悬索桥英文词汇.docxVIP

2 Description and modeling of the bridgeBeing a type of multi-tower suspension bridge, the TaizhouYangtze River Bridge is longest in the world with the dualmain spans reaching 1080m. As shown in Fig.1, the bridgeconsists of three towers, making two main spans (1080m) andtwo side spans (390m). The sag-span ratio of cable is 1/10, andthe transverse spacing between the two main cables is 35.6m.The streamlined steel box girder is 3.6m high and 36.9m wide.Of the three towers, two side-towers are made of concrete witha height of 178m. The tower located in the middle is 192m inheight and constructed with steel. All the towers are doorshapedin the transverse direction. But in the elevation view,the middle tower differs from the two side-towers with aninverted Y-type.Fig. 1.Taizhou Yangtze River BridgeThe computer program SAP2000 is used to establish a 3Dfinite element analytical model of the bridge. The steel girder,as well as the towers, is idealized as 3D beam elements, and thehangers and the cables are modeled using 3D bar elements. Inconsidering the nonlinear behaviors, effects of axial forceunder dead load on structural components’ geometricalstiffness are incorporated in the model. The girder is connectedby an elastic spring to the mid-tower but remains relatively freeat the side-towers in the longitudinal direction. In thetransverse direction, however, the girder is constrained to allthe three towers. The 3D finite element analytical model ofTaizhou Yangtze River Bridge is shown in Fig.2.1/2/of the bridge site is carried outby Jiangsu Earthquake Bureau. According to the analysis, theseismic fortification intensity of the bridge site is assessed tobe 7 degree and the peak ground acceleration is 1.65m/s2：地震设防烈度为7度Fig.3presents one of these three pieces of horizontal groundaccelerations.3/4.1 Seismic demands on structure componentsFor Taizhou Yangtze River Bridge, a multi-tower suspensionbridge with large spans, nonlinear time history analysis methodcould be most proper