场地条件对地表地震动特征的影响  

Effect of Site Condition on Ground Motion Characteristics

作　　者：董菲蕃[1,2] 金丹丹[1,2] 陈国兴[1,2] 

机构地区：[1]南京工业大学岩土工程研究所,南京210009 [2]江苏省土木工程防震技术研究中心,南京210009

出　　处：《防灾减灾工程学报》2013年第6期712-718,共7页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家科技支撑计划项目(2009BAK55B00)资助

摘　　要：以安徽省滁州市地震小区划场地为研究对象，基于ABAQUS显式有限元并行计算平台，采用大尺度二维精细化有限元非线性分析方法，研究了局部地质条件差异对场地地震效应的影响。结果表明：该场地地震动放大效应明显，河漫滩地表PGA放大效应尤为显著；相比一级阶地，河漫滩地表加速度反应谱谱形加宽，谱峰向长周期方向移动，移动幅度约为0．05～0．25S，相应的特征周期增大。地表加速度反应谱呈双峰甚至多峰特征，大尺度场地非线性有限元分析能定性反映出局部地质条件对场地地震效应特性的影响，可为城市地震小区划提供更为合理的科学依据。Based on the explicit FE method and 32 CPU parallel computing cluster platform of ABAQUS, a large-scale refined two-dimensional（2D） FE nonlinear analytical model for seismic micro-zoning site of Chuzhou city in Anhui province is established in the time domain. The influ- ences of local geological conditions with different characteristics on the ground surface seismic re- sponse are emphatically analyzed. The results show that： the peak ground acceleration （PGA） will be amplified compared to the peak acceleration of input motion, the amplification effect of floodplain area presents especially remarkable. It presents a wider acceleration response spectra shape in floodplain area than that in first terrace area, meanwhile the spectra peak moves to a lar- ger period in the floodplain area compared with that in first terrace area and the period difference comes to be from 0.05 s to 0.25 s. Besides the ground surface acceleration response spectra of floodplain area gradually appear a double-peak or multi-peak phenomenon and the corresponding characteristic period increases. In some way, the large-scale nonlinear analysis may reflect the nonlinear seismic response characteristics of the site, which will provide a reasonable basis for the earthquake zoning work of cities.

关 键 词：场地地震效应 局部地质条件 大尺度二维精细化有限元 非线性分析 地表峰值加速度 加速度反应谱 

分 类 号：TU43[建筑科学—岩土工程]