降雨诱发浅表层黄土滑坡机理实验研究

发布时间：2018-02-25 19:41

本文关键词： 黄土斜坡降雨滑坡物理模型实验孔隙水压力　出处：《工程地质学报》2017年05期 　论文类型：期刊论文

【摘要】：黄土较松散,内部大孔隙和垂直节理发育,因其特殊的结构为雨水的快速入渗提供了通道。降雨型黄土浅层滑坡已造成了大量的经济损失与人员伤亡。为了有效减轻降雨诱发黄土滑坡对社会和经济的影响,开展降雨型滑坡室内实验研究,具有重大的现实意义。本文旨在研究不同降雨形式和不同坡体结构对黄土斜坡变形破坏过程影响,设计并进行了3组室内物理模型实验,分别为持续强降雨斜坡实验、持续强降雨斜坡(带垂直节理)实验和间歇性强降雨斜坡实验,且每组斜坡内埋设体积含水率传感器、基质吸力传感器和孔隙水压力传感器3种传感器记录其内部变化。通过对每一个黄土斜坡体内传感器的读数变化及实验现象进行分析,同时对不同实验条件下实验过程及结果进行对比,进而得出降雨条件下浅表层黄土滑坡的变形破坏规律,总结出该类滑坡的破坏模式及其诱发机理。实验前期,随着体积含水率不断增大,基质吸力逐渐减小至基本稳定,土体强度随之减小,实验后期上部土体饱和,斜坡产生的变形和土体排水不畅产生了超孔隙水压力,有效应力随之减小,土体强度减小至最小,导致滑坡产生。同时,坡体结构对斜坡稳定性的影响大于降雨形式的影响。
[Abstract]:Loess is looser, with internal macropores and vertical joints developed, Because of its special structure, it provides a passage for Rain Water's rapid infiltration. Rainfall loess shallow landslide has caused a lot of economic losses and casualties. In order to effectively reduce the impact of rainfall induced loess landslide on society and economy, It is of great practical significance to carry out indoor experimental research on rainfall landslide. This paper aims to study the influence of different rainfall forms and different slope structures on the deformation and failure process of loess slope, and designs and carries out three sets of indoor physical model experiments. The experiments are continuous heavy rainfall slope experiment, continuous heavy rainfall slope experiment (with vertical joint) and intermittent heavy rainfall slope experiment. Three kinds of sensors, matrix suction sensor and pore water pressure sensor, recorded their internal changes. At the same time, the experimental process and results under different experimental conditions are compared, and then the deformation and failure law of shallow loess landslide under rainfall condition is obtained, and the failure mode and induced mechanism of this kind of landslide are summarized. With the increasing of volume water content, the suction of the matrix decreases to the basic stability, the strength of the soil decreases, the upper part of the soil is saturated, the deformation of the slope and the poor drainage of the soil result in the excess pore water pressure. The effective stress decreases and the soil strength decreases to the minimum, which leads to the landslide. At the same time, the influence of slope structure on slope stability is greater than that of rainfall form.
【作者单位】：中国地质科学院地质力学研究所;成都理工大学地质灾害防治与地质环境保护国家重点实验室(成都理工大学);中国地质大学(北京)地球科学与资源学院;
【基金】：国家自然科学基金项目(41472296) 中国地质调查项目(DD20160271)资助
【分类号】：P642.22

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