深圳老街地铁车站自由场地地震动力特性数值分析  

Seismic Numerical Analyses of Free Field around Shenzhen-laojie Subway Station

作　　者：崔春义[1,2] 孟坤[1] 梁志孟 朱江山[1] 杨刚[1] 

机构地区：[1]大连海事大学土木工程系,辽宁大连116026 [2]北京工业大学建筑工程学院,北京100124

出　　处：《沈阳建筑大学学报（自然科学版）》2016年第6期1008-1016,共9页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金面上项目(51578100);中央高校基本科研业务费项目(3132014326;3132016216)

摘　　要：目的探讨场地类别差异对峰值加速度和反应谱卓越平台值的影响.方法建立深圳某地铁车站自由场地动力有限元数值模型,采用Lanczos特征值法提取自然频率与振型,通过Newmark逐步积分方法,求解考虑几何和材料非线性的动力平衡方程,并在此基础上,针对地震力作用下自由场地,进行了动力固有特性和动力响应时程分析.结果该场地在以淤泥质土、砂质黏土为主软土层内,频宽变窄,极值谱幅增大,6Hz以上高频成分谱值显著减弱,频谱分布呈现典型的软土双峰特征;在以粗砂、人工填土为主的土层双峰特征变弱,卓越平台幅值增大.结论该自由场地地震动频谱和加速度谱呈现出低频放大、高频过滤典型中软场地地震动特征.In order to discuss the effect of field difference on peak acceleration and spectrum values of seismic response, dynamic numerical analyses of the free field around shenzhen-laojie subway station with both dynamic characteristics and step-by-step integration methods are conducted by u- sing Lanczos eigenvalue extraction technique to obtain natural frequencies and modes, and by Ne- wmark implicit method to solve dynamic equations based on considering geometric and material nonlinearity. The computational results show that the distributions of frequency spectrum for the soft layer of silty soil and sandy clay display typical twin peak feature and the spectrum values cor- responding to high frequency content decrease apparently. Furthermore, the twin peak feature of frequency spectrum for the layer of coarse sand and artificial fill is not clear, and the spectrum am- plitudes of peak platform corresponding to dominant frequency content increase comparatively. Therefore, both seismic frequency spectrum and acceleration spectrum of the free field show typical seismic characteristics of medium-soft field.

关 键 词：自由场地 时程分析 地震作用 频谱 

分 类 号：TU473[建筑科学—结构工程]