Research and monitoring analysis of coal roadway bolting system in very weakly cemented stratum

The displacements,plastic zone and stress distribution were revealed by FLAC3 D in three cross section shape of rectangle,tangential arch and straight wall arch after excavation according to the characteristics of very weakly cemented stratum with low self-stable ability,short stable time and deformation severely. The reasonable section shape of coal roadway was determined in very weakly cemented stratum.Combining with the roadway supporting theories and technologies at home and abroad,a “Double anchorage balance arch structure”in very weakly cemented stratum was put forward.The different roadway supporting technology solutions was proposed based on the coal seam thickness and buried depth of roadway.The rationality of the supporting scheme has been validated by FLAC3 D.Based on the real-time monitoring and analysis,the surrounding rock deformation and supporting structure stress were dynamically known; the supporting effect and supporting schemes feasibility were valued. Monitoring results show that the circle arch roadway form is a good form,and its stress is uniform.It is in favor of the overall stability of the surrounding rock,and the stabilityand bearing capacity are raised.Combining supporting scheme with bolting wire mesh technology solutions can effectively control the large deformation and destruction of roadway surrounding rock in very weakly cemented stratum,and the longterm stability and safety of the roadway surrounding rock and supporting structure can be warranted.