The Kenya Rift Valley is relatively prone to underground erosion ground fissures and associated disasters,which gravely hinder local engineering construction and economic development.In this research,we performed field and experimental studies on ground fissures in the Kenya Rift Valley area,and determined the structural characteristics of underground erosion fissures.Based on a geological survey of the area,we generalized a geological model for typical ground fissures and reproduced the intermediate process of ground fissure propagation using a large-scale physical model test.Further,the development process of underground erosion fissures were categorized into four stages:uniform infiltration,preferential infiltration,cavity expansion,and collapse formation stages.During the development of underground erosion fissures,water content was distributed symmetrically along the fissures,and these fissures acted as the primary infiltration paths of water.When the ground collapsed,the increase in negative pore water pressure was greater,whereas the increase in positive pore water pressure was less in the shallow soil;moreover,in the deep soil,the increase in positive pore water pressure was greater than that of negative pore water pressure.Additionally,the earth pressure increment initially increased and then decreased with the development of erosion.During underground erosion collapse,the water content and pore water pressure appeared to increase and decrease rapidly.These results can be employed to predict the occurrence of underground erosion ground fissures and the resulting soil collapse.

LIU Yang;PENG Jian-bing;JIANG Fu-qiang;LU Quan-zhong;ZHU Feng-ji;Xu Qiang

Department of Geological Engineering,Chang'an University,Xi'an 710054,China;Key Laboratory of Western China Mineral Resources and Geological Engineering,Ministry of Education of the People's Republic of China,Xi'an 710054,China;CCCC Railway Consultants Group Co.,Ltd.,Beijing 100000,China;China Jikan Research Institute of Engineering Investigations and Design Co.,Ltd.,Xi'an 10043,China

山地科学学报（英文版）

[1]LIU Yang;PENG Jian-bing;JIANG Fu-qiang;LU Quan-zhong;ZHU Feng-ji;Xu Qiang-.Model test study on the formation and development of underground erosion ground fissures in the Kenya Rift Valley)[J].山地科学学报（英文版）,2022(04):1037-1050

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