Three-dimensional slope stability and anti-slide pile treatment of Zhangjiayao landslide under rainfall

Abstract

PurposeTo solve the instability problem of Zhangjiayao landslide caused by rainfall, the internal mechanism of slope instability and the supporting effect of anti-slide piles are studied. The research results can provide theoretical basis for the prevention and control of loess landslides.Design/methodology/approachA three-dimensional finite element model of Zhangjiayao landslide is established by field geological survey, laboratory test and numerical simulation.FindingsThe results show that Zhangjiayao landslide is a loess-mudstone contact surface landslide, and rainfall leads to slope instability and traction landslide. The greater the rainfall intensity, the faster the pore water pressure of the slope increases and the faster the matrix suction decreases. The longer the rainfall duration, the greater the pore water pressure of the slope and the smaller the matrix suction. Anti-slide pile treatment can significantly improve slope stability. The slope safety factor increases with the increase of embedded depth of anti-slide pile and decreases with the increase of pile spacing.Originality/valueBased on the unsaturated soil seepage theory and finite element strength reduction method, the failure mechanism of Zhangjiayao landslide was revealed, and the anti-slide pile structure was optimized and designed based on the pile-soil interaction principle. The research results can provide theoretical basis for the treatment of loess landslides.HighlightsA three-dimensional finite element model of Zhangjiayao landslide is established.Zhangjiayao landslide is a loess-mudstone contact surface landslide.The toe of Zhangjiayao slope is first damaged by heavy rainfall, resulting in traction landslide.The deformation of Zhangjiayao slope is highly dependent on rainfall intensity and duration.The anti-slide pile can effectively control the continuous sliding of Zhangjiayao slope.