The Numerical Analysis Of The Stability Of The Large Section-Y Arched Roadway Intersections

According to statistics, at present, with the increasing of the mining depth in mine, about6000km engineering quantity of roadway and the large number of intersections to meet the need of pedestrian, ventilation and transportation with it. However, because of its large section, and the influence of stress concentration which cause the deteriorate of arched roadway intersections and more instability renovations, which also costs much money and what’s more, it’s harmful to the security of underground and people who work there.But at present, the stability study on intersection is mainly on the rectangle roadway intersections and a few of them are on the systematic and detailed ones of long-year service and high demand of stability. In addition, due to the stability of the arch itself, so stable research of rectangular roadway crossing point has its limitations, there is no much reference value.Based on previous studies, on the one hand, considering the issue of Y-cross point of surrounding rock stability control, articles using FLAC3D software S-B modeling method for different crossing angle, depth of rock strength, coefficient of lateral pressure and excavation sequence of factors affecting the value simulation analysis. On the other hand, in order to reveal the law of complex bended roadway intersection influenced by excavation sequence and to find the reasonable excavation sequence, the excavation sequence of complex bended roadway intersection was numerical simulation analyzed using FLAC3D software. The results show that:1. Compared with the coefficient of lateral pressure with a cross-point perspective, depth and intensity of surrounding rock, excavation sequence a more significant impact on the cross-point. Depth and rock strength on the stability of the intersection of the existence of a turning point, when the parameter is greater than the inflection point will have a greater damage. Coefficient of lateral pressure cross point is mainly reflected in the cross point of the plastic zone size, although no law, but the fluctuation range. 2. The plastic zones of intersection are affected by excavation sequence relatively obvious, the plastic zones caused by B and E excavation sequence less than the others. While, the surrounding rock deformation and vertical stress of intersections are affected by excavation sequence is not obvious, it mainly embodies that the asymmetry of roof deformation and the difference of roadway’s sides displacement with the excavation sequence changing. Therefore, the balance unloading method should be selected when excavating the complex bended roadway intersection and the conditions permit, avoid excavation along direction from branch roadway to main roadway and superposition effect comes from Non-simultaneous excavation to improve the stability of roadway intersection and insure safety and high effective product of mine.