Retrogressive failure pattern and retrogression distance in sensitive clays induced by river erosion

Abstract

The failure patterns and retrogression distances in sensitive clays induced by river erosion are two significant factors of concern in landslide risk assessment. For the former, empirical criteria, based on past events and numerical results, can hardly produce a unified guideline and explain their complex mechanism. For the latter, the capacity of the river cross section is rarely considered in existing studies, even though the failed soil would deposit on the riverbed and further affect upslope failure extension. The present study proposes an analytical method to quantitatively assess the failure patterns and retrogression distance by combining the shear band propagation method (SBP) with limit analysis on active block failure. A closed‐form active earth pressure (CAEP) and the shape function of the failure surface are proposed with the variational calculus method (VCM), providing a tool to understand the transformation mechanism of the failure patterns. The criteria for initiation failure positions and stages are formulated following the competition results between the induced minimum slope‐parallel force by foot unloading and the proposed CAEP. Further, the terminal retrogression distance is given considering two possible river cross sections. The proposed CAEP solution is validated against Buss's solution and further applied to a parametric study on the failure patterns. Finally, three practical cases are analyzed with the proposed method, and the predictions are shown to agree well with the field observations.

Slope stability analysis with a hypoplastic constitutive model: Investigating a stochastic anisotropy model and a hydro‐mechanical coupled simulation

“…Under the influence of geological conditions and environmental factors, slopes may experience sudden sliding failure or gradually transform into landslides with sliding zones. [5][6][7] For example, reservoir landslides are common geological disasters in reservoir areas. Many reservoir landslides evolve from bank slopes under the influence of heavy rainfall and water level fluctuations.…”

“…Depending on the geological environment in which a slope exists, it can take various forms, 4 such as road slopes, dam slopes, pit slopes, mountain slopes, and reservoir bank slopes. Under the influence of geological conditions and environmental factors, slopes may experience sudden sliding failure or gradually transform into landslides with sliding zones 5–7 . For example, reservoir landslides are common geological disasters in reservoir areas.…”

A GIS framework for prediction of basin‐wide post‐failure geometry of confined subaqueous landslides

“…22 Over the years, a considerable amount of work has been devoted to the understanding of these mechanisms and the estimation of their potential dimensions. Among the methods used were analytical energy-based criteria 20,[23][24][25][26] and limit equilibrium [27][28][29] and various numerical methods such as large deformation finite element analysis, 28,[30][31][32] material point method, 33,34 smooth particle hydrodynamics, 35 particle finite element method, 36 depth-integrated methods [37][38][39][40][41][42] and more.…”