Characterization of Thermal‐Hydraulic Coupling Behavior for Moraine Soil With Ice Inclusions in a Warming Environment

Abstract

AbstractA warming environment is promoting the thawing process in ice‐rich moraine soils in cold alpine regions, thereby accelerating the formation/development of geohazards in these regions. The mechanism of these geohazards is closely related to the thermal‐hydraulic (TH) coupling behavior of moraine soils, which has rarely been investigated. Here, we conducted a series of bench‐scale TH coupling simulations of moraine soils with ice inclusions in a warming environment. The numerical model was conceptualized from a field survey on the Qinghai‐Tibet Plateau, which consists of a porous medium embedded with multilayer ice cubes with warmer water continuously flowing through it. A TH coupling framework considering ice‐water phase change was established to implement this coupled simulation with different initial ice contents and hydraulic gradients. The simulated results showed phased and nonlinear evolutionary features of temperature, ice content, and permeability for the moraine soil system. Further analyses showed that these complex evolutionary features can be reproduced by empirical formulas, with concise expressions following dimensional consistency and some coefficients having potential physical meanings. The discriminant models of two equilibrium states were finally developed to predict the critical times of structure stabilization and thermal equilibrium of the moraine soil system. This study presents the complex evolution of TH coupling properties of moraine soils, and simultaneously demonstrates that these properties can be predicted and characterized.