灌溉作用下浅表层黄土滑坡变形破坏机理实验研究

发布时间：2018-10-09 09:45

【摘要】：为有效减少泾阳地区大面积灌溉活动诱发黄土滑坡对社会和经济带来的巨大损失,开展灌溉型滑坡室内实验研究,研究坡度在灌溉条件下对黄土滑坡变形破坏过程影响,具有重大的现实意义。本次实验设计了可用于坡顶和坡面的灌溉装置,同时进行了45°斜坡和60°斜坡的两组室内灌溉模型实验,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三种传感器记录其内部变化。通过对两组实验过程及结果进行对比分析,进而得出灌溉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。实验结果表明,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,坡度越大,滑坡越易发生,滑面深度和滑动距离越小。
[Abstract]:In order to effectively reduce the social and economic losses caused by large area irrigation activities in Jingyang area, the laboratory experiment of irrigated landslide was carried out to study the influence of slope on the deformation and failure process of loess landslide under irrigation conditions. It is of great practical significance. In this experiment, an irrigation device was designed for the top and surface of a slope. Two groups of indoor irrigation model experiments were carried out on 45 掳and 60 掳slopes at the same time, and the volume water content sensor was embedded in each group of slopes. Three kinds of sensors, matrix suction sensor and pore water pressure sensor, record their internal changes. Through the comparison and analysis of the two groups of experimental processes and results, the deformation and failure law of shallow loess landslide under irrigation condition is obtained, and the failure mode and induced mechanism of this kind of landslide are summarized. The experimental results show that in the early stage of the experiment, with the increasing of the volume moisture content, the suction of the matrix gradually decreases to the basic stability, and the strength of the soil decreases, and the upper part of the soil is saturated at the later stage of the experiment. The deformation caused by the slope and the poor drainage of the soil resulted in the excess pore water pressure and the decrease of the effective stress and the minimum of the soil strength, which led to the occurrence of the landslide. At the same time, the larger the slope, the easier the landslide is, and the smaller the depth and distance of sliding surface.
【作者单位】：中国地质科学院地质力学研究所;国土资源部新构造运动与地质灾害重点实验室;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;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(41472296,41672282) 中国地质调查项目(DD20160271)
【分类号】：P642.22

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