Research On GIS-based Three-dimensional Slope Stability Analysis Model And Prediction Of High-speed Landslide Sliding Speed

The landslide has a wide distribution range,strong destructive power,and great social impact.Evaluation of the hazard of landslides is one of the main research objects in the evaluation of geological hazards.Especially for high-speed landslides,the loss of stability will cause the landslide body to move quickly,and all vegetation and house facilities in the landslide channel will be washed away.When the sliding body slides into the water,it will swell and will bring great threats to people's lives and property.In the evaluation of high-speed landslide hazards,its stability evaluation is an important basis for judging whether landslides will cause harm,and sliding speed is an important evaluation factor for evaluating the scale of disasters that can occur from landslides.Therefore,how to evaluate the stability of the landslide,and on this basis to establish a set of calculation methods to predict the sliding speed of high-speed landslides,is of great significance to accurately assess the magnitude of the high-speed landslide hazards.Based on the spatial data processing capabilities of GIS,a three-dimensional slope stability calculation method based on the assumption of normal stress distribution on the sliding surface is proposed.On this basis,a three-dimensional landslide sliding speed calculation model is established,and the results are calculated through indoor experiments.Verified.The main work of the paper is as follows.(1)Combined with the spatial data processing capability of GIS,through analyzing the composition of the normal stress on the three-dimensional sliding surface,the approximation function of the normal stress distribution on the three-dimensional slope sliding surface was constructed based on the grid column element.It provides the theoretical calculation basis for establish the three-dimensional limit equilibrium method of surface normal stress assumption.(2)Based on the spatial analysis method of GIS,a calculation method of three-dimensional slope stability based on assumed normal surface stress distribution was proposed.Considering the three-dimensional spatial relationship of the grid cylinder elements,the spatial calculation expressions of the required parameters were given.Through the force analysis of the grid cylinder elements,the force equilibrium equation system for solving three-dimensional safety factor was derived under the limit equilibrium condition.Combined with the approximation function of the normal stress distribution on the sliding surface and the Mohr-Coulomb strength criterion,the three-dimensional safety factor was solved.(3)Based on the grid column elements,a three-dimensional calculation model of landslide speed was established.And the theoretical calculation value was verified through the indoor shear vibration experiments in the locked section.Based on the calculation method of the three-dimensional slope stability of the grid cylinder element,combined with Newton's law of motion,dynamic equation based on the grid cylinder element was established.Therefore,the starting acceleration speed and sliding speed of the sliding body were solved.The existence of shear rupture vibration in the system was confirmed by the indoor shear vibration experiments in the locked section of the rock mass.According to the experimental data,the starting acceleration of the sliding body was obtained,and the theoretical calculation value was verified.(4)In order to make the above calculation more convenient,an expansion module for calculating slope stability and landslide sliding speed was developed based on GIS,and the feasibility and accuracy of this module were verified through practical cases.