Load Test Research Of Cable-Stayed Bridge With Long Span

The appearance of cable-stayed bridge injected new vigour to the world bridges. Now, cable-stayed bridges are being designed to the direction of long span because of its spanning ability and other advantages. Load test is an important testing method, which can provide advantageous and immediate references for administrators to evaluate load carrying capacity and the service state of complete bridge. Especially for the new structures, bridge design theory and working state.it can provide valid actual data. Based on the methods of modern bridge design, finite element, random vibration, vibration testing and analysis technology, this thesis studies and designs the load test plan of a home Cable-stayed with long span bridge by summarizing the load test plans of some concerned bridges.Through the theoretical analysis of the bridge, this thesis makes sure the controlling load and loading case under the condition of ensuring the load test efficiency. Tests the deflection of the beam and the tower, the change of tension of the cables, and the stress of the beam and the tower under static loads. The test results indicate that the beam and tower work at elastic state under the normal applying load. The design of the structure is rational, and has enough strength and stiffness, satisfying the designed request.Theoretical mode analysis is made by establishing finite element model with software ANSYS, concluding natural vibration frequency and mode shape. Under dynamical loads, the natural vibration and damping ratio of the structure is tested, and the impact of the passing vehicles is analyzed.The comparison between actual results and those in theory indicates that the bridge is qualified with satisfactory dynamical behavior.