灌溉诱发黄土滑坡的离心试验研究

发布时间：2018-02-28 03:56

本文关键词： 黄土滑坡灌溉水入渗离心模型试验黑方台　出处：《人民长江》2017年S1期 　论文类型：期刊论文

【摘要】：黑方台从开始农业提灌以来,持续发生成群滑坡,台缘部位密集裂缝逐年增加,滑坡规模和频率呈逐年增大趋势。以黑方台焦家13号滑坡为地质原型,利用原状黄土制成1:200室内灌溉模型,采用大型土工离心机进行离心试验。试验结果表明:(1)自制灌溉水模拟装置,能有效模拟不同灌溉程度(不同渗透水量和渗透深度);(2)灌溉诱发黄土滑坡变形及破坏程度与灌溉水入渗阶段密切相关,主要分为灌溉水下渗阶段、地下水壅高阶段、初次剪滑阶段、溯源滑动阶段,由此可以判识灌溉水渗流阶段及该类滑坡发育阶段;(3)该类滑坡形成机理为:灌溉水下渗、阻水层地下水壅高→阻水层上部黄土软化、蠕滑(峰值强度)→坡脚泥流潜蚀、前缘剪滑(残余强度)→前缘临空、溯源滑动、后缘新拉裂。研究再现了灌溉诱发黄土滑坡形成过程,指出了灌溉水与黄土相互作用的致灾机理,可为灌溉诱发黄土滑坡研究提供试验依据。
[Abstract]:Since the beginning of agricultural irrigation and irrigation, the Heifangtai landslide has continuously occurred in groups, the dense cracks in the edge of the platform have been increasing year by year, the scale and frequency of the landslide have been increasing year by year, and the Heifangtai Jiaojia No. 13 landslide is taken as the geological prototype. An indoor irrigation model of 1: 200 was made from undisturbed loess, and centrifuge tests were carried out with a large geotechnical centrifuge. The experimental results showed that the irrigation water simulator was made by ourselves. It can effectively simulate the deformation and damage degree of loess landslide induced by different irrigation degree (different permeable water quantity and infiltration depth), which is mainly divided into irrigation water infiltration stage and groundwater accumulation stage, and the damage degree is closely related to irrigation water infiltration stage. The formation mechanism of this kind of landslide is as follows: infiltration of irrigation water and high level of underground water in blocking layer. 鈫扡oess softening and creeping (peak strength) in the upper water-resistance layer. 鈫扴lope foot mudflow erosion, front shear slip (residual strength). 鈫扵he forming process of loess landslide induced by irrigation is reappeared, and the mechanism of interaction between irrigation water and loess is pointed out, which can provide experimental basis for the study of loess landslide induced by irrigation.
【作者单位】：四川省交通运输厅公路规划勘察设计研究院;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;
【分类号】：P642.22

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