In recent years, with the increasing difficulty of foundation pit projects, the frequency of leakage accidents has also increased. In order to ensure that the excavation of foundation pits is carried out smoothly, water-stop curtains are generally used to protect the foundation pit. Once leakage occurs in the water-stop curtain, it will inevitably delay the schedule, cause significant harm, and even jeopardize life. Therefore, this paper analyses and investigates the two-steady-state seepage field of the foundation pit when the permeable anisotropic soil layer suspends the leakage of the water curtain. To calculate head distribution solutions, the soil layer surrounding the curtain was divided into five regular regions, and the superposition method and method of separating variables were used. These results were then combined with the continuity conditions between the regions to obtain the explicit analytical solutions of the seepage flow field around the pit. Calculations were compared using finite element software and other references, and the results were in good agreement, verifying the correctness of the analytical solution. Parameter analysis showed that the location and width of vertical leakage cracks have limited influence on the head distribution of the foundation pit and water pressure around the water curtain, but significant influence on the seepage flow at the leakage location.

During the construction of coastal projects, the formation of seepage channels within the soil body, induced by fluctuating water pressure, can result in consequential damage to the soil structure, ultimately culminating in sudden water gushing sand disasters. In order to investigate the impact of static and dynamic seepage pressures on sand flow and water flow conditions, an intelligent water pressure loading device was devised to consistently apply a confining pressure of 60 kPa to the specimens. The three static seepage pressures and nine fluctuating seepage pressures were applied to the specimens under the condition of constant confining pressure to study the effect of static and dynamic seepage pressures on sand flow and flow conditions. The outcomes of the experiments revealed that, when the base water pressure of the dynamic seepage pressure is the same as the static seepage pressure, the cumulative seepage volume and permeation velocity of the dynamic seepage pressure are always larger than that of the static seepage pressure. Moreover, higher static pressures increase forces on particles, enhancing permeation velocity, and cumulative seepage volume. Notably, longer periods of pressure fluctuations in dynamic seepage pressures and lower basic water pressures weaken the effect of dynamic seepage pressures.