堆积层斜坡地震动地形效应试验研究

发布时间：2018-01-26 21:39

本文关键词： 边坡工程地形效应振动台模型试验动力响应加速度响应峰值　出处：《岩石力学与工程学报》2017年03期 　论文类型：期刊论文

【摘要】：地震中已经观测到斜坡的地震响应会受地形的影响。因此,在划分堆积层斜坡坡面类型的基础上,开展不同坡形振动台模型试验。试验结果表明:输入强度较强的地震波时,斜坡表面加速度响应峰值放大系数大于斜坡内部,且斜坡中上部及表面曲率变化较大处(AC2)加速度放大效应更为显著。坡形的变化影响着斜坡自振频率,表现为上凸下凹型斜坡的自振频率接近于5 Hz,其他坡形斜坡接近于10 Hz。模型破坏的临界加速度阈值为500~700 Gal与斜坡稳定性计算结果基本一致。坡形影响斜坡的滑动面位置及厚度,曲率半径越大(凸型为正、凹型为负)的坡形滑动面厚度越大。滑动距离(与坡脚的距离)量测显示:直线型和上凹下凸型斜坡滑动距离最远危害范围大,凸型和上凸下凹型斜坡运动距离较远危害范围较大,凹型坡运动距离较近危害范围较小。因此,直线型和上凹下凸型斜坡的危险性(危害性)最高,凸型和上凸下凹型斜坡危险性较高,凹坡危险性最低。本研究的意义在于加强地震力作用下地形效应对斜坡稳定性研究的认识,为防灾减灾和灾害风险评价提供科学依据。
[Abstract]:It has been observed that the seismic response of slopes is affected by topography. Therefore, based on the classification of slope types of accumulative layers. The test results show that the peak magnification factor of the acceleration response of the slope surface is larger than that of the slope interior when the seismic wave with strong input intensity is input. In addition, the acceleration amplification effect of AC2) is more obvious where the curvature of the upper and middle parts of the slope varies greatly, and the slope shape affects the natural vibration frequency of the slope. The natural frequency of the slope is close to 5 Hz. Other slope slopes are close to 10 Hz. The critical acceleration threshold of failure of the model is 500,700 Gal, which is basically consistent with the results of slope stability calculation. The slope shape affects the sliding surface position and thickness of the slope. The larger the radius of curvature (positive convex and negative concave), the greater the thickness of slope slip surface. The measurement of sliding distance (distance between slope foot and sliding distance) shows that the sliding distance of straight line slope and concave convex slope is the farthest harm range. The distance between convex slope and concave slope is larger, and the distance between concave slope and convex slope is smaller. Therefore, linear slope and concave convex slope are the most dangerous. The risk of convex and concave slope is higher, and the risk of concave slope is the lowest. The significance of this study is to strengthen the understanding of the topographic effect on slope stability under the action of seismic force. To provide scientific basis for disaster prevention and mitigation and disaster risk assessment.
【作者单位】：中国科学院山地灾害与地表过程重点实验室;中国科学院水利部成都山地灾害与环境研究所;东京大学土木工程系;
【基金】：国家自然科学基金资助项目(41301009,41471429) 中国科学院STS项目(KFJ-EW-STS 094)~~
【分类号】：P642.27
【正文快照】： 1 引言滑坡与坡形的关系密切,适度的坡形产生滑坡的几率更高。在大环境中,地貌条件可以大体控制滑坡的分布规律、规模和发育趋势。具体滑坡则是由斜坡形状决定[1]。影响斜坡地震动响应的因素很多,其中地形效应是影响高山峡谷地区堆积层斜坡稳定性的主要因素之一[2],目前国

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