Mechanism Of Floor Heave In Pump House Of CiXi Mine And Optimization Of Reinforcement Scheme

With the deepening of mining depth,domestic and foreign mines have entered the state of deep resource mining.The deep rock mass is in the complex geomechanical environment of "three high and one disturbance",which shows the nonlinear mechanical characteristics of soft rock such as high pressure,large deformation and difficult support.The floor heave phenomenon has become one of the difficulties hindering the normal production and construction of coal mines.Therefore,it is of great significance to study the causes and control measures of floor heave in deep mines.Taking the pump room of-850m horizontal main shaft in CiXi No.1 mine as an engineering example,the following achievements have been achieved through theoretical analysis,numerical simulation and field monitoring.(1)On the basis of summarizing the research on the mechanism and prevention measures of floor heave at home and abroad,this paper expounds the influencing factors and types of floor heave in deep mine chamber.Combined with the actual engineering situation of CiXi mine,it is analyzed that the main factors affecting the floor heave of pump room are the surrounding rock properties and structural state,support strength,section shape,and rock stress.The type of floor heave in pump room is determined as stress type floor heave.On the basis of modern mechanical theory,the mechanical mechanism and control mechanism of stress type floor heave are mainly analyzed,and the relevant expressions are obtained.The influencing factors and mechanism of floor heave of expansion type and plastic extrusion type are briefly introduced.(2)Aiming at the floor heave problem of pump room under the condition of adopting the original support scheme,the floor reinforcement scheme is optimized,including support form design and support parameter optimization.Firstly,the support form is designed,and the FLAC3D numerical simulation software is used to conduct numerical analysis on different working conditions,and the prevention effect of floor heave is compared to select the best support form;secondly,the parameters of the length of grouting anchor bolt and the spacing of anchor cable bundle in the scheme are optimized to ensure the support effect and consider the economy at the same time.(3)By comparing the monitoring data with the numerical simulation results,it is proved that the support scheme is reasonable and feasible,which can effectively improve the stress distribution of surrounding rock,greatly reduce the deformation of the chamber floor and roof,improve the bearing capacity of the support structure,ensure the long-term stability of the chamber,and effectively solve the floor heave problem of roadway and chamber under complex conditions There is a certain guiding significance for the treatment of floor heave.