CFD-DEM modeling of geotextile clogging in tunnel drainage systems

In this study, a coupled Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) method we used to investigate the hydraulic deterioration of a geotextile due to clogging in tunnel drainage systems. Initially, a framework was developed to generate and test a numerical representation of a typical non-woven geotextile. Following model validation, we carried out parametric analysis to examine the effect of fine content, crack angle, and groundwater inflow. The results showed a general trend of pressure increase associated with increasing both the crack angle and fine content. This increase was found to decay at larger crack angles and high content of fines. Interestingly, increasing groundwater inflow was found to had minimal effect on the final deposition of the clogging particles. Finally, an approximate semi-analytical model was developed to describe the pressure increase due to clogging. The model was able to provide a good match with the data obtained from the numerical analysis.