行波激励下防波堤地震动力响应分析

考虑到行波效应对防波堤地震动力响应的影响,建立了基于弹塑性本构的防波堤-地基系统三维有限元模型。分析中考虑了结构间的动态接触作用,并采用基于接触负载均衡的显式并行计算方法,解决了大规模非线性有限元问题的求解困难。计算给出了不同视波速下行波效应对防波堤挡浪墙沉降、防波堤残余变形以及挡浪墙截面弯矩的影响程度及规律。结果表明:挡浪墙震后沉降随视波速增大而增大,并逐步逼近一致激励响应;行波效应对防波堤残余变形模式几乎没有影响,行波激励与一直激励下所得的残余变形模式基本一致,横波地震动输入下引起的震后残余变形要大于纵波输入下的残余变形;多数情况下,行波激励下的挡浪墙弯矩会比相应的一致激励下的响应大。分析方法及结果为防波堤三维整体抗震设计提供了参考。

Seismic dynamic response analysis of breakwater under traveling wave excitations

Three-dimensional finite element model of breakwater-ground system is established for calculating the influence of traveling wave excitation based on elastoplastic constitutive model. Considering the dynamic breakwater-soil interaction, the model is solved by supercomputer based on contact balanced algorithm for explicit parallel computing. The difficulty of calculating the large-scale nonlinear finite element problems is solved based on this method. The settlement of wave barrier, the permanent deformation of breakwater and the bending moment of wave barrier under different wave velocities are researched. The results show that when considering the wave travelling effect of ground motion，the settlement of wave barrier increases with the wave velocity increasing, and gradually approaches the response of uniform excitation. The travelling wave effect has little effect on the residual deformation mode of breakwater, and the deformation mode under different wave velocities are almost the same. The permanent displacement of breakwater under SH wave excitation is bigger than the one under P wave excitation. In most cases, the bending moments of wave barrier under nonuniform excitation are bigger than ones under uniform excitation. The results are valuable for the choice of aseismic measures for breakwater.