Research On The Law Of Large Deformation And Stability Control Of Surrounding Rock Of Mining Roadway

With the increasing inclination to deep mining of coal resources in our country, the post-pear large deformation of surrounding rock in mining roadway has become a common phenomenon. Because of limitations in the roadway layout and lithology selection,as well as great impacts from working face mining and adjacent roadway excavation,mine pressure appears relatively severe.Thus the mining roadway surrounding rock is highly vulnerable to post-peak large deformation, and vast majority of surrounding rock even stay in deformation state since the excavation begin. Mining roadway always characterises with short service life, long excavation mileage, high mining frequence and safety performance requirements. And for most researches, there always stands a difficult problem, that is how to strike a balance between security and economy.In order to effectively control the fracture of roadway and disaster caused by post-pear deformation of surrounding rock. The evolution and instability law of large deformation of mining roadway, supporting and balancing law, supporting control technology are deeply investigated based on theoretical analysis,laboratory physical, mechanical tests and RFPA numerical simulation. The maincontents and conclusions obtained are listed as follows:(1) Fracture law of rock mass in one direction and three direction compression state are studied by laboratory mechanics test and RFPA numerical experiments.Especially with the use of RFPA simulation method, detailed process from initial crack to great damage of rock mass is analyzed, thus the acoustic emission laws accompanied with the whole process of rock fracture is obtained.(2) Gradual evolution law of four typical mining roadway is studied with RFPA numerical simulation. Results explained the evolution of the mining roadway, that is with the deterioration of the weak parts of the roadway, the overlying roof will be unstable and collapse which furtherly leads to the overall instability of roadway.(3) The surrounding rock of mining roadway is partitioned based on the research of rock mass fracture law. The results illustrate that the post-peak deformation of large deformation roadway is a dynamic and gradual evolution process,the deformation and unstability of the roadway show certain progressive and dynamic characteristics.(4) The size of required supporting force is obtained, and to a certain extent,the balance rule between the post-peak area of surrounding rock and supporting force is verified based on the Systematic analysis of Fluctuating equilibrium law of Surrounding rock in large deformation of mining roadway and deducing of load distribution of surrounding rock from the perspective of damagemechanics.(5) A type of grouting anchor rod is theoretically conceived based on the research on interaction mechanism of individual partition’s load belt and bearing belt of post-peak surrounding rock in large deformation roadway.Consequently,the post-peak surrounding rock in in different partition can give full play to its carrying capacity, so as to control the surrounding rock deformation.