Stability assessment of coastal clay slopes considering strength nonlinearity and sea level drawdown: Fid-Bau Portal

Stability assessment of coastal clay slopes considering strength nonlinearity and sea level drawdown

Wu, Di / Shen, Feng

Sea level drawdown may lead to the stability decrease and even the failure of coastal clay slopes. Since few attempts have been made to illustrate the impact of sea level drawdown on coastal slope stability considering three-dimensional (3 D) geometry and nonlinear strength, this paper extended 3 D limit analysis approach with nonlinear criterion for slope stability under different sea level drawdown conditions. The least upper bound on stability number was derived by using an optimization procedure. Stability charts were presented and the influences of sea level drawdown on slope stability were illustrated. The drops of sea levels in three cases were found to have different effects on the decreases in slope stability caused by nonlinear parameters. 3 D slope tends to be unstable in the case of rapid drawdown, but it will become stable when the inside water drops after sea level has rapidly decreased. In the case of sea level slow drawdown, slope stability will reduce to minimum and then increase. Effects of sea level drawdowns on slope stability become less significant for slope soils with obvious nonlinear strengths. Certain reinforcement measures can be taken to improve the stability of coastal slopes undergoing sea level rapid drawdown or slow drawdown.