A multiphysics model for assessing the stability of cold region slope subjected to environmental dynamics

Abstract

The stability of slopes in cold regions is governed by complex interactions between thermal, hydrological, and mechanical processes. This paper proposes a multiphysics model to investigate the effects of various environmental dynamics on cold region slope stability. These dynamics encompass ambient temperature, wind speed, solar radiation, precipitation, relative humidity, groundwater table fluctuations, and geothermal heat. The concept of the Local Factor of Safety (LFS) was introduced as an index to evaluate the slope safety. A case study was performed using the proposed model with data from a site in Norway. Through this simulation, a heat budget analysis was conducted to quantify environmental impacts on the freezing and thawing states of the slope. Subsequently, the influence of slope temperature and moisture distribution on LFS at moments before freezing, during freezing, and during partial thawing was investigated. A low-high-lower LFS transition pattern was found along the slope surface associated with pre-freezing/freezing/thawing processes. The potential surface-parallel sliding and water blocking effects, characteristics of slope in cold regions, were also captured by the model simulation results. With its comprehensive consideration of climatic factors, the model stands as a promising tool for adapting slope design to climate change. Its multiphysics analysis capability offers an insightful way to elucidate the intricate mechanisms underlying the failure of slopes consist of unsaturated frozen soil.