Coal Engineering ›› 2019, Vol. 51 ›› Issue (9): 127-131.doi: 10.11799/ce201909028

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The deformation law of borehole under different stress state is studied

  

  • Received:2019-03-18 Revised:2019-05-09 Online:2019-09-20 Published:2020-05-11

Abstract: The COMSOL numerical simulation software was used to establish a three-dimensional rectangular roadway borehole crossover model to study the circumferential stress distribution and displacement of the borehole under the influence of different ground stresses. The research shows that by analyzing the Mises stress distribution around the borehole under different ground stresses, the compressive stress on the left and right sides of the borehole is obtained, and the upper and lower sides are subjected to tensile stress, showing a "butterfly shape". Through numerical simulation and field test, it is shown that the borehole is affected by overburden rock stress and roadway stress redistribution, and it is easy to produce borehole damage within the range of 0~20m from the orifice, which is about twice the width of the roadway. By analyzing the stress distribution and displacement variation of the borehole under different earth stresses, the circumferential stress and displacement of the borehole exhibit a strong power exponential relationship with the increase of the bore depth.