Abstract:
The traditional Newmark model often neglects the partial shear strength provided by the negative pore water pressure above the groundwater level. This is reasonable for the main part of the sliding surface below the groundwater level. However, the calculation results are too conservative for slope with a deep groundwater level or considering shallow sliding. Therefore, the Newmark cumulative displacement model is extended to the field of unsaturated soil mechanics in this paper. Based on the consideration of matrix suction, the Newmark model calculation formula is improved. The Newmark traditional model and the improved Newmark model are used to classify the susceptibility zoning about the earthquake landslide of the Lixian county map of Gansu Province. On this basis,the hazard zoning and risk assessment of earthquake landslide under 10% probability in 50 years are carried out respectively. Finally, ROC curve is used to verify and compare the evaluation results. The results show that the calculated results of the susceptibility areas and the hazard areas obtained with the improved model are obviously better than those with the traditional model, and the calculated results of the risk areas obtained with the improved model are better than those with the traditional model although the improved results are not obvious. The improved Newmark model, which takes the effect of matric suction into account, gives full play to the contribution of matric suction and makes the calculation results more reasonable. The research results can provide a new reference for earthquake landslide susceptibility zoning, hazard analysis and risk assessment in relevant regions.