动力扰动下深部巷道围岩力学响应FLAC分析

FLAC Analysis of Mechanical Response of Surrounding Rock Mass in Deep Tunnel

深部巷道具有强烈的动力扰动特征。采用有限差分数值计算软件FLAC(Fast La-grangian Analysis of Continua)对动力扰动下巷道围岩力学响应进行了数值分析。结果表明:动力扰动增大巷道顶、底板的水平应力峰值,并使峰值位置后置;扰动后巷道顶板下沉量及巷道围岩塑性区范围显著增加。原岩应力越大,动力扰动对巷道围岩应力场、位移场及塑性区范围影响就越显著,对于深部高应力巷道,动力扰动可使巷道顶、底板的水平应力峰值达到极高应力状态,并存在大范围的塑性屈服区域,具有发生岩爆的危险。

The deep tunnel has strong dynamic disturbance characteristics. A series of numerical simulation tests have been carried out using a finite difference code FLAC （ Fast Lagrangian Analysis of Continua） to study mechanical responses of tunnel surrounding rock mass under the action of dynamic disturbance. A 60m×60m plane strain model containing a single 4m×4m centrally located tunnel is built and the dynamic disturbance is simu/ated by adding a sinusoid wave at the bottom of the model The results show that after the action of dynamic disturbance, the magnitude of the highest horizontal stress both in the roof and floor of the tunnel will increase. And the distances from the roof line and floor line to the location of the highest horizontal stress will also increase. Significant downward roof movement increasing and plastic yield fields increasing can also be observed. The higher the in situ stress, the more significant dynamic disturbance influences on stress fields, displacement fields and plastic yield fields. Especially for the high - stress deep tunnel, dynamic disturbance may lead the highest horizontal stress increasing to a very high status in company of a large plastic yield fields and a critical status of rock crump.