| On September 15,2020,a landslide occurred in Jianshanying,Fa’er Town,Shuicheng County,Liupanshui City,Guizhou Province,affecting the safety of 1,062 people from 274 households in villages such as Jingwei,Jiudianzi,and Xiaozhai.The landslide,was identified as a rock landslide that involved both the initial failure and subsequent movement phases.The landslide exhibited distinct zoning characteristics,and the Jianshanying slope was a completely unloaded slope with three open faces.The stability of the slope was affected by long-term mining activities in the area,which had progressed from partial extraction to full extraction.Under the cumulative influence of various factors,the slope rock mass experienced deformation and eventually triggered the rock landslide.This study focused on the Jianshanying landslide and conducted a comprehensive analysis combining field investigations and laboratory analyses.The study aimed to analyze the deformation and failure characteristics of a single-faced slope in a fully unloaded state,considering the disturbance caused by underground mining and the impact of fully extracted coal seams.The research outcomes are as follows:(1)Prior to the occurrence of the landslide,the Jianshanying slope experienced frequent collapses and instabilities due to underground mining,with continuous rainfall preceding the landslide event.The mining activities in the slope included shallow mining in the mountainous M1 and M3 areas,while the remaining areas involved repeated mining in multiple layers.The deformation process of Jianshanying slope can be summarized as follows: disturbance caused by mining in a single coal seam → bending deformation of overlying strata → repeated mining → intensified deformation of the rock mass→ collapse and collapse of the slope.It is concluded that the formation mechanism of landslide is : caving subsidence-tensile fracture-creep slip-shear slip.(2)The Jianshanying slope was a single-faced slope with three open faces,distinct from the surrounding topography and landforms.Under the long-term influence of mining,the slope exhibited a high density of joint fissures and developed significant structural planes.The slope reached a fully unloaded state.The landslide was a rock landslide influenced by mining activities in the lower slope.The deformation and failure range of Jianshanying slope included the already damaged rock landslide,the areas affected by the subsequent movement of the landslide,and the cliffs experiencing deformations such as collapses and block falls.The movement of the landslide was affected by micro-geomorphological features,such as topographic ridges.(3)High-density electrical resistivity tomography was conducted to reveal the development of micro-geomorphological features related to sediment accumulation.A topographic ridge was identified above the Jiudianzi formation,which had a hindering effect on the landslide.Referring to the regulations,the selection of mining angles and delineation of the influence range of goaf were performed.Surface settlement calculations were carried out as mining progressed deeper into the coal seam.The maximum surface settlement continuously increased,indicating that the mining had reached a state of full extraction.(4)Overall,the deformation and failure process of the Jianshanying rock landslide can be summarized as follows:underslope of completely unloaded slope initial mining→overburden deformation and fracture development→the overburden of repeated mining develops from incomplete mining to full mining→the deformation of rock slope intensifies,resulting in settlement and cracking→repeated mining,cracks through,slope local collapse→rock landslide was induced by long-term rainfall accumulation... |
PDF Full Text Request