Fifty Year Development: Cons/ruction of Steel Arch Bridges 9 MIIDERII CIINSTRUCnll1l ..
PUblished by VOLUME xv I NUMBER 2 I SECOND QUARTER 1975 American Institute of Steel Construction CONTENTS 1221 Avenue of the Americas New York. N,Y. 10020 Fifty Year Development: Construction of Steel Arch Bridges 3 AISC Regional Engineering Staff 16
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Van W. Coddington, President 1975 ARCHITECTURAL AWARDS OF D. B. Hughes, EXCELLENCE COMPETITION First Vice President George W. Hall, The American Institute of SteeL Construction takes pleasure in Second Vice President announcing its sixteenth annual Architectural Awa"ds of Ex Robert P. Stupp, Treasurer cellence Program to recognize and honor outstanding achitec John K. Edmonds, Cural design in steel and to encourage further exploration of Executive Vice President the many aesthetic possibilities inherent in steeL construction. Leslie H. Gillette, Assistant Executive Vice President William W. Lanigan, All registered architects practicing professionally in the Secretary and General Counsel United States are invited to enter stee!-.framed buildings of their design constructed anywhere in the United States (de fined as the 50 states, the District of CoLumbia, and aU U. S. Territories), and cO'Yltpleted after January 1, 1974 and prior to • • DIT ORIAL STA .... August 29, 1975. Each building must have been designed, de Daniel farb, Director of Publications tailed, fabricated, and erected in the U. S., and aU structural Mary Anne Stockwell, Editor steeL and plate ,nust have been produced in the U. S. The structuraL frante of the building must be steeL, alth(}ugh it is not a requirement that the steeL be exposed and a part of R IiOIONAL 0 .... IC. 8 the achitecturaL expression. Buildings of aU c/.assifications are Atlanta, Georgia eLigible, with equal emphasis given to all sizes and types in the Birmingham, Alabama judging. There is no limit to the number of entries by any Boston, Massachusetts individuaL or firm. Buildings named as previous AAE winners Chicago, Illinois will not be eligible. Cleveland, Ohio Columbus, Ohio The members 0/ the 1975 Jury of Awards are: Dallas, Texas Max Abramovitz, FA IA Harrison & Abramovitz, New Denver, Colorado Detroit, Michigan YQ1'k, New York Charlotte, North Carol ina Fred Ba"elli, FA IA Fred Bassetti & Company/ Archi Hartford, Connecticut tects, Seattle, WCUlhington Houston, Texas Los Angeles, California Charle. William Brubaker, FA IA Perkins & Will, Chi Memphis, Tennessee cago, Illinms Milwaukee, Wisconsin Milo Kelchum, F.ASCE Minneapolis, Minnesota S. Profess()T of Civil Engineer New York, New York ing, University of Connecticut, Storrs, Connecticut Oklahoma City, Oklahoma Consultant: Ketchum, Konkel, Barrett, Nickel & Austin Omaha, Nebraska Denver, CoLorado Philadelphia, Pennsylvania Harlan E. McClure, FA IA Dean, CoUege of Architecture, Pittsburgh, Pennsylvania Clemson University, Clemson, South Carolina St. Louis, Missouri San Francisco, california Competition rules are available from AISC, 1221 Avenue Seattle, Washington Of . Syracuse, New York the Ame!'icas, New York, N.Y. 10020. Entries must be post Washington, District of Columbia marked prior to August 29, 1975. Q Cl.. :» '< -l ::r rn 0 0 -e- rn- C/} CO OJ ... OJ c-.> ~ rn '< (""')- :::l ...... VI ...... ::r ,..., CO OJ OJ rn (""') :z c::r -~ ::r :::l G) VI rn Cl.. (""') :z ~ Cl.. ~ ,..., -0. rn ...... rn ,..., ...... :::l CO :::u 0 <: ~ rn :::l :z :::> G) ...... 0 0 "0 '- ...... rn C> ::r C rn :::u :z :» r- • ,
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PERM IT No. 62 NEW YORK . N, Y BUSINESS REPLY MAIL NO POSTACE STAMP NECESSARY If MAILED IN THE. UNITED STATES - POSTAGE WILL BE PAID BY AMERICAN INSTITUTE OF STEEL CONSTRUCTION 1221 Avenue of the America s New York. New York 10020 Attention; Paul R. Johnson ------• FIFTY-YEAR DEVELOPMENT: - :-'" --~-- -;.:-~~ ;. ~ Fig. l.-EadB Bridge, erection with. tieback cables (Courtesy 0/ J08eph E. Vollmar, Jr.) Construction of Steel Arch Bridges The past 50 years have been a time Historical Background of remarkable accomplishment in One of the eminent engineers at the bridge buildi ng_ During this period start of this 50-year period, J. Waddell, By William F_ Hollingsworth, M_ASeE there has been unprecedented growth often stated that bridge building did Engineer, American Bridge Diy_, and achievement in engineering, mate not become a science until the early Un ited States Stee l rials, fabrication, construction, and part of the 20th century. However, in Pittsburgh, Pa _ aesthetics_ retrospect, perhaps there was a touch It is the purpose of this article to of science a little earlier. In 1868, con review some of these developments as struction was started on the boldest they pertain to steel arch bridges_ Pri bridge of its day- The Eads Bridge at mary emphasis will be on field con SI. Louis, Mo. This bridge, designed by struction. However, pertinent changes James B. Eads, was the forerunner of in the related areas of fabrication, ma arch bridges today. It was the first steel terials, and design will also be re bridge, and actually it was the first im viewed. After these innovations have portant use of steel in any type of con been examined briefly, they will be struction. The superstructure was the further explored by reviewing the first that utilized hollow tubular mem actual construction of several repre bers for structural strength. It was the sentative arch bridges that have been biggest bridge ever built and the first built in the United States. to make extensive use of the cantilever method of erection. Reprinted with permission from the March 1975 The bridge was built without fal se Issue of the Journal of the Construction Divi· sian-Proceedings of the American SOCiety of work by cantilevering out from the piers Civil EnKineers (Vol. 101, Proceedings Paper • 11187). in counterbalanced stages. A temporary SECOND QUARTER 1975 wooden tower was mounted on each would occupy nearly all of his produc duce the amount of dead load and kept pier to support steel bars that acted as tive time; now he can spend his time the size and thickness of sections down forestays and held up each half section in a truly productive manner. to a practical limit. Following chrom of the arch as erection progressed. The If an engineer is designing, his time ium steel, the carbon-manganese steels • dead weight of the bars was supported can be spent on investigating many arrived at approximately the same time by additional wooden towers that were different types of bridges to give his as the heat-treated high-strength eye stationed at intervals along the arch client an aesthetic and pleasing struc bars. These steels offered new design (Fig. 1). ture at the least cost. In the area of possibilities and have been extensively Erection went smoothly until the first construction, the computer allows the used for many years. two arch halves neared completion at engineer to explore numerous types of The constant quest for a more eco midspan. The gap turned out to be too erection schemes to obtain the one nomical and stronger steel has led to short and the closing piece could not that is safest and the most economical. the present family of steels. These range be inserted. To obtain a larger opening, The computer also serves an ever in from carbon steel with a yield of 36 ksi it was decided to pack ice in wooden creasingly important function in plan (ASTM A36) to high-strength low-alloy troughs that were installed around the ning the sequence of construction. It steels with a yield of 50 ksi (ASTM A588 bottom portion of the tubular arch tells the engineer and builder which and A441), and to quenched and tem members. Unfortunately, the weather parts of the construction path are most pered alloy steel plate with a yield of turned unseasonably hot and, even after critical-in other words. where he should 100 ksi (ASTM A514) . using 60 tons of ice, the gap was still invest his time and energy. Some of these steels (e.g., ASTM too short. The closure was finally made A242 and A588) are corrosion resistant Surveying-In recent years there have by substituting tubes with screw threads and do not have to be painted. This been numerous changes in the art and on the ends that provided adjustable type of steel forms a tightly adherent science of surveying. With the use of lengths. This idea of a specially made protective oxide film that substantially laser beams and small computers, ac keystone piece is still being used today. seals the surface against further corro curacy that was previously unheard of The Eads Bridge stands as an im sion. This protective oxide film grad can now be obtained. For example, dis portant landmark in the history of ually darkens and assumes a dark tances across canyons can now be bridges, for it ushered in the age of steel brown color. Not only does this color measured to an accuracy of less than and with it a reliance on exact mathe blend into the natural surroundings, '!ii-in. in several thousand feet. The matical calculations, the analysis and but it also reduces maintenance and present surveying instruments combine technique of materials, and modern eliminates first-time paint costs. the capa bilities of a theodolite, a dis methods of bridge construction. tance measuring device, a small elec Shop Fabrication-The two most revo With the possible exception of the • tronic computer, and a tape punch Honeymoon Bridge near Niagara Falls, lutionary developments in shop fabrica recorder-all in one instrument. At the tion are the use of numerically con· the concept, procedure, and equipment touch of a button, everything is done trolled (N / C) equipment and welding. used on the Eads Bridge remained un automatically, i.e., atmospheric correc While the full effects of N/C drilling improved upon in arch bridge construc tion, signal strength changes, calibra tion for 40 years. However, with the are just beginning to be realized, weld tion, and slope changes. Substantial ing has already had an enormous im construction of two major bridges in savings and greater accuracy have been New York City-the Hell Gate Bridge pact o~ field construction. the end result. The N/ C equipment ca n trace its be in 1916 and the Bayonne Bridge 15 ginning to the 18th century, when a years later, there began a period of Aesthetics-The bridge engineer is also French engi neer developed a loom con remarkable accomplishment. The ac deeply concerned about aesthetics. Due trolled by an endless chain of perfo complishments have culminated in re to improved materials, connectors, and rated wooden ca rds. However, it was cent years with the jacking of the Fre· equipment the engineer has had greater not until the early 1950's that the first mont Bridge in Oregon and the con success in fitting his bridge into the true automatically controlled machine struction of the New River Gorge Bridge surrounding terrain. The steel bridges tool, a milling machine, was developed. in West Virginia. The intervening steps of today express the dominant spirit of This machine had the facility for re have led to enormous changes and ad the material-its simplicity, its strength, membering a set of instructions, which vances in bridge engineering, materials, its power, and its beauty of form. controlled the speed and feed rates of application, and construction. Material-The grades of steel have un the milling cutters. Major Developments dergone a significant change. It has Recently, the industry has seen the only been 100 years since the use of quantity and application of N/ C ma Computer-The greatest impact in the steel was initiated in bridge construc chines expand at an impressive rate, area of engineering has been the de tion. In the early part of this century, especially in the area of drilling. It has velopment of the electronic computer. the designer was limited to carbon, been demonstrated that the N/ C drill The computer has liberated the engi chromium, nickel, and silicon steel. A ing machine can produce a superior neer. No longer is he bound by mun chromium steel was the first of the quality product at less cost than by dane mathematical calculations that high·strength steels. It helped to re- traditional methods. Accuracy, repeti- • 4 MODERN STEEL CONSTRUCTION • • Fig. f.-Hell Gate Bridge, cantile116 t' arm and tieback '1I8tem. tiveness, and consistency are all more Welding has many advantages. The the new American Association of State easily obtainable with numerical con more important ones include reduced Highway Transportation Officials specifi trol. Shop assembly of field connec weight, economy, rigidity, appearance, cations. tions is no longer required. The N/C adaptability, efficiency, and the silence equipment has revolutionized certain of the welding operation. Erection-Over the past 50 years, the areas of fabrication and its potential is methods of erecting have vastly im still unlimited. High-Strength 601t-The high-strength proved the efficiency, time, and safety Fifty years ago arc welding was little bolt also has had a tremendous impact of bridge construction. The equipment more than a tool for repairing ma in the area of connecting steels. The and the contractor's method of erection chinery. Progress was slow due to lack principal fastener in steel construction, have repeatedly been improved upon of suitable electrodes and welding until after World War II. was the hot and perfected. power sources. Its use in manufactur driven rivet. However, with the forma Three general methods concerning ing and fabricating was regarded with tion of the Research Council on Riveted bridge erection have developed in re suspicion. However, as welding ma and Bolted Structural Joints in 1947, gard to supporting the structure while chines, electrodes, and knowledge of the high-strength bolt soon became the it is being built: (1) falsework; (2) us welding techniques improved, this sus prime fastener of structural steel. The ing some sort of tieback system during picion gradually disappeared. Finally, ASTM A325 bolt provides joints of the cantilevering operation; and (3) during the 1950's, welding began to be equal or greater strength than rivets at various special schemes, e.g., the float used in the fabrication and erection of a considerable savings in both time and in, jacking, and lifting. highway bridges. Since then, progress cost. This savings will be even more Until the late 1920's falsework was has been steady and arc welding is apparent with the use of the ASTM made of square timber formed into now universally used in steel bridge A490 bolt that has recently been ap bents resting on wooden mud sills or • construction. proved for bridge construction under piles. However, due to the advent of SECOND QUARTER 1975 5 heavier and longer bridges, plus year The roadway is suspended from the to "fatigue" from overstresses caused . round erection, there soon developed a arch and carries four railroad tracks on by the bending and twisting of the demand and need for lighter reusable a heavy ballasted solid concrete deck. hangers during a storm. Remedial ac- steel falsework. Presently, steel piles The arch is a two-hinged spandrel tion consisted of adding a line of struts surrounded by steel cages are used braced truss made from high-carbon that cut down the slenderness ratio. underwater. The piles, in turn, support steel. This warning on aerodynamic oscilla- light steel bents. The Bayonne Bridge The arch was erected by cantilever tion instability was not fully understood was one of the first structures to utilize ing each half from the abutment until nor always heeded as a design or erec- steel falsework. the two halves met and were joined at tion criterion. In 1940, this type of in Often clearance requirements, strong midspan. To hold up each arch half, a stability resulted in the collapse of the tides, or the character of the river or massive steel tieback system including Tacoma Narrows Bridge. canyon preclude the possibility of erect a 5,300-ton counterweight was used Engineer: Modjeski, Masters & Chase ing falsework. In cases of this nature, (Fig. 2). This system consisted of a Fabricator-Erector: American Bridge Oi'o' " United States Steel the cantilever portion of the bridge is tower located over the abutment that held in place by a tieback system. On supported girders from the permanent the Eads Bridge, the tie system was a structure. These girders acted as fore· Bayonn e Bridge (Completed 1931) mixture of steel straps (called cables stays and backstays by holding up half The Bayonne Bridge, across the Kill van at the time) and timber falsework. This of the arch as erection progressed. Ad Kull in New York City, is a structure of soon progressed to massive steel mem ditional approach span girders, stacked enduring greatness. It is a two-hinged bers with huge counterweights (as on at the rear of the backstays, formed the steel arch with a length of 1,652 ft be the Hell Gate Bridge). As the years counterweight. tween end pins. The arch rib consists passed, lighter materials, e.g., wire To control the erection of the two of two steel trusses 74ft center to bridge strand, were utilized. On the halves and their final connection, four center, 67 ft deep at the ends, and 37 New River Gorge Bridge, presently being large 2,500-ton hydraulic jacks were ft deep at the center of the span. The erected, the contractor is using a system placed at the top of the temporary roadway is of the half-through type of wire strand and oil drilling casing towers. At the time of closing, these with the central portion of the floor a material with exceptionally good ten jacks were able to move the ends of suspended from the arch ribs by wire sile load-carrying capabilities. each cantilever a distance of 22V2 in. rope hangers. Various special erection schemes The erection cranes (stiffleg der At the start of fabrication, the con have been used successfully. The re ricks), which traveled along the top tractor offered to substitute a new type cent jacking of the 6,000-ton Fremont chords, were capable of lifting the of steel. This offer was accepted and • arch span makes it one of the most heaviest pieces, which weighed up to this new steel was used in place of the remarkable events in the history of 185 tons each. After the arch was com expensive nickel steel that had been bridge building. A smaller arch, over pleted, the deck was hung below it. specified for the bottom chord of the Rondout Creek, near Kingston, N.Y., This bridge carried the steel arch to arch truss. This steel, a carbon-man had its rib sections jacked up from a new dimensions of span length and ganese type, was about 50% stronger barge on specially designed towers. weight and was, indeed, a monumental than carbon steel and considerably The enormous changes and develop undertaking at the time. Hell Gate held cheaper than the nickel steel. ments in arch construction can prob the record span length for 16 years The wire ropes supporting the sus ably best be explored and understood until the construction of the Bayonne pended deck were galvanized and de by reviewing the actual construction of Bridge. signed for minimum elongation rather several representative arch bridges. than strength. These ropes .were "pre Engineer: Gustav lindenthal While this paper will not cover all the Fabricator-Erector: American Bridge Div " stretched," a new process, before cut structures worthy of analysis, it will United States Steel ting. Because of the prestretching and present an overall view of the devel the accuracy of the enti re rope manu opment of steel arch bridge construc Tacony·Palmyra Bri dge (Completed 1929) facturing process, only a small amount tion. The opening of the Tacony-Palmyra of shims were required to adjust for Bridge in Philadelphia, Pa., was cele erection tolerances. Repre sentative Structures brated as a great occasion. However, the The bridge was built by cantilevering building of this 550-ft tied trussed arch each half from its abutment with trav Hell Gate Brid ge (Completed 1916) should have been noted in the history elers mounted on the truss top chords. The Hell Gate Bridge was the prelude books as an occurrence that was little There were 10 steel falsework bents to this period of development in arch understood or appreciated at that time. used to support the arch halves. These bridge construction. It was heralded as The 18-in. I-beam hangers, which bents were placed and released succes a "triumph of modern bridge engineer supported the tie and the deck road sively as erection proceeded toward the ing" and a "truly monumental bridge." way, cracked lafter only a few : month's center of the river. Transfer of load The bridge spans the East River in of service due to wind vibrations. It from one bent to another was done by New York City and has a 977-ft span. was reported that the failures were due jacks located in the falsework bents. • 6 MODERN STEEL CONSTRUCTION • The falsework bents rested on piers On the longer arch half, it was After closure, the remainder of the that consisted of four groups of square necessary to erect a temporary toggle wire rope hangers were erected fol· creosoted timber piles encased in steel truss to reduce the stresses. This toggle lowed by the deck. boxes and all tied together by angle was made up of a post that was sup Presently. this bridge stands as an bracing. ported at a falsework bent location and example of an engineering feat that in Due to the location of the ship chan inclined eyebar members connected to 1930 wa s considered little short of nel, the closure took place about 250 the top chord in both directions. Jacks miraculous. Its conception, its size, ft beyond the center of the arch. This were placed in the base of each toggle and its construction rema in outstand erection scheme required the strength post to determine the relationship be· ing. Its monumental span length is only ening of several members by an in tween stress and required shim thick now being surpassed-a record that crease in section or use of a higher ness. has stood for 45 years. grade of steel, or both. At the point of closure, a 16-in. diam Ensineer: O. H. Amm.nn Erection of the arch rib started with pin was used as a convenient method Fabric.tor-Erector: Americ.n Bridge Dlv., United St.tes Steel building a temporary tower behind each of centering the lower chord members abutment upon which a stiftleg derrick as they came together. A supplementary was mounted. This derrick then erected mechanism to ensure horizontal aline Henry Hudson Bridge (Completed 1936) the first few arch panels and an erec ment of the arch trusses was an inter The Bayonne Bridge was Soon followed tion traveler. The traveler consisted of locking device that had a tongue pro by construction of the Henry Hudson a 90-ton A-frame derrick mounted on jecting from one arch half arm to en Bridge over the mouth of the Harlem legs that could be adjusted to keep the gage a slot on the other arch half. River in New York City. This bridge is a working platform level as the inclina Closure was obtained by lowering the solid-rib deck arch with a span of 800 tion of the truss chord changed . The two arch halves simultaneously by ft. Each rib was a box consisting of two traveler ran on two lines of rails and means of jacks located in falsework solid web riveted plate girders that were was moved by a block and falls. bents (Fig. 3). laced together to form a box. The arch • Fig. S.-BaJlonne Bridge, arch nearing cloaure • SECOND QUARTER 1975 7 • Fig. 4.-Henry Hudson Bridge, arch after closure Fig. 5.-Rainbow Bridge, crection by traveler (Courtesy 0/ Bethlehcm Stccl Corporation) • • 8 MODERN STEEL CONSTRUCTION rib carries laced box columns that sup blocks and the forestays went out from Sl Georges Bridge (Completed 1941) port the deck girders. the bent top to connections on the A different arch type was introduced at The two halves of the arch we re arch. The forward ties were connected the crossing of the Chesapeake and Del· cantilevered from the abutments on to the rib sections by bar and pin aware Canal near St. Georges, Del, The • steel adjustable falsework bents (Fig. devices that allowed shortening and consulting engineers designed a 540-ft 4). Those bents over water were sup lengthening of the tie lengths in in· span solid-rib tied arch with an extreme ported on steel piles located inside crements of one in. ly stiff tie and a shallow rib, The stan· steel cages. The piles were driven Transferring the stra nds from one dard design practice up until this time through slots in the framework of the point of rib attachment to the next was had been for the rib to be considerably cages that served as submarine brac a slow and tedious process. Each suc heavier and stronger than the tie, ing. This piling was a large improve cess ive strand group was designed to The erector took advantage of this ment over the wooden pi les used just create a minimum of interference so stiffness in the erection scheme. The five years earl ier on the Bayonne Bridge. that one set of long strands could be bridge was erected by utilizing false Also, the falsework bent was made up pulled forward past a connected set. work on one side of the river and from standard reusable sections. The strands were pulled forward by a cantilever erection involving a tieback Since the main channel of the river continuous haul-line that ran from the on the other side. With the stronger had to be left free of falsework, the hoisting engine up over the top of the tie, the erection required less false contractor supported the ends of the cable bent down to the abutment, out work since the tie could cantilever over cantilever arch halves by a toggle tie to a snatch block at the rib connection, a longer distance without support and back system . A steel bent was built on and then back to another drum on the could also carry heavier erection equip top of the arch at a location direclly hoist. A loose tie strand would first be ment. Also, additional savings resulted over the outermost falsework bent. This attached to this haul·line near the from less overall weight and from the bent supported a light tiebar system of abutment and then pulled by the haul· milling of compression splices in the forestays and backstays that held both line out through the strands already lighter smaller rib. the cantilever arch sections and also connected to the new rib connection. Engineer: Parsons, Klapp, Brincke,hoff & DoUal.s a traveler that was used to lift and Pulling the tie strands to the actual Fabricator-Erector: Phoenix Bridae Comp.ny place the steel sections. After comple connection and adjusting them to tion of the arch ribs, the deck girders length was done by a special arrange Fort Pitt Bridge (Completed 1957) were erected as the traveler backed off ment of falls that were pinned to the The Fort Pitt Bridge is a 750·ft, double the arch. adjustable links, Cable stresses were deck truss-tied arch which spans the measured by a special dynamometer Engineer: 0 , B. Steinm.n Monongahela River at Pittsburgh, Pa. Fabricator·Erector: American Bridge Oiv., clamped to the tie strand near the top • United Slates Steel The bridge carries four lanes of one· of the cable bent. Handling these fore way traHic on each level and utilizes stay strands was the most cosily single Rainbow Bridge (Completed 1941) shallow box sections as arch ribs and a One of the most spectacular deck arch item in the erection sequence. 25-ft deep truss as a tie. Most of the Due to the inherent requirements of bridges is the Rainbow Bridge at Ni main members were fabricated with agara Falls. This bridge is a SOlid-rib a fixed arch for predetermined mo high-strength carbon-manganese steel deck arch and has a span of 950 ft. ments and forces, closure operations (ASTM A440), The arch rib is a riveted steel box 12 at the crown required a heavy jacking The final design was based on the ft deep with an additional horizontal and alining device. This device con analysis of a structure that was inde· plate at mid-depth. Closed-box type sisted of two 500-ton jacks mounted terminate to the 15th degree, the un columns, supported by the arch rib, along the top flange and two along the knowns being the 14 hanger stresses carry the deck. The solid rib section bottom flange and an alinement guide and the arch thrust. On earlier struc was chosen instead of a trussed rib that connected to the bottom flange. tures, the solving of this many simul because of its architectural simplicity. After the installation of the keystone taneous equations would have taken However, this early concern for aesthe piece, the deck system and its columns several man-weeks. With the use of the tics led to a very slender or flexible were erected by the traveler derricks as computer, which was still in its infancy, arch in which secondary stresses had they moved backward down the ribs the mechanical solution was performed (Fig. 5). to be considered. in two hours. (Today, that same mechan Due to the condition of the river This bridge, the largest hingeless ical solution would take less than one bottom, a cable tieback system was arch span at the time it was built, was minute.1 The erector also utilized the chosen as the most economical way to one of the first to utilize a specially computer to insure that the structure fabricated keystone piece. Construction support the cantilever arms. The tie· conformed to the correct geometrica I back system consisted of a steel bent involved an elaborate cable tieback outlines as erection progressed, to ob made from permanent steel, which was system including stress measurement, tain proper fit-up of the wire su spenders, placed on the forward end of the con which was a definite advancement over rib, and tie at closing. crete approach viaduct. The backstay previous tieback systems. The bridge was built by supporting tie strands went from the top of the the truss tie on successive stages of Enlineer: Waddell and Hardesty • bent back 350 ft to concrete anchor Fabricator-Erector: Bethlehem Steel CorporatIon falsework which were located out to the SECOND QUARTER 1975 9 • • Fig. 6.-Fort Pitt Bridge, erection by barge-mounted derrick quarter-point of the arch. The stiffness Glen Canyon Bridge (Completed 1959) behind the arch skewback, consisted of the tie, as in the 5t. Georges Bridge, The Glen Canyon Bridge spanning the of a steel braced bent that supported was such that the truss tie could be Colorado River is a deck arch located the tieback cables. The most unusual cantilevered 175 ft beyond the last 700 ft above the canyon floor. Bu ilt for feature of the tieback system was the falsework bent to the ce nter of the the Bureau of Rec lamation, the arch is jacks that permitted the varyi ng of ten river. The erection of the rib followed a two-hinged truss type with a span of sion in the lines. These jacks were lo immediately behind the truss, with the 1,028 ft. cated in strongbacks at points where rib being supported by temporary col At the start of construction, a 12'12- the tieback cables were connected to umns mounted on the truss. The initial ton capacity cableway was erected 30 the arch. As erection progressed, the pieces were erected by a tower stiffleg ft off the ce nter line of the bridge. This jacks were also used to re lieve tension derrick mounted on a barge (Fig. 6). As cableway was used for the purpose of in the rear tieback cables to transfer the pieces became lighter, erection was transporting men and equipment to the load to the forward tieback cables. aided by travelers that were mounted either side of the canyon. Later, a Erection of the arch proceeded in a on the top chord of the tie truss. 1,540-ft, 25-ton capacity cableway was normal fashion with closure taking place Closure was achieved by jacking lon built to erect the actual steel. The two approximately 90 days after the start of gitudinally to close the truss tie top masts for this cableway were mounted arch structural steel erection. The erec chord. The falsework bents located at on two pins at right angles to each tion of the deck system and its sup the quarter-point of the arch were then other so they could be tilted either porting bents was completed about 70 lowered by jacks to close the rib. forward or backward or to either side . days later. The arch halves were supported dur Enaineer: Richardson, Gordon & Associates ing erection by a tieback system. The Engineer: U. S. Bureau of Reclamation Fabricator-Erector: American Bridge Oi ..... Fabricator: Judson Pacific Murphy Corporation United States Steel tieback towers, located about 150 ft Erector: Kiewit-Judson Pacific Murphy • 10 MOOERN STEEL CONSTRUCTION Sherman·Minten Bri dl e (Completed 1961) Fig. 7.-Cold Spring Canl/on Bridge, cablewal/ a)ld cantilct'e r aTm The Sherman·Minton Bridge, across the Ohio River at Louisville, Ky., is of partic· ular interest. This six·lane double-deck • bridge consists of twin (end to end) tied truss arches, each with a span of 800 It. Some of the developments incorporated during the design stage were the use of three different grades 01 steel, shop welding, high·strength bolts, and exten· sive use of the computer both lor de· sign and erection conditions. The tie and some of the more highly stressed rib members were designed with what was then a new alloy heat· treated steel with a 100 ksi yield (ASTM A514). A 50 ksi yield steel (ASTM A242) was used for the floor beam frames and arch members where it would be most economical. The reo maining members were of 33 ksi yield carbon steel (ASTM A373). Since all these materials were weld· able, it was economical to design the bridge for shop·welded fabrication. Gusset and splice plates were shop bolted to the main material and high· strength bolts were utilized in the field connections . The consulting engineer made exten· sive use of the computer in several of • the design phases. It was advantageous to be able to reanalyze the entire arch with a minimum of effort for each change in the design. The erector also made use of the computer in pre· paring the erection scheme. The south arch was first erected by use of falsework bents. The north arch was built by cantilevering its north half Irom lalsework bents while the south hall cantilever arm was held by a tieback to the south arch that was already built. All steel was erecte d from the river by mea ns of a Iloa ting derrick. EnlinNr: Hazelet & Erd.1 Fabricator: R. C. McM.hon Company Erector: J. F. Beasley Construction Company Lewisten·Queenston Bridge (Com pleted 1962) The Lewiston·Queenston Bridge across the Niagara River was also one of the lirst arch bridges to use high·strength bolts. The bridge consists of riveted box girder spans supported by a solid·ribbed deck arch. The arch spa ns 1,000 ft be· • tween skewbacks in the gorge. SECOND QUARTER 1975 11 • Fig. B.-Fremont Bridge, lilting 01 arch span • During erection, the arch halves were which the center 11 spans are supported the cableway so it could be positioned supported by long braced falsework by a 700-ft solid-ribbed deck arch. anywhere within the width of the bridge bents rather than by a tieback system. Welding was used extensively on this project (Fig. 7). The bent nearest the river was 310 ft bridge, which resulted in reduced cost Under each tower leg were hydraulic in height and was built on a slope to and several extra benefits. For example, jacks that permitted the towers to be reduce the amount of arch half that this bridge was one of the first where lowered. This adjustability was utilized had to be cantilevered. Material han the box bent columns were designed as during closure so that after the last rib dling was done by deck travelers. airtight. With this sea l against corro sections were inserted, the arch halves Two hydraulic jacks were placed on sion, it was not necessary to paint any could be precisely lowered until bear each arch rib at midspan to obtain the of the interior surfaces. While no spe ing was obtained at the crown hinge. proper stress distribution and sufficient cific monetary value can be placed on During erection of the arch ribs, the clearance to enter the keystone pieces. aesthetics, consideration must be given tieback cables were connected to the Travelers were also used to erect the to the simple smooth unblemished lines arch by pins to a gusset plate that in deck system after arch closure. of this arch, which blends well with the turn was bolted to the side of the box surrounding countryside. ribs. As each section of arch rib was Enain",: H.rdesty & Hanove, fabricators: Bethlehem Steel Corporation; A traveler was used to erect the ap placed and secured with tieback cables, Dominion Steel .nd Coal Corp. Erector: Bethlehem Steel Corporation proach spans and cableway tower bent. the load in the preceding cables was The cableway tower bent was erected released. After closure, the tieback Cold Spring Canyon Bridge (Completed 1963) atop the permanent bent that supported cables were removed and erection of The Cold Spring Canyon Bridge, Calif. the last approach span at the arch the bent columns and girder deck sys was one of the first arch bridges to skewback. The top cross beam of this tem was begun. Steel erection required fully utilize welding. The bridge road tower bent supported a trolley over approximately 9 to 10 months. way is over 1,200 It in length and con which the cableway's main cable sists of 19 gi rder stringer spans sup passed. The trolley rode on rails that Ensineer: Californl. Division of Hlahways Fabricator-Erector: American Bridge Div., ported by steel box column bents, of provided for transverse movement of United States Steel • MODERN STEEL CONSTRUCTION Fremont Bridle (Completed 1973) The lifting units consisted of 32 Paducah Bridge (Completed 1973) One of the most notable tied arch erec threaded rods that were installed (eight A jacking procedure similar to Fremont tion procedures belongs to the Fremont to a corner) between the top of the was also used on two 1,600-ton 535-ft Bridge across the Willamette River in anchor span and the bottom of the tied tied arch spans on the Tennessee River • Oregon. This bridge incorporates a stiff arch span. In each corner of the anchor near Paducah, Ky. One of the major ened solid·rib tied arch with an ortho span there were eight center-hole jacks. differences between the two schemes tropic upper deck and a conventional The rods extended through these jacks. was that on this bridge the jacking lift concrete lower deck. The arch spans The jacking was done in 24-in. strokes took place adjacent to the final posi 1.255 ft between spring points, which during which time a follower nut was tion of the span . After the lift was com makes it the world's longest tied arch co ntinuously tightened agai nst the sup pleted, the span was skidded sideways span. port bracke t. This insured independent to rest on co ncrete piers. mecha nical support and the nut also The erection of the tied arch portion Enaineer: Kroboth Enliin ..,s of the bridge was done in a single lift sustained the load while the jack was fabricator·Erector: Allied Structural Steel Co. ing operation (Fig. 8). This lift included being fleeted. Th e nuts we re split down the ribs, cable suspenders, tie gi rders, the middle and held in place by a slip Glenfield Bridle (Scheduled 1975) and the orthoptropic upper deck. Even in collar so they could be removed to The Glenfield Bridge across the Ohio with the lower deck not included, the permit rod coupling to pass through River at Pittsburgh, Pa., incorporates lifted portion weighed 6,000 tons and them. The span was jacked approximate several of the latest developments in was 902 ft long. This portion was as ly 180 ft in about 40 hours of continu tied arch bridge design and construc sembled as one unit on falsework lo ous operation. tion. The main river crossing is a 750-ft cated upriver from the bridge site. After tied solid·ribbed arch, flanked by ap Enlinur: Parsons, Brinckerhoff, Quade & Douala, proach girder spans. The bridge will assembly was completed, a barge was Fabricators: Murphy Pacific Corporation floated in place and the span moved to AmeriQn Bridge Oi ... .. carry six lanes of traffic and will utilize United St.tes Steel the bridge site. Erector: Murphy Pacifte Corporation three different grades of steel. Fig. 9.-Glenfield Bridge, r ib erection • • SECOND QUARTER 1975 II • Fig. lO.-New River Gorge Bridge As on several other recently tied the tooth gear acted to close the gap. unit is unbolted and moved to the new arches, the tie for this bridge is con Consequently, when the full load of the point. As the unit is moved, the length siderably stiffer than the rib and car last piece was on the structure, the rib 01 the ropes are automatically ex ries a sUbstantial portion of the live was basically closed without jacking. tended, thereby providing a very simple load moments. This extra depth of the Ensineer: Richardson, Gordon & Associates and inexpensive method of adjusting tie allowed the erector to first erect and Fabricators: PittSbU'fh-Des Moines Steel Company the lorestay cables. Bristol 5 eel Company close the tie portion of the arch prior Erector: American Bridge Dill " United States Steel Ensineer: Howard, Needles, Tammen & Bergendoff to working on the rib. Fabricator-Erector: Allied Structural Steel Co. The arch tie was erected by using falsework bents to support the initial Snake River Bridge (Scheduled 1976) tie sections and then cantilevering the A 993-ft trussed deck arch is presently Hew River Gorge Bridge (Scheduled 1976) remainder of the tie section halves over being built to carry United States High The world's longest arch bridge, New • the main channel of the river. The tie way 93 over Snake River near Twin Falls, River Gorge, is presently being built in sections were erected by cranes Idaho. The arch has a rise of 210 It and West Virginia (Fig. 10). This bridge is mounted on barges. In order not to supports the center portion of a 1,500-ft 3,030 It in length and consists of two block the main channel for more than long girder roadway. Since both types of 34-ft roadways supported by 18-ft deep a few minutes during erection of the the high-strength steels used have a cor deck trusses. The deck trusses are di closing piece, a tie landing device was rosion resistance of four times that of vided into three continuous units. Two utilized to erect this final 150-ft sec carbon structural steel, the bridge will of the units serve as the approach struc tion. This device consisted of beams not have to be painted. tures and are supported by welded box attached to the top flange of the clos The arch truss is being erected by column bents anchored into the moun ing section. Each beam was cantilev cantilevering each half from its skew tainside. The box columns are tapered, ered out beyond the end of the closing back. The cantilever arms are sup with the tallest nearly 400 It in height. section so that it would come to rest ported by an ingenious tieback system . The remaining deck unit is supported on the previously erected portion of the The arch is light enough so that the by similar column bents mounted on a tie. This device not only provided im forestay cables can be made up of truss arch. mediate support for the last tie section three or four parts of 1 ¥loin. diam wire The truss arch has a span of 1,700 without having to wait for the splice to rope. These cables stretch from the It and varies in depth from 53 ft near be completed, but also allowed the en arch tieback panel point back and up the skewbacks to 34 It at its center. tire tie to be jacked longitudinally to to the river end of the approach girders. The center of the arch is 800 ft above eliminate the closing clearance. The ropes are essentially endless in the bottom of the gorge. The truss The erection of the last rib section that one part stretches from a hoisting chords are welded boxes up to 6 It in was accomplished by a similar device engine drum up to a set of sheaves on depth, with web plates up to 4 in. in (Fig. 9). This rib landing device was the girder, down to a sheave unit on thickness. All of the material in the mounted on each end of the closing the arch, and back to the sheave on bridge is unpainted corrosion-resistant rib piece and acted as a one-tooth gear. the girders as many times as required steel (ASTM A588). Du ring the design, As this last piece was entered into its to obtain the necessary strength. To the engi neer used the computer to • position and as the 10M was trans move the tieback cables forward to a analyze stress patterns and determine ferred from the rig to the adjacent ribs, new position on the arch, the sheave the final geometric shape. MODERN STEEL CONSTRUCTION All of the main field connections in done with jacks located in a jacking Bibliography • the deck truss spans and most of the frame embedded in the casing tieback "Arch Spans Jacked Up and Over Onto main arch field connections were N/C anchorage. After closure, all tieback Piers," Eng ineering-News Record, Vol. 191 . drilled. This resulted in the elimination cables will be removed and erection of No. 12, September 13, 1973, pp 18-19. or reduction of the amount of shop the center deck truss unit with its Billings, H.t Sridges , Viking Press, New assembly with a sizable cost savings bents will start from the center and York, N.Y., 1956. for the owner. move toward the approach spans. Bruce, W. H" and Kring , C. V" "How St. The field material handling system Georges Tied Arch was Erected," Engineer· En8ineer: Michael Baker. Jr., Inc. ing-News Record, Vol. 128, No. 1, January consists of twin 3,500-ft cableways Fabricator-Erector: American Bridge Div" United States Steel 1, 1942, pp. 26-28. with two main cables suspended over "Cables Carry Niagara Arch to Closure," the gorge from 330-ft towers. Each Engineering-News Record, Vol. 127, No. 9, cableway has a 50-ton capacity. The Conclusi ons August 28 , 1941 , pp. 288-293. cables are continuous over sheaves that The two longest span arch bridges "Closing a 1652-FI. Steel Arch Bridge 2SO are mounted at the top of the towers were built at opposite ends of the 50- Ft. Off Center," Engineering-News Record, Vol. lOS, October 23, 1930, pp. 640-64S. and run down to anchorages located year period that is covered in this paper. 700 ft behind the towers. Each tower These two bridges illustrate several of Feidler, L. L" "Erection of the Lewlston Queenston Bridge," Civil Englneer;ng, can be luHed 36 ft to each side by the significant changes in arch bridge ASCE , Vol . 32, No. 11 , Nov., 1962, pp. adjustable luffing guys. The first line construction that have developed over SI).S3. for the cableway was flown across the the past 50 years . Gahbauer, S, F , "World's Largest Fixed gorge by a helicopter. The design for the New River Gorge Arch Bridge," Engineering and Contract The approach spans were the first Bridge utilized the electronic computer. Record, Vol. 7S , No. 7, July, 1962, pp. 60- 62. items erected. Due to the large ca The design for the Bayonne Bridge was completely manual. The foundations for Glen Canyon Bridge, BUreau of Reclama pacity of the cableway, it was possible tion , United States Department of the In to assemble the deck trusses in the New River were located to within '!II terior, Denver, Colo., 1959 yard and then lift an entire truss span in. of theoretical, a far greater accuracy Hardesty, S., at aI., "Rainbow Arch Bridge utilizing the cableways. A bent and an than was achieved on Bayonne. On over Niagara Gorge--A Symposium." T rans entire span of trusses, floorbeams, and New River, material of up to 4 in. in aelions, ASCE , Vol. 110, Papar No, 2236, stringers could normally be erected in thickness was utilized, while the thick 1945, pp. 1-178. Hazelet, C. p .. and Wood , R. H.. "Six-Lane • less than one week. est plate on Bayonne was only 11,1., in. The New River Bridge is made from Tied-Arch Bridge Across the Ohio," Civil Once the approach spans were com Engineering , ASCE , Vol. 31, No. 11 , Nov .. pleted, the tieback system for the can weathering steel and does not have to 1961 , pp. 43-47. tilever arch halves was built. The for be painted. The various components of "Hlghline Erects Arizona Bridge," Western ward cable ties of this system are New River are shop welded, numerically Conslruclion, Vol. 40, No.8, Aug ., 1965, pp. connected to jacking rods at the arch controlled drilled, and field bolted. 51-53. tieback points. The jacks are used both Those of Bayonne were riveted and "High Wind Breaks Hangers In New Tled to attach and stress the wire ropes as reamed at assembly. Field handling of Arch Steel Bridge," Engineering-News Rec ord, Vol. 103, October 17, 1929. well as to insure an equal stress dis material is done by cableways on the Shulman, M. A., "California Scenic Bridge tribution among the various parts. New River Bridge. On Bayonne, trav Features 700-FL Welded Steel ArCh ," Mod These forward ties extend back and up elers were required to move and lift the ern Welded Structures, James F. Lincoln from the arch to connect to a rocking heavy steel pieces. The New River Arc Welding Foundallon, Cleveland, Ohio, device that is mounted at the front end Bridge is being supported during con 1965. of the approach span . The horizontal struction by a tieback system of wire Steinman, D. B., and Watson, S. R., Bridges component of these ties is carried back rope and oil drilling casing. Bayonne and Their Builders, Dover Publications Co., New York, N.Y., 1957. a distance of 600 ft to a concrete an utilized falsework with wooden piles chorage by four lines of high-strength and eyebar toggle ties. Also, there is Tokola, A. J., "Erecllng the Center Span 01 The Fremont Bridge," Civil Engineering. oil drilling casing. the change in aesthetics. The Bayonne ASCE, Vol. 43, No.7, July, 1973, pp. 62-6S. Bridge is massive and monumental in As succeeding sections of arch truss Troelseh, H. W.. The Kill Van Kull Bridge, are erected and secured with new for size. The New River Gorge Bridge has a American Bridge Division, Plllsburgh, Pa., ward tieback cables, the preceding light and open overall appearance. 1931 . cables are released. At the time of With both of these bridges, as well Vollmar, J. E.. James B. Eeds and Ihe closure, with the arch halves canti as those that came in between, there areal 51. Louis Bridge, Engineers' Club of levered B50 ft, each half will be sup have been numerous accomplishments. St. Louis, St. Louis, Mo., 1974. ported by tieback cables from two dif However, what stands out in this past Waddell, J. A. L , Bridge Englne.rlng, Vot . half century of achievement is man's 1, John Wiley and Sonl, Inc., New York, ferent panel points. N.Y., 1916. The arch is being erected higher continual thrust forward. The present "World's Biggest Heaviest Lilt Opens Bridge than its final position so that the arch steel arch bridges, as well as those of Building Chapter," Engineering-News Rec • halves can be precisely lowered until the future, fully express this irresist ord, Vol . 190, No. 13, March 29, 1973, pp, bearing is obtained. This lowering is ible urge of man. 22-23. SECOND QUARTER 1975 15 I AMERICAN INSTITUTE OF STEEL CONSTRUCTION BULK RAIE 1221 Avenue of the Americas US POSTAGE New York, N. Y. 10020 P A 10 ----- NEW YORK. N Y. Address Correction Requested Permit No 6662 • r ~ Steel ~~ ~ "!.) AISC REGIONAL ENGINEERING STAFF Pacific Coast Area Southwestern Area Southeastern Area • lOS ANGELES, CALIF. 90015 DALLAS, TEXAS 75247 ATLANTA, GA. 30305 Room tJOl-7f4 W. Olympic Boulevard Suite 233-E, Mockingbird Tow.,. Room 223-3071 Peachtree Ro.d. HE. James W. Mar.h, RegIonal Englneer-Supefv/slng 1341 W. MockIngbird Lene Roben W. Green, Reglon.' Engine" Earl Roy aecker, Reglone' Engln ••, Frederick S. Adams, Senior R.glonel Eng(neer BIRMINGHAM, ALA. 35216 3228E Lorn. Ro.d SAN FRANCISCO, CALIF. ~105 HOUSTON, TEXAS 77006 Roben J . Sch.lfh.usen, R"glon.' Englne.r 215 MalhI Str•• t, Room 827 Sull. 1SO-L, Two Corpore'e Squlr. Howard A. Schirmer, Regional Engl"•• , 3930 Kirby D,lve CHARLOTTE, N,C. 28203 V. Del. L.n., Reg'on.' Engln." SEATTLE, WASH. 98104 P.O. BOK 3188, 1409 E.s' Bouf.~.rd Howlld F. Morris, Region.' Englne.r 405 Centre' Building. 810 3td "'"nue OKLAHOMA CITY, OKLA. 73118 Elmer E Qunnelte, Se"'or R~lon.' Eng/n,., 1016 N.W. 44th Street MEMPHIS. TENN 38111 Floyd E. Hensley, Reglon.' Engln ••r Room 445-Th. C.ntury Building, 3294 Popl'r Ayenu. Midwestern Area Lewis B. Burgett, Region.' Engineer WASHINGTON, DC.-Sprlnglield, V•. 22152 CHICAGO, Ill. 60603 Suit. AJ04, 8138 Old Keen. 1.4111 Roed Sufi. 1S123-25-176 We" Adams Str•• t Eastern Central Area F Ayers Wliliamlon, Reglonel Engineer Victor A. Walther, Jr., Reglon.' Eng/n ..t-Supervlslng Robert W. Shulde., Reglon.' Eng/,..ff CLEVELAND, OHIO 44113 Northeastern Area DENVER, COLO.-Englewood, Colo. 80110 Room 1232-$tend"d Building, 1370 Ont."o St. Encull"l Sui'. 3237, 5 Denve, hchnologlcal Cenl., WIIII.m C. Keene, Reglon.1 Engln." Oe"'.' A. Dunlap, Reglone' Eng /" .., BOSTON, MASS. 02116 COLUMBUS, OHIO 43214 25 Huntington A~.nu. MILWAUKEE, WISC. $3222 Sufte 203--4501 North High Stre.t Emil. W. J . Troup, Reglonel Engineer 10031 W. Lisbon A~.nu. H.yw.rd H. Dick, Reglonel Engln • ., Robert F. Lorenz, R.glon.1 Eng ln ••r HARTFORD, CONN . 06103 119 Ann Sl/eel DETROIT, MICHIGAN 48226 Clprl.n A. Paurolo, Reglon.1 Engln .., MINNEAPOLIS, MINN. 55420 "80 Penobscot BuildIng, 845 Gllswold Su/l. 133C, 8053 Bloomington F, •• w.y Harold W. Gilley, Region.' Engln •• , R.ymond H. R. TIde, R.glon.' Engln ••r NEW YORK , N.Y. 10020 Suit. 1580, 1221 A~.nue 01 the Amerlc.s PHILADELPHIA, PA. 19102 S.mlMl H. Marcus, Englneer~Su"'fVl.lng OMAHA, NEB. 68102 Reglon.' Room 82E-Clty N.tlon.' B.nk Building 302 M.,lIn Tower Building, 1518 We/nul 51 . Remon P. Nlldon" Reglonel Engln.er Lawrence G. Adams, J.ck A. Donnelly, R.glon.' Engln ..r Reglonel Engln• ., Charles Pesh,k, Jr., Region.' Engine., ST. LOUIS, MO. 63105 PITTSBURGH, PENNA. 15219 SYRACUSE. N.Y 13210 143Q Boul.~ard, Suit. 222-230 S. Beml.ton A~.nu. Q80·8 Union Trust Bulld/ng E," E. Clyd. A. Guder, Reglon.' Engln •• , Chari,s M. Schubert, Regional Engine., Chart .. L. Burnl, Reglon.' Engine., •