Coupled Numerical and Analytical Stability Analysis Charts for an Earth-Fill Dam under Rapid Drawdown Conditions

• Published in: Applied sciences Vol. 12; no. 9; p. 4550
• Main Authors: Azadi, Ali, Esmatkhah Irani, Arash, Azarafza, Mohammad, Hajialilue Bonab, Masoud, Sarand, Fariba Behrooz, Derakhshani, Reza
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2022
• Subjects: Charts; coupled-stability analysis; Dam stability; Dams; Damsites; Drawdown; Earth dams; earth-fill dam; Failure; Flow stability; Instrumentation; Mathematical models; Permeability; rapid drawdown; Safety factors; Seepage control; Slip; Slope stability; Stability analysis; transient flow; Unsteady flow
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app12094550

The presented article provides a comprehensive study on the stability analysis of earth-fill dams under rapid drawdown and transient flow conditions used to prepare stability analysis charts by conducting coupled finite-element numerical and analytical limit equilibrium procedures. In this regard, the impacts of different rapid drawdown conditions on the safety factor of the Alavian earth-fill dam are determined. The slope stability charts present for both shallow and deep slip surfaces with various permeabilities are verified by ground information obtained with extensive instrumentation on the dam’s site. The results showed that by decreasing the permeability of the core’s material, despite preventing seepage, the instability risk of the upstream slope as a result of rapid drawdown intensifies. Also, as stability charts can be stated, with increasing the slip surface’s depth and decreasing the hydraulic hydration, the reliability decreases, and the sliding surfaces’ sensitivity increases based on the drawdown rates, which have been revealed to be from 0.2 to 0.6, the most critical state for safety factors, showing significant declines.