强夯激励下黄土边坡动力响应模型试验研究  

Model test study of dynamic responses of loess slope by dynamic compaction

作　　者：龚成明[1,2] 程谦恭[1] 刘争平[3] 

机构地区：[1]西南交通大学地质工程系,成都610031 [2]铁道部工程管理中心,北京100844 [3]西南交通大学土木工程学院,成都610031

出　　处：《岩土力学》2011年第7期2001-2006,共6页Rock and Soil Mechanics

基　　金：国家重点基础研究发展计划(973计划项目)(No.2008CB425801);国家自然科学基金项目(No.50908234)

摘　　要：设计并完成了1:20比尺的黄土边坡大型动力模型试验,探讨了模型试验中的相似律、边界条件处理等问题;研究了强夯激励下黄土边坡的动力特性变化规律与动力响应规律,以及边坡坡率对动力特性和动力响应的影响。试验结果表明,边坡坡率越大,动力响应幅值越大;强夯激励下黄土边坡的动力响应幅值均随冲击荷载作用而产生并迅速衰减;振动周期在1 s之内,主频率在25～45 Hz之间,不会出现振动叠加现象。强夯激励下黄土边坡对径向加速度的放大效应更显著,下部边坡以竖向振动为主,上部边坡以径向振动为主。黄土边坡的边缘部位对强夯冲击振动的反应幅值较之内部存在放大现象。沿坡高方向,边坡对输入加速度具有明显的放大作用,坡顶处的放大效应最为显著。试验结果有助于揭示黄土边坡在强夯激励下的动力响应规律,为黄土地区的工程设计和施工提供有益的参考。This article has accomplished the large model test for 1：20 loess slope, investigated the law of similitude, boundary condition treatment in the model test, studied the change rules of dynamic properties and dynamic response rules for loess slope in dynamic compaction, as well as the dynamic properties and dynamic response rules under the influence of the slope ratio. Results show that the amplitude of dynamic response increased with increasing slope ratio. The amplitude of dynamic response for loess slope in dynamic compaction fades out rapidly with the impact loading effect; the vibration cycle is less than ls and the major frequency is between 25-45 Hz that no superimposed vibration will occur. The amplification effect on radial acceleration is more obvious for loess slope in dynamic compaction; the vertical vibration prevails at lower part of slope while radial vibration prevails at upper part of slope. There is amplification effect for response amplitude on impact vibration of on the ridge of loess slope. There is obvious amplification effect on slope for input acceleration along the slope, especially the most obvious amplification effect at the top of slope. The test results have favorable influence on revealing the rules of dynamic response for loess slope in dynamic compaction, so as to provide instructive reference for the engineering design and construction in loess regions.

关 键 词：强夯 黄土 动力响应 模型试验 

分 类 号：U416.16[交通运输工程—道路与铁道工程]