# Modeling Wicking Fabric Inhibition Effect on Frost Heave
Given the high cost of transporting materials to remote sites and the long distance, the most practical method for reducing frost heave is reducing the water content in the pavement structure [7]. Recently, geotextiles and geocomposites have been used as capillary barriers in pavements to reduce water absorption and frost heaving. However, capillary barriers only obstruct the upward flow of capillary water. The excess water could accumulate beneath the capillary barriers, ultimately reducing the pavement stiffness. A new type of woven geotextile with wicking ability was recently developed to minimize upward water migration and drain excess water effectively [8]. As shown in Figure 1, when WF is installed in the subgrade, the air humidity above the roadway is typically dry (less than 50% relative humidity), the soil, as well as the geotextile, is wet (close to 100% relative humidity), and a large suction gradient would form between the geotextile and soil [8]. Thus, installing WF in the subgrade helps carry both gravitational and capillary water to the face of the road slopes and eventually evaporate to the ambient atmosphere. Specifically, upwardly migrating moisture that reaches the WF can be laterally diverted to the pavement shoulders [9]. Researchers have conducted several successful laboratory tests and field applications to investigate the drainage efficiency of wicking fabrics in recent years. For instance, [PERSON] and [PERSON] [8] installed two layers of WF at the Beaver Slide area of the Dalton Highway and successfully prevented frost heave and subsequent thaw weakening; [PERSON] et al. [7] found that the WF installed five years ago in that project conducted by [PERSON] and [PERSON] [10] continued functioning well. According to [PERSON] [11], WF has also been successfully applied to soft subgrades, saving USD 2.5 million in the initial construction phase. In addition, it has also been used to address differential settlement-induced pavement deterioration by [PERSON] [12]. [PERSON] et al. [13] analyzed the microstructure of WF and presented an explanation for the water absorption working mechanism of this material. An experiment conducted by [PERSON] et al. [14] indicated that the capillary of the WF could effectively drain water from the soil column up to a considerable distance through the WF. [PERSON] et al. [15] performed a comprehensive laboratory test to characterize the property of the WF and soil-WF interactions, and the results showed that the WF can effectively drain water until the suction reaches the inner-yarn air entry value. Furthermore, several researchers have attempted to simulate the drainage process of WF with numerical tools. For instance, [PERSON] et al. [15] conducted a numerical simulation to quantify the drainage ability of a soil-WF system, which demonstrated that the soil-WF system can reduce the water content of the pavement by 2% from the optimum value. [PERSON] et al. [16] performed a numerical simulation and indicated that WF could drain water and inhibit frost heave. Although several models have been developed to estimate the effectiveness of WF in draining moisture, limitations in applying the boundary condition of WF remain. Most previous numerical models do not  
Figure 1: Mechanisms of water removal by WF in a pavement system. take into account the influence of the surrounding environment on the water absorption process of WF. In general, the water absorption process is simulated by setting a constant pressure boundary at the end of the WF. Indeed, such a simplification might still be able to reproduce the WF absorption process. Nevertheless, it has been demonstrated that the absorption effect of WF can be impacted by ambient conditions (e.g., temperature, relative humidity) [14]. It is therefore very important to consider the influence of the environment conditions when simulating the water absorption process of WF. The primary objective of this study was to evaluate the inhibition effects of WF on frost heave under different experimental conditions in the freezing process.