Tunnel leakage can cause changes in stress and pore water pressure of the ground, which may affect tunnel stability and ground movement. Long-term or large-scale water leaks may cause adverse effects on tunnel stability and the surrounding ground environment, such as tunnel lining instability and surface settlement. In the present study, the water leakage-induced behavior of a tunnel and the surrounding ground was numerically investigated. The tunnel was assumed to be under undrained conditions for preventing water from entering the tunnel and groundwater level drawdown. Leakage occurred in the concrete lining after the completion of the tunnel construction. A Python-based TOUGH-FLAC simulator was developed for coupling analysis. To verify the applicability of the developed simulator, the computational accuracy of the simulator was evaluated based on a benchmark problem with an analytical solution, which involves the coupled behavior of the ground around a heat source. The present simulator was then applied to a coupled hydro-mechanical problem related to tunnel leakage. The coupled responses of the tunnel lining and ground induced by leakage were analyzed, and the impact of leakage conditions was examined under different conditions of the location and amount of water leak. Additionally, the effect of the hydro-mechanical coupling terms of the governing equations involved on the results of the coupled response was investigated and discussed.

中文翻译：

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渗漏水对地表沉降及隧道稳定性影响的数值研究

隧道渗漏会引起地面应力和孔隙水压力的变化，从而影响隧道稳定性和地面移动。长期或大面积漏水可能会对隧道稳定性及周围地面环境造成不利影响，如隧道衬砌失稳、地表沉降等。在本研究中，对隧道和周围地面的漏水引起的行为进行了数值研究。假设隧道处于不排水条件下，以防止水进入隧道和地下水位下降。隧道施工结束后，混凝土衬砌发生渗漏。开发了基于 Python 的 TOUGH-FLAC 模拟器用于耦合分析。为了验证所开发的模拟器的适用性，基于解析解的基准问题评估了模拟器的计算精度，其中涉及热源周围地面的耦合行为。然后将本模拟器应用于与隧道渗漏相关的耦合流体力学问题。分析了渗漏引起的隧道衬砌和地面的耦合响应，考察了不同渗漏位置和渗漏量条件下渗漏条件的影响。此外，还研究和讨论了控制方程的水力耦合项对耦合响应结果的影响。