Abstract Pore pressure evolution induced by tunnel excavation in low permeability anisotropic ground is investigated by means of a fully coupled hydro-mechanical finite element simulation. The goal is to explore the main trends of the pore pressure evolution on the basis of a poroelastic analysis, taking into account: on the one hand, the influence of excavation and face advance; on the other hand, the inherent anisotropy of the material. It is shown that overpressures can be induced before the passage of the face, depending on: the consolidation time of the rock, the rate of excavation and the degree of anisotropy of both the material and the initial stress state. Finally, a discussion about pore pressure evolution at tunnel wall is presented. An analysis is performed in order to propose a pore pressure release rate at the tunnel wall for 2D models.

中文翻译：

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低渗透率各向异性地基隧道开挖二维/三维多孔弹性分析的主要见解

摘要 通过全耦合水力-力学有限元模拟研究了低渗透率各向异性地层中隧道开挖引起的孔隙压力演化。目的是在多孔弹性分析的基础上探索孔隙压力演化的主要趋势，同时考虑：一方面是开挖和工作面超前的影响；另一方面，材料固有的各向异性。结果表明，过压可以在工作面通过之前诱发，这取决于：岩石的固结时间、开挖速度以及材料和初始应力状态的各向异性程度。最后，讨论了隧道壁面孔隙压力的演变。