Stability Analysis And Support Design Of Roadway Surrounding Rock After Water Inrush In Coal Mine

After the occurrence of flood in coal mine,it is not uncommon to see roadway failure and instability.After the impact of water disaster,the strength of roadway surrounding rock decreases,stability becomes worse,and physical and mechanical parameters are weakened.However,the existing understanding of roadway failure mode and surrounding rock force after water inrush is not comprehensive,and the theoretical basis is insufficient,leading to unreasonable treatment and repair methods,and failing to reach the expected treatment effect.In order to resume production,roadway maintenance and reinforcement need to be carried out again,which wastes more manpower and material resources,and also brings hidden dangers to the safety production of underground workers.In view of these problems,this paper studies the stability and safety evaluation of roadway surrounding rocks after water inrush and the repair of roadway after disaster.The main research conclusions are as follows:(1)Summarize the current situation of prevention and control after water disaster and basic measures of prevention,and control,and understand the safety plans and measures for mine recovery after disaster and the treatment effect.After water inrush,the stiffness,elasticity and residual strength of rock become smaller,and the characteristic curves of rock strength and deformation under the action of water are obtained.According to the actual lithologic changes of roadway roof and roadway failure forms after water inrush,reasonable and safe support methods and materials are selected,providing guidance for later roadway support reinforcement and reinforcement.(2)After the water inrush mechanics model is set up and carry on calculation and analysis of roadway,the original function and water disasters affect the surrounding rock of roadway supporting role equivalent for the cohesive force and the change of the internal friction Angle,water results in the decrease of physical and mechanical parameters of surrounding rock,with the change of water pressure Pw,surrounding rock plastic zone radius R’p also with change,the water pressure increase scope of the plastic zone also increases gradually,finally lead to instability and destruction of roadway.With the change of surrounding rock plastic zone radius,the tunnel wall displacement gradually increases,and the tunnel wall displacement is in direct proportion to the water pressure borne by the roadway.The reinforcement and reinforcement of roadway support after water inrush can ensure the safety of underground workers in the resumption of production.The actual scheme should be determined according to the specific situation of the site,and reasonable,effective and safe roadway repair and support scheme and reinforcement parameters should be selected.(3)By analyzing the change of plastic zone of surrounding rock of roadway after water inrush,proceed the anchor rope(rod)reinforcing roadway supporting and reinforcement design and analysis of the supporting effect of rationality,after calculating the reinforcing supporting intensity,the results show that the new supporting design can guarantee the roadway deformation,satisfies the requirement of production safety,and surrounding rock grouting reinforcement concrete parameters should make reasonable according to the practical situation.This paper studies surrounding rock deformation and failure mode,surrounding rock stress and displacement variation rules after water inrush,providing theoretical guidance for later roadway support design,reinforcement and safety evaluation,and guiding mine post-disaster production to put forward corresponding reasonable and safety prevention and control measures.