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Many large landslides in reservoir areas have been recognized as the presence of multi-sliding zones owing to the distinctive deformation characteristics. Due to water-level fluctuations, the deformation mechanism of the multi-sliding zones landslide is poorly understood. Herein, a simplified model of a multi-sliding zones landslide subjected to the operation reservoir was conducted to reproduce the deformation process and obtain the deformation characteristics, pore water pressure, and earth pressure to investigate the deformation mechanism. The results suggest that the deformation exhibited by the multi-sliding zones landslide subjected to the operated reservoir take on a regional deformation characteristic with the multi-sliding zones as the boundary and correspond to the abrupt change in earth pressure and pore water pressure. According to the effective stress principle, the deformation mechanism is investigated by relying on the response relationship between effective stress and deformation. It shows that the softening effect caused by initial water infiltration, outward seepage force caused by initial water-level drawdown and the driving force are the external factors triggering the regional deformation of the multi-sliding zones landslide, while the immediate cause of the regional deformation is the rapid change in effective stress, which combined with the decreasing trend before the rapid effective stress release, is crucial for accurately assess whether the multi-sliding zones landslide is about to deform. This research provides improved insight into the deformation mechanism of the multi-sliding zones landslide. [ABSTRACT FROM AUTHOR]

Well-connected seepage channels are the key components of tunnel water inrush. To study the trends of the pore water pressure in the rock mass in a seepage channel, the physical experiment and corresponding numerical model were established. First, in the seepage experiment under excavation disturbance, the propagation rate of the high-pressure water source and the growth rate of the pore water pressure in the rock mass were analyzed by considering the different water pressures. Second, under the same model size, parameters, and working conditions, the finite element method was used to simulate the seepage process of water in the rock mass. From the microlevel, the evolution process of the pore water pressure isosurface was obtained. The results showed that the pressure water head is positively correlated with the pore water pressure in the rock mass, which displays multiple approximate relationships. Moreover, when the water pressure is high, excavation disturbance can significantly increase the pore water pressure in the rock mass. The disturbance caused by the first excavation is larger than the subsequent excavations. In addition, the research results were compared with previous results. Reasonable agreements that would provide a reference for the conditions of high water-pressure disasters in deep buried tunnel construction were obtained. [ABSTRACT FROM AUTHOR]