The Formation Mechanism of Surface Landslide Disasters in the Mining Area under Different Slope Angles

Abstract

Slope stability analysis is important for the safe mining of mineral resources. The collapse of goafs in loess gullies can lead to natural disasters such as surface landslides. In this context, this study analyzes monitoring data obtained from surface observation in the Shendong mining area of the Hanjiawan coal mine based on the geological conditions therein. The monitoring results show that the working face experiences a starting period, an active period, and a declining period, from the start of mining to the end of the working face. At the initial mining stage, there is no evident surface movement or deformation in the mining area. When the advance distance of the 12106 working face is between 13 m and 109 m, the surface movement and deformation vary significantly, and the maximum subsidence reaches 1963 mm, which is enough to cause landslides. We select the physical and mechanical parameters of the rock and soil in the mine and then simulate the formation mechanism of surface landslides under different slope angles of the mining area using FLAC3D software. Because of the collapse of the mined-out area, the overlying strata structure is destroyed, the subsidence basin is shifted to the center as a whole, and the slope mass is subjected to tensile and compression deformation, resulting in plastic damage, which develops downward along the crack and leads to a collapse because of the discontinuous movement and deformation of the surface; moreover, step-type ground fissures are produced. The results also show that when the slope angle is greater than 60°, the displacement of the slope mass is not uniform, and the rock stratum in a position with large displacement loses its support, leading to landslides; when the slope angle is less than 30°, the bedrock surface forms a sliding surface and develops to the surface, thus decreasing the possibility of landslides. Based on the stability analysis of the collapsed slope in the goaf of the loess gully, a scientific basis is provided for the effective prevention and control of geological disasters in the Shendong mining area.

Subsidence Monitoring Base on SBAS-InSAR and Slope Stability Analysis Method for Damage Analysis in Mountainous Mining Subsidence Regions

“…The slip caused by mining in the gully area is closely related to the stability of the slope in the gully area [25]. Chi Mu et al have also confirmed that underground mining can cause landslides by analyzing the mechanism of landslide disaster [18]. In the loess gullies, the slope stability is usually evaluated with G in the following formula as an index of terrain mining conditions [18,26,27]…”

“…Xinpeng Diao et al evaluated the building's damage in mountainous mining regions by combining the subsidence theory and slope stability analysis method [12]. Based on the slope stability analysis of loess gully collapse, Chi Mu et al provided a scientific basis for effective prevention and control of geological disasters in Shendong mining Area [18]. Xugang Lian et al analyzed the slope stability caused by longwall mining based on realtime monitoring with global navigation satellite systems (GNSS) [19].…”

Mechanism of Stratum Instability and Dynamic Deformation under Discontinuous Boundary Conditions

“…The instability of the fault structure and the fragmentation of the surrounding rock will change the pressure step of the overlying rock, the stability of the masonry beam structure and the stress distribution of the surrounding rock, etc. [1][2][3][4]. The theories of structural modeling, destabilization criteria, energy transfer criteria, and stability control of surrounding rock for independent faults have been gradually improved.…”

Study of the Stability of the Surface Perilous Rock in a Mining Area

“…The surface perilous rock mass in a mining area refers to the rock structure that is distributed on a steep slope or cliff at the surface of the mine. Under the action of external forces, such as natural conditions or mining engineering activities, perilous rock is in, or near, the limit of the equilibrium state in which cracks or structural planes develop [1][2][3][4][5]. As a result of the rapid development of China's construction sector, human engineering activities have increased rapidly in many southwest regions of China's mountains, and perilous rock collapse disasters often occur [6][7][8].…”