摘要
采用勒让德(Legendre)谱元法,结合动力学有限断层破裂理论,对一邻近隐伏发震断层的山体进行三维地震动模拟分析,获得山体表面加速度、速度、位移响应时程和加速度反应谱。结果表明:(1)加速度方面,60°倾角倾滑逆断层作用下,山体背向断层一侧的PGA明显大于迎向断层一侧;对90°直立型断层情况,山体背向断层一侧的水平向PGA同样明显大于迎向断层一侧,但对于竖向PGA分布,该现象不明显;倾滑断层作用下最大PGA一般均出现于山顶附近,60°倾角逆断层情况下山顶PGA可达山脚平坦位置的5倍左右,而垂直断层情况下则放大2~3倍,同时山体表面多处产生竖向峰值大于水平向峰值的现象;加速度反应谱显示场地山顶处卓越周期明显长于其他位置。(2)速度方面,山体表面各观察点位在时程上表现出单向和双向长周期大脉冲特性,反映出明显的方向性效应。
By using Legendre spectral element method(SEM)and combining finite fault theory,seismic response of a mountain near a buried seismogenic fault was analyzed. The response time-history and acceleration response spectrum of acceleration,velocity,displacement at observation points on the mountain were obtained. For the spatial position relationship of the fault and mountain in the presented example,the results show that under the action of 60° dip-slip thrust faults,the peak ground acceleration( PGA)on the side of the mountain which is far from the fault is obviously larger than that near the fault. And under the action of 90° vertical faults,the horizontal PGA distribution is similar to that in the former case,but for the vertical PGA distribution,this phenomenon is not obvious. Under the action of dip-slip faults,the maximum PGA usually occurs near the top of the mountain. For 60°dip-slip thrust faults,the maximum PGA that appears at the top of the mountain can reach about 5times that at the foot of the mountain,while under the action of vertical faults,the maximum PGA can be magnified 2-3 times. Meanwhile,there are several places where the vertical peak value is larger than the horizontal peak value. And the acceleration response spectrum shows that the predominant period at top of the mountain is obviously longer than that at other places. In terms of velocity,the time histories at the observation points on the mountain show the characteristics of unidirectional and bidirectional long-period large pulses,reflecting an obvious directivity effect.
作者
冯广军
刘中宪
陈頔
黄磊
李程程
刘国瑞
FENG Guangjun;LIU Zhongxian;CHEN Di;HUANG Lei;LI Chengcheng;LIU Guorui(Tianjin Chengjian University,Tianjin Key Laboratory of Civil Structure Protection and Reinforcement,Tianjin 300384,China;China Energy Engineering Group Tianjin Electric Power Design Institute Co.,Ltd.,Tianjin 300372,China)
出处
《防灾减灾工程学报》
CSCD
北大核心
2022年第4期778-787,共10页
Journal of Disaster Prevention and Mitigation Engineering
基金
国家自然科学基金项目(51878434)
天津市杰出青年基金项目(19JCJQJC62900)
天津市科技重大专项与工程(18ZXAQSF00110)资助。
关键词
谱元法
隐伏断层
有限断层
动力学模型
山体
地震动
spectral element method(SEM)
buried fault
finite fault
dynamic model
mountain
ground motion
