Stability evaluation of multilayer slopes considering runoff in the saturated zone under rainfall

Abstract

Rainfall represents one of the most significant cause of landslide hazards. With runoff in the saturated zone of shallow soil considered, an improved Green–Ampt model was proposed to depict the rainfall infiltration process. Furthermore, a formula for calculating the depth of wetting front was derived, and the slope stability was evaluated accordingly. Finally, a formula for calculating the safety factor of multilayer slopes above different surfaces was obtained via the limit equilibrium method. An illustration is a multilayer colluvial slope in Guangdong Province of China, the results indicated that the downward speed of wetting front decreases gradually within the same layer with continuous rainfall but increases significantly when it extends to the interfaces between the soil layers. Safety factor of the slope decreases sharply at the initial stage of rainfall but then more slowly. Slope failure is more likely to occur along the first interface between the soil layers than along the surface of wetting front. The result from the proposed model is closer to the result of the physical model test than from the existed Green–Ampt model. The improved Green–Ampt model for multilayer slopes can accurately evaluate the infiltration process and related stability of multilayer slopes under rainfall.

Keywords:

• Multilayer slope
• rainfall infiltration
• runoff
• improved Green–Ampt model
• stability evaluation

Disclosure statement

No potential conflict of interest was reported by the authors.

 

Funding

The present work is supported by the National Key R&D Program of China (2018YFC1507200, 2017YFC1501304), the National Natural Science Foundation of China (No. 41672317, 41472261, 41772252, 41772259), the research program for geological processes, resources and environment in the Yangtze River Basin (No. CUGCJ1701) and the Open Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Grant No. SKLGP2017K017).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work is supported by the National Key R&D Program of China (2018YFC1507200, 2017YFC1501304), the National Natural Science Foundation of China (41672317, 41472261, 41772252, 41772259), the Research Program for Geological Processes, Resources and Environment in the Yangtze River Basin (CUGCJ1701) and the Open Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (SKLGP2017K017).