Analysis of the Influence of Water Level Change on the Seepage Field and Stability of a Slope Based on a Numerical Simulation Method

Abstract

River floods, dammed lake flood discharge, reservoir discharge, seawater recession, etc. all cause the water level in front of a slope to drop, which changes the original steady-state seepage field in the soil, leading to harmful slope instability. To study this phenomenon, a numerical model was established through theoretical analysis combined with the coupling of the Seep/W and Slope/W modules of the GeoStudio finite element software, and the numerical model was verified by the model test results of indoor medium sand and silt. This paper focuses on the effects when the water level in front of a slope drops at different speeds, different drop ratios, different initial water levels, different filling materials, and matrix suction on the seepage field and slope stability. The conclusions are as follows: (1) the greater the speed at which the water level in front of a slope falls, the greater the downward seepage force formed by the seepage field of the slope to the slope body; (2) the change curve of the safety factor at a higher speed is steeper when the water level falls at different speeds, and the safety factor value when the water level in front of the slope is constant is smaller; (3) the safety factor of the slope decreases with an increase in the drop ratio; when the drop ratio is the same, the loss of stability is worse if the initial water level is lower; (4) when there is a drawdown of water levels in front of the slope, the non-cohesive medium sand slope is more prone to instability failure than the cohesive silt slope; and (5) when this modeling method is applied to matrix suction, the effect of matrix suction increases the safety factor of the slope.

Delving into Earth Dam Dynamics: Exploring the Impact of Inner Impervious Core and Toe Drain Arrangement on Seepage and Factor of Safety during Rapid Drawdown Scenarios

“…the slope's seepage field. This alteration becomes more pronounced as the rate of descent increases [32].…”

Study on the Influence of Wet Backfilling in Open Pit on Slope Stability

“…Figure 7 shows a slide analysis of some sections under different operating cases considering seepage field conditions. As the backfill height increases and the load on the slope increases, the water channel between the slope and the pit bottom/surface decreases, thereby reducing the impact of water seepage on the stability of the slope [19][20][21]. In summary, considering the effect of the seepage flow field, the stability evaluation conclusions for open-pit slopes with different backfill heights are as follows.…”

Instability of Embankment Slopes Due to Overflow and Drawdown

“…Gruner $$(1967) [8] Takase $$(1967) [9] Babb and Mermel$$(1968) [10] Biswas and Chatterjee$$(1971) [11] USCOLD$$(1975) [12] Overtopping 30 23 Overtopping poses significant risks, leading to potential landslides in concrete gravity dams and total or partial failures in earth or rockfill dams. The primary causes of overtopping are attributed to a lack of hydrological data and errors in hydrological design.…”

“…For this reason, it is necessary to analyze the stability of the embankment against overflow with consideration for extreme rainfall due to climate change. In order to evaluate all these situations, this study aims to analyze the drawdown and overflow conditions based on the basic design cross-section of soil dams or embankments [23][24][25]. this process can be found in the work of Na et al ( 2014) [22].…”