王刚, 孙萍, 吴礼舟, 石伦炎, 祝恩珍. 2017: 降雨诱发浅表层黄土滑坡机理实验研究. 工程地质学报, 25(5): 1252-1263. DOI: 10.13544/j.cnki.jeg.2017.05.010
    引用本文: 王刚, 孙萍, 吴礼舟, 石伦炎, 祝恩珍. 2017: 降雨诱发浅表层黄土滑坡机理实验研究. 工程地质学报, 25(5): 1252-1263. DOI: 10.13544/j.cnki.jeg.2017.05.010
    WANG Gang, SUN Ping, WU Lizhou, SHI Lunyan, ZHU Enzhen. 2017: EXPERIMENTAL STUDY ON MECHANISM OF SHALLOW LOESS LANDSLIDES INDUCED BY RAINFALL. JOURNAL OF ENGINEERING GEOLOGY, 25(5): 1252-1263. DOI: 10.13544/j.cnki.jeg.2017.05.010
    Citation: WANG Gang, SUN Ping, WU Lizhou, SHI Lunyan, ZHU Enzhen. 2017: EXPERIMENTAL STUDY ON MECHANISM OF SHALLOW LOESS LANDSLIDES INDUCED BY RAINFALL. JOURNAL OF ENGINEERING GEOLOGY, 25(5): 1252-1263. DOI: 10.13544/j.cnki.jeg.2017.05.010

    降雨诱发浅表层黄土滑坡机理实验研究

    EXPERIMENTAL STUDY ON MECHANISM OF SHALLOW LOESS LANDSLIDES INDUCED BY RAINFALL

    • 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: The loess is loose, and contains numerous large pores and vertical joints inside, which provides channels for the rapid infiltration of rainfall. The shallow loess landslides have caused significant casualties and economic losses. In order to effectively reduce the social and economic impact of landslides induced by rainfall, it is of great realistic significance to carry out the laboratory experimental study on rainfall-induced landslides. The purpose of this paper is to study the effects of different rainfall pattern and different slope structure on the deformation and failure process of loess slope. Three groups of indoor physical model experiments are designed and conducted. They include loess slope with continuous heavy rainfall, loess slope containing a vertical joint with continuous heavy rainfall, and loess slope with intermittent heavy rainfall. Three kinds of sensors including volume moisture sensors, matric suction sensors and pore water pressure sensors are buried to record the internal changes in each loess slope. Analyzing the changing readings of sensors and experimental phenomenon, and comparing the experimental procedures and results under the different experimental conditions disclose the deformation and failure law of shallow loess landslide under rainfall condition. The failure mode and triggering mechanism of this kind of landslides are summarized. The experimental results show that, in the early stage of the experiments, the matric suction of the loess decreased gradually and maintained stable in the end, therefore the strength reduced, with the continuous increases of volume moisture. In the later stage, the upper loess of the slope reached the saturation stage, excess pore water pressure generated by the slope deformation and poor drainage of the loess decreased the effective stress and the strength of the loess, and as a result, the strength reached the minimum, which resulted in landslides. And meanwhile, the influence of slope structure on slope stability is greater than that of rainfall pattern.

       

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