Study On Slope Instability And Prevention Technology Of Layered Dump Under Heavy Rainfall In South Of The Five Ridges

The dump is a place for storing waste rock and residue produced in the open-pit mining process.Its stability is related to the safety of production,the safety of people’s lives and property and environmental protection.The characteristics of rock and soil,rainfall and soil drainage technology have great influence on the stability of the slope of the dump.Especially in the coastal area of South of the Five Ridges,there is abundant rainfall and high rainfall intensity.The infiltration of rainwater will lead to the increase of water content of slope volume and the increase of soil gravity,which will easily induce deformation and landslide of the dump slope,which will affect the stability of the slope of the dump.Therefore,it is of great significance to study the instability and prevention and control technology of the slope in layered dump under the condition of heavy rainfall in South of the Five Ridges.Taking the slope of a layered waste dump in South of the Five Ridges as the research object,based on the relevant theories of soil mechanics and rock mechanics,combined with field investigation,mechanical test,theoretical analysis,numerical simulation and engineering application,this paper studies the stability of layered waste dump slope under heavy rainfall,and puts forward engineering prevention and control technology.The main work of this paper is as follows:(1)According to the investigation results of climate and vegetation,engineering geological conditions and hydrogeological conditions in a mining area in South of the Five Ridges,the influencing factors of slope instability of layered waste dump are analyzed in detail.Carry out soil mechanical tests such as density test,permeability test,direct shear test and triaxial shear test to obtain corresponding physical and mechanical parameters.(2)The rainfall infiltration model of layered waste dump slope under different rainfall conditions is constructed,the rainfall infiltration depth of layered waste dump slope is calculated,and the safety factor is calculated according to the principle of strength reduction method.Considering the difference of saturated permeability coefficient of different soil layers,combined with numerical simulation,the variation laws of volume moisture content,rainfall infiltration depth and safety factor of waste dump slope are quantitatively analyzed,and the stability of layered waste dump slope under different rainfall conditions is studied.(3)Based on the characteristics that layered waste dump is alternately stacked by different slag soils,according to the idea of limit equilibrium and the method of automatically searching any slip surface,a calculation method of slope safety factor of layered waste dump under heavy rainfall is proposed.Taking a layered waste dump project as an example,a numerical model is constructed to study the dynamic changes of displacement,stress distribution characteristics,potential slip zone and rainfall seepage of layered waste dump under the condition of short-term and continuous heavy rainfall,and analyze the stability of waste dump slope.(4)Taking a waste dump as an example,based on the principle of feasibility and safety,a series of technologies for slope instability prevention and control of waste dump are proposed from six aspects: active prevention and control such as drainage diversion technology,strong drainage technology of discharge culvert,layered rolling technology,vegetation soil consolidation technology,real-time online monitoring technology of displacement,emergency rescue and other passive prevention and control,and the effect of instability prevention and control is evaluated.The research results of this paper have a guiding role in the safety management of the slope of layered dump in South of the Five Ridges.