Deformation and Failure Process of Slope Caused by Underground Mining: A Case Study of Pusa Collapse in Nayong County, Guizhou Province, China

Abstract

Pusa village is located in the karst mountain area of Nayong County, Guizhou Province, China. Laoyingyan mountain rock is gently dipping, the upper part consists of hard rock formations, and the lower part is made up of soft rock composed of 3 coal seams. On August 28, 2017, a massive landslide occurred in this area, resulting in 82,3000 m3 of debris, which resulted in significant casualties and brought up the malaise in society. In this paper, the geological conditions and long-term mining activities in the study area are analyzed by field investigation. The base friction tests and numerical models are used to simulate and analyze the failure and deformation process of Pusa collapse to accommodate the research on the deformation and failure mechanism of the slope and provide better prevention and treatment suggestions. The results show that the Pusa collapse can mainly be attributed to unique geological conditions, underground mining activities, and the topography of the slope. The intensified mining activities promoted the development of fractures and cracks in the slope, resulting in unstable upper slopes. The failure process of the Pusa collapse can be summarized into four-stage: the development of goaves roof deformation, the crest of the slope cracks, intensification of deformation, and occurrence of collapse. The upper slope with high strength rock developed crack-toppling failure. Meanwhile, the upper slope with low strength rock developed subside-crack-sliding failure, and those two failures together contributed to the mechanism of Pusa collapse. Slope deformation and failure mechanism can be summarized as subside-crack-toppling-shear sliding type.

Numerical simulation study on the deformation and failure of a gently inclined bedding slope: a case study of the Jinhaihu landslide in Guizhou, China

“…The histogram of rainfall in the landslide area for the past month shows that the amount of rainfall is much less than the storm threshold, which indicates that rainfall is not the main factor triggering landslides. However, the long-term in ltration of rain into cracks at the rear edge of the slope is linked to a gradual reduction in the physical and mechanical properties of the claystone interlayer in the sliding zone (Xiong et al 2022). In addition, no landslides have been found on the nearby slopes of the same type over the years, indicating that the main factor triggering landslide occurrence is not direct rainfall but rather the softening of the clay rock interlayers accelerated by the participation of water after rainfall in ltration.…”

Failure Mechanism of Anti-Inclined Karst Slope Induced by Underground Multiseam Mining

“…On the other hand, discontinuous deformation analysis (DDA) [20] and distinct element method (DEM) [21] can simulate the large deformation of blocks. Do and Wu [13] and Xiong et al [4] studied a mining-induced rock avalanche at Nattai North, Australia, using DDA and DEM methods, respectively, which verify that DDA and DEM can be applied to clarify the failure process of a mining-induced landslide. UDEC is a mature DEM software, verified by Cui et al [22] that it can reveal the progressive failure process of Daguangbao landslide induced by Wenchuan earthquake.…”

“…Mining-induced landslide is a research that has been concerned for more than 100 years [1,2]. With the continuous exploitation of coal resources in mountainous terrain, catastrophic landslides induced by underground coal mining occur frequently, resulting in a large number of economic losses and casualties [3][4][5][6][7][8][9][10]. The failure process and mechanisms of mining-induced landslides are becoming an increasingly important research [11][12][13].…”

“…Although there were several methods for predicting rock movement induced by coal mining, such as influence function methods [14,15] and physical test [16,17], there is no doubt that numerical method can reveal the failure process more comprehensively [4,18]. Finite element method (FEM) has been widely utilized in engineering, but it is more suitable for analyzing small deformation problems rather than large deformation problems like landslides [19].…”

Retrieving the Kinematic Process of Repeated-Mining-Induced Landslides by Fusing SAR/InSAR Displacement, Logistic Model, and Probability Integral Method

“…Especially, the eastward displacement induced by mining activities in Figure 10f is opposite to the sliding direction of the slope. This uneven surface displacement is highly susceptible to forming tensile cracks at the crown of the slope [27,51]. Furthermore, intense rainfall also plays a crucial role in slope deformation, as it can infiltrate the rock mass through ground fissures and rock fractures, softening the rock layer and increasing the load on the slope.…”