The High Slope Of The West Side Of An Open-pit Iron Mine In Liaoning Research On Deformation Mechanism And Control Strategies

Open pit mining is the main mining method of mineral resources.As the mine enters the stage of slope deep mining,high and steep slopes are often formed.Under the combined action of engineering disturbance and natural factors,the high and steep final slope is easy to lose stability,and then the slope,collapse,dumping and other damages occur,posing a serious threat to personnel and equipment within the slope range.The reverse inclination of the slope rock stratum on the west side of the study area leads to the formation of multi-level reverse benches on the platform and steps.Therefore,it is of great significance to analyze the deformation mechanism,failure mode,stability and control measures of the reverse inclination rock stratum on the slope to ensure the safety of mine production.This paper has made a detailed investigation on the slope situation,structural plane development,hydrogeology and engineering geology of the mine.The slope rock stratum of the mine is an anti dip rock stratum,and there is intrusive rock in the seam.The distribution,scale and mechanical characteristics of the structural plane are studied in detail,and the deformation mechanism of the anti tilting slope is analyzed,and the mechanical conditions leading to its deformation and relevant influencing factors are given.The calculation model under the corresponding anti dip rock deformation mode is established to solve its stability coefficient,so as to guide the safe construction and normal operation of the project.The main research contents and achievements are as follows:(1)Through collecting the existing working data and field investigation results of the mine,the structural planes of each area were investigated,and it was preliminarily judged that the slope deformation control factors were mainly stratum structure and fault structure.The upper stress area of the slope is large and the load is heavy,while the lower stress area is small and the stress is concentrated.The rock mass is squeezed and staggered along the anti tilting structural plane,and the upper Quaternary stratum is cracked and deformed due to its dislocation.(2)The measured structural planes are classified according to their mechanical effects,and the failure mode of the slope is determined by using the stereographic projection graphic method considering the structural type of the slope rock mass,the degree of fragmentation,the development degree of the structural plane and the combination relationship of large discontinuities.The potential slip surface of the slope on the west side of the mine is determined,which provides a scientific basis for further quantitative research on the stability of the slope.(3)Through two methods of limit equilibrium and numerical simulation,an accurate and reliable geological analysis model is established by using SLIDE software to calculate the stability of the slope under different load combinations such as concentrated rainfall,groundwater and earthquake.The displacement distribution,stress distribution and plastic distribution of the slope anti dip rock failure are obtained by using MIDAS GTX NX finite element software,and the failure form of the slope is displayed,It provides a basic basis for mining safety production.(4)Combined with the results of numerical analysis,the comprehensive treatment scheme of slope cutting+monitoring+bolt reinforcement is designed.The SLIDE software is used to calculate the stability of the reinforced composite slope.The safety factor of the reinforced slope is far greater than the limit value of the safety factor,and the slope is stable after comprehensive treatment.