Risk Assessment Of Gantianba Landslide In Ningnan County

Landslide hazard is one of the most common types of geological hazards. According to statistics, the landslide disaster in China caused heavy loss of life and property to the people and the country. It is urgent and important to predict and evaluate the harm degree of landslide disaster to the life and property of people in the face of serious landslide disaster.On the basis of comprehensive analysis and utilization of the existing research results of domestic and foreign scholars, the author used the theory and method of landslide risk assessment to evaluate the risk of landslide. This risk assessment mainly consists of five parts, which are the analysis of landslide failure probability, the analysis of landslide arrival probability, the vulnerability of disaster bearing body, the value loss of disaster bearing body and the level of risk acceptance. In particular, this method can calculate the probability of landslide failure, the probability of landslide arrival and the risk of landslide hazard.(1)Based on the analysis of field investigation and laboratory tests, the stability of Gantianba landslide is evaluated. The numerical simulation was made by FLAC3 D software, which was used to verify the stability of the landslide, and the results were basically consistent with the actual situation.(2)Monte Carlo method was used to calculate the probability of failure under the three conditions of natural, rainstorm and earthquake.At the same time, the 2d-block discrete element software was used to simulate the movement process and the sliding distance of the landslide. Based on the different strength parameters and the corresponding different sliding distance, the polynomial fitting of the sliding distance is completed. By fitting the formula and the Monte Carlo method, the probability of arrival at different positions of the three conditions are calculated.(3)In this paper, the vulnerability assessment of hazard bearing body is carried out. After calculating the results of landslide instability probability, landslide arrival probability, vulnerable and value loss of hazard bearing body, according to the calculation formula of the value of the risk, the risk value of the landslide in three kinds of different conditions is calculated.(4)Finally, the acceptable risk level of Gantianba landslide is studied in this paper. The results showed that, in the three conditions of natural, heavy rain and earthquake, personnel risk was not acceptable risk, and property risk were two, three, four respectively.This paper taking Gantianba landslide as an example to study the single landslide risk assessment methods, and achieved certain results. The achievements and research ideas have some value and use for reference to other single landslide.