Earth Structures Stability Under Rapid Drawdown Conditions

Zofia Zięba,Michał Molenda,Kinga Witek

doi:10.21307/acee-2017-009

Abstract

Abstract The paper presents the slope stability analysis of the unmodernised section of the Groszowice separation levee in the condition of water level changes, particularly after rapid drawdown. Based on soils field and laboratory tests, the stability analysis of the construction was conducted with GEO5 software. For the upper levee, the utilisation degree of slopes resistance was determined according to the Eurocode 7. Calculations were conducted for normal and high water level, as well as after rapid drawdown. The analysis was carried out with the use of five most commonly applied methods. The results have shown that at normal and high water level, the structure was stable. However, it does not correspond with its existing damages. The loss of stability was proved only under rapid drawdown conditions. Additionally, for the central part of the separation levee, the filtration curve position was conducted with the use of the Finite Elements Method (FEM). The water seepage on the slope above normal water level explains the suffosion displacement of soil particles that occurs due to damaged slope sealing and drainage.

Highlights

Earth structures such as flood embankments, earth dams or separation levees are a large part of hydrotechnical structures in Poland
Based on the conducted field and laboratory tests it was found that the upper separation levee consists mainly of medium dense non-cohesive soils with an addition of stones
The obtained results were subsequently used for the slopes stability analysis on the upper part of the levee and for the prognosis of the position of the filtration curve in the central part of the structure

Summary

Objectives

The aim of this paper is to analyse the phenomena that affect the stability of the unmodernised part of the Groszowice separation levee under conditions of rapid changes of external water level

Methods

Results

Conclusion