Study On The Seismic Response Of Concrete Piers In Deep Water Considering Influence Of Moisture Content

More and more construction of deep-water bridge makes seismic design of bridges in deep water become an urgent research topic. In this paper, emphasis is focused on the impact of hydrodynamic pressure and moisture content on seismic responses of deep water piers and the factors associated with the impact level.Frequent appearance of deep-water bridge makes seismic design of bridges in deep water become an urgent research topic. In this paper, emphasis is focused on the impact of hydrodynamic pressure and moisture content on seismic responses of deep water piers. Meanwhile, the factors associated with the impact level are analyzed.Based on the analysis of impact of moisture content on physical and mechanical properties of concrete, two-class pore soften mixture model is applied to calculate elastic modulus and gravity density of saturated concrete, and then the finite element model is established to calculate the impact of moisture content on seismic response of bridge piers in deep water.The Morison Equation is used to analyze hydrodynamic pressure where the water is considered as the added mass. The dynamic properties and seismic responses of the concrete pier in deep water are analyzed considering the hydrodynamic pressure. And based on analysis in the previous, considering the impact of moisture content changes on mechanics parameters, the seismic responses of the concrete pier in deep water are analyzed by using the finite method with the moisture content and the hydrodynamic pressure taken into account comprehensively.The results show that:(1) Elastic modulus and gravity density of concrete increase with the increase in moisture content. (2) Increase in elastic modulus and gravity density of saturated concrete will increase the stiffness of the pier, which causes the displacement of pier crown decrease and make the internal forces of pier bottom increase due to the influence of moisture content. So, it is necessary to consider the impact of moisture content. (3) In the earthquake, because of the role of hydrodynamic pressure, both the displacement of pier crown and the internal forces of pier bottom increase significantly due to the influence of hydrodynamic pressure. As a result of the effect of rectangular shape, the impact of hydrodynamic added mass on the deepwater pier seismic response in different directions has certain differences, which verify the necessity to consider hydrodynamic pressure for seismic design of bridge piers in deep water. (4) When comprehensively considering of the role of moisture content and hydrodynamic pressure, the overall effect of the water on the pier in deep water is not the simple sum of effects of two factors acting alone. (5) The impact level of moisture content and hydrodynamic pressure on the seismic response of bridge piers has relations to calculation direction, calculation item, the quality on pier, water depth and so on.