冲击载荷作用下不同断面形状巷道稳定性数值仿真分析

为了研究动载荷作用下井巷的稳定性,基于波动冲击理论,利用FLAC~(3D)值模拟软件,对深井不同断面巷道在动载荷作用下的围岩位移场变化规律进行了数值仿真。结果表明:不同巷道断面形式对冲击荷载作用的响应程度存在显著差别,巷道顶板监测点的速度产生波动从大到小依次为矩形、直墙拱形和圆形断面巷道;巷道顶板均产生明显下沉,矩形断面巷道的下沉量最大,其次是直墙拱断面巷道,圆形断面巷道的下沉位移最小;对于巷道围岩垂直应力的分布范围,圆形断面巷道最小,矩形断面巷道最大,直墙拱断面巷道居中,并得到了现场监测结果验证。

Numerical simulation analysis of the different cross-sectional roadway stability under the strong shockwave loading impact

Based on the shock wave theory with the help of the numerical simulation software FLAC3D,this paper is aimed to make an analysis of the changing regularity of the migrant behavior of the surrounding rock under the dynamic load,which is also affected by the different shapes of the cross-sections of the deep wells of the tunnel roadways.The results of our simulation show that the shapes of roadway sections have an important impact on the shockwave loading responses.Practically speaking,there exist different speed fluctuations at the monitoring points from the roadway roof.What is more,such fluctuations can be done in an decreasing order in different ways,such as in rectangular,straight or circular directions in the wall arch or along the roadway,resulting in the subsidence of the roadway roofs.The biggest subsidence may take place where the shape of the roadway section is rectangular.The middle way of the subsidence goes on in the straight wall arch,whereas the smallest occurs with the circular part of the roadway section.According to the data given by the site monitoring,remarkable deformation tends to take place in the area of the surrounding rock,whereas the deformation speed of the other sections of the roadway slows down gradually.On the other hand,when the vibration shock occurs,the convergence of the surrounding rock along the roadway becomes rather obvious.Generally speaking,the above said three kinds of surrounding rock migration can be characterized by a gradually increasing tendency.While the migration of the surrounding rock of the rectangular roadways appear near the biggest,the straight wall arch part of the roadway tends to be migrating in the middle,with the circular section of the roadway being closer to the minimum.Thus,the conclusion of our numerical simulation has been proved by the site monitoring,which has made it qualified to serve as a valuable theoretical reference for cross section optimization of roadway under the action of impact load and the stability control of the surrounding rock of roadway.