盾构偏仰角影响下隧道掌子面稳定性分析

Stability Analysis of Tunnel Face under the Influence of Shield Tunneling Inclination Angle

为探究任意偏仰角影响下纵向倾斜隧道掌子面的稳定情况,以Hoek-Brown强度准则为例,考虑隧道纵向倾角的影响。利用空间离散和点生点技术,改进现有的隧道掌子面三维主被动破坏模型,求解了倾斜隧道掌子面的主被动破坏极限支护压力,并建立了非线性Hoek-Brown准则下倾斜隧道掌子面三维主被动破坏模型。通过本文模型计算结果与数值模拟结果对比分析,以验证本文所建立的非线性Hoek-Brown准则下倾斜隧道掌子面三维主被动破坏模型的合理性。结果表明:本文所建立的非线性Hoek-Brown准则下倾斜隧道掌子面三维主被动破坏模型与数值模拟结果之间最大误差小于5%,拟合效果良好,适用于倾斜隧道的掌子面稳定性分析问题;任意偏仰角引起隧道与水平面之间的倾角是影响掌子面稳定性的重要因素,在实际施工中应予以格外关注,可为类似隧道盾构施工的安全性提供有效的理论指导与参考。

In order to investigate the stability of the longitudinal inclined tunnel face under the influence of any inclination angle,using the Hoek-Brown strength criterion as an example,considering the influence of the longitudinal inclination angle of the tunnel,using spatial discretization and point generation techniques,the existing 3D active passive failure model of the tunnel face was improved,and the ultimate support pressure of the active passive failure of the inclined tunnel face was solved.A three-dimensional active passive failure model for the inclined tunnel face under the nonlinear Hoek-Brown criterion was established.By comparing and analyzing the calculation results of this model with the numerical simulation results,the rationality of the three-dimensional active passive failure model of the inclined tunnel face under the nonlinear Hoek-Brown criterion established in this paper is verified.The results show that:The maximum error between the three-dimensional active passive failure model of the inclined tunnel face established in this paper and the numerical simulation results under the nonlinear Hoek-Brown criterion is less than 5%,and the fitting effect is good,which is suitable for the stability analysis of the inclined tunnel face.The inclination angle between the tunnel and the horizontal plane caused by any deviation in elevation is an important factor affecting the stability of the tunnel face,and special attention should be paid in practical construction,providing effective theoretical guidance and reference for the safety of shield tunneling similar to tunnel construction.