关键词: 非饱和土, 水位升降, 渗流场, 孔隙水压力, 高滩岸坡

Abstract:

To further analyze the stability of high floodplain bank of Zhongzhouzi reach in Jingjiang River, the seepage field of high floodplains slope constituted with dual soil structures was simulated by using module Seep/w of Geo-studio software according to the characteristics of water level variation, based on the saturated-unsaturated seepage theory. It showed that in the initial rising period and drop period of river water level, the slope seepage mainly points to the river side and its direction would change with the fluctuation of water level. The phreatic line changes synchronously with the water level when the velocity of water level fluctuation is less than or close to the permeability coefficient; otherwise, the phreatic line would lag behind the water level change. What′s more, with the increase of water level descending velocity, the gradient of ground water increases, which is adverse to the slope stability. When the water level rises, the maximum value of pore-water pressure increases and the negative pore-water pressure area (unsaturated area) decreases, on the contrary, the maximum value of pore-water pressure decreases and the negative pore-water pressure area increases.

Key words: unsaturated soil；water level fluctuation, seepage field, pore-water pressure, high floodplains bank slope