Experimental Study On Seismic Performance Of Tower Of Deep-water Cable-stayed Bridge Based On Fluid Structure Coupling

In today’s world,with the progress of science and technology and the rapid development of economy,various bridge projects play an irreplaceable role in transportation.Now,in the field of bridge anti-seismic in our country,the problem that bridge structure acts together in earthquake and hydrodynamic pressure is a big difficulty in this field.In this paper,based on the Shuanghe cable-stayed bridge,the shaking table test of the bridge tower model of Shuanghe cable-stayed bridge is carried out,and on this basis,the finite element model of the bridge tower of Shuanghe cable-stayed bridge is numerically simulated,and the dynamic characteristics and dynamic response of the bridge tower model under the earthquake action under different water depth are studied,which is helpful to understand the interaction between the dynamic water pressure and the bridge tower model It provides a reference for the application of the fluid structure coupling effect between water body and bridge tower in practical engineering.The main work of this paper is as follows:(1)Based on the Shuanghe cable-stayed bridge located in the deep-water reservoir area of Baihetan Hydropower Station,a cable-stayed bridge tower model with a scale of1:50 is designed according to the similar theory.The shaking table test of the tower model is carried out under the water depth of 0.0m(no water),0.3m,0.9m and 1.5m.First of all,the whole process of shaking table test of Shuanghe cable-stayed bridge tower model under different water depth is described in detail from the aspects of test model,test equipment and test scheme;then,the test data of bridge tower model under different water depth are analyzed and studied.In the shaking table test,the reduced E1 seismic wave was input along the longitudinal direction + 2 / 3 vertical direction and the transverse direction + 2 / 3 vertical direction of Shuanghe cable-stayed bridge tower model to record the seismic excitation.The dynamic response of the bridge tower model was measured under different water depth,and the dynamic characteristics of the bridge tower model under different water depth,the displacement of the tower top and the strain(stress)of the tower bottom were analyzed.The results show that due to the existence of water around the bridge tower model,the natural frequency of the bridge tower model decreases,the natural vibration period increases,the existence of water around the structure will change the dynamic characteristics of the structure;the existence of water around the bridge tower model will also affect the dynamic response of the bridge tower model,compared with the 0.0m water depth(no water)state,the peak displacement of the longitudinal bridge and the transverse bridge under the 1.5m water depth state is divided The peak values of strain(stress)in longitudinal and transverse directions increased by 39.70% and 14.69% respectively under the condition of 1.5m water depth.In addition,the distribution of hydrodynamic pressure of water around the bridge tower model to the bridge tower model under earthquake excitation is measured in the model test.(2)Based on the shaking table test condition of Shuanghe cable-stayed bridge tower model,the finite element model of Shuanghe cable-stayed bridge tower under the water depth of 0.0m(no water),0.3m,0.9m and 1.5m is analyzed.In order to study the influence of hydrodynamic pressure on the dynamic characteristics and dynamic response of the finite element model of Shuanghe cable-stayed bridge,we input the reduced E1 seismic wave along the longitudinal direction + 2 / 3 vertical direction and the transverse direction + 2 / 3 vertical direction of the finite element model of Shuanghe cable-stayed bridge,and then compare the numerical simulation results with the model shaking table test results to verify the correctness of the model shaking table test results 。 The comparison results show that the numerical simulation results are basically consistent with the model shaking table test results.Under the water depth of0.0m(no water),the average error of displacement peak is 2.4%,and the average error of stress peak is 7.5%.In general,this is reasonable.