陡坎地形对地面运动的影响  

Effects of scarp topography on seismic ground motion

作　　者：丁海平[1,2] 朱容初[1] 宋贞霞[1] 

机构地区：[1]苏州科技学院江苏省结构工程重点实验室,江苏苏州215011 [2]中国地震局工程力学研究所,黑龙江哈尔滨150080

出　　处：《地震工程与工程振动》2013年第5期28-32,共5页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(51278323)

摘　　要：局部不规则地形对地震地面运动有很大影响。本文针对陡坎地形,采用数值模拟方法,探讨了不同坡角情形下,垂直入射不同SV波时陡坎地形对陡坎上侧(坡顶)和陡坎下侧(坡底)的影响程度和影响范围。结果表明:(1)陡坎上侧的放大系数大于水平自由地表,陡坎下侧的放大系数则小于水平自由地表;(2)x方向,随着坡角的增大,陡坎上侧的放大系数也增大,而陡坎下侧的放大系数随之减小;z方向,随着坡角的增大,陡坎上、下侧的放大系数都增大;(3)坡角发生变化时,陡坎下侧的影响范围基本不变,而在陡坎上侧,影响范围随坡角的增大有少许增加;(4)由于陡坎的存在,场地表面z方向出现了振动,放大系数随着坡角的增大而增大,放大系数与输入波有关,但是,x方向的放大系数受输入波的影响很小。Local irregular topography has a great impact on earthquake ground motion. For scarp topography, using numerical simulation method,we discuss the influence extent and scope of the scarp terrain on scarp＇ s upside and downside ground motion in case of different vertical incident SV waves. The results show that ： （ 1 ） The amplifica- tion factor of scarp＇ s upside region is greater than that of the free surface, while the amplification factor of scarp＇ s downside part is less than that of the free surface ; （2） When the slope angle increases, for x direction, amplifica- tion factors of the scarp upside also increase, while the downside part decrease with it; for z direction, both of the upside and downside amplification factors will increase; （3） When the slope angle changes, the influence scope of scarp＇ s downside part is almost unchanged, but for the upside part, it slightly becomes greater with the increase of slope angle; （4） Due to the existence of the scarp, the z direction ground motion appears at the surface. Its ampli- fication factor increases for waves. However, larger input wave slope angle, and the peaks of the surface responses are related with incident has little effects on the x direction amplification factors.

关 键 词：陡坎地形 地面运动 放大系数 垂直入射地震波 

分 类 号：P315.3[天文地球—地震学]