首先,介绍了基于Open Sees独立开发的一套用于挡土墙-土地震反应相互作用有限元分析计算软件RW_2DPS.据此建立了俯斜式混凝土重力挡土墙-土强震相互作用有限元模型.模型中,引入非线性有限元计算方法,选用多屈服面弹塑性本构模型模拟砂土的动力属性,应用零长度接触单元模拟墙与土体之间的接触特性,且采用一致耗能阻尼边界与速度边界条件.最后,输入随机地震动,进行挡土墙-土强震反应分析,并重点探讨墙背地震土压力和水平地震惯性力沿挡土墙高度分布规律.结果表明,墙背动土压力峰值出现在距挡土墙底约1/3墙高处;挡土墙背加速度具有放大效应,加速度峰值出现在挡土墙顶部;不同地震动作用下,加速度放大系数沿墙高分布规律不同,动土压力沿墙高变化规律基本一致.
Firstly,finite element software based on Open Sees,named as "RW_2DPS",which is independently developed and can conduct the seismic response interaction analysis of retaining wall-soil,is introduced. A strong seismic finite element analysis model of inclined concrete gravity retaining wall-soil interaction is established with the aid of this computing platform. In this model,nonlinear finite element analysis method is adopted. The multi-yield surface elastic-plastic constitutive model is chosen to simulate the dynamic properties of sand. Zero length contact element is used to simulate contact characteristic between retaining wall and soil. The consistency dissipative damping boundary is applied to consider lateral boundary effect along the direction of vibration. And velocity boundary of base is used to consider excitation effect on base boundary. At last,random earthquake motions are input on the model base to conduct the seismic response analysis of retaining wall. What is more,gravity retaining wall seismic earth pressure and horizontal seismic inertial force distribution characteristics along wall height are discussed emphatically. It is shown that the of dynamic earth pressure appeared in a third of the wall height. Retaining wall back acceleration present amplification effect,acceleration peak appear at the wall top. Under the action of different ground motions,factor distribution of horizontal acceleration amplification along wall height is different,but dynamic earth pressure peak distribution along wall height is basically consistent.