Research Of Roadway Deformation Feature And Instability Discriminant Based On Similar Simulation Experiment

Roadway which is bearing the ventilation, transportation, pedestrians and other functions, plays an important role in coal mining and the stability of roadway is critical to coal mine safety and efficient production. In recent years, due to the strength of mining and mining depth increases, coupled with the complicated geological conditions, mining stress and tectonic stress superimposing, so that the roadway of underground mining area produce large deformation, instability and failure easier, and even due to rock burst, shock bump or Strong mine pressure behaving causes the damage of roadway. How to monitor the stability of roadway that is in the range of stress and timely making early warning of dangerous conditions such as roadway deformation and instability is an important research content in coal mine safety monitoring.For the actual of roadway deformation and instability in monitoring, in this article, the simulation experiment of roadway deformation and failure and strain test system are established. On the basis of the strength test within different material ratio which determines the optimum ratio needed by similar model,the physical simulation research of deformation of surrounding rock in roadway is conducted,and the variation characteristics of macroscopic stress and strain of loaded roadway model deformation and failure is tested. At the same time variation Characteristics of roadway internal strain is also tested by the pre-implantation FBG sensor. Combined with RFPA numerical simulation results, the deformation failure mechanism of surrounding rock is analysed. Finally, according to the timing variation characteristics of bending tensile strain in internal surrounding rock of roadway,the surrounding rock instability determination conditions based on internal strain monitoring is proposed. The thesis makes the following research results:(1)Through the experiment of strength of similar material within different ratio,the main mechanics parameters of Sand paraffin mixture ratio of 8 kinds of circumstances are tested,then to determine the sand / paraffin 100: 12 as similar model materials needed for the best ratio.(2)With establishing a simulation experiment of roadway deformation and failure,Surrounding rock deformation process physical similarity simulation test is conducted,obtaining that complete stress-strain curve of the model deformation and failure process can be divided into four stages: Consolidation stage, loading stage, failure stage and stage after damage.(3)The roof sinking and supporting pressure in deformation and failure process of roadway model under load is tested and analysed, but also the Variation Characteristics of Vertical and lateral load, and the internal strain Variation Characteristics of surrounding rock.(4)Within the RFPA2 D software, the numerical simulation analysis for plane stress distribution concentrated and flat crack propagation generating development of roadway model is made.(5)Based on internal strain monitoring, roadway instability determination conditions is proposed:①strain showed increasing trend, and its absolute value is large or strain values increase rapidly in a short time; ②strain showed increased and then decreased after the first characteristic, or irregular fluctuations.This paper provides a new way of thinking for the roadway surrounding rock experiment simulation research, and has important theory value and practical significance to understand and instability of surrounding rock of roadway deformation and destruction.