液化土层对地表位移谱的影响  

Effect of liquefied soil layers on surface displacement spectra

作　　者：孙锐[1] 袁晓铭[1] 陈龙伟[1] 曹振中[1] 

机构地区：[1]中国地震局工程力学研究所,黑龙江哈尔滨150080

出　　处：《世界地震工程》2009年第3期1-7,共7页World Earthquake Engineering

基　　金：国家科技支撑计划项目(2006BAC13B02);国家自然科学基金重大研究计划项目(90715017);国家自然科学基金项目(50778165);国家"973"项目(2007CB714201)

摘　　要：通过现场地震记录分析和理论计算，研究了液化土层对地表位移谱的影响规律，提出了液化位移增量谱和液化修正位移谱。对比了美国Superstition Hills地震和日本阪神地震中液化场地加速度时程和位移时程，分析了液化和非液化场地位移谱区别。采用改进的一维有效应力分析方法，计算了在不同强度和波型地震波输入下厚度和埋深不同的液化砂层对地表位移谱的影响。结果表明：液化对地表位移和位移谱有显著放大作用，位移谱在1s左右开始增大，加震最显著频段为1—5s，谱位移增加0．1～0．7m，烈度8度时平均加震增幅0．1～0．25m，9度时平均增幅0．4～0．7m。The effects of liquefied soil layers on surface displacement spectra are investigated, and the incremental displacement spectra and revised displacement spectra due to liquefaction are presented in terms of earthquake re- cords and theoretical analysis. The surface acceleration and displacement histories in the liquefied sites of the Su- perstition Hills of USA and the Kobe Earthquake of Japan are compared and the difference of the displacement spectra for the liquefied and the non-liquefied sites are identified. Also, by the modified effective stress method, the effects of the liquefied sand layers with different depth and thickness under the input of seismic waves with dif- ferent intensities and different forms on the displacement spertra are investigated. The results indicate that the liq- uefied soil layers show significant amplification on the surface displacement spectra. The amplification is started at ls and the most amplification period range is 1 -Ss by increasing of 0.1 -0.7m for spectrum displacements. The spectrum displacements increase by 0.1 -0.3m and O. 4 -0.7m for the intensity Ⅷ and the intensity Ⅸ ,respec- tively.

关 键 词：液化 地表位移 位移谱 增量谱 修正谱 

分 类 号：TU435[建筑科学—岩土工程] P315.98[建筑科学—土工工程]