Riviere the and Durance, over the bridge the Viaduct, Saint-Cloud the Bridge, Bia Can the Bridge, Saint-Georges Villeneuve the Bridge, aBinson Port the Bridge, Vaux Seine the Sur Bridge, the ­ in found also were defects system posttensioning and other deficiency, grout corrosion, tendon in Additionally, 1972. and reconstructed demolished was The bridge tendon corrosion. severe by caused Bridge Chazey the of span the side in cracks concrete several of finding the with discovered documented. and program, inspection of the aresult As Road. Trunk on the located bridges concrete posttensioned existing for all program inspection special afive-year launched of Transport Department UK 1992 the In place. in still is joints, epoxy with bridges segmental including bridges, concrete posttensioned segmental However, for precast moratorium the in1996. bridges concrete posttensioned cast-in-place for lifted was The moratorium 1992. September in Agency) Highway called (currently or replacement. major repairs required which tendon corrosion, serious with were discovered Kingdom United the in bridges sioned concrete In December 1985, a single-span precast segmental bridge in the United Kingdom, namely Ynys- namely Kingdom, United the in bridge segmental precast 1985, asingle-span December In Other countries such as Germany, Austria, and Italy also have their share of corrosion problems with problems with of corrosion share have their also Italy and Austria, Germany, as such countries Other posttensioned 120 investigated and inspections conducted Corporation Public Highway Japan was in France bridges concrete posttensioned problems of of durability sign serious first 1970,In the

Durability Problems of Posttensioned Bridges around the World the around Problems Bridges ofPosttensioned Durability Lessons Learned initiated aban initiated 447 The inspection results inspection The posttensioned concrete bridges were completely inspected inspected completely were bridges concrete posttensioned were on internally grouted posttensioned concrete bridges bridges concrete posttensioned grouted on internally systematically documented. Such a study allows the the allows astudy Such documented. systematically led to the UK Department of Transport of Transport Department UK to the led . Choisy- ­le-Roi 167 - - - - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 this type of investigation in the United States. Unfortunately, there is no single coordinated effort effort coordinated no single is there Unfortunately, States. United the in of investigation type this for leader the become has (FDOT) of Transportation Department Florida the of investigation, type for this guideline no national is there While Massachusetts. and Island, Rhode Iowa, Indiana, Carolina, South Kansas, Delaware, Mississippi, Georgia, Texas, Virginia, of Florida, States the in of record durability. have agood structures of the majority the that finds the report Therefore, Kingdom. United the in bridges highway concrete posttensioned of number asmall in occurred has duct grouted internally in tendons of posttensioned corrosion that concluded study The problems. unique own its has country each that believed it is countries, between shared bridges of posttensioned durability with problems associated common are there Although bridges. concrete posttensioned their affecting factors important the todetermine Agency Highway UK 168 response to the moratorium (The Concrete Society 1996). Society Concrete (The moratorium tothe response in bridges concrete of posttensioned durability with todeal Society Concrete UK by the produced ever documents important most 47) one 47 of is (TR the Report Technical bridges. of posttensioned detailing and design including specifications, materials and construction tothe revisions make and to review Industry and Society Engineering Bridge the challenged also It has ways. positive very world in of the industries bridge concrete the impacted has moratorium the time, at that countries by most reaction over an considered was bridges on posttensioned moratorium DOT 1992 UK well-known the While 3.9.4 today: bridges tensioned the States. United in and Kingdom the United in bridges posttensioned of findings investigation the in verified been has This undamaged. and intact still are systems tendonor protection more of the States: investigations. countries’ theEuropean in findings tothe similar very are states Texas other and Florida, as such the States, United in investigations bridges concrete posttensioned of To findings States. the date, different from completed inspections/investigations the study and to collect States United the in In the United States, special inspection and investigation of posttensioned bridges were ­ bridges of posttensioned investigation and inspection special States, United the In It is believed that there are three factors that may have contributed to the durability problems of post durability to the may have contributed that factors three are there that It believed is one long as as structures, of posttensioned durability the compromise Grout do not voids necessarily theUnited in investigation bridges posttensioned of findings summary the brief is The following • • • • • • 2. 3. 1. Lack of historical data and testing on emerging new technologies in posttensioned bridge designs designs bridge posttensioned in technologies new on emerging testing and data of historical Lack Generally, grouted tendons are perceived as adequate corrosion protection to the prestressing prestressing tothe protection corrosion adequate as perceived are tendons grouted Generally, at allowed (notension prestressing full of design concrete of prestressed philosophy The original ducts. the inside grout of the quality and condition the toinspect inability the notwithstanding steel, and construction methods. or no maintenance. minimal required therefore and free crack be should concrete prestressed that aperception loads) created working methods detection corrosion and specifications in Tendon of shortcomings aresult as corrosion contamination chloride and materials grout Tendon of unsuitable aresult as corrosion system protection of tendon due tofailure intrusion oxygen and of water aresult as Tendon failure and corrosion detailing and design, control, quality practice, construction of poor aresult Grout as voids bleed of water result as anchorages and duct posttensioned the Grout in voids tendon of external duct polyethylene Cracked Posttensioned Concrete Bridges Concrete Posttensioned New Direction for the Next Generation of Generation Next for the New Direction Bridge Engineering Handbook, Second Edition: Superstructure Design Superstructure Edition: Second Handbook, Engineering Bridge conducted conducted - - Downloaded By: 10.3.98.104 At: 16:29 02 Oct 2021; For: 9781439852293, chapter3, 10.1201/b16523-4 details since 2003 ( 2003 since details and specifications posttensioned new the implemented have fully Florida in projects bridge concrete 2001.posttensioned new The since a year once conducted Seminars Certification Training Grouting up ASBI by setting details posttensioning and control, quality workmanship, practice, grouting ing improv in (ASBI) contributed Institute Bridge Segmental American the PTI, and of FDOT support In specifications. grouting its rewritten has also (PTI) Institute The Posttensioning details. posttensioning semistandard including requirements, certification and manuals, control quality specifications, system has FDOT Kingdom, United to the Similar States. United the in bridges concrete of posttensioned generation future for the direction new the Bridges Concrete Segmental FDOT. 2003. FDOT. 2001. FDOT. 1989. ConcreteThe Society. Durable 1996. M.P.Collins, and Mitchell, D. 1991. CEB. 1991. AASHTO. 2012. AASHTO. 2004. AASHTO. 2002. AASHTO. 1999. AASHTO. 1989b. AASHTO. 1989a. References maintenance. and inspection routine require bridges concrete posttensioned of bridges, types toother Similar bridges. concrete of posttensioned durability the compromise indeed will above one of the any Neglecting maintenance. preventive and inspection, system, detection corrosion control, quality assurance, quality workmanship, detailing, design, methods, construction materials, including board the done across improvements are required the provided life service the tolast constructed be can structure posttensioned Adurable method. tion construc segmental precast the with mostly associated are and areas coastal of Florida environment corrosive the very in are located corrosion by affected are that above mentioned bridges posttensioned of the all almost that Observe States. United the in bridges concrete posttensioned of all condition the represent do not necessarily country the of parts in other and Florida in problems found The durability 3.9.5 FDOT and TxDOT (Texas Department of Transportation) are leading in developing and ­ and developing in leading are of Transportation) (Texas TxDOT Department and FDOT Department of Transportation, Tallahassee, FL. Tallahassee, FL. Florida Department of Transportation, Tallahassee, FL. Society, London, U.K. Association of State Highway and Transportation Officials; Washington, D.C. Highway and Transportation Officials; Washington, D.C. Highway and Transportation Officials; Washington, D.C. Washington, D.C. Specifications; of State Highway and Transportation Officials; Washington, D.C. Washington, D.C. Specifications; Conclusions CEB-FIP Model Code 1990; Segmental Manual: AGuide to the Construction of Segmental Bridges; New Directions for Florida Post-Tensioned Bridges; Mid-Bay Bridge Post-Tensioning Evaluation; AASHTO LRFDBridge Design Specifications; Standard Specifications for Design;Bridge Guide Specification for theDesign andConstruction Segmentalof Bridges and Interim AASHTO LRFD Bridge Design Specifications; Guide Specifications for Thermal Effects in Bridge Superstructures; Guide Specification for theDesign andConstruction Segmentalof Bridges and Interim FDOT 2nd Edition, American Association of State Highway and Transportation Officials; 1st Edition, American Association of State Highway and Transportation Officials;

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