波浪作用对单柱式桥墩地震反应特性的影响

以ABAQUS有限元软件为计算平台,建立了考虑波浪作用影响的单柱式桥墩-桩-土体系非线性地震反应分析二维有限元模型,土体以四节点实体单元离散,采用土体粘塑性记忆型嵌套面本构模型描述土的动力特性;桥墩以及桩以两节点梁单元离散,采用动塑性损伤模型描述混凝土的动力特性;根据Stokes五阶波浪理论,将基于Morison公式计算所得的波浪力以分布力的形式施加于桥墩之上,比较了静水条件下和考虑波浪作用时不同地震动激励下单柱式桥墩结构的地震反应特性,结果表明:波浪作用的影响使桥墩墩身相对墩底的位移反应、桥墩墩底的剪力和弯矩反应有较明显的增大,但对桥墩墩身加速度反应的影响可忽略不计,波浪作用影响的大小与输入地震动特性有关.在单柱式桥墩的抗震设计中考虑波浪作用的影响是必要的。

Dynamic analysis of a single-column pier underground motion and wave action

This paper presents the 2D finite element analysis using the ABAQUS software to simulate the pier-piles-soil system.In the finite element analysis,the soil is represented as an assembly of 4 node solid elements,and the viscous-plastic memorial nested yield surface model of soil is used to describe its nonlinear;the pier and piles are represented as an assembly of 2 node beam elements,and the dynamic plastic-damage model is used to describe the concrete dynamic character.Based on the Morison's hydrodynamic pressure formula,the wave force is applied to the pier as a distributed load.Both results of the pier's seismic response under combined hydrostatic force and seismic loads and under combined seismic loads and wave action are compared and discussed.The results show that the wave action increases the pier's peak response of relative displacement,shear force and moment obviously,but has slight influence on the acceleration.And the degree of the influence on the pier's seismic response is related to the earthquake wave characteristics.So it is necessary to consider the effect of the wave action on the pier's seismic response.