The Local Weak Supporting Conditions Of Deep Soft Rock Tunnel Surrounding Rock Deformation Law Research

Since the beginning of the 21 st century,China's energy demand has surged,and coal as the main supply mode of energy in China has increased greatly.Transfer gradually from the surface to the deep coal mining,and in the process of deep soft rock tunnel supporting a large number of urgent problems,such as the deep parts of the high voltage stress,surrounding rock of roadway in deep rock mass deformation and knobbly rationality and roadway surrounding rock crushing,such problems as loose.Therefore,the support problem of deep soft rock roadway under high ground stress has become an important and urgent problem in coal mining.Study of deep soft rock tunnel surrounding rock characteristics change over time,the deformation of surrounding rock under the condition of local supporting situation and for the deformation law of surrounding rock of roadway supporting method has important research and practical value.Paper considering the creep of the rock and dilatancy effect at the same time,the uniform in deep soft rock tunnel excavation under the support of surrounding rock creep theory analysis,analysis of the surrounding rock displacement change over time,the surrounding rock under the condition of uniform support different supporting force and the displacement of wall rock,the surrounding stress field distribution,the creep rate of change of surrounding rock and different influence on the displacement of surrounding rock dilatancy effect,studies have shown that the uniform supporting force of the surrounding rock displacement has obvious constraint effect,increase the supporting force of wall rock and support in advance to support an important role.Papers on the condition of the local weak support circular roadway cross section for the model,using the theory of elastic mechanics and plastic mechanics knowledge,combined with the radius of elastic-plastic,three dimension stress and principal stress rotation Angle concept,analysis of surrounding rock stress path,the deep soft rock tunnel surrounding rock under the condition of the local weak supporting stress changes.Studies have shown that under the condition of the local weak support for the destructive effect of surrounding rock in addition to the stress and supporting stress,the main factors of surrounding rock stress path also occupies an important share,surrounding rock spalling,the bass drum,and other forms of damage are related to this.On the basis of the above theory,semirigid type combined bolting and shotcrete net shell structure was applied to south alleys Du Er ping mine of xishan coal and electricity,for south alleys and broken zone adopt semi-rigid net shell structure design of new technology support by rockbolt and shotcrete.The engineering application shows that the shotcrete supporting structure of semi rigid reticule has obvious supporting effect on deep soft rock roadway.