Analytical method for quantifying performance of wicking geosynthetic stabilized roadway

The moisture content of roadway subgrade may increase substantially due to upwards water migration and/or downwards invasion of rainfall, resulting in the softening of the subgrade and the deterioration of the roadway, characterized by the occurrence of rutting and/or cracking. Wicking geosynthetic with wicking fibers can remove the moisture in subgrade actively to improve the serviceable performance significantly. However, there is no analytical solution to quantify the benefit of the wicking geosynthetic in improving roadway performance. In this study, the solution of a multi-layered elastic geosynthetic-stabilized soil system was derived to quantify the elastic responses. Thus, a mechanistic-empirical method was developed for analyzing the roadway performance (i.e., rutting). In the analysis, layers adjacent to the wicking geosynthetic with a reduced moisture content was considered as layers with improved material properties. The results show that the analytical method developed in this study is capable of quantifying the benefit of wicking geosynthetic in stabilizing roadways, with the influ-ence depth and the moisture reduction as known inputs. The benefits attributing to the reinforcing effect and wicking effect can be quantified separately according to this analytical method. The base-subgrade interface is a better location for the wicking geosynthetic since both the resilient moduli of the base course and subgrade were improved due to the wicking effect and the reinforcing effect is also considerable. For the paved roadway structure analyzed in this study, the wicking effect contributed 18-30%, while the reinforcing effect contributed 8-11% when placing the geosynthetic at the interfaces.

Automated summary

The study developed a mechanistic-empirical method to analyze the improvement of roadway performance using a multi-layered elastic geosynthetic-stabilized soil system. This method can quantitatively measure the benefit of wicking geosynthetics in stabilizing roadways, and separate the contributions from the reinforcing effect and the wicking effect. The wicking effect contributed 18-30%, while the reinforcing effect contributed 8-11% when placing the geosynthetic at the interfaces.