关键词: 弱胶结软岩巷道, 围岩控制, 失稳机理, 塑性区

Abstract: Based on the geological conditions in shallow-buried, weak-cemented soft rock in the west of China, the failure mechanism of mine roadway is revealed by the X-ray diffraction, electron microscopy, test of rock mechanics and on-site monitoring; FLAC3D numerical simulation mode is established to simulate the stress distribution, surrounding rock displacement and range of plastic zone in mine roadway by the large deformation theory of mine roadway. The results show that the maximum principal stress of the surrounding rock of weak cemented soft rock roadway determines the failure depth of the surrounding rock, which is approximately distributed with the depth of the surrounding rock in the shape of “へ”. The relationship between the deep deformation “s” in different directions of the surrounding rock and the surface distance “h” of the roadway is negative exponential decay. The accord of plastic zone range in mine roadway proved true by the comparative analysis of the FLAC3D simulation and GPR exploration, giving a scientific guideline for the stability analysis, design of supporting and reinforcement scheme of the roadway surrounding rock in slight contact cement rock conditions. Finally, targeting the range of the plastic zone in slight contact cement rock roadway, the technology of combining support of anchor net spray active support +36U steel support + full section anchor injection is proposed to determine the plastic zone range of mine roadway in slight contact cement rock conditions, which can control the deformation of the surrounding rock and the expansion of the plastic zone effectively, having been showed by on-site monitoring results.