Research On High Ground Stress And Soft Rock Roadway Supporting Technology Of Bide Coal Mine

Soft rock roadway which characterized by large deformation,pressure comes fast, sidewall heave,floor heave and difficult support under the effects of high ground stress have aroused common concern in rock mechanics and underground engineering field all the time, and soft rock roadway supporting is always a tough problem obsessing the mining industry ,which has seriously been affecting the coal mine's safety production and economic benefits, This paper, based on the distortion and failure character of soft rock roadway in Bide coal mine, analyzed deformation and failure mechanisms of soft rock roadway that all are effected by factors of ground stress, lithology, mining influence, unreasonable support parameters and water. By means of carried out coal mine area in-situ stress measurement,mechanics parameters determination of roof and floor rock, surrounding rock classification, monitoring of anchor, stability analysis and deformation monitoring of roadway and so on, this paper have achieved the following results:The researcher have tested the rock stress of Bide coal mine by use of principle of stress relieving method and hollow inclusion stress gauge technique, and achieved the magnitude, azimuth and dip of the three principle stress. The results showed that the rock stress of coal mine area was interaction of tectonic stress and gravity stress, and the magnitude of three principle stress were linearly correlated with the buried depth. According to the results of in-situ stress measurement and combined with the deformation and failure characteristics of roadway ,then analyzed the relationship between the deformation and failure of roadway and ground stress.This paper experimental studied the mechanical properties of roof and floor rock and obtained the mechanics parameters using MTS815 rock mechanics test system. On this basis, the type of Bide coal mine rock mass was classified by the rock mass geomechanical dassification method of South Africa, which belong toⅢsurrounding rock and the stability of rock mass is normal.According to the results of in-situ stress measurement, classification of surrounding rock and mechanics parameters test, this paper designed the supporting parameters of anchor, anchor cable, shotcrete layer and grouting, then supporting schemes of mining roadway and development roadway were provided, and the best schemes were put forward through numerical analysis of roadway stability and many years of coal mine supporting experience. In the new drifting roadway, the effect test of best supporting scheme have been taken, the monitoring results of horizontal and vertical direction displacement showed that the deformation of roadway was convergent, which indicated the new supporting scheme could controlled the deformation of soft roadway effectively and improved the stability of roadway.In Bide coal mine roadway support, this paper based on the principle of"control slope before control roof, control floor before control slope"and designed 45 degrees base angle bolt to controlling the floor heave in the new supporting scheme, the base angle bolt could reduce the stress concentration of base corner and lower the range of plastic zone, prevented floor rock mass produce shear slip.The construction monitoring results of district roadway showed that the construction process have large influence to the roadway surrounding rock deformation, the original stress state have been destroyed with the excavation of roadway, and produced stress concentration, the early deformation velocity was faster, but with the increase of time, the rate of deformation velocity began to reduce and the roadway surrounding stress tended to stable, then the deformation of surrounding rock was tending toward to stability and went into a state of convergent with the supporting effects of shotcrete layer and grouting.