Research On Control Technology Of Roadway With Soft Surrounding Rock In Tectonic Stress Area

With the increase of coal mining depth,the tectonic stress is complex and changeable,causing the surrounding rock control problem of deep soft rock roadways to be particularly prominent.Therefore,it is very important to study the deformation and failure characteristics of the soft surrounding rock roadway in the tectonic stress zone,the surrounding rock deformation mechanism and the surrounding rock control technology.This article takes the soft surrounding rock roadway in the tectonic stress area of Nuodong Coal Mine as the research object,combines the existing support methods of the auxiliary tunnel,and uses the method of field investigation and monitoring,laboratory test,theoretical analysis,numerical calculation and underground engineering test.The deformation and failure laws of loose and soft surrounding rock roadways in the tectonic stress zone are studied,and based on the stress control principle,the combined control technology measures of "blasting pressure relief(stress transfer)+ grouting reinforcement + anchor cable reinforcement" are proposed for the soft surrounding rock roadway in tectonic stress zone.The main research results obtained are as follows:(1)Aiming at the deformation and failure characteristics of the surrounding rock of the roadway in the tectonic stress zone,the XRD diffraction experiment and the surrounding rock mechanics test are used to preliminarily analyze the cause of the deformation and failure of the surrounding rock of the roadway,combined with on-site drilling detection and comprehensive monitoring of underground pressure,to analyze the appearance of underground pressure of the original support The results show that the surrounding rock of the roadway is extremely soft and in the plastic failure zone under the influence of tectonic stress,resulting in low anchoring force of the bolt(cable)and poor anchoring effect;showing the bottom heave volume of the roadway and the moving of the two sides.(2)Applying elastoplastic theory,rheological mechanics theory and FLAC3D numerical simulation calculation to study the deformation and failure mechanism of soft surrounding rock roadway in tectonic stress zone.The research results show that:under the influence of tectonic stress,the degree of deformation of the surrounding rock of the roadway is related to the accumulation of time.The longer the time,the more serious the deformation and the creep characteristics;with the increase of the horizontal tectonic stress,the roadway floor will be damaged,and the stress of the surrounding rock The transfer of the roadway and shoulder angles leads to the gradual increase of the plastic zone range,the surrounding rock stress reaches the maximum at the range of 5-6m from the roadway wall,and the damage depth range can reach 5m,indicating that the horizontal tectonic stress affects the deformation and failure of the surrounding rock of the roadway.Play a leading role.(3)Aiming at the problems of large buried depth,stress concentration and supporting problems of the soft surrounding rock roadway in the sub-flat cave tectonic stress zone,the combined support technology measures of "blasting pressure relief(stress transfer)+ grouting reinforcement + anchor cable reinforcement" are proposed.Underground tests were carried out.The mine pressure monitoring showed that the stress concentration of the roadway floor and sidewall was reduced,the overall strength of the roadway surrounding rock was improved,the deformation of the roadway surrounding rock was reduced,and the deformation of the soft roadway surrounding rock in the tectonic stress area was effectively controlled.