Seismic Response Analysis Of Hydrodynamic For Cable-stayed Bridge

In recent years, with the constant improvement of transportation network, there are many bridges that in water under construction and proposed in our country.Under the action of earthquake, the lower part of bridge structure under seismic action can cause the water around the structure produce radiation wave motion, and due to the relative motion of the structure and the water, there will produce dynamic water pressure at the bottom of the bridge structure, the dynamic water pressure will not only change the dynamic characteristics of the structure, and will also affect the dynamic response of the structure.Thus realize the dynamic water pressure on dynamic response of cable-stayed bridge structure under earthquake excitation effect, that has the vital significance in the bridge seismic design and seismic safety evaluation.This article’s main research content and conclusions include the following aspects:1. On the basis of the Morison equation, with additional quality to consider the effects of water to the piers and pile foundation, using the finite element software Midas established the east Saudi bridge’s finite element numerical analysis model, respectively analysis the dynamic characteristics of the bridge with or without dynamic water situation, the results show that the dynamic water causes the natural frequency of the cable-stayed bridge decreased.2. To the east Saudi bridge with or without dynamic water situation for the longitudinal and vertical or horizontal and vertical this two kinds of working conditions of response spectrum analysis and time history analysis, the results show that dynamic water has big effect on every key point position of cable-stayed bridge structure’sdisplacement and internal force of the key section.3. Great mass method is used for the east Saudi bridge with or without dynamic water situation to carry on the traveling wave effect analysis, to explore the influence law of non-uniform excitation of cable-stayed bridge, and comparing with the results of the same incentives. The results show that traveling wave effect reduce the structure dynamic response, and the response results consistent with wave velocity increases and gradual approximation of motivation result; When considering the traveling wave effect,with the different apparent wave velocity the dynamic water pressure have different influence on the dynamic response of the bridge structure, in consistent excitation and traveling wave effect this two situation the dynamic water pressure have different influence on the dynamic response of the cable-stayed bridge.4. By set up the viscous damper on the east Saudi bridge, Studied the change of the damping coefficient C and the speed index α on the influence of structure dynamic response of cable-stayed bridge. The results show that by adopting proper dampers parameters, can significantly reduce the cable-stayed bridge’s main tower bottom bending moment and the displacement of each key point position; Considering the main tower bottom bending moment, the key point of the longitudinal displacement and the influence of dynamic water, the damping coefficient of the recommendations will be set to 14000 k N·s/m, speed index is set to 0.35.