This article was downloaded by: 10.3.98.104 On: 01 Oct 2021 Access details: subscription number Publisher: CRC Press Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: 5 Howick Place, London SW1P 1WG, UK

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

Towers

Publication details https://www.routledgehandbooks.com/doi/10.1201/b15621-4 Wai-Fah Chen, Lian Duan Published online on: 24 Jan 2014

How to cite :- Wai-Fah Chen, Lian Duan. 24 Jan 2014, Towers from: Bridge Engineering Handbook, Substructure Design CRC Press Accessed on: 01 Oct 2021 https://www.routledgehandbooks.com/doi/10.1201/b15621-4

PLEASE SCROLL DOWN FOR DOCUMENT

Full terms and conditions of use: https://www.routledgehandbooks.com/legal-notices/terms

This Document PDF may be used for research, teaching and private study purposes. Any substantial or systematic reproductions, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden.

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: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 or for bad. for or for good of bridges, appearance Towers the do impact of statics. surely equations three tothe according equilibrium in be and of forces nature and loads the resist must they that is common towers have in designers! the of whims the and not towershapes these between differences the dictated roadways the of 3.8); heights (Figure the Bridge River Cooper 2005 towers of the full-diamond-shaped concrete to the ­ concrete bulky and have no heavy and bridges suspension self-anchored are of these 3.6). Both Korea (Figure South Incheon, Yeongjong Bridge, Grand 2000 towers of the quasi-diamond-shaped the chapter) with the and 3.19d, in later (Figure bridge suspension single-tower its with Span East Bridge Bay Francisco–Oakland York New in 3.5). Bridge (Figure Williamsburg 1903 towers of the steel confusing and awkward the 3.4) (Figure with Bridge 1883of the Brooklyn stone rugged massive, the between 3.3); disproportions the (Figure ponder Suspension Bridge 3.2). (Figure Bridge Bay Francisco–Oakland San 1936 towers of the of the architecture but timeless, 3.1) utilitarian, (Figure the Bridge Gate Golden with esthetics. overall of the part important towers an making itself, bridge that of impression lasting their as recall can people Towers that bridge. image bridge a mnemonic project particular that identify can people which from a motif theme, identity, a unifying a characteristic bridge Towers users. bridge toa and give viewers by both directions all from seen be can and superstructure the above project they because bridges, of elements long-span structural Towers visible most the are 3.1 Transportation Department of California Fan Jason Consulting Engineer Charles Seim One can easily see that there is great diversity in bridge tower designs; the only requirement that these these that requirement only the tower bridge designs; in diversity great is there that see easily can One 3.7) (Figure Bridge Island the Glebe towers1995 of quasi-diamond-shaped concrete the compare Then San distinctive and new the with older, those Bridges, Iconic one may contrast Alternatively, of Forth the Firth towers of delicate the 1964 of those towers to robust these compare Then 1937 towers of the deco art elegant the contrast of towers, imagery powerful of the examples As Introduction anchorages visible at each end. at each visible anchorages References 3.8 Summary 3.7 Construction 3.6 3.5 3.4 3.3 Esthetics 3.2 Functions 3.1 Introduction Final Design Final Design Conceptual Bridges Towers Spectacular and Loads Design Materials •Forms and Shapes •Erection ...... • ...... Other Design Considerations Design Other ...... Towers 3 ­towers 63 68 68 63 85 83 87 87 69 74 Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 64 3.2 FIGURE 3.1 FIGURE Golden Gate Bridge, San Francisco. (Courtesy of Charles Seim.) of Charles (Courtesy Francisco. San Bridge, Gate Golden San Francisco–Oakland Bay Bridge. (Courtesy of Charles Seim.) of Charles (Courtesy Bridge. Bay Francisco–Oakland San Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 Towers 3.4 FIGURE 3.3 FIGURE Brooklyn Bridge, New York. (Courtesy of Charles Seim.) of Charles York. New (Courtesy Bridge, Brooklyn Firth of Forth Suspension Bridge. (Courtesy of Charles Seim.) of Charles (Courtesy Bridge. Suspension of Forth Firth 65 Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 66 3.6 FIGURE 3.5 FIGURE Yeongjong Grand Bridge, Incheon, South Korea. South Incheon, Bridge, Yeongjong Grand Williamsburg Bridge, New York. (Courtesy of Charles Seim.) of Charles York. New (Courtesy Bridge, Williamsburg Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 Towers 3.8 FIGURE 3.7 FIGURE Glebe Island Bridge, Sydney, Australia. (Courtesy of T. Y. International.) (Courtesy Lin Sydney, Australia. Bridge, Island Glebe Cooper River Bridge, Charleston, South Carolina, under construction. (Courtesy of Charles Seim.) of Charles (Courtesy construction. under Carolina, South Charleston, Bridge, River Cooper 67 Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 structures, such as girders, trusses, or arches, usually do not project above the deck. Piers and columns columns and Piers deck. the above do not project usually or arches, trusses, girders, as such structures, of bridge types for other superstructure the support that columns and Piers 6. Chapter in ­discussed are Abutments structure. approach or toan roadway approach toan transition structures these which lives. long service help toensure will program maintenance awell-executed and access, maintenance and for inspection provisions materials, durable longer. or perhaps designs, for Robust 100–150 last years, can well-maintained and well-designed that engineers to bridge a reminder as serve they structures; of ­ examples excellent are bridges These 150 years. be could Yeongjong Bridge the Grand and 100 years. for another toserve continue could bridges these all ­maintained, 68 towers that produce the much-admired proportions of these world-renowned bridges. The towers The for a world-renowned bridges. of these proportions much-admired the produce towers that of the heights the within ratios the in changes subtle It these is ratio. aspect the member, smaller the the higher the tower base; the above heights increasing with ratios of these reduction but subtle, important, He found Bridges. Bay Francisco–Oakland San the and Gate Golden the towers of both ofnents the 2013.in is opened the bridge after impression more even distinctive leave an perhaps will bridge suspension self-anchored Span East Bridge Bay Francisco–Oakland San new tower of the single white, elegant The paint. aluminum shiny and bracing cross robust-looking by its Bridge Bay Francisco–Oakland Bay, San the the across and towers, steel red tapered, tall, by its Bridge Gate Golden towers! of their because famous are most Indeed, towers. by the revealed as structure, of the image of the 3.1 illustrations good are Section in examples as used The bridges of a bridge. or motif, character, true the towers reveal the mere esthetics, beyond visual— is function secondary important an structural, towers is of the function main the Although 3.3 funds. of public wasteful not tobe as so lives, long service having statements esthetic attractive, and towersbe that bridges demands The public users. toits service good continuous toprovide tions func maintenance and inspection out both of carrying for ease toallow towers designed be and bridge bridge. the down tearing without replaced be towers cannot components, bridge other unlike as bridge, of the life entire for the serviceable and reliable be also must atower. as but functions itself support cannot that amember describe to used is word chapter, “spar” the this In ground. tothe forces and loads bridge some tower carrying a as function does however, spar for support; the its on cables depend must and not self-supporting are toavoid confusion. not used, “pylons” is ­self-supporting; are that for structures word chapter, used “tower” is the this In bridge. tower of a cable-stayed the designate to used The word sometimes “pylon”is structures. suspension-cable-stayed ground. tothe subjected is bridge the which to forces the and loads the tocarry function and cables bridge the and themselves both tosupport deck the bridge above that project structures concrete or steel the vertical as defined “Towers” usually are 3.2 2. Chapter in discussed are Both suspension and cable-stayed bridges are supported by abutments or piers at the point at point or at piers the by abutments supported are bridges cable-stayed and suspension Both Bay Bridge Francisco–Oakland San the of span suspension self-anchored the new of lives service The are well they If century. of a three-quarters than older all are above noted bridges famous The Seim (1996) measured the aspect ratios of the length, divided by the thickness of the visible compo visible of the thickness by the divided length, of the ratios aspect (1996) the Seim measured the towers, arched-masonry gothic, by its Bridge Brooklyn of the character the visualize people Many the that requires This design. component bridge of good important an is serviceability Structural Towers constructible. and pleasing esthetically be economically, Towers functions its perform must that members or near-vertical vertical todescribe introduced been has “spar” term anew Recently hybrid or bridges, cable-stayed bridges, suspension only for used are towers definition, this by Thus, Functions Esthetics Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge ­single-shaft structures ­structures enduring enduring - - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 of the bridge, a double plane at the sides of the roadway girder, or a single plane on one side of the tower on one side of plane the orgirder, a single roadway of the sides at the a double plane bridge, of the centerline the along plane in asingle arrayed be can cables The bridge. of asuspension cables large do the tapered. usually towers are the case which in cable, employsion asingle bridges afew suspen Just design. bridge of the motif the project they and elements, supporting visual the them making height, full extend and bridge the as wide as are bridges of suspension types common these roadway. of elements the towers The of supporting of the impression visual overall tothe contributors important the as out stand them makes cables the of diameter large The enjoy viewing. instinctively public. viewing of the eyes tothe image visual soaring sturdy, but graceful, and astrong bridge entire that togive as so proportioned and shaped carefully be should bridge long span Towers 200-m (656-ft) single span and anchors the single plane, harp-arrayed cables. harp-arrayed plane, the single anchors and span (656-ft) single 200-m is a roadway girder box concrete The of Seville. old town the from landmark avisible it is white, painted degrees; 68 boxsteel at angled tower, concrete-filled, a tall, 142-m features The bridge (466-ft) engineer. and architect both as acted who Calatrava, by Santiago designed It was Spain. Seville, in 1992 Expo the towers. distinctive featured that bridges spectacular constructing and designing by developments new relatively these toexploit begin would architects and engineers that inevitable was engineers tomost accessible nonetheless of art, aform and art,” structural “extravagant considered may be bridges such bridge. a conventional more than cost they because not economical, are they and cient manner, effi most the in foundation toits bridge (1983), of forces the the do not conduct they Billington because by defined as art,” “Structural not considered are bridges such Regardless, not elegant. are types bridge these spectacular, may be they although that argue also could One not restricted. is cost and objective tobridges. impact” towers “visual toadd or kinked inclined, curved, featured also trend This bridges. of these statements esthetic principle the tobecome cables stay the allowing thus ­towers, them! construct and design could engineers bridge because bridges, or “distinctive” “picturesque,” “spectacular,” demanding began both, or the public, owners, as bridge started trend This designers. bridge of prime objectives the economybeen and oftenhave not efficiency 1990s, the since ally, occasion design, bridge in the major elements usually are economy, efficiency, and elegance Although 3.4 Fundamentals Edition: Second Handbook, Engineering 2and Chapters in more detail in discussed is of bridges Esthetics bridges. for cable-stayed and suspension for both arrangements cable and tower shapes many with bridges ofples completed exam Leonhardtmany (1984) presents structures. elegant and economical, efficient, are that bridges tohonor Art” words “Structural the coined Billington Prof. design. bridge development of modern the systems. structural and systems visual both as ered consid be should the towers together and cables the tower. over the Thus, visually dominates that array fan aradiating as such arrangements, cable other are towers as bridge tothe obtrusive as not be will usually array, example, for harp of a cables tower. of the form parallel The of the context the in sidered Second Edition: Design Superstructure tower. Chapter See 10, atwo-shaft with used usually array double plane and a tower asingle-shaft with used usually is array plane Asingle side. other on the adouble plane and The cables of most cable-stayed bridges are small in diameter and usually do not visually stand out as out stand visually do not usually and diameter in aresmall bridges cable-stayed of most cables The people many that towers between curve parabolic in a drape bridges suspension cable main two The One of the first of these “spectacular” bridges was the Alamillo Bridge (Figure 3.9), constructed for 3.9), (Figure constructed Bridge Alamillo the was bridges “spectacular” these of first ofOne the became programs engineering when provenstructural 1990s, early the in started extravaganza This an is not efficiency because attention, to attract aredesigned types bridge spectacular new These the that may dominate arrays unusual in cables stay the configuring for calls often atrend Such of history the in role of esthetics of the importance (1983) of the overview an presents Billington con be should harp, little-used or the fan, radiating a fan, as such stays, cable ofHowever, the arrays Towers and Spectacular BridgesTowers Spectacular and , and high-performance steel and concrete were readily available; thus, it thus, available; were readily concrete and steel high-performance and , Cable-Stayed Bridges. , Cable-Stayed . Bridge Engineering Handbook, Handbook, Engineering Bridge . 3 of of Instead, Instead, Bridge Bridge 69 ------Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 70 Berkel, features a tapered-steel tower with a “kink” near the midpoint that instantly attracts attention, attention, attracts instantly that midpoint the near a“kink” tower with atapered-steel features Berkel, van Ben architect by designed bridge, This it. view who by all admired is that bridge of aspectacular icon. acity as bridge designed aspectacularly desiring cities or tothe owners bridge tothe factor important not an is cost whenever bridges, outstanding construct and to design architects and for way engineers the cleared Bridge Alamillo the of day. More time importantly, the tells that ashadow tower casts pointed single, the where California, in Bridge Dial on Sun notably most since, times several used successfully been has motif This cost. the worth well it tobe consider and bridge a little. tower tilts simply the and equilibrium, horizontal in are thenot tower at cable loads the but cables, the and loads girder the deflects bridge the crossing 1996).traffic The (Petroski cables backstay with ground tothe tower not anchored is the because bridge, cable-stayed not agenuine is structure However, bridge. the this viewing of people attention the attracts FIGURE 3.10 FIGURE 3.9 FIGURE The Erasmus Bridge of Rotterdam, the Netherlands (Figure 3.10), opened in 1996, is another example example 3.10),another (Figure is in 1996, the opened Netherlands of Rotterdam, Bridge Erasmus The attractive as a very it see structure the view costly. However, who people the very was The bridge immediately that structure dramatic beautiful, a create cables parallel the and tower tall The very Alamillo Bridge, Seville, Spain. Erasmus Bridge in Rotterdam, the Netherlands. (Courtesy of Charles Seim.) of Charles (Courtesy Netherlands. the Rotterdam, in Bridge Erasmus Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 great success because Rotterdam now has a city icon, and the people can marvel at the bridge’s unique bridge’s at the unique marvel can people the and icon, acity now has Rotterdam because success great a is bridge However, compression loads. and this huge bending the tower toresist the toreinforce costs considerable added kink the and arrangements cable these of total sum The kink. the moments from bending the and backstays, the compression from forces cables, stay span main the compression from the and moments bending the thecarries tower tower. the Thus, compression in forces large adds cables backstay the fromcomponent tower. top of the at The the vertical attached are that cables backstay two by the resisted is tower that top of the force at the areaction produce also they bending; and pression tower cost. the increasing moment, substantially that toresist steel extra toadd engineer the requires moment, which bending alarge introduces acompression member in akink sion members; compres are they because kinked, Towers not usually unusual! are atower highly is in akink because Towers the lower portions of the two shafts do not have cross-struts but are curved to simulate the curvature of curvature the tosimulate curved are but do havecross-struts not shafts two of the lower portions the masterpiece of Eiffel’s beauty the with impressed was and Paris visited had them one of because Eiffel in Paris, Tower curved tothe similar tolook bridge towers of the two the of each wanted fathers city The towers. steel 215 of 628 mand mtall span acentral with 2005 in opened was when it China, in type this theof longest was 3.12). bridge (Figure cable-stayed This type of this side. on its laid Harp Irish an tomimic designed supposedly was and Bridge, Alamillo tothe compared bridge, atrue it is costly, span. main the support that cables stay forward the with transversely is loaded as it arch tilted-up as a acts spar curved The passage. ship toprovide open toswing structure the allows that structure aself-anchored tocreate combine cables stay forward the and cables backstay a “V.” forming The edge-girders, backstay two to the and spar of the tip tothe both connects cables stay back two of the Each spar. high 48-m of its base the under directly on pivots apier located that bridge 3.11). (Figure spar curved tubular aforward-leaning, as described tower curved thin, a having structure, a picturesque certainly is bridge This by Calavatra. designed and architecture! FIGURE 3.11 FIGURE The modified, fan-arrayed stay cables in the main span load the upper portion of the tower in com in the tower of portion the upper load span main the in cables stay fan-arrayed The modified, The upper portions of the two steel shafts of each tower are straight and braced by three cross-struts; cross-struts; three by braced and straight are each tower of shafts steel two the of portions The upper example is a good Bridge Third Nanjing Yangtze the and bridges, distinctive many built has China Although spar. curved and a cables, girders, of assemblage ingenious an is bridge picturesque very This swing as a balanced is that bridge cable-stayed long 120-m short, is a Bridge Beckett Samuel The writer, Irish famous the after named Bridge, Beckett Samuel the opened of Dublin city the 2009, In Samuel Beckett Bridge by Calavatra. (Courtesy of Charles Seim.) of Charles (Courtesy by Calavatra. Bridge Beckett Samuel . 71 - - - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 72 together. towers twin the tie arrayed, parallel cables, Horizontal towers. the supporting piers side of the on each roadway. bridge the across spanning arch concrete acurved ing support each and other each away from inclined and support acommon from springing struts concrete two features The bridge bridge. of this architect the as acted Tang, also who by Man-Chung designed towers. of the appearance curved the admire users bridge the and delighted, are Fathers City The towers. looking dull- be could otherwise towhat effect adynamic add shafts curved the because bridge, successful the tower. of base the at shaft inclined each from cap caisson tothe distributed thrust directed outwardly towers. of the construction to the cost added items these All compression forces. and bending both tocarry bolts of high-strength number large and a plates splice thick very required connections bolted These connections. bolted used therefore and segments the between connections welded to use enough accurately controlled not be could segments each in angles and dimensions the that believed contractor The proper curvature. on the placed accurately was segment each that ensure to surveying field accurate very required which ­control, geometric required segment Every angles. and dimensions different to fabricated was tower shafts icon. that Paris of shafts corner four the moments in bending the reduce the to towerheight along spaced Eiffel The cross-struts has value. Tower acceptable moment toan bending large the from stress the to reduce steel additional that required and shaft, of the portions lower curved the of each in moment bending large extremely produced Eiffel the Tower.curvature The FIGURE 3.12 FIGURE From each inclined tower, cable stays, arrayed in a harp arrangement, support the 100-m roadway roadway 100-m the support arrangement, aharp in arrayed tower, stays, cable inclined From each 3.13), (Figure City, China Shenyang in Bridge Sanhao the is bridge of adistinctive example Another However, a very it is tower construction. and bridge Tower to the cost Eiffel added The emulation the tocontain steel of prestressing amount amassive required cap concrete caisson the addition, In the in segment each thus high; 10–12 approximately m segment in fabricated was tower shaft Each Third Nanjing Yangtze River Bridge Towers under construction. (Courtesy of Charles Seim.) Charles of (Courtesy construction. under Bridge River Towers Nanjing Yangtze Third Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 Towers enclosing the bridge. the enclosing inward, lean that tower types conventional to the compared for drivers horizon to the bridge the up open outwardly leaning arms The stays. cable up the holding arms out-stretching as acting roadway, the above project towers that of the portion but the span main not the is bridge of the tion attrac but m, the 250 is span main The of m. 126 height atotal with and roadway the above 33 m towers projecting unconventional with 3.14), bridge (Figure cable-stayed aconventional is which delighted. are streets city from bridge the view and use who people the and icon, adistinctive now has City Shenyang because FIGURE 3.14 FIGURE 3.13 FIGURE Another distinctive bridge by Man-Chung Tang is the Jiayue Bridge, in Chongqing City, China City, Chongqing China in Bridge, Jiayue Tang the is by Man-Chung bridge distinctive Another success, isa bridge The bridge. distinctive very this to cost small a added cables and towersThe Jiayue Bridge, in Chongqing City, China. (Courtesy of Man-Chung Tang.) of Man-Chung (Courtesy City, China. Chongqing in Bridge, Jiayue Sanhao Bridge, Shenyang, China. (Courtesy of Man-Chung Tang.) of Man-Chung (Courtesy China. Shenyang, Bridge, Sanhao 73 - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 of the bridges that bridge engineers are required to design, construct, and maintain. and construct, todesign, required are engineers bridge that bridges of the the repertoire have entered these as types such bridge Thus, desires. up such money toback have the and elegance. economy, and efficiency, of definition Billington’s toProf. according Art” “Structural considered be cannot ever, they how structures; elegant or even artistic, art, considered be can all bridges; todistinctive to picturesque, bridge. of asuccessful feature principle to enjoy, the is which 74 A frame, weathering steel towers of the Luling Bridge near New Orleans, 1983 (Figure 3.16). 1983 (Figure Orleans, New near Bridge Luling towers of the steel weathering A frame, 3.15). (Figure 1968 in built was bridge in 1951,parallel the and built was bridge first the Bridges: Memorial Delaware two of the steel. in fabricated easily be could that shapes similar or other tees, cruciforms, as rectangles, shaped sections cross having elevation, in towers Such wererectangular often sion bridges. suspen and cable-stayed for towers for used both material predominant the was steel 1970s, the Until 3.5.1 bridge. beautiful and astrong produce will disciplines two their between union fruitful and asuccessful that so resolved be must they occur; viewpoint in differences these if understand should professional Each of conflict. type for this point focal the areoften the bridge, components visible of the most Towers, conflict. engineer of the lations effort. joint of their success tothe vital is them between respect and cooperation bridge, nomical eco and elegant an tobuild is architect the and engineer the of both objective common the As budget. for that. of practice however, no codes are there function; esthetics the only involve generally will architect the The role of of practice. codes tothe according bridge of the function work. the of phase that during set is bridge of the esthetics the as phase, design conceptual the during start should design. conceptual bridge of Fundamentals Edition: Second Handbook, Engineering 1of Chapter designers. bridge tohelp guide present examples and extensively very sion bridges structure. that of maintaining cost for pays the also and structure of a cost the pays for ultimately user The or tocriticize. toadmire for users there be always will the bridge constructed, is it Once process. design conceptual the in role towers play asignificant thus, towers; the from hang will superstructure the because framework Towers bridge the as act structure. the of design conceptual by the or for for good bad, determined, be all will facility of the serviceability and thereliability the appearance, cost, The constructed. be then and design afinal into developed be mately ulti will that concept design structural the is of a bridge new design the in step important The most 3.5 Any future discussion of towers for these spectacular bridges is beyond the scope of this chapter. of this scope the beyond is bridges spectacular of towers for these discussion future Any extravaganzas bridge desire people wherever constructed be to continue will types “bridge” These spectacular truly the from range can of bridges types these that see one can fewexamples, From these all for bridge distinctive a create do they but the bridge, to cost little added arms The outward-leaning An example of a cable-stayed bridge that is an exception to the rectangular tower form, is the ­ the tower is form, rectangular tothe exception an is that bridge of acable-stayed example An towers steel rectangular typical, the are steel-tower designs Two suspension-bridge of such examples calcu structural the and architect the of desires esthetic the when occur may However, differences within is that design structural functional and esthetic an achieving in two do roles overlap Their structural the ensure and adequacy structure the todevelop is engineer role of the the Generally employed if architect An team. design of the part tobe architect toemploy is an trend A recent suspen and cable-stayed of both issues design (2012) conceptual the treat Georgakis and Gimsing Materials Conceptual Design Conceptual Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge presents typical practice and general principles principles general and practice typical presents modified modified Bridge Bridge ------Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 Towers shear and absorb energy when activated by strong earthquakes (Figure 3.17). (Figure earthquakes by strong activated when energy absorb and shear in yield beams steel structural the and elements, esthetic attractive both are beams shear-link The ance. appear their the topenhance to toward tapered are that shafts the between topermeate light allowing 2 m, about separated are The shafts tower beams. shear-link by connected shafts, shaped cross-sectional pentagonal, separated of four composed toweris This Span. East Bridge Bay Francisco–Oakland San the saddles. the from load concentrated local, for the designed be must saddles, tower in top of the over the passing stays with bridges cable-stayed and for bridge, towers forsteel suspension a The cables. of the anchorages numerous the from forces local for the designed towers be must the into framing cables with bridge cable-stayed towers for a ft to40 20 (6–12cellular from steel m) long.The units in together plates steel welding FIGURE 3.16 FIGURE 3.15 FIGURE An excellent example of such a steel tower is the new 525 new ft tower the is a steel of such (160 of example Span excellent m)the tower Suspension An for shop- by formed cells, adjoining of series as a designed usually toweris steel of a section cross The Luling Bridge, New Orleans, Louisiana. (Courtesy of Charles Seim.) of Charles (Courtesy Louisiana. Orleans, New Bridge, Luling Delaware Memorial Bridges. (Courtesy of D. Sailors.) (Courtesy Bridges. Memorial Delaware 75 - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 76 the final design phase. Figure 3.19 lists distinctive towers for cable-stayed and suspension bridges. andsuspension towerscable-stayed for distinctive 3.19lists Figure phase. design final the during determined be will the towers of height final The tower height. total approximate the determine ­ tothe clearance the and girder of the depth structural the added be must To value this bridges. (SL). of typical ratios 3.18 length the Figure span lists length, main-span of the 20% ­approximately tobe assumed be can deck the above tower (TH), towers, height of cable-stayed heights the design, 3.18). (Figure forms and of shapes For ­ variety have awide Towers can bridges of cable-stayed 3.5.2.1 3.5.2 evaluation. by present worth usually compared, and evaluated tobe need operations of those frequencies the and operations maintenance then important, is cost life-cycle If compared. and developed tobe need material. economic most the is or concrete steel whether determine likely will influences site-specific and details, design equipmentavailability, ­contractor’s experience, above. noted as Bridge, Luling for the as environments for nonmarine used be can steel weathering maintenance—painting—although periodic require towers will Steel towers. concrete than time less in erected be can and more ductile, more be flexible, generally towers will Steel costs. foundation in savings tower shafts. the into framing cables of the anchorages numerous the from forces local or for the used, top, if at the saddles the from load concentrated for the designed towers be must concrete towers, steel with As required. bars reinforcing and of concrete amount the reduce and weight save to shafts hollow as designed usually towers are Concrete towers. in used extensively tobe began FIGURE 3.17 FIGURE During the conceptual design phase of the bridge, approximate construction costs of all the ­ the of all costs construction approximate bridge, of the phase design conceptual the During conditions, market hence, of factors; anumber with vary towers can or concrete of steel Costs for potential giving thus concrete, in towers designed than lighter be will Towers steel in designed concrete reinforced 1970s, the about starting structures, cable-stayed and bridges For suspension

Forms and Shapes and Forms Cable-Stayed Bridge Towers Bridge Cable-Stayed Tower of new San Francisco–Oakland Bay Bridge self-anchored suspension span. suspension self-anchored Bridge Bay Tower Francisco–Oakland San of new Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge

160 m (525 ft) Fo T T ower found ower le oting bo be Sh Ro Ba C Be IDH pile am ea dr ck so y mu pedestri Bike Ro gs r lin oc s x ad deck k cket d ation k s s an s path foundation to to foundation conceptual conceptual materials materials Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 Stonecutters Bridge Towers Bridge to Russky Island FIGURE 3.18 FIGURE carries dual three-lanecarries (Morgenthal etal. 2010), (plans), TH/SL: 0.23 (230 ft), opened: July 2012 (3621 ft), clearance: 70m longest span: 1104m height: 320.9m(1052ft), (Novosiltseva cape). Pylon Russian Island (Nazimov and peninsula) Strait, Vladivostok crosses Bosphorus Eastern four lanes of roadway, (SK-MOST 2011),carries 2009, TH/SL: 0.22 December (241 ft), opened: clearance 73.5m below: span: 1018m(3340ft), stainless steel skin, longest inner concrete ring with a top 120mconsisting of 175 mlevel and composite concrete from up base to with(978 ft), reinforced height:Pylon 298m Channel, Hong Kong. highway, crosses Rambler (e) Inclined shafts, A (a) Single Tower, I Generic forms and typical examples of towers for cable-stayed bridges. for cable-stayed of towers examples typical and forms Generic ANZAC Bridge (Moore Øresund Bridge (Gimsing (b)  1995, TH/SL: 0.27 2, opened: December reinforced concrete, 27m(88ft), below: (1132 ft), clearance longest span: 345m height: 120m(390ft), Sydney, Australia. Pylon crosses Johnstons Bay, andpedestrians bicycles, freeway,1996), carries, TH/SL: 0.3 opened: July 1,2000, 57m(187 ft), below: 490 m(1608ft), clearance concrete, longest span: 204 m(669ft), reinforced (Sweden). height: Pylon (Denmark) and Malmö Copenhagen between crosses Oresund Strait and Oresund railway line, of European route E20 four2012), carries lanes 2009; Oresund Bridge (f)  (f) H Double shafts, vertical diamond Inclined shafts, John James Audubon Yangpu Bridge (Ma and (c)  (1583 ft), clearance longest span: 482m height: 152.4m(500ft), Louisiana, USA.Pylon crosses Mississippi River, four lanes of 10, LA 2007),carries Duggar Bridge (Fossier and TH/SL: 0.24 1993, October concrete, opened: (257 ft) reinforced clearance 48m below: span: 602m(1975ft), 223 m (731ft),longest height: Pylon China. crosses Huangpu River, six-lane motorway, Fan 1993),carries TH/SL: 0.23 opened: May 5,2011, reinforced concrete, 40m(130 ft), below: the roadwaythe with cross struts above Double shafts vertical (g) Inverted Y Talmadge Memorial Bridge (d)  Sundial Bridge (Sundial 56 m(185ft), reinforced (1100 ft), clearancebelow: longest span 335m height: 127m(418ft), USA.Pylon Georgia, crosses Savannah River, lanes of US17to I-16, (Tang four 1995),carries (26 ft), opened: July 4, 2004 clearance 8m below: height: 66m(217ft), USA,pylonCalifornia, Sacramento River, Redding, crossespedestrians, bicyclescarries and spar cable-stayed bridge, Bridge 2013),cantilever November 1990,TH/SL: 0.2 concrete, opened: (h) Single inclined tower θ =40°≈60 Inclin roadway with cross strut above the Double cranked shafts ed angle Roadwa y dir ec tion 77 Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 78 nally, usually away from the main span; rarely toward the main span. Even more infrequently, on short, on short, Even more infrequently, span. main the toward rarely span; main the away from usually nally, longitudi inclined be may shaft single the Occasionally, girders. edge longitudinal the with to connect outwardly splayed be or can girder center alongitudinal with to align plane asingle in arranged be can bridge. of the designers by the considered carefully be towers should the thus, bridge; of the feature important most the towers visually Shanghai Yangtze River with avery Pylon Special FIGURE 3.19 FIGURE 3.18 FIGURE TH/SL: 0.22 31,2009. opened: October 54m(177 ft), below: 730 m (2395ft), clearance (695 ft),longest span: height: Pylon China. 212m crosses Yangtze River, six-lanecarries freeway, 2008), cable stayed bridge, Bridge (Zhang and Lu between. roadway, located in instead of straddling the long neck inverted Y-shape, The simplest tower form is a single shaft, usually vertical (Figure tower single 3.18a). from(Figure a cables Stay vertical usually shaft, is asingle tower form simplest The of the portion this roadway, the above making towers projecting the view over abridge People driving (a) ( Continued Distinctive towers for cable-stayed and suspension bridges. suspension and for cable-stayed towers Distinctive )

Generic forms and typical examples of towers for cable-stayed bridges. for cable-stayed of towers examples typical and forms Generic Rio–Antirrio bridge Unique with four Pylon Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge TH/SL: 0.2 opened: August 7,2004. 52m(170 ft), below: (1837 ft), clearance longest span: 560m height: 164m(538ft), of Corinth, Greece. Pylon bicycle lane, crosses Gulf and one and pedestrian six-lanecarries roadway cable-stayed bridge, five-span four-pylon (Combault etal. 2005), legs (b) Third Nanjing Yangtze TH/SL: 0.3 7,2005. opened: October 24m(79ft), below: (2125 ft), clearance longest span: 648m height: 215m(705ft), River, Pylon China. freeway, crosses Yangtze towers, six-lane carries ladder-shaped steel with two curve 2009), cable-stayed bridge River Bridge (Cun etal. (c) Single tower self-anchored 2013. TH/SL: 0.34. beams, opened: September connected with shear link tower with four legs 30 m (100ft),single steel (1263 ft), clearancebelow: (525 ft),longest span: 385 m USA. Tower height: 160m Francisco Bay, California, way,pedestrian crosses San 10-lane I-80,bike and Maroney 2007),carries Bridge Span East (Nader and Francisco-Oakland Bay suspension bridge, San (d) - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 “A” frame, similar to that of the Luling Bridge towers (Figure 3.16) or the two shafts inclined to bring to bring inclined 3.16) towers (Figure shafts Bridge two or the Luling of the to that “A” similar frame, the towers. stabilize to theoffset at tower shafts the between used always is strut A horizontal (Figure 3.20). Georgia Bridge, the for used Talmadge was method This towers. the through continuously pass can that girder the to and attached plane in a vertical aligned be to cables the 3.18d). allows This roadway the (Figure above offset or bealso “cranked” can towerThe shafts system. support deck the across component atension of abox introducing girder, edges or tothe girders edge tothe toconnect inward 3.18b (Figure 3.18c). of and cables incline planes two cables stay The with used be tower,simple can which the tower.the top of from array,radiating star in a arranged usually are cables The bridge. of the esthetics tothe factor adynamic adds which transversely, tower inclined is asingle curved spans, Towers may become very wide and costly. and wide very may become roadway, foundations the above the as slope same at the foundations tothe down carried are frame “Y” low clearances. with on sites particularly and roadway the above used was as slope same the bridge. of the designers by the considered carefully be and should it the bridge, of the motif displays it because important is view total This unit. structural of acomplete part towers as the see will adistance from abridge People viewing costs. and esthetics both towers. steel curved with China in bridge cable-stayed first the was and Eiffel the in Paris Tower from copied towers was of these form the 3.5, 3.19d).(Figure Section in noted As example excellent an is Bridge Third NanjingYangtze The shafts. have curved bridges built recently A few of the of construction. for ease members, straight as designed are bridges towers for cable-stayed system. support deck the compression component across adesirable producing outward, inclined full are 3.18e). a “A” to cables form (Figure stay tops together of frame planes two shafts The the 3.20 FIGURE The two shafts of cable-stayed bridges can be inclined inward toward each other to form a modified modified a other to form each toward inward inclined be can bridges cable-stayed of shafts two The the roadway,abovea form struts cross without or the roadway,with straddling shafts Two vertical However, at high-clearance locations, if the shafts of the towers for a full full the towersinverted for“A” a of an or for frame shafts the if locations, However, at high-clearance at foundations their down to carried be the can towersmodified for a of bridge frame shafts The “A” of for reasons important also is the roadway below bridge thecable-stayed towers of a of The form full-diamond-shaped and the quasi-diamond- and A-shaped, the H-shaped, of shafts two ofMost the Talmadge Bridge, Georgia. (Courtesy of T. Y. International.) (Courtesy Lin Georgia. Bridge, Talmadge 79 Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 cable-stayed bridges, except for those with very wide decks. Four-shaft towers are best used to support support to used best are towers Four-shaft decks. wide very with for those except bridges, cable-stayed used for are not 3.19c). (Figure generally towers Three-shaft shafts four has Greece, Bridge, Antirrio resistance. wind for action frame and stiffness add legs inclined the and required, tower is height tional addi which for spans long forvery effective is very form This China. Bridge, River Yangtze Shanghai the in 3.19b)the (Figure 3.18g) Pu Bridge inas and as (Figure shape Yang “Y” inverted an forming shaft vertical asingle “A” by using the towers, extended be can tall frame requiring long spans (Figure 3.21). For very Texas Bridge, Baytown the in 3.8), as (Figure or adouble diamond Carolina South Charleston, Bridge, River Cooper the in as diamond, afull form can inclination inward the roadways, 3.7). high For very (Figure Sydney, Bridge, Australia Island Glebe towers of the to the 3.18f), similar (Figure diamond 80 To this value, one must add the structural depth of the deck and the clearance to the foundations to foundations tothe clearance the and deck of the depth structural the one add must To value, this 1:10. approximately is value 1:8 about to1:12. from preliminary Agood vary can which ratio, to-span 3.24. Figure in shown are bridges of suspension forms and shapes Typical towers. “A” an of form with “Y” designed have inverted been or bridges an suspension afewsingle-cable Only esthetics. for ratio good aspect large the tower The accommodate must saddles. cable tothe foundation the top.and one at mid-height the near struts—one two towerswith 833 concrete ft has high (254 m) 3.23),in 1999, (Figure opened Denmark in way sea Belt theGreat of 3.22).towerscrossing (Figure The concrete and multistruts spaced ft uniformly 4626 of the (1410used 1983, England, Bridge, m) Humber span long The very for bridges. some However, proven economical tobe towers have concrete recently (Figure 3.15). Bridges Memorial Delaware towers for the steel by the illustrated is as of cables, planes life span. its during encounter will bridge asuspension forces wind great and loads large the adequately support to bridge, of acable-stayed those are than more robust far be must bridge towers of asuspension the Thus, bridges. cable-stayed are than on much longer spans used tobe designed are bridges Suspension 3.5.2.2 costs. on depending foundations, own their mayhave of shafts pairs or two foundation, common a ofa share tower may shafts The four deck. one wide tosupport than rather structures, separate two 3.21 FIGURE The numbers of shafts within the towers of cable-stayed bridges can vary from one to four; the Rio- the from one to four; vary can bridges cable-stayed the towers of within shafts of The numbers or“squat” the roadway, a modified under producing inward inclined are lower shafts the Sometimes For conceptual designs, the heights of suspension bridges towers, above the deck, depend on the sag- on the depend deck, the above towers, bridges of suspension heights the designs, For conceptual the from the towers, of height full the for designed usually are bridge towers suspension of shafts The two and shafts vertical two using design, atraditional follow bridges towers of suspension the Usually Suspension Bridge Towers Bridge Suspension Baytown Bridge, Texas. (Courtesy of T. Y. International.) (Courtesy Texas. Lin Bridge, Baytown Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 Towers against each other with struts or “X” cross bracing to form a tower-frame action. atower-frame toform bracing or cross “X” struts with other each against be tobraced then need which tower shafts, tops of the to the loads seismic and wind lateral carry cables large the because bridges for suspension required usually towers is the between of strut form Some strut. single large a with the top at connected are tower, of the shafts height or the the along bracing or cross struts, several with together connected usually are shafts The tower height. total approximate the obtain 3.23 FIGURE 3.22 FIGURE Humber Bridge, England. (Courtesy of Charles Seim.) of Charles (Courtesy England. Bridge, Humber Great Belt Bridge, Denmark. (Courtesy of Ben C. Gerwick, Inc.) Gerwick, C. of Ben (Courtesy Denmark. Bridge, Belt Great 81 Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 Akashi Kaikyō Bridge 82 works on the design for a year, and develops a bridge model for the design of the bridge; that model can can model that bridge; of the design for the model abridge develops for ayear, and design on the works intimately, structure the knows designer the because designer, bridge the is scheme erection this design to person best The members. the all in stresses acceptable with and alignment and position, camber, money. paying up end will someone designer, and the including involved, become will everyone happen, does above listed plan. erection detailed a require or forces loads erection or resisting supporting towers or towers temporarily or inclined curved, thin, however, much difficulty; without erected be usually towers can Ordinary scheme. erection a detailed prevented by having be can they because troubling very are collapse or full or partial stresses ticipated however,unan risks; first of the control have little designers Bridge collapse. or full topartial dures, proce erection of faulty because stresses unanticipated tolocked-in late, toservice bridge the opening of cost high the from occur can happenings Adverse phase. this during highest is happenings adverse of risk the because structure that of time theerection is of a life bridge the in stage crucial The most Erection 3.5.3 3.24 FIGURE X-braced moment frame world with two steel suspension bridge inthe (HSBA 1998),longest April 5,1998,TH/SL: 0.11 opened:65.7 m(216ft), clearance(6532 ft), below: longest span: 1991m height: 282.8m(928ft), Strait, Japan. Tower roadway, crosses Akashi towers, sixlanes carries of A better solution is to design a detailed erection scheme that will construct the structure to the proper tothe structure the construct will that scheme erection adetailed todesign is solution A better however, something if contractors; of the responsibility the is erection that say designers bridge Some (a) Generic forms and typical examples of towers for suspension bridges. for suspension of towers examples typical and forms Generic Höga Kusten Bridge, Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge TH/SP: 0.12 1,1997, December (131 ft), opened: clearance 40m below: span: 1210m(3970ft), 180 m(591ft),longest Sweden. Tower height: Ångermanälven river, crosses mouth the of the of European route E4, towers, four carries lanes two reinforced concrete suspension bridge with (b) Østbroen Bridge (East Denmark. Tower height: crosses Great Belt, motorcarries vehicles, struts above roadway, the roadway with two cross shaftsthe straddling frame of two vertical towers with moment two reinforced concrete 2012), suspension bridge, 1998, TH/SL: 0.12 (213 ft), opened: June 14, clearance 65m below: span: 1624m(5328ft), 254 m(833ft),longest (c) Golden GateGolden Bridge, below: 67m(220 ft), below: m (4200 ft), clearance (746 ft), longest span: 1280 Tower height: 227.4m Gate, San Francisco, USA. bicycles, crosses Golden andUS 101,pedestrians frame, sixlanes carries of steel towers with moment suspension bridge, two TH/SL: 0.13 opened: April 19,1937, (d) - - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 inclined towers, or curved spars, can be difficult to estimate and may add significant costs to the project. to costs significant add and may estimate to difficult be can spars, or curved towers, inclined as such towerdesigns unusual erecting of costs The constructible. is consideration under scheme the that toensure phase concept-design the during developed of erection one method have at least should considered alternative Each cost. and constructability, for esthetics, evaluated be should each sidered; begins. before erection scheme approveand the check should designer the bridge scheme, theerection develop to contractor the require specifications the If scheme. erection aseparate or todevelop scheme that tomodify freedom full contractor the allow should specifications the done, is this If structure. for the stages erection all todevelop used be also Towers uniform appearance, and having a short span at each end. These multispan bridge roadways will deflect deflect will roadways bridge multispan These end. at each span ashort having and appearance, uniform for spaced towers evenly the with structure continuous a long, to form together linked bridges, pension towers. on forces the horizontal and vertical both induce can but the superstructure, on downward acting effects, gravity all are These analysis. structural a from obtained be must loads moving such towers from tothe imparted forces the and bridge, the across move loads These facility. the of the owners or by specifications and codes design in prescribed superstructure. of the construction during over-stressed be towers will the whether todetermine ture, thesuperstruc of erection staged for a analyzed the towerbemay to distributed The forces structure. completed the of analysis structural by a calculated be the towercan to distributed are that The forces superstructure. the tower and the for both used materials of the weights unit the by utilizing process Fundamentals Edition: Second Handbook, 6of Chapter case. load controlling for the checked and designed, analyzed, be must structure, entire the as well as The towers, cases. load different many to aresubject towersThe 3.6.1 structure. the may erect contractor experienced an that todemonstrate scheme one erection of at least analysis include also should design Prudent determined. tobe are erections if program nonlinear one geometric by at least analyses careful require both and indeterminate highly are bridges suspension and cable-stayed Both connections. its conditions. boundary as imposed deformations and forces their with units substructural as towers modeled may be the analysis, global From a whole. the as treated is structure theentire which in analysis global of a part be towers The should bridge. entire for the ogy bridges. for cable-stayed theory design (1999) present detailed also Second Edition: Design Superstructure in design bridge 10 Chapter for and cable-stayed design bridge suspension for Chapter 9 See earthquakes. as such events natural large after expectations performance bridge and requirements, maintenance operations, their toinclude as so facility, of the owners the with cooperation in developed be to need also may criteria special-design The designer. and/or the owner by the developed tobe may need criteria design special projects, bridge cable-supported for long-span and bridges, tant Specifications Design Bridge The 3.6 During the concept-design phase, many different tower forms and cable arrangements may be con be may arrangements cable and tower forms different many phase, concept-design the During A current trend for spanning wide widths of waterways is to design multispan cable-stayed and sus and cable-stayed multispan to design is of waterways widths wide for spanning trend A current usually are pedestrians, or trucks, transit, trains, as such bridge, the using traffic from loads Design design the in obtained is the towers, self-weightthe of including superstructure, the of The weight the tower,and of components, its designs final for the basis the form analyses structural Detailed methodol design the does as practices same the follow towers should for the methodology Design AASHTO Standard Specifications for StandardAASHTO Highway Specifications Bridges Final Design Final Design Loads Design (AASHTO 2012) apply to bridges 150 m (500 ft) or less in span. For impor 2012) For (AASHTO span. 150in m(500 ft) apply tobridges or less . Troitsky (1988), Podolny and Scalzi (1986), (1988), . Troitsky al., et Walther and Scalzi and Podolny presents a detailed discussion of highway bridge loading. bridge of highway discussion adetailed presents (AASHTO 2002) and the the and 2002) (AASHTO Bridge Engineering Handbook, Handbook, Engineering Bridge Bridge Engineering Engineering Bridge AASHTO LRFD LRFD AASHTO 83 - - - - - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 along the height of the tower. of the height the along twisting and torsional deflection cause may effects temperature Such sunset. until morning from them on shines that sun the from of heat because tower their height along differentially contract and expand Towers movement tower itself. of the may temperature-induced the and towers, the into framing cables chapter. of this scope the beyond is this but the towersexternally; tostiffen ways various in arranged cables touse be would method 3.19). (Figure Greece Asecond of Corinth, Gulf of the crossing Bridge Antirrio Rio done tothe was as roadway. multispan flexible, the are supporting that cables from pull the resist to stiff not sufficiently are towers ordinary because is This stiffness. for added designed specially towers are the unless excessively 84 fastened into position to take the unbalanced cable loads from the center and the side spans. the and center the from loads cable unbalanced the totake position into fastened permanently are saddles the completed, is trusses girders or stiffening the of tower.erection the After on alignment final into rolled gradually are towers or saddles the loads, totake begins cable the and tion intoposi erected being are trusses or girders stiffening the As on rollers. temporarily, displaced be can saddles the For long spans, cables. heavy with them towers by pulling tops of the the by displacing spans forshort accomplished usually is This side spans. the toward displaced be saddles the that requires ally usu sequence erection the side span, of the cables the into loading To correct plans. the induce struction forces. cable these to resist designed be must anchorages saddle permanent tower.the top of the and towers The the to cable location, each at anchorage cable-saddle the through transmitted are forces These side spans. the and main the between forces cable unbalanced or any earthquake, wind, temperature, from forces longitudinal and transverse but important, smaller, as well as force, vertical alarge produces A cable tower. top of the tothe anchored usually are that saddles over cable pass cables bridge Suspension 3.6.2 the towers. of design final for the cases loading for all ­requirements Design Seismic Edition: Second Handbook, Engineering Bridge in discussed is of bridges analysis dynamic The loadings. seismic for code-prescribed least at checked be should tower design the activity, lower seismic with For locations activity. seismic high with locations in tower may control design displacement and forces Seismic excitations. seismic dampen to installed be also can Tuned towers. dampers of the modes mass vibrational the by exciting structure personnel. by maintenance for access elevators and ladders requires which maintenance, periodic need dampers of types These vibrations. excessive out dampen towers will the within locations at various dampers tuned-mass installing response, the ing chang in not effective are methods these If towers. of the characteristics dynamic the tochange added, or afaring tower made, may be of the section cross the in changes appropriate occur, tower does of the excitation wind-induced where instances rare the In the tower itself. excite may wind the flows, wind of 22 Chapter See tunnel. wind alarge in test model aeroelastic afull bridges, for important and tunnel awind in superstructure of a proposed model sectional on a test wind-tunnel a require usually will This loading. adynamic as for them. designed be must which the towers, to carried be will forces additional These themselves. cables onforces the wind the from and superstructure on the pressure wind by the cables the into induced be Force will Towers are also subjected to temperature-induced displacements, from the superstructure and the the and superstructure the from displacements, totemperature-induced Towers subjected also are the towers to shafts four adding as such towers, these tostiffen proposed have been methods Several The erection of a suspension bridge must be analyzed and the chosen sequence shown on the conthe on shown sequence chosen the and analyzed be must bridge suspension of a erection The design and other displacements, the forces, all reveal will design final of the analysis A full the within responses inducing loadings, inertia dynamic as treated be should excitations Seismic treated be should factor wind the speeds, high-wind known with locations and bridges For long-span the tower.in displacements and forces both induce will shape abluff towers as on the blowing Wind Other Design Considerations Design Other Bridge Engineering Handbook, Second Edition: Fundamentals Edition: Second Handbook, Engineering Bridge Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge . . Under certain . Under certain Chapter 3 Chapter of of - - - - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 must be deeply embedded in the concrete footing block in order to transfer their loads to the footing footing tothe loads their order totransfer in block footing concrete the in embedded deeply be must bolts The bolts. tower to the the from loads overturning totransfer proportioned be must bolts Such ers. tow of steel base at the used generally are bolts Anchor point. at this at amaximum moments are and abutments. the to trusses girder or stiffing by the carried be must forces longitudinal the arrangement, For this forces. but not forces, longitudinal may transverse produce this tower opening; the through continuously of abox girder passing for the provide usually designs bridge suspension More recent point. tower at this on forces the longitudinal and transverse produces that towers; at the girder,boxthe or truss, stiffening the terminate usually designs bridge tower. suspension the Traditional and deck of the connections of the framing structural roadway. on the the depend forces Such carrying Towers require backup bars that must be removed carefully if the weld is subject to fatigue loading. tofatigue subject weld is the if removed carefully be must that bars backup require welds Full-penetration wind. and out water keeps that covering aprotective within made be should Fieldwelding andwelds. overhead thevertical particularly difficult, welds ductile weather, making windy to exposed when control to difficult may be Field welding completed. weld is the while position in rigidly component the in holding difficulties presents Field welding method. turn-of-the-nut as such tension required the to achieve needed results consistent to give bolts strength high the of tensioning amethod use should contractor the For bolting, bolts. high-strength with together orwelded bolted cell. each equipmentinside painting and cleaning and painters painted, tobe is steel the if and equipment, welding and welders toallow enough large be must Cells cells. toform shapes rolled and 3.5.3. Section in as noted plan erection an to according constructed be should andsuperstructure towersThe 3.7 totowers. loads the distribute to continuity girder the of benefit without yet are that arms the load equipmentcan tion construc heavy and towers, torque the and arms the displace can winds High span. of center the at the girders, the of arms two the of closing the before is just sequence erection critical The most vulnerable. are very the towers, from outward cantilevered are they as girders, The plans. construction on the shown cables. for the support long-life reliable, toprovide designing special tension require forces These points. anchorage at the section towertower, cross the in tension producing of the walls the within at anchors terminated be also can Cables points. anchorage at the section cross the tower in compression produces anchoring of tower. method side of the This far on the anchored be then and section tower cross the through completely tower may pass the in terminating Cables saddles. tower on cable the through cable the pass arrangements tower, other the in whereas cables the nate connection. reliable and efficient, constructible, a produce should the foundation to tower shafts of joint the of the design The connection. tower-to-footing amore robust and reinforcement, the ment around of concrete place easier with congestion, less in result will or splices welded mechanical compact Using areas. for high-seismic used be cannot splices lapped and developed, be then cannot bars of the strength the connections; the tocongest tends lapping the avoided as usually are splices bar reinforcing Lapped bolts. anchor tothe protection some provide will and tower base at the system paint reinforcement. The most critical area of the tower design is the tower-to-foundation connection. Both shear forces forces shear Both the tower-to-foundationconnection. is the towerdesign of area critical The most truss stiffening or the tower, box girder on the the from imposed may forces be other level, deck At the The steel tower components are transported to the bridge site and are erected by cranes and are either areeither and cranes by areerected and site the bridge to transported are towercomponents steel The plates steel together ashop by welding in fabricated usually are steel of structural Towers constructed be sequence the and analyzed, be must bridges of cable-stayed erection the bridges, for suspension As termi arrangements Some varied. and many are bridges cable-stayed for arrangements cable The moment connections. and shear full with foundations tothe joined towers be must Concrete steel the of life the increase will tower shafts the down running for rainwater drainage good Providing Construction 85 - - - - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 stacked together and steel tendons tensioned to form the towers. the toform tensioned tendons steel and together stacked be can segments concrete precast spans, For shorter accommodated. be can geometry cross-section in changes Some towers. cross-section for constant particularly economical, be can forming Slip pleted. tower com is the until clock the around operation one continuous in placed concrete the and positioned areas. seismic in allowed are not these but make, to easiest the are splices Lapped lift. each with spliced tobe bars forcing therein requires This crane. by intoposition lifted are and or on awork barge, ground, on the sembled preas usually are cages bar Reinforcing concrete. placed freshly the (6–12 from pressure m), tolimit 20–40 ft toapproximately restricted usually is for concrete height Placing level. next tothe or “jumped,” 86 for long-span bridges. long-span for and Maintenance Construction Edition: 4of 1and Chapters tower completed compliance. into the bring to modified tobe or needs design original of intent the the meet will staging tower erection proposed the whether determine to enough full be should evaluation This approval. and evaluation for an engineer design the to submitted be to stages the towererection require also should specifications construction The stage. erection at each safety and for contractor, employed stability engineer, by the by an checked be theerection tower require should specifications The tower construction deflections. and stresses tower new component. of each erection the tower following of the face up the themselves towers by pulling steel to erect used are cranes traveling vertical Occasionally, 3.8. Figure in seen be can materials raise and forms the tojump used tower crane A towers. of concrete erection for the forms steel for choice handling agood are and towermost designs employed be for can erected, it tower is as tothe Tower connected for long spans. designed ers cranes, of tow heights tothe toreach capacity have the rarely cranes tower Floating tops. on the erected to be saddles cable require bridges cable-stayed some and tower. bridges of the height Suspension full to the afailure. cause could case, extreme an in and, the tower of safety of factor the lower will that deflections and stresses “lock-in” can detail construction important this Neglecting tower erection. the in step essential an is but cost adds procedure jacking The used. be can stress induced tolower the material adding and deflection for the tocompensate leg the cambering then small, is stress of secondary amount the If stresses. bending locked-in the torelease of force or displacement amount by acalculated apart legs the jacking by adjusted be must effects secondary of these Both legs. of the slope of the plane the in 3.19. Figure in visible are Bridge Baytown towers of the diamond double- for the supports form concrete of Some the for support. other each tower against legs crete con cast partly the braces arrangement This shaft. for each together forms concrete the tie that struts cross and supports temporary by vertical supported be can forms concrete sloping The tower design. inclined thelongitudinally as construct to difficult as are not These shapes. “Y,” or similar adiamond, methods. erection special require of towers types These budget. project the within covered be can cost extra the and esthetically, and ally structur be justified can design a such if be done can This or kinked. curved or are span main the from costs. tolower just erection compromised be cannot tower design the course, Of formed. easily are that tower shapes and cages bar reinforcing assembled components or easily steel assembled and fabricated easily more incorporating by costs construction reduce can design the Often towers. the Slip forming is an alternative method that uses forms that are pulled slowly upward, reinforcing bars bars reinforcing upward, slowly pulled are that forms uses that method alternative an is forming Slip reused, removed and be can that forms in cast usually are concrete of reinforced Towers constructed Because the tower erection must be done in stages, each stage must be checked for stability and for and for stability checked be must stage each stages, done be in must tower erection the Because forms components or concrete steel equipmenttoerect special requires usually Tower construction deflection lateral moments and bending may induce inclination the erected, are legs sloped the As “A,” an toform other each inverted toward have an sloped legs bridges towers of cable-stayed Many or away toward longitudinally angled are towers that design architects many and engineers Some constructing in may use contractors that of erection method Tower the consider should designers Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge present more detailed construction procedure and techniques techniques and procedure construction present more detailed Bridge Engineering Handbook, Second Second Handbook, Engineering Bridge ------Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 reliable, serviceable, economical, and esthete manner for the entire life of the bridge. Towers bridge. of the also life must entire for the manner esthete and economical, serviceable, reliable, in a function their Towers bridge. of the fulfill life must the during replaced be cannot they ponents, com bridge other most Unlike foundations. tothe bridge on the imposed forces the and bridge of the people’s in bridge minds. of the impression enduring the form and statement esthetic identifying its and motif, its character, its or forgood bad, for the bridge, give They toanother. one point from travel they as pass people which through portals visible form Towers abridge. in elements usually structural visible most the are and roadway the above Towers project superstructure. bridge of the of support means visible and Towers structural the provide 3.8 Towers Combault Billington, D. P. 1983. AASHTO. 2012. AASHTO. 2002. References 1992). (Cerver society service to a bridge long-life to provide effort the of all results the view and maintenance, and construction its pay for facility, the use people who the made by always is project successful ofa judge final The project. of the phase construction the and phases design and conceptual the during made be must that decision achieved construction. in for actually is paying he is that reliability and serviceable the that means by this only assured owner The documents. design the with complies construction the to ensure contractor by the submitted is that step erection each understand must engineer design The stages. construction the into project the follow engineer design the that It preferred is shown. be also should tower erection the used, is tower design constructed. economically be can bridge the toensure phase this during developed be should scheme erection tual Aconcep bridge. of the constructability and economics, esthetic, the determines It towers. also of the shape and materials the and system, deck of type length, span the items, among other sets, phase This future. seeable the foreinto continue will trend This impact. visual to add or inclination kinks, shapes, have unusual towers that of featuring opposite or the bridge of the statement esthetic principle the as act towers and the dominate can that arrays unusual in cables bridge andsuspension a few cables stay configuring in resulted This bridges. or distinctive picturesque, spectacular, desires or both, public, or the owner the bridges. suspension on a few used havebeen shafts single although struts, cross several one or with connected shafts vertical totwo restricted usually are bridge suspension for a towershapes Practicable shapes. various forming inclined, to from vertical arrayed shafts several cost. extra topay for the willing are and bridge aspectacular want public or the owners the is requirement economical to this exception the expense; extraordinary without to erect practicable be Towers are the most critical structural element in the bridge as their function is to carry the weight weight the tocarry is function their as bridge the element in structural Towers critical most the are The successful design of towers for cable-stayed and suspension bridges involves many factors and factors many involves bridges andsuspension of towerscable-stayed for design successful The usual a If bridge. the for materials and dimensions, shape, specific the sets phase design final The of towersbridges. for span long design the in phase important the most is phase design conceptual The because an objective always wereand cost not low efficiency where began atrend 1990s, early the In have one or can towers These varied. and many are bridges for cable-stayed tower shapes Practicable Summary Design, andDesign, Construction,” New York, NY. Association of State Highway and Transportation Officials, Washington, DC. Highway and Transportation Officials, Washington, DC. , J., Pecker, A.,Teyssandier, J. P. and Tourtois, J. M.2005. “Rion-Antirion Bridge, ­ Standard Specifications for Highway Bridges AASHTO LRFDBridge Design Specifications The Tower and the Bridge, TheNew Art of Structural Structural Engineering International Engineering Structural , 17 , th Edition, American Association of State Customary U.S. Unit , 15(1):22–27.

Engineering , 2012,American Greece-Concept, , Basic Books, Books, , Basic 87 - - - Downloaded By: 10.3.98.104 At: 11:33 01 Oct 2021; For: 9781439852309, chapter3, 10.1201/b15621-4 Leonhardt, F. 1984. HSBA. 1998. Gimsing, N. J. and Georgakis, C. T. 2012. Gimsing, N.J. 2009.“From Bridges across Great and Belt Øresund towards aFemern Bridge,” Belt Fossier, P. and Duggar, C.2007.“John James Audubon Bridge Project Design-Build Update,” Cun, B., Zhao, C. H., Dong, M. and Tang, L. 2009. “Design of Steel-Concrete Segment of Main Tower of 88 Zhang, C. L. and Lu, Y. C. 2008. “Design of Main Tower of Shanghai Yangtze River Bridge Main Span,” Walther, Houriet, R., B., Isler, W., Moia, P. and J.F. Klein, 1999. Troitsky, M.S.1988. SK-MOST. 2011. Tang, M.C.1995.“Talmadge Memorial Bridge, Savannah, Georgia,” Sundial Bridge. 2013. C.1996,“SanSeim, Francisco Bay’s Jeweled Necklace,” Podolny, W. J. and Scalzi, B. 1986. Petroski, H.1996. Øresund Bridge. 2013. Nader, M.and Maroney, B. 2007.“One-of-a-Kind The Design, SanNew Bay Francisco-Oakland Bridge Morgenthal, G.,Sham, and West, R. B. 2010.“Engineering Tower the and Main Span of Construction Moore, D. 1996. Ma, X. B. and Fan, Q. G. 1993. “Construction Planning and Management of Yangpu Bridge Main Tower,” Workshop –Recent Major Bridges Conference Transportation Engineering Louisiana Thrid the Naijing YangtzeRiver Bridge,” Shanghai Highway Thomas Telford Ltd.London, UK. StraitinV ladivostok 5(1): 15–16. John Wiley &Sons, New York, USA. Span”,Eastern Stonecutters Bridge,” Technology Construction Shikoku Bridge Authority, Japan. Wiley &Sons, New York, NY. The Akashi-Kaikyo DesignBridge – andConstruction of the World’sLongest Bridge To build aBridge, Glebe Island, Sydney, Australia Construction of acable-stayed bridge to the Russky Island across the Eastern Bosphorus Engineers of Dreams Bridges, Aesthetics and Design STRUCTURE magazine Cable Stayed Bridges Stayed Cable http://www.turtlebay.org/sundialbridge http://en.wikipedia.org/wiki/Great_Belt_Fixed_Link , No. 4,Shanghai, (In China. Chinese). , http://rusbridge.net/2011/01/ Journal of Bridge Engineering Bridge of Journal Bridge Engineering Handbook, Second Edition: Substructure Design Substructure Edition: Second Handbook, Engineering Bridge , No. (In China. 3.Beijing, Chinese). Construction and Design of Cable Stayed Bridges Stayed Cable of Design and Construction , Vintage New York, Books, NY. , May 11–20,Shanghai, China. Cable Supported Bridges - Concept and Design and Concept - Bridges Supported Cable , Van Nostand Reinhold Co, New York, NY. , October. Highway , MITPress, Cambridge, MA. , February 12,Baton Rouge, LA. ASCE Civil Engineering , No. (In China. 5,Beijing, Chinese) . , ASCE, 15(2):144–152. . , Chapter &Verse, Sydney, Australia. Structural Engineering International Engineering Structural Cable Stayed Bridges Stayed Cable . , 66(1):14A,January. , 3rd Edition, John , Second Edition,, Second , 2nd Edition, , Honshu- IABSE 2007 ,