地震作用下含软弱夹层顺层岩质边坡表面放大效应研究  

Surface Amplification Effect of Bedding Rocky Slope with Weak Interlayer under Earthquake

作　　者：冯志仁[1] 刘红帅[1] 于龙 

机构地区：[1]中国地震局地震工程与工程振动重点实验室、中国地震局工程力学研究所,哈尔滨150080 [2]黑龙江省水文地质工程地质勘察院,哈尔滨150040

出　　处：《防灾减灾工程学报》2014年第1期96-100,共5页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金研究项目(40702055)资助

摘　　要：为了研究地震作用下含软弱夹层顺层岩质边坡表面的放大效应,借用FLAC3D软件,建立了含软弱夹层顺层岩质边坡动力分析数值模型;在合理考虑地震动输入、边界条件、网格划分与模型参数的基础上,分析了地震动峰值、频率、持时以及初动方向等因素影响下的边坡表面放大效应。研究结果表明:①地震动峰值、频率和初动方向对边坡表面放大效应的影响较显著,而地震动持时对边坡表面放大效应的影响微小;②随着地震动峰值的增加,放大效应由软弱夹层之上的坡面及坡顶面向坡肩点逐渐增大,坡肩点的放大效应最大;③当输入地震动频率小于边坡的自振频率时,边坡表面加速度放大倍数较小,且频率越小,放大倍数越小,当输入地震动频率大于边坡的自振频率时,边坡表面加速度放大倍数较大,且频率越大,放大倍数亦越大。This paper deals with the surface amplification effect of bedding rocky slope with weak interlayer under action of earthquake. Software FLAC3D was employed to establish a numerical model with consideration of earthquake input, boundary condition, mesh divison and model pa- rameters. The effects of peak value, frequency, duration and initial direction of earthquake on the surface amplification were analyzed and discussed. The results shown that, （1） the peak val- ue, frequency and initial direction of earthquake ground motion play a significant role in the sur- face amplification effect of rocky slope, while the duration of earthquake play a small role. （2） With increase of peak value of ground motion and the height of slope, the amplification factor in- creased, especially in the top corner. （3） When the frequency of ground motion is smaller than the natural vibration frequency of slope, the amplification factor of surface of slope decrease. However, when the frequency of earthquake is greater than the natural vibration frequency of slope, the amplification factor is greater and increases with increase of frequency.

关 键 词：软弱夹层 岩质边坡 地震 加速度放大效应 数值模拟 

分 类 号：P315[天文地球—地震学]