Research On Surrounding Rock Control Technology Of Deep Roadway In Jinqingding Mining Area

The Jinqingding mining area has entered deep mining,which is affected by the multiple influences of deep high stress and strong excavation disturbance,coupled with the broken rock mass,the development of joints and fissures,and the stability of the roadway is greatly challenged.In view of the complex engineering rock mass environment in the deep,the mine adopts the conventional support method to support the roadway,and there is a great risk of support instability.Therefore,it is necessary to carry out research on the excavation mechanism of the deep roadway and the stability control technology of the surrounding rock.Combined with the deep geological conditions of the Jinqingding mining area,this paper comprehensively considers factors such as the magnitude of in-situ stress,the influence of groundwater and the integrity of surrounding rocks,on the basis of the quality evaluation and classification of surrounding rock,the support theory of the deep roadway in the mining area is analyzed.The numerical simulation method is used to optimize the support parameters,and then the support design and surrounding rock stability control measures for the deep roadway in Jinqingding mining area are proposed,which realizes the purpose of supporting the deep roadway safety.The main research contents and research results of the paper are as follows:(1)The deep geological data of Jinqingding mining area were consulted and analyzed,and the on-site investigation of rock fracture,roadway support and instability was carried out in the mining area.The characteristics of the deep engineering environment of Jinqingding,the supporting structure of the roadway and the form of supporting damage were found out,provided basic parameters and basis for support design and surrounding rock control;(2)Based on the five conventional evaluation indexes of RMR,a rock mass quality evaluation and correction method is proposed,which adds the rock mass strength-stress ratio and blasting vibration coefficient as supplementary indexes.Combined with the specific stress environment in the deep part of the mining area,the quality of the surrounding rock in the deep roadway of Jinqingding was evaluated,and it was determined that the quality of the surrounding rock in the mining area was mostly grade III,and a small amount was grade II;(3)According to the instability mechanism of rock formation,a design scheme of deep roadway support in Jinqingding mining area,which is supported by prestressed resin bolts + shotcrete + local metal mesh,is proposed.Numerical simulation method and entropy extension matter element method are used to establish the evaluation model of deep roadway support effect,and the roadway support parameters are optimized;(4)A method is proposed to use the self-developed intelligent monitoring equipment for metal mine ground pressure to monitor the stress and failure vibration parameters of surrounding rock in real time,so as to test the pros and cons of the support scheme and the stability of the roadway.The monitoring results show that without support,the thickness of the surrounding rock loose area can reach 2.6m,and the damage is serious;while after the roadway is supported,the stress changes gently,and the surrounding rock damage and vibration events are greatly reduced,indicating that the support scheme is reasonable and the support design effect is good.