悬臂抗滑桩加固堆积型滑坡地震响应离心模型试验研究  

Centrifugal model test on seismic response of colluvial landslide reinforced by cantilever anti-slide pile

作　　者：涂杰文[1] 刘红帅 汤爱平[1] 郑桐[3] 

机构地区：[1]哈尔滨工业大学土木工程学院,黑龙江哈尔滨150090 [2]地壳运动监测工程研究中心,北京100036 [3]中国地震局工程力学研究所,黑龙江哈尔滨150080

出　　处：《岩石力学与工程学报》2016年第A01期2925-2934,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(41172293)~~

摘　　要：为研究悬臂抗滑桩加固堆积型滑坡的地震响应、抗滑桩桩后动土压力和桩身弯矩分布规律,设计完成50倍重力加速度条件下的悬臂抗滑桩加固堆积型滑坡离心振动台模型试验。试验过程中,采用汶川地震清溪台站反演的基岩波作为基底输入,不断增大输入地震波的幅值,通过监测滑坡不同位置加速度响应、抗滑桩桩后动土压力和桩身应变研究不同强度地震动作用下悬臂抗滑桩加固堆积型滑坡的抗震性能。试验结果表明:滑坡土体中加速度响应随高程增加而增大,趋于坡顶时放大效果最大,具有明显的高程放大效应,而滑坡坡面处呈现浅表放大效应;抗滑桩加固使滑体土体响应受到一定限制;桩后动土压力随着地震动的输入迅速增大至峰值,此后保持稳定形成残余动土压力作用于抗滑桩上;抗滑桩各截面动弯矩呈现出凸形分布规律,弯矩最大值出现在基岩面附近处;桩后动土压力和桩身动弯矩均随着地震动强度的增大而增大。所得到的成果为边坡悬臂抗滑桩抗震设计提供良好的基础。Centrifuge shaking table model test of colluvial landslide reinforced by cantilever anti-slide pile was designed and carried out on a centrifuge shaking table at 50 gravitational accelerations in order to research its seismic response, the distribution regularity of dynamic soil pressure after pile and dynamic bending moment of the anti-slide pile. During the processing of the model test, bedrock wave（Qingxi wave） was inputted from the bottom of the model by scaling the amplitude of the input seismic wave. The seismic performance of colluvial landslide reinforced by cantilever anti-slide pile under earthquakes of different intensities is studied by monitoring the acceleration response of landslide at different positions, the dynamic soil pressure after pile and the strain of the anti-slide pile. Results show that the acceleration response of landslide increases with the increasing height of landslide. The landslide shows an obvious elevation amplification effect, i.e., the increasing rate of the peak ground acceleration（PGA） amplification coefficients becomes notably larger approaching the slope crest, and the acceleration response characteristic of the landslide surface shows the surface effect under earthquake. The dynamic response of the soil is restricted by anti-slide pile to a certain degree. The dynamic soil pressures after pile rapidly increase to peak value and then keep roughly stable along with the excitation of earthquake motion. And they will form dynamic soil pressures to act on the anti-slide pile. The maximum dynamic bending moment of the pile appears near the bedrock surface, which the distribution rule reflects the convex form. Both the dynamic soil pressure after pile and dynamic bending moment of the pile will increase with the increasing the strength of seismic wave. The results provide a good foundation for seismic design of the cantilever anti-slide pile.

关 键 词：工程地质 悬臂抗滑桩 堆积型滑坡 离心振动台 地震响应 

分 类 号：P642[天文地球—工程地质学]