Research On Deep Mine Vertical Shaft Wall Of Soft Rock Section Fracture Goverance

The rapid development of the industry promote the development of coal, but also has brought unprecedented difficulties and challenges. Soft rock section of deep vertical shaft support problem performance is particularly prominent. For this reason, Niaoshan coal mine as the background, the lining fracture reasons, repair methods and deformation monitoring technology in the application for soft rock section of deep vertical shaft lining has carried on the detailed research. The main conclusions are as follows:(1) Through the comparative analysis to the breakup of wall surface soil subsidence and deep vertical shaft wall fracture characteristic, which summarizes the characteristics of deep vertical shaft wall itself. According to Niaoshan coal mine wall-system’s engineering hydrogeology conditions and characteristics of shaft wall fracture, thinking the main reasons of shaft wall bursting is the factor that weak clay expansion effect of rock mass of the wall behind.(2) For soft rock rupture section of the wall reinforcement method is studied, analysised the conclusion that composite lining structure repair method is more reasonable. In the first support method as lining grouting、anchor cable、metal net、anchor injection together with shotcrete combined at a time, which contains the advantages of every supporting method, secondary support using C50 steel reinforced concrete lining.(3) With the aid of geotechnical engineering analysis software FLAC3D, according to the characteristics of surrounding rock around the wellbore, different methods of secondary lining is simulated analysis, it is concluded that the wall repair plan of overall using C50 concrete more safe and reliable, but considering the economic factors of non-uniform wall repair method is more suitable for wall repair request. Meanwhile, The influence of under different row spacing between anchor cable anchorage effect was studied, spacing choose slightly greater than 1.0m and row spacing choose between 1.0～1.8m more conducive to play a role of anchor cable anchorage effect and protect the safety of the shaft.(4) In order to ensure the safety of the shaft, the modern monitoring techniques be applied on the soft rock section of the wall and the monitoring data are analyzed and predicted. By the comparative analysis with the actual monitoring data, the result is good. Strength of Tresca、Von Mises、Mohr-Coulomb criterion has carried on the comparative analysis, it is concluded that the Mohr-Coulomb strength criterion is more suitable for the concrete material safety status of judgment.(5) On the trend of fitting curve Change and borehole wall stability criteria.The projections for time of shaft wall fracture compared with the actual rupture of time is less than one day.It have great significance to ensure the safety of the shaft construction and prevent the occurrence of safety accidents.