The Analysis Of Dump Field Slope's Seepage Characteristics And Stability Effect By Rainfall

Rainfall,especially the rainfall caused by typhoon,is the main factor that influences the slope disasters of rock disposal dumps.The research to the stability and prevention of rock disposal dumps is synthesis problem about mine safety and economically production.It is also relevant to environmental protection,safety of life and property.If the rock disposal dumps lose their stability,the mine will bear huge economic losses.Therefore,the research about how rainfall affects the characteristics of seepage and stability is be of great meaning in scientific theory as well as practical projects.The article is based on limestone disposal dumps in Lingdou,Zhangping City,Fujian Province.The research studied geological and hydrogeological conditions in research area and got the particle grading curve of condemned materials.Building a model matches research area well.According to the indoor rainfall simulation experiments,combined with numerical simulation and theoretical analysis,soil moisture content and pore water pressure,displacement from the differ ent suction as experimental soil are analyzed in the condition of rainfall.The results of the research are as followed:(1)According to the Statistical Yearbook of weather bureau from local departments and province,the research analysis the feature of rainfall distribution of research area,in the meantime,we conclude that the rock disposal dump is layered coverage from low stage to high stage.(2)We do research about the discipline of grain size distribution of condemned materials in research area,and we get the constitution characters of grain size in different measuring height,by the mean of sieving and measuring indoor in the stage of 600m and 580m:as the height goes,median diameter,average diameter,contents of coarse aggregates...these characters decrease.Higher the height is,finer the grain size is.(3)According to the study area dump slope physical and mechanical characteristics of the generalization of indoor physical model simulation,to dump set the process of the formation of the steps as the experimental object,respectively,from the dump slope soil moisture rate,pore water pressure and deformation damage characteristics of the evolution of the rainfall of row soil steady seepage field analysis.According to the monitoring data and the damage form,in the initial stage,because of the human's activity and car's load is few,the pile's degree of consolidation is low and the permeability is larger;the degree of consolidation of the bottom step is increased because of the time fly,and the permeability becomes smaller,the stability is increased,and the rain water infiltration response time becomes longer.The failure modes are mainly divided into three stages:the stage of rill erosion,gully erosion stage,collapse stage.(4)The response time of the soil moisture content and the matrix suction is different from that of the soil under different rainfall intensity.The heavy rain response time is short,the light rain's is long.The bottom step response time is long and the top step is short.The concentration of matrix suction and water cut is approximately equal in the same time period.The moisture in the soil can reduce the suction,and then reduce the shear strength of the soil,so that the slope failure.(5)By the numerical simulation of the stability of the study area,the safety factor of the stepped slope is the biggest and most likely to be destroyed.The short time high intensity rainfall has a greater impact on the stability of the soil.The safety factor of the multi-step dump site is more controllable than that of the single-step dump site,and should be fully considered in the space capacity.Engineering should be based on the flexible combination of terrain pressure type at the bottom of the slope and cover two heap set technology,rational use of clamping effect,slope sliding resistance and space effect,promote the dump of stable stacking.