Abstract: With the increasing traffic mileage and operation time of tunnels in China, more and more tunnels have entered a period of high disease incidence. Groundwater is one of the most important factors easily causing the water leakage in tunnel lining. In this paper, a three-dimensional geomechanical model test system was developed to investigate the mechanism of the water leakage disease in tunnel lining with different buried depths. The model test system was composed of an extendable model bench, a loading system of ground stress and hydraulic pressure, a multivariate information real-time monitoring system and water leakage real-time measuring device. Using oil jacks and multi-function water pump, the system can simulate the behaviors of tunnels at different buried depths by the stepwise loading method. This model test system was applied to simulate the water leakage in tunnel lining under different buried depths. The evolution law of seepage disease in the tunnel lining crossing cross-fault tunnel under different burial depths was revealed through the analysis of seepage quantity, the seepage pressure and displacement information. At the same time, a preliminarily study was conducted on the combined treatment of blocking and drainage. The positive effect of drainage on reducing the lining seepage quantity was verified. The test results are in good agreement with the results from Kaiyuan tunnel lining seepage disease in operation period. This study proves that the system is stable and reliable, and the research methods and results can provide useful references for related projects.

Key words: crossed faults, operational tunnel, lining water leakage disease, model test