civil-engineering-(土木工程概論英文課件)CHAPTER-FIVE

1、CHAPTER FIVETECHNICAL INNOVATIONS IN WORLD'S BRIDGE DEVELOPMENT5.1 Introduction-Historic ReviewSeveral thousand years ago, bridges were already built to cross rivers and valleys and make traffic convenient Before the Christian era, the Chinese already learnt to build simple beam bridges. Bing LI

2、 conducted the construction of a pedestrian suspension bridge with bamboo cables early in 250 B. C For this bridge, suspended cables were adopted as main supporting structures to cross a valley or river.Before the 18th century, bridges were made mostly of natural materials, for instance, wood, stone

3、, bricks, etc. As wooden bridges can only have short spans, and their fire resistance and durability are poor, they do not last for a long time. The wooden bridge shown, in the Chinese traditional painting of Northern Song Dynasty, painted on the scroll entitled "The Festival of Pure Brightness

4、 on the River", is a masterpiece among them. The span of stone arch bridge is generally shorter than 30 meters. Zhao Zhou Bridge(Fig. 5.1) in Hebei Province, China, with main span of 37 meters, has a history of more than 1300 years and is still in service at present. It is one of the most ancie

5、nt stone arch bridges in the world.In the 6th century, iron chains began to be used in the footbridges in China. This technology was imported into Europe in the 18th century.In 1779, the first cast-iron arch bridge-Coalbrookdale Bridge with a span of 30. 65 meters was constructed in Britain. In 1801

6、, the Thames Bridge with a span of 183 meters was built in London. From the middle of the 19th century, the advent of steel followed by high strength steel wires enabled building of long span steel bridges and suspension bridges in the western countries. In 1850, Britannia Bridge with a141m long mai

7、n span was built in Britaia It was the first railway bridge designed as deep box girder. In 1883, an urban suspension bridge, Brooklyn Bridge, with a 486m long main span was built in New York, America. In 1890, a railway cantilever truss bridge, Firth of Forth Bridge appeared in Scotland Its main sp

8、an reached to 520 meters (Fig. 5. 2). Fig. 5. 1 Zhao Zhou Bridge(China)Fig. 5. 2 Firth of Forth Bridge(UK)The buckling problem of the upper chords of an open type bridge in Russia in 1875 and the lower chords of the Quebec Bridge in Canada in 1907 accelerated the development of the theory of bridge

9、stability.5.2 Technical Innovation in the First Half of the 20th CenturyThe development of bridge engineering is closely related to social development. In the 1920's, the engineers of the United States of America took the lead in building expressways in the period of severe recession. In the 193

10、0's in Germany, the Nazis came into power and began to build expressways for the war which promoted more bridge construction. The "Milan Method* which involves a stiffened skeleton arch bridge, was initiated in Europe and changed the backwardness of the full span staging method, at the same

11、 time, improving bridge technology.The invention of concrete played an enormously important role in bridge developments. In 1867, the French invented the concept of reinforced concrete, which was firstly applied to building structures and then to bridge construction in 1905. From then on, reinforced

12、 concrete bridges became the mainstream of short and medium span bridges to replace steel bridges.In the first half of the 20th century, many long span suspension bridges and arch bridges were constructed. In 1931, the George Washington Bridge was built in New York, with a main span reaching 1067 me

13、ters ( Fig. 5. 3). In 1937, The Golden Gate Bridge in San Francisco with a main span of 1280 meters was built (Fig. 5. 4). The main span of the Bayonne steel arch Bridge built in 1931 reached to 503. 6 meters(Fig. 5. 5).Fig. 5.3 George Washington BridgeFig. 5. 4 Golden Gate Bridge(USA)Fig. 5. 5 Bayo

14、nne Bridge(USA)Before World War ， there were three great suspension bridge designers in America. Roebling designed the Brooklyn Bridge； Amman succeeded in designing Golden Gate Bridge; Steinmann established his own position in the history of the bridge by designing a unique magnificent truss-type py

15、lon.Besides America, bridge construction in other countries also made great progress during this period. In 1932, the Sydney Harbor Bridge with a 503-meter main span, designed by British Consultant Freeman Fox, was built in Australia (Fig. 5. 6). In 1943, the reinforced concrete archSando Bridge wit

16、h a 260-meter main span was finished in Sweden(Fig. 5. 7).In the 1930's, structural analysis and design theories for many types of bridges were set up successively with the development of the bridge technology. Here are some famous theories:Design theory of reinforced concrete, by Guyont and Fre

17、yssinet in FranceDeflection theory for suspension bridges and space analytic theory tor steel girder frames, by Melan, BleichStussi, Homberg, Leonhardt in GermanyStability and the vibration theory of structures and thin wall bar theory, by Timoshenko, Dinnik, Vlasoff in RussiaSpecial analysis and no

18、n- linear theory of structures, by Von Kannan. Newmark in U. S. AAnalytic theory for grillage and the analytic theory for box girders, by Massonett, R. C. in BelgiumPractical deflection theory for suspension bridge, by LI Guohao(K. H. Lie)inChinaIn 1940, the Tacoma Bridge in Washington of the Americ

19、a was damaged by wind (Fig. 5. 8). leading to new theories of wind-resistance to evolve.5. 3 Technical Innovation in the 1950'sWorld War inhibited bridge development The concept of prestressed concrete was created by Eugene Freyssinet of France in 1928, but failed to be applied in practice becau

20、se of the War. Neither did the concept of modern cable-stayed bridges which was proposed by Franz Dischinger of Germany in 1938. After the 1950's, these two technologies found wide application when damaged European bridges were rehabilitated and rebuilt.In 1950's, prestressing technology and

21、 the renaissance of cable-stayed bridge were the two greatest achievements in bridge development. Bridge technology in France and Germany developed rapidly in this periodFreyssinet's company developed a whole series of equipment including prestressing material， anchorages, corrosion protection a

22、nd construction tensioning devices. In 1953, when Finsterwald's company in Germany built Worms Rhine Bridget it developed the cast-in-situ balanced cantilever construction method and the Dywidag Prestressing System. In 1956, Franz Dischinger firstly succeeded in building a modern cable-stayed br

23、idgeStromsund Bridge with a 182- 6m main span (Fig. 5. 9). Shortly after that, cable-stayed bridges became popular in Germany with the construction of the Dusseldorf North Bridge (Fig. 5. 10) and the Cologne Severin Bridge was the representative among them. Cable-stayed bridge defeated traditional b

24、ridge and became the mainstream of long span bridges.Fig. 5. 9 Stromsund Bridge( Germany) Fig. 5. 10 Dusseldorf North Bridge (Germany)At the same time, Fritz Leonhardt of Germany initiated the technology of orthotropic steel deck, which replaced cumbersome reinforced concrete girders. He also initia

25、ted the concept of concrete-steel composite action in the design of cable- stayed bridges.At this stage, various kinds of theories(prestressed concrete, orthotropic decks, composite girders, etc. )were established and gradually became mature. This laid the theoretical foundation for the first climax

26、 of bridge construction in the 1960's after World War II.5. 4 Technical Innovation in the 1960'sIn the 1960's, construction technology developed rapidly during the large scale civil engineering construction in Europe and America. This included wedge-type prestressing anchorages and fatig

27、ue-resistant button-headed anchorages for cables, balanced cantilever construction method of precast prestressed concrete segments, the erection method with moving scaffoldings and launching girders, the fiction connection of high strength bolts instead of the connection of rivets, etc.The back anal

28、ysis approach for the construction control of cable-stayed bridges initiated by Fritz Leonhardt also became popular and helped cable-stayed bridges to reach longer spans. The competitive potential and the scope of application of cable- stayed bridges have been greatly improved since then using from

29、sparse cables to dense cables, from steel girders to prestressed concrete and various kinds of composite. The following examples are famous cable-stayed bridges built during that period:The Maracaibo Bridge(L=235m)in Venezuela designed by an Italian, Marandi, in 1962, the Hamburger Kohlbrand Bridge(

30、L=367m)in Germany in 1970, the Bonn Ebert Bridge(L = 280m)in Germany in 1967, the Dusseldorf Knie Bridge(L = 320m) in Germany, etc.There were also long span bridges built by advanced construction technologies in this period, such as Bendorf Bridge in Germany, by cast - in - place construction method

31、 with form travelers, Oleron Bridge in France, by precast segmental construction using a launching girder (Fig. 5.11).The British suspension bridge was another innovation during this period. This bridge type has the following characteristics: using flat box girders rather than steel truss girders an

32、d concrete pylons than steel pylons (box type or truss type). The Severn Bridge in UK with a 988-meter long main span built in 1966 is a good example. Fig. 5.11 Oleron Bridge(France)Fig. 5. 12 Severn Bridge(UK)5. 5 Technical Innovation in the 1970'sDuring the 1970's, prestressing technology

33、became mature. The combination of prestressing technology with cable - stayed bridges started an epoch in bridge development and the concept of cable-stayed bridges spread from Germany to other parts of Europe, America and Japan.In 1974, the Brottone Bridge with a 320-meter main span crossing the Se

34、ine River was built. The bridge was designed by Jean Miiller. With prestressed concrete box girders, a single cable plane and a single column pylon, this bridge symbolized another kind of cable-stayed bridges, where in the first time cable forces reached one thousand tons and the bearing capacity of

35、 pot bearings reached ten thousands tons. (pig. 5. 13). The DUsseldorf Flehe Bridge built in Germany in 1979 featured a hybrid deck, a single asymmetric pylon and a 368-meter main span(in other words, the span of a cable-stayed bridge with two such pylons would be over 700 meters) ( Fig. 5.14Fig. 5.

36、 13 Brottone Bridge(France)Fig. 5. 14 Diisseldorf Flehe Bridge(Germany)The incremental launching technology in the construction of prestressed concrete continuous bridges was also introduced in the 1970s. Segments of the bridge superstructures are cast in place in lengths of 10 to 30m in stationary

37、forms located behind the abutments. Each unit is cast directly against the previous one. After sufficient concrete strength is reached, the new unit is post-tensioned to the previous one. The assembly of units is pushed forward with the help of a nose girder in a stepwise manner to permit casting th

38、e succeeding segments. Normally a working cycle of one week is required. The friction force during the launching is reduced by polyethylene bearings. This method provides economical construction of long or curved bridges over deep valleys.The Salginatobel Bridge with a sickle shaped arch, designed b

39、y the famous Swiss designer Robert Maillart, took first place in the appraisal of the ten most beautiful bridges in the 20th century organized by IABSE. (Fig. 5. 15). Sunniberg Bridge, designed by the Swiss professor, design master Christian Menn. with the feature of low pylons and adopting external

40、 prestressing tendons as stay cables, was a new type bridge with the mixed behavior of both continuous beams and cable-stayed bridge (Fig. 5. 16). The continuous rigid frame bridges* the Fegire Bridge- whose main span exceeded 200 meters, was designed to overcome the temperature effect and decrease

41、the negative moment in virtue of the flexible double-thin-wall piers. In 1983fig.5.15 Salginatobel Bridge Switzerland) Fig, 5. 16 Sunniberg Bridgethe main span of the West Gate Bridge in Australia reached 260 meters in span and was also a rigid frame bridge.5 6 Technical Innovation in the 1980's

42、During the 1980s Japan developed the construction method for main cables with prefabricated parallel - wire strands (PPWS Method) for suspension bridges. This replaced in most instances the traditional "aerial spinning method" (AS Method) from America. Strengthening technology using fiber-

43、reinforced plastics(FRP) was also developed during this period.The strength of concrete developed rapidly from C20, C25 in the 1950's to C60, C80 by 1985 using ground fine cement and silica powder. High performance concrete can reduce the self-weight of bridges increasing the span ability and im

44、proving the index of corrosion protection and durability of bridges. At the same time, the experimental bridges made of CI00 or C130 were also constructed.External prestressing techniques were developed by USA and France in the early 1980's. In America, span-by-span segmental construction with e

45、xternal prestressing bettered AASHTO composite construction in many long bridges, as in Long Key Bridge and Seven Miles Bridge, for its economy and fast construction. In France, the mixed prestressing tendon layout, i.e., an arrangement using both internal prestressing tendons for cantilever prestre

46、ssing and external prestressing tendons for continuous prestressing, was adopted in bridges by balanced cantilever construction method, for the external prestressing tendons have good durability and can be easily inspected, replaced and readjusted after completion of the bridge.The concept of steel

47、and concrete mixed structures had also developed and fully took advantage of the two materials. Lateral mixing and longitudinal mixing expanded the field of composite construction.The spine girder urban viaduct with large side overhangs was another innovation in this period. The construction include

48、s: installation of small precast middle spine girder and single column piers forming a skeleton frame by means of longitudinal prestressing; erection of the precast large overhanging slabs on both sides of the central spine girder by means of transverse prestressing.During this period, there were tr

49、emendous developments in bridge construction in China, Chinese engineers introducing the Western technologies developed since the 1960s5. 7 Technical Innovation in the 1990'sThe 1990's was a period in which many bridge records were broken. Bridges with record spans were built one after anoth

50、er.The Normandie cable-stayed Bridge in France completed in 1995(Fig. 5.17)has a main span of 856-meters, noticeable for parallel strand cables and construction control technology.The Great Belt suspension Bridge in Denmark completed in 1997 has a main span of 1624-meters, noticeable for the collisi

51、on-resistance technology of pylons and piers.The Wanxian arch Bridge over the Yangtse River in China completed in 1997 has a main span of 420 meters, noticeable for the construction control technology of the concrete filled steel arch and cantilever construction(Fig. 5.18).Fig. 5.17 Normandie Bridge

52、( France)Fig. 5.18 Wanxian Bridge over the Yangtse RiverThe Akashi Kaikyo suspension Bridge in Japan completed in 1998 has a main span of 1991 meters, which was noticeable for the deepwater foundations and the usage of the 1800MPa high strength steel wires for piers, earthquake resistance design of

53、pylons and vibration-reduction technology (Fig, 5. 19).In Norway, the Stolmasundet continuous rigid frame bridge with a main span of 301 meters was completed in 1998. It is the longest span of this type of bridges in the world.The Oresund Strait Link connecting Denmark and Sweden is a combined highw

54、ay and railway bridge. The 108m approach spans were constructed by full span erection method with a 9000t huge floating crane(Fig. 5, 20).Fig. 5. 19 Akashi Kaikyo Bridge (Japan)Fig. 5.20 Oresund Bridge(denmark, Sweden)Tatara cable-stayed Bridge has a main span of 890 meters. It was completed in 1998

55、 and noticeable for rain-induced vibration resistance technology for its very long stays.Inspired by Japan and Denmark who had finished bay - crossing projects successfully, the work of preliminary stage for many other bay-crossing projects boomed in the world, including: The Messina Strait Bridge p

56、roject in Italy; The Eurafrica Gibraltar Strait crossing project; The bay-crossing projects linking three islands of Britain; The Eurasia Bering Strait project; The Second territory axle project in Japan(The freeway along the coast of the Pacific Ocean), including six bay-crossing projects; the Kore

57、a Strait project linking Japan and Korea; and the La Perouse Strait and Tartar Strait projects linking Japan and Russia. In China, the expressway along the Pacific Ocean coast has five bay-crossing projects, including: Bohai Bay, the Entrance of the Yangtse River, Hangzhou bay, the Entrance of the P

58、earl River and Qiongzhou Strait; the islands linking project in Zhoushan, Zhejiang province; the Taiwan Straits project linking the mainland to Taiwan. The Malacca Strait project linking Malaysia and Indonesia; The island connection projects in Indonesia(Such as between Java and Bali)? The island co

59、nnection projects in the Philippines. With the development of computer technology, the analysis of bridge structures tends to get numerical solutions more precisely. The innovation includes: The application of IT technology to the planning, design, structural analysis, construction management, health monitoring and maintenance management, etc. ; The elastic/plastic stability analysis considering the whole loading stage up to the ultimate stage; The three dimensional spatial