汶川地震中土石坝地震灾变过程三维再现

Three-dimensional reappearance of the earth-rock dam disaster process in Wenchuan earthquake

基于三维地质建模软件GoCAD和数值分析软件FLAC3D,在编制接口程序和二次开发的基础上,建立了汶川地震中典型震损土石坝及其周围局部场地的三维复杂分析模型。通过共振柱和动三轴试验给出了模型材料的模量和阻尼比随动应变幅值的变化曲线,利用滞后阻尼实现了变模量和阻尼比的土石坝三维弹塑性灾变过程模拟。数值模拟和震后现场调查结果吻合较好,表明本文考虑局部地形效应的三维弹塑性建模方法是模拟土石坝地震破坏过程的有效方法。

This paper presents a method of 3D reappearance of earth-rock dam disaster process under earthquakes.This method is based on an interface program and secondary development of the 3D geological modeling software GoCAD and analysis software FLAC3D.Using the method,we developed a complex 3D numerical model for a typical earth-rock dam which was damaged seriously in the Wenchuan earthquake,along with its surrounding sites.Experimental data of resonant column tests and cyclic triaxial tests were adopted to determine the curves of the dam materials＇ modulus and damping ratio that vary with dynamic strain amplitude,and a good agreement of the simulations with field test data was obtained.The present work shows that the proposed method is effective in simulating the 3D elastic-plastic disaster process of earth-rock dam under earthquakes,and its consideration of local site effects is sufficient.