基于有限差分法的非饱和砂土层地震反应研究  

Seismic Response of Unsaturated Sand Layer Based on Finite Difference Method

作　　者：邬俊杰 咸甘玲 刘娟 兰景岩 WU Junjie;XIAN Ganling;LIU Juan;LAN Jingyan(College of Civil Engineering and Architecture,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin 541004,China;Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China)

机构地区：[1]桂林理工大学土木与建筑工程学院,广西桂林541004 [2]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004 [3]中国地震局工程力学研究所,黑龙江哈尔滨150080

出　　处：《洛阳理工学院学报（自然科学版）》2023年第3期17-21,25,共6页Journal of Luoyang Institute of Science and Technology：Natural Science Edition

基　　金：国家自然科学基金项目(52168067);广西自然科学基金项目(2021GXNSFAA220017)。

摘　　要：利用有限差分法建立非饱和砂土层-基岩的自由场模型,分别在水平向和竖直向天然地震动输入条件下,分析非饱和砂土层的饱和度对地震反应分析结果的影响,通过计算分析地震动峰值和反应谱等参数,初步揭示非饱和砂土层对地震动响应规律。饱和度变化影响土体剪切模量和体积模量而导致场地地表峰值加速度出现差异;加速度反应谱方面,饱和度较大的工况加速度反应谱峰值到达周期会出现滞后现象;加速度反应谱峰值大小以及到达峰值周期时长受地震波输入方向和饱和度共同影响。A free field model of unsaturated sand layer-bedrock is established by using the finite difference method.Under the conditions of horizontal and vertical input of natural ground motion,the saturation degreeof the unsaturated sand layer on seismic response analysis results is analyzed.By calculating and analyzing the peak value of ground motion and response spectrum,the response law of unsaturated sand layer to ground motion is preliminarily revealed.The results show that the saturation degree affects soil shear modulus and bulk modulus.In terms of the acceleration response spectrum,the peak arrival period of the acceleration response spectrum will be delayed under the condition of high saturation.The peak value of the acceleration response spectrum and the peak time are affected by the input direction and saturation of the seismic wave.

关 键 词：非饱和砂 有限差分法 饱和度 场地效应 

分 类 号：P315[天文地球—地震学]