The Comparative Analysis About The Stability Of The Slope Berore And After Reinforcement At The Top Of Mine Wellhead

Slope engineering stability research is a complex system engineering involving many factors such as technology,economy and safe production.Coal resources in China's energy structure occupies an important position in order to meet the demand for coal,open-pit coal mining from shallow mining to deep-seated conversion,slope-type open-pit mining to deep concave open-pit mining during the formation of high and steep slope,Stability is a threat to mine production safety and normal life,so the stability of high steep open pit slope stability is of great significance.In this paper,taking the slope at the top of the wellhead of Ping shuo Open-pit Mine as the research object.The stability analysis of the slope before and after the reinforcement is carried out by means of theoretical analysis and numerical simulation,and the reinforcement and optimization measures are put forward.1.Combined with the geological characteristics and the status quo of the open pit slope,the factors affecting the stability of the slope are analyzed and studied,which include the lithology,rock structure,rainfall,weathering,earthquake,slope vegetation,open-pit mining and so on.2.The stability of the slope is analyzed based on the limit equilibrium method.The advantages and disadvantages of the Bishop method,Janbu method and Spencer method are compared.SLIDE software is used to calculate the safety factor of slope.By comparison,it is found that Bishop method is more suitable for the slope.The safety factor is less than the specified value,which means the slope stability is poor and the safety reserve is insufficient.By analyzing the sensitivity of the c and ? values to the safety factor of the slope,it is found that the sensitivity of the sand layer is the highest,and the analysis of the broken weathering zone shows that the influence degree of ? is greater than c.3.Slope is reinforced by prestressed anchor cable,unbalanced thrust method is used to calculate the thrust force of slope slide,and a reasonable design of single cable anchor force is obtained.The length of anchor section,length of anchor section and length of free section are calculated.Anchor cable inclination angle,combined with the specification and engineering actual value.On this basis,continue to cut slope slope load shedding,drainage,ecological slope protection,to prevent non-dominant factors cause slope damage.4.The stability of slope before reinforcement is analyzed by FLAC^3D software,and the results show that the safety factor and the dangerous slip surface is the same as that the results of limit equilibrium method,which indicates that the slope needs reinforcement treatment.5.The numerical analysis of the slope strengthened by prestressed anchor cable is carried out by using FLAC^3D software.The safety factor of the slope is calculated to be higher than the specification,which shows that the slope is in a steady state and has a high safety reserve strength.The stress and strain analysis of the limit state shows that the plastic penetration area at the middle part of the slope.The reinforcement position of the anchor cable is improved and the stability of the slope is improved.6.The relationship between the reinforcement angle and the safety factor of the slope is analyzed by numerical simulation.The fitting curve is made to determine the most suitable anchor reinforcement angle.