Dynamic Characteristics And Aseismic Behavior Analysis For Cable-stayed Bridge With Twin Towers And Single Central Cable Plane

Cable-stayed bridge is a combination structure system bridge, which has the pressure of the tower, the tension of the cable and bending of beam. In the new era of the 21 st century, bridge engineers are constant breakthrough in the technology of building a bridge and people also pay attention to the beautiful of a bridge more and more. At the same time, the cable-stayed bridge has a special position in the bridge for its superior spanning capacity and unique modeling, and the cable-stayed bridge still has great potential for development in the future. However, as the earthquake disaster of the world occurs frequently, the broken cable-stayed bridge leads to the irreparable life and property loss in the earthquake disaster. Therefore, it’s very urgent to analysis of the dynamic characteristics of a bridge structure in the earthquake zone and to conduct the aseismic protection effectively.Based on a cable-stayed bridge with twin towers and single central cable plane in this paper, firstly, it introduces the development status of cable-stayed bridge at home and abroad, focusing on listing some historic cable-stayed bridge in our country. Secondly, it summarizes the different system by different connection of the tower, the pier and the beam. It also introduces the earthquake damage of the bridge, aseismic design research status and the aseismic analysis method of the bridge.In the thesis, the bridge model is built by using large-scale general commercial software Midas Civil 2012. In the model, tower, piers, beam, pile caps and pile foundations are using beam element to simulate, but the stay-cable is using the truss element to simulation. On the basis of the completion of the model, the thesis analyzes the dynamic characteristics of the cable-stayed bridge in steel structure system and the half floating system, which is using the response spectrum method and seismic time history analysis. It details the form and graphics of the previous section vibration modes. By comparing the two kinds of system’s vibration mode characteristics and the aseismic performance of cable-stayed bridge, we can sum up the conclusion: the cable-stayed bridge can meet the aseismic requirements under the two kinds of system. But considering the structural safety reserve and economy and so on, the half floating system is more beneficial for the structure aseismic. However, it is important to pay special attention to the control of displacement in the earthquake.