Abstract:
According to the stress of a circular hole in elastic-plastic mechanics and using Mohr-Coulomb strength criterion, we deduced the boundary equations of circular roadway plastic zone in uneven stress field. From the perspective of theoretical analysis and numerical simulation, and compared and analyzed the effect on the distribution of the circular roadway plastic zone under the factor of lateral pressure coefficient, rock lithology and tunnel radius. The results show that under the non-uniform stress field, the lateral pressure coefficient has more influence on the shape and distribution of plastic zone, the plastic zone size of the larger load direction is smaller than that of the smaller load direction; the harder of the roadway rock, the smaller of the range of plastic zone; when the surrounding rock is weak rock, the plastic zone is approximate butterfly distribution, and when the surrounding rock is harder rock, the plastic zone distribution is approximate elliptic. The influence of roadway excavation on the distribution range of the plastic zone of surrounding rock is larger; at the same angle, the radius of plastic zone is linear increase with the increase of tunnel radius.