| China’s terrain and landforms are complex and diverse,and geological disasters are widely distributed.The degree of development gradually increases with the development of society.The main types of geological disasters are collapses,landslides,mudslides,and so on.In this paper,the failure mechanism and main control factors of a landslide triggered by rainfall are studied by means of detailed field geological survey,geological hazard mechanism analysis,numerical simulation calculation and machine learning of a landslide in Hongfenghu Town,Guiyang City,and the knowledge of rock(soil)mechanics,engineering geology,hydrogeology,general geology and other related disciplines.In this study,the internal causes,inducing factors and the laws of landslide development under the influence of various factors are qualitatively analyzed in theory.On the basis of obtaining the relevant physical property parameters of rock and soil mass in different media,the saturated unsaturated finite element model is established using Geo Studio simulation software,and the stability of the slope is quantitatively analyzed.The rainstorm The impact of the earthquake on the slope under these two conditions was analyzed in detail with different rainfall intensities.Then,through comparison and selection,random forest was used for in-depth learning on the impact of rainfall,and the weight of the impact of rainfall intensity and rainfall days on landslide development was calculated.Finally,based on the aforementioned research,suggestions for the prevention and control of this landslide were proposed,providing theoretical basis and reference for the prevention and monitoring and early warning technology of geological disasters caused by rainfall.The research conclusion is that the deformation mechanism of the landslide is due to the excavation of the slope toe by human engineering activities,which makes the front edge of the slope produce a steep free surface,which provides a favorable space for the deformation of the slope body,and the free surface of the front edge reduces the resistance of the lower part of the slope body and destroys the stability of the slope.The overlying medium of the slope body is mainly mud-bearing gravel and fully weathered granite,with large porosity,loose structure and easy softening in water.When the rainfall infiltration intensity is large,it may cause the slope to quickly become saturated and cause the matrix suction to decrease sharply,thus making the slope unstable and triggering rainfall-induced landslides.In this paper,the limit equilibrium theory is used to simulate the underground seepage field before and after rainfall infiltration through the SEEP / W module in Geo Studio.Then the stability of the landslide under natural and different rainfall conditions is calculated,and it is concluded that the stability of the landslide under natural conditions is less stable,which is consistent with the conclusion of field investigation.Rainfall will adversely affect the stability of the landslide,and the rainfall intensity is inversely proportional to the stability of the landslide.Then,the Quake / W module is used to simulate the situation of the slope under the seismic condition.By coupling the Slope / W module,the Newmark method is used to obtain the change of the safety factor and the permanent displacement of the slope under the seismic condition,so as to determine the instability and high damage degree of the landslide under the seismic condition.Through the above simulation analysis,it is concluded that the landslide is very sensitive to the earthquake.Compared with the influence of rainfall,it is not in a time dimension,there is no comparability,and the results are obviously unstable.Therefore,the machine learning of random forest method is used to study the influence of rainfall on landslide,and the weight of adverse effects of rainfall intensity and rainfall time on landslide is obtained.According to the analysis results of the landslide,the geological disaster prevention and control suggestions are put forward. |
