Landslide is a common geological disaster that poses a major threat to people’s production, life and social activities, and is seriously destructive to the surrounding environment. At present, with the acceleration of human industrialization and the intensification of engineering activities, more and more landslides caused by human engineering activities appear, among which the landslide caused by mining is one of them. Open-pit mining engineering changes the balance state of the original ground stress. With the excavation of the open pit, the deformation of the slope rock mass also occurs, and most of the open pit coal mines have appeared on landslides. In view of the prevention and control of landslide disasters in open-pit mines, it is particularly important to scientifically and reasonably predict the harm degree of mine landslides to personnel and economic property, effectively reduce the losses caused by mine landslides, ensure the safe and economic operation of mines, and strengthen the research work of mine landslide disaster risk evaluation.
It is of great practical significance to carry out quantitative risk assessment of landslide disaster to protect people’s lives and property safety and maintain the sustainable development of social economy. The delineation of landslide disaster range is the key link of landslide risk evaluation in open-pit mine.
This study took the open-pit coal mine coal mine in Block I of Thar coal field in Pakistan as the research background, and constructed a framework for landslide risk evaluation in open-pit mines. Based on the numerical simulation method of large deformation of landslide, the disaster range of landslide in open-pit mine was delineated. The stability of stope slope was analyzed based on rigid body limit equilibrium method. The probability of landslide instability was calculated based on Monte Carlo method. And the comprehensive fuzzy evaluation model was established to calculate the total risk value of landslide.
The results showed that: through numerical simulation and empirical formula calculation, the landslide disaster range was accurately delineated, and the comprehensive vulnerability of the disaster bearing body was determined to be medium vulnerability; the annual probability of landslide instability under natural conditions was 0.003, which belongs to moderate risk. The annual probability of landslide instability under rainstorm conditions was 0.024, which was highly dangerous; the annual probability of landslide instability under seismic conditions was 0.018, which was highly dangerous. Under natural conditions, the total risk value of landslide was 114,686.4 rmb, and the annual mortality rate of population was 0.0255 people/year. The total risk value of landslide under rainstorm condition was 11,707,570 rmb, and the annual mortality rate of population was 0.18375 people/year. The total risk value of landslide under earthquake condition was 43,007,400 rmb, and the annual mortality rate of population was 0.135 person/year, which was an unacceptable risk.
The economic loss was a small geological disaster risk under natural conditions, and it was a medium-sized geological disaster risk under both rainstorm and earthquake conditions. Therefore, landslide prevention and control and management measures such as slope deformation monitoring were proposed to ensure the safety of personnel and property in open-pit mines.
This study evaluated the risk level of economic loss and personnel loss of landslide bearing body. The personnel loss was characterized by annual mortality rate, and its risk level exceeded the acceptable risk level. The economic loss was evaluated by the risk level, and the analysis showed that it belonged to the medium-sized geological disaster risk under the conditions of rainstorm and earthquake. Therefore, it was recommended that the open-pit mine in Thar Coalfield, Pakistan needed to take certain landslide prevention and control measures.
Sources:
Scientific Reports
https://www.nature.com/articles/s41598-023-42736-4 .
Provided by the IKCEST Disaster Risk Reduction Knowledge Service System
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