Abstract:

Excavation and construction of hydraulic structures and other human activities in natural slope disturb the original stability of the slope, change the original structure of the slope and then form a more complex hydraulic slope. At the same time, the stability of the hydraulic slope is directly related to the safety of hydraulic structures, and even affects the safety construction and normal operation of the entire project. In this paper, the stability of the surge shaft slope in a hydropower station is analyzed with both rigid limit equilibrium method and finite element method from two-dimension and three-dimension perspectives. The results show that when studying the stability of slopes which have shafts, the three-dimensional analysis is required. When studying the stability of these slopes with two-dimensional method, the position of selected sections should be considered. If the selected sections cross the shafts, the results are usually different from the actual situation and show the slope is unstable while the slope is actually stable. So if two-dimensional method is employed to research the stability of these slopes, the stability of both sections which crosses the shaft and sections beside the shaft should be considered comprehensively. This research serves as a reference for the stability analysis of complex hydraulic slopes with shafts.

Key words: hydraulic slope, slope stability analysis, rigid limit equilibrium method, finite element method, three-dimensional effect