Multi-Tower Cable-stayed Bridge

Tower cable-stayed bridge with single tower cable-stayed bridge in the process of development, is the extent and development of multi-tower cable-stayed bridge. The earliest tower inclined cable-stayed bridge was built-in 1963, by Italy who designed by Ricardo Morandi Venezuela Maracaibo Bridge, as shown in Fig. 3.55. It is the first prestressed concrete cable-stayed bridge in the world, its structural concept is clear: a series of pre-stressed concrete truss rigidity support cantilevered sections, simply supported beams hanging connections.

Fig. 3.55 Maracaibo Bridge overall print (size: m).

Later, Many scholars performed a study of multi-tower cable stayed bridge. Now there are basically rigid tower system and Jiajinsuo system the two systems. Typical rigid tower system with Greece’s Rion-antirion Bridge, as shown in Fig. 3.56; stiffening cable fragrance Ting Kau Bridge in Hong Kong, as shown in Fig. 3.57. Yiling Changjiang River Bridge in tower cases do not use rigid tower and jiajinsuo, through reasonable matching ideal stiffness of the structure, as shown in Fig. 3.58.

Fig. 3.56 Rion-antirion Bridge (size: m).

Fig. 3.57 Ting Kau Bridge.

Multi-tower cable-stayed bridge in the France of the Millau Viaduct is a characteristics of one seat, as shown in Fig. 3.59. High pier of 240 m, connected to energy beams. Bottom of the reinforced concrete column type piers 17 m × 27 m, at a certain height along the vertical forks, fork height 90 m. Such designs make the pillars have greater flexibility, better to adjust the horizontal and vertical direction of change. The construction method is also very original, first pushing steel box girders, in order to reduce the pushing distance across erecting a set fitted with tow equipment of steel-tube truss of Falsework. After the closure, tower trailers delivered to the deck is not installed the appropriate bridge directly above the pier. Tension and temporary support towers above the pier, tower tilted

upward reversal, installed directly above the pier.

Fig. 3.58 Of Yiling Yangtze River Bridge.

5. Suspension Bridge

Development of modern suspension bridge started in 1883 with United States Brooklyn Bridge, as shown in Fig. 3.60. Its main span is 486 m, cross 286 m on both sides. By the famous engineer John A. Roebling designed. Roebling had already involved in the design work of several suspension bridges, and in 1854, at wheeling a suspension bridge that spans the Ohio river disaster after largely influenced his design ideas. The accident inspired him using other than the rigidity of cable itself has greater stiffening girder and cable way to make up for the shortcomings of simple suspension system. At the time of construction of the Brooklyn Bridge, roebling suspension bridge high-order hyperstatic systems cannot be accurately calculated. But through the component force between a reasonable distribution, and guarantees that the overall balance to guarantee against failure of security.

Fig. 3.59 Elevation of Millau Viaduct.

In 1931, and completed the construction of long-span Bridge 1000 m—George Washington Bridge for the first time, as shown in Fig. 3.61. The bridge span arrangement for 186 m + 1067 m + 186 m. The bridge began plans to double-deck, upper pass cars, lower passing trains. However, due to the great depression in the late 1920 of the 20th century, the original design was cut, only built upper deck, because this begun to not actually stiffened girder of the bridge, set only at the deck stringer small bending stiffness of carriage way. Still, the bridge still has sufficient stability, this is because bridge uses concrete and dead loads great, while 8-lane bridge the width as well. In addition, the main span length is less than one-sixth’s short side spans are to some extent compensated for the lack of longitudinal stiffness, increased cable system of strong performance. Finally, in 1962, built on the lower deck of the bridge deck is complete.

Fig. 3.60 Brooklyn Bridge.

Fig. 3.61 George Washington Bridge.

Completed in 1937, Golden Gate Bridge main span is 1280 m, span larger than the George Washington Bridge 20%. But this use of the two main cables, each 930 mm, mainly because only one layer of the deck of the bridge. While George Washington Bridge uses four main cables of each 910 mm. In beam high regard, Golden Gate Bridge shows suspension bridge in a long refinement development direction, height-span ratio of only 1:168. Space trusses composed of only 3 pieces of plane truss and two vertical and a horizontal truss-to-truss. Such structure allows the torsional stiffness of truss section is small, at that time did not fully understand importance of torsional stiffness for aerodynamic stability. In December 1951, 4 h of winds, the vertical amplitude of the bridge achieves the 3.3 m, had to shut down the bridge. In the aftermath of the Tacoma Narrows Bridge wind destroyed, Golden Gate Bridge is in vertical add horizontal support between the bottom chord of the truss. In this way, contains 3 pieces of space truss trusses with open sections into contains 4 pieces the closed section of truss (Fig. 3.62 and 3.63).

In 1940, of the Tacoma Narrows Bridge main span is 852 m and height-span ratio is 1 : 350. This is due to the large deflection theory is extended to three-dimensional stress characteristics of the ultimate results. Wind speed wind destroyed the bridge to 56~67 km/h, far below the designed resistance to most wind speed. However, when it comes to structural analysis and consider only the static air pressure without noting beam angle formed by fluctuating wind vortex dynamics. Selection of wind destroyed the bridge reveals a maximal length of fine design prone to aerodynamic instability.

Fig. 3.62 Front opening space trusses before Reinforcement.

Fig. 3.63 Front opening space trusses after Reinforcement.

Tacoma Narrows Bridge after the accident, engineers focused on vibration characteristics of suspension bridges and air on the dynamic vibration response, established a method for aerodynamic vibration of suspension bridge design, and this approach has become to build important part of the design of cable-supported bridges.

After World War II, other suspension bridge in the west came from behind to form different from United States-style suspension bridge points. United Kingdom the Severn Bridge main span was built-in 1966, 988 m (Fig. 3.64), the main span was built-in 1981 to 1410 m of the Humber Bridge is representative. Continental suspension bridges in the United States for breakthrough in accumulated technology and experience in the construction of suspension bridges. In order to reduce the weight while maintaining good aerodynamic properties, continental used set a steel Crossbeam of suspension bridge cell box girder. Beam shape design is used with a good aerodynamic shape. From the anti- seismic point of view, stiffening of flexible undertaking only limited earthquake load, while the bridge relatively rigid Suo Tacheng under strong ground motions.

Fig. 3.64 Severn Bridge.

Severn Bridge uses a flat steel box girder of 3 m (first flat steel box girders), height- span ratio 1 : 324, similar to that of the Tacoma Narrows Bridge main span. But by the closed section of the streamline of wind tunnel experiments and makes wind stability and torsional stiffness has been very satisfactory.

Fig. 3.65 Great Belt East Bridge.

Denmark Great Belt East Bridge (Fig. 3.65) is a European Cable Bridge an outstanding representative of the bridge, which span arrangement for 535 m + 1624 m + 535 m. Upper structure made of flat steel-box-girder, high 4 m, wide 31 m. The bridge anchorage structure is unique, by the anchor room, cable saddles as well as between the hollow knot structure-composition, as shown in Fig. 3.66.

In Asia, economic power Japan started in in the 1960, of the 20th century built for long-span suspension bridge larger than 300 m (1962, Fukuoka-Seto bridge main span of 367 m), to the South like bridge was built-in 1988 (main span 1100 m) put an end to Asia’s non-kilometer TRANS-bridge history. 10 years later, in 1998, the Akashi Kaikyo Bridge (main span of 1 990 m, (see Fig. 3.67) built, marks a long-span suspension bridge construction has shifted to Asia.

Fig. 3.66 Hollow gravity anchor.

Fig. 3.67 Akashi Kaikyo bridge, Japan.

In the 1990, of the 20th century, the suspension bridge of China also entered the development team, in 1995, completed the construction of the Xiling Yangtze River Bridge (main span 900 m), Humen bridge was completed in 1997, (main span of 888 m). In 1998, Hong Kong’s Tsing Ma Bridge (main span of 1377 m) and 1999. Years of Jiangyin Yangtze River Bridge (main span of 1385 m, as shown in Fig. 3.68) respectively into the fifth in a series of long-span bridges in the world at that time and in fourth place. 452 m Shantou Bay Bridge main span pre-stressed concrete stiffening girder, span bridge of its kind in the world rank one. Shanxi Hou men bridge main span of 1650 m, 26 m longer than Denmark Great Belt East Bridge. The bridges built, not only to fill the Blank modern suspension bridges, and to modernise the Chinese entered the master design, analysis, construction technology of large-span suspension bridge’s advanced ranks.

Fig. 3.68 Yiling Yangtze River Bridge.

6. The Combination of Cable-stayed Suspension Bridge

In 1938, Germany renowned bridge designers Dischinger design across the Elbe river suspension bridge with a main span of 753 m railway time proposed cable-stayed suspension system different from the Roebling. Its base idea was similar to A. Arnodin thoughts close to cable-stayed and suspension cable his responsibilities. Unlike Roebling cable on cable reinforcement ideas, dischinger’s system is a true mutual collaboration. While he established a cable design of the original—Only under very small dips, cables can be rigid enough to keep the main beam deflection at the lower limit. But because just after people have come to realise the advantages of structural system of cable stayed bridge, the bridge out of the outlook of people.

Given the advantages of cable-stayed suspension, programmes all over the world to build bridges among this type is frequently raised. In 1998 years, the United Kingdom of Flint and Neil company and jointly presents Javan Halcrow (Java), Bali channel meter scale cable-stayed bridge programme in collaboration with cable, as shown in Fig. 3.69. But this type of bridge is not a very mature type has its own deficiencies. First, as a cable- stayed suspension bridge that brings together two different types, then in construction requires two sets of different mechanical device and secondly, two cable forms and suspension cable of cable-stayed force and deformation characteristics vary, therefore at the junction there is often a deformation compatibility problems; and, third, two cable stiffness differ, on load distribution, be very careful.

In October 1997, China’s Guizhou province, has built the world’s first combination Dischinger system cable-stayed suspension bridge, Black River Bridge (Fig. 3.70), the bridge of long-span 288 m.

Tongji University in Lingdingyang Bridge connecting Zhuhai in Guangdong and Hong Kong (Fig. 3.71) scenario, cable-stayed-suspension system construction control of bridge fatigue control and Sling were studied was proposed for this system is very advantageous construction methods, and by setting the cross sling and supporting piers as a way to decrease the sling alternating axial force. Mechanical properties of cable-stayed- suspension bridges and the chai were studied, and points out that in terms of mechanical properties, than the loss of height to span suspension bridge in the role of global design parameters in degraded partial design parameters, while lifting span is also local design parameters.

Fig. 3.70 Wujiang River Bridge.

Fig. 3.71 Lingdingyang Bridge main navigation plan.

7. Self-anchored Suspension Bridge

Second half of the 19th century, Austria Yuesefu·langjin engineers and United States engineer chalisi·bende independently conceived from anchor type hanging bridge looks. Patented Bender in 1867, Rankin’s in 1870, in Poland built a small self-anchored suspension bridge type railway. In 20th century, self-anchored suspension bridge already in Germany. In 1915, Germany Designer on the Rhine river in Cologne built the first large —Cologne Dizzle self-anchored bridge, mainly because of the geological conditions constraints enable engineers chose this type of bridge, the main span of the bridge 185 m, wood scaffolding support beam until the cables are in place.

Since then, the United States, Pennsylvania, Pittsburgh 3 bridges across the Allegheny R. and Japan Tokyo-built Ching Chau Bridge under the influence of Diez bridge in Cologne. Diez 25 years after the completion of the bridge in Cologne in Germany and built 4 suspension bridge on the Rhine river. One of the most famous Cologne Mülheim bridge was built-in 1929, the bridge main span of 315 m, although the bridge was destroyed in 1945, but it so far (2006) still retains its self-anchored suspension bridge span on record. Initially stiffening girder of self-anchored suspension bridge-production

Steel structures, such as traffic in 1990, Japan the flower bridge, Korea wing suspension bridges, Estonia muhudaoqiao as well as the United States old gold mountain- Oakland Bay Bridge, and so on.