无衬砌浅埋隧洞松散压力的数值分析法

将极限平衡理论和弹塑性理论相结合,利用ANSYS和FLAC3D数值分析软件来计算浅埋隧道松散压力。计算时先将土体强度参数进行折减,隧道开挖后不做衬砌,在拱顶施加与重力方向相反的节点力,通过调整施加的反力大小使隧道处于破坏极限状态,即极限平衡状态;通过软件是否收敛来判断隧道是否破坏。该方法考虑了土体材料的特殊性,有严格的力学依据,计算结果与实际情况更加接近,为求解浅埋隧道松散压力提供了一种新的方法。

Numerical Analysis of Surrounding Rock Pressure on Shallow Buried Tunnel

Based on the limiting equilibrium theory and elastic-plastic theory,surrounding rock pressure on shallow buried tunnel was calculated by the numerical analysis software ANSYS and FLAC3D.The soil strength parameters should be reduced before calculation,then nodal force was applied in the opposite direction of the gravity on the vault after excavation of tunnel with no-lining;then the nodal force was adjusted to get the limit state of the tunnel destruction,that was,the limit equilibrium.In the calculation,the convergence reflected whether the tunnel was destroyed.The method not only takes into account the speciality of soil material,but also has strict mechanics basis.The calculating result is more coincident with the reality,and this method offers a new way to calculate the surrounding rock pressure on shallow buried tunnel.