基于数字高程模型的山谷地形效应分析*
赵凤仙1,2,郭明珠1,胡海芹1,3,郭云峰4

(1.北京工业大学 建筑工程学院,北京 100124; 2.山东圣翰财贸职业学院,山东 济南 250316; 3.华夏幸福基业股份有限公司,北京 100125; 4.北京城安建设工程检测有限公司,北京 100124)

地形效应; 有限元分析; 数值模拟; 数字高程模型

Research on Terrain Effect of Valley Based on Digital Elevation Model
ZHAO Fengxian1,2,GUO Mingzhu1,HU Haiqin1,3,GUO Yunfeng4

(1.Beijing University of Technology,100124,Beijing,China)(2.Shandong Shenghan Finance and Trade Career Academy,Jinnan 250316,Shandong,China)(3.Huaxia Happiness Base Industry,LTD,100125; Beijing,China)(4.Beijing Construction Enginear Detection Co.LTD,10012

topography effect; finite element analyze; numerical simulation; digital elevation model

备注

采用DEM数据建立基于数字高程模型的三维有限元山谷地形模型,研究了输入不同地震波情况下,山谷地形不同监测点处的动力响应特性。数值模拟结果表明,地形效应对地震动的振幅影响很大,随高程增加振幅幅值不断增大; 山谷地形的顶部加速度峰值大于底部峰值,地形的放大效应在顶部比底部明显; 同时,存在地震波的行波效应,表现为山谷顶部相对于山谷底部的滞后性; 山谷地形对高频段(>10 Hz)的地震波存在滤波作用,对地震波低频段(2～5 Hz)的能量起到放大作用; 山谷地形跨度大小对场地地形效应的数值模拟结果表明,当跨度减小时,峰值加速度放大作用趋于明显,即由地表引起的地形效应,随着跨度的增大逐渐趋于平缓。

The remote sensing data is used to establish the 3D finite element valley terrain model based on digital elevation model.When inputting different seismic waves,the dynamic response characteristic of different monitoring point of valley terrain is studied.The numerical simulation results show that the topographic effect has the great influence on the amplitude of ground motion,and the amplitude increase with the increasing of elevation.The acceleration peak at the top of valley is greater than at the bottom of the valley,the topographic amplification effect on the top is obvious than that at the bottom.Meanwhile,there exit the traveling wave effect of earthquake wave,it perform that the ground motion on the top of valley present hysteretic nature relative to that at the bottom of the valley.The valley topography has the filtering effect on high-frequency(>10 Hz)of seismic wave,and the amplification effect on energy of low-frequency of seismic wave(2～5 Hz).The numerical simulation results about the different span of valley terrain on the site terrain effect show that,when the span reduces,the amplification effect of peak acceleration becomes more obvious.The terrain effect caused by the surface tends to be gentle with the increase of the span.