Seepage Characteristics and Stability Analysis of Transmission Line Tower Bank Slope Under the Action of Reservoir Water

Abstract

Based on the saturated unsaturated seepage theory and Geo-studio software (SEEP/W and SLOPE/W modules), this article calculates the seepage feature and stability coefficient of the reservoir bank slope of a 220kV transmission line N47 tower in Western Sichuan, it shows that the slope stability and seepage field are affected by the rising and falling speed of reservoir level. The analysis results explain that with the increase of the rising rate of reservoir level, the pore water pressure increases rapidly, the slower the rise of a phreatic line is, and the more obvious the depression is. The faster the drawdown rate of reservoir water level is, the faster the decrease of pore water pressure is, the slower the decline of saturation line is, and the more obvious the upward convex is. During the rise of reservoir level, it is beneficial to landslide stability, but with end of the rise, this favorable trend gradually weakens or even develops in the opposite direction; The dropping of reservoir level is unfavorable to landslide stability. After the descent, this unfavorable trend gradually weakens and develops in the opposite direction.