Experimental And Simulation Study On The Process Of Retaining Debris Flow With Rigid Net Protective Structure

Debris flow is usually produced by landslides,and its huge impact will cause serious damage to the industrial and civil facilities along the way.Therefore,it is of practical significance to explore the movement process characteristics of debris flow and the blocking effect of different protective structure settings on debris flow for optimizing the design of protective structure and further realizing the comprehensive safety evaluation of protective engineering.Because of the complexity of debris flow movement,it is necessary not only to carry out field investigation of debris flow disaster,but also to use the indoor model test and numerical simulation methods,in order to better realize the research of debris flow blocking process of protective structure.In this paper,the process of blocking debris flow by rigid mesh structure is studied by combining model test with numerical simulation.The interception efficiency,accumulation form and impact process are analyzed and discussed.The main research works are as follows:First of all,the flow model test tank is used to carry out the experiment of rigid mesh blocking debris flow.The test mainly considers the influence of the particle size,gradation,weight and rigid mesh setting on the interception efficiency and the final accumulation form of debris.At the same time,the experimental data are used as the basis for further verification of the correctness of numerical simulation.Secondly,based on the experiment of rigid mesh blocking debris flow,a numerical model is established to simulate the process of rigid mesh blocking debris flow.The numerical simulation results are in good agreement with the experimental results,which verifies the effectiveness of the numerical calculation.Through numerical simulation,the velocity of debris flow and the stress process of rigid mesh can be obtained,which can not be obtained under experimental conditions.The calculation results show that the multi-level rigid mesh can achieve high efficiency of arresting particles and share the impact of debris flow,so that the structure is more reasonable and safe.Finally,a typical test case with stress time history curve is selected to conduct numerical calculation and Analysis on the process of debris flow blocking by wire net.On the basis of numerical verification,the process of debris flow blocking by single-stage and multi-stage Xianwang protective structures was studied by numerical simulation.The calculation results show that by adjusting the spacing,position and mesh size of the wire mesh in the numerical simulation,the mass distribution of debris particles intercepted by each mesh and the correlation between the accumulated debris particles can be realized,and then the rigid wire mesh structure can be optimized.