Study On Instability Mechanism Of Soft Rock Roadway And Its Control In No.1Mine Of Chagannuoer

Aiming to the problem of soft rock supporting in No.1Mine of Chagannuoer, based on field measurement, laboratory experiments, theoretical analysis, similar simulation experiments, combined with numerical simulation methods, this paper has studied the instability mechanism and control measurements systematically. The results show that floor was the main instability weak-plane of roadway and mudstone’s inflationary pressure was the prime source of pressure. This paper has established expansive mechanical model of plastic zone in roadway’s surrounding rock, and proposed supporting idea with "Hard" supports. This paper pointed out that high strength and stiffness of supporting structure was the key factor to keep stability of surrounding rock effectively. After roadway’s instability mechanism simulation experiments under closed supporting methods, we gained evolution rules of stress and displacement when surrounding rock destroyed, which verified the validity of bolts. Contrasted with the strength of different improved supporting structures, this paper obtained that the structure with jointing beams in roof and floor was the most optimal one, whose top arch strength became3.51times and bottom arch became2.715times stronger than the original structure without additional beams. Through similar simulation experiments of frameworks, this paper obtained different evolutionary rules of structure’s strength and stiffness. And we evaluated improved framework’s supporting effects by numerical simulation.