Experimental study on the wicking performance of a wicking geotextile in coarse-grained soils under freezing-thawing actions

Abstract

The effectiveness of a self-developed wicking geotextile under different freezing-thawing cycles (0, 1, 3, 5, 10) in draining water from the coarse-grained railways soils with varying initial water contents (12 %, 15 %, 18 %, and 21 %) and fine contents (5 %, 10 %, 15 %, 20 %, 30 %) was evaluated using a series of vertical wicking tests. Results show that: 1) the wicking geotextile demonstrated efficient vertical water drainage from coarse-grained soils, with its performance significantly influenced by soil properties (initial water content and fine content) and freezing-thawing cycles; 2) the maximum liquid vertical wicking heights (LVWHs) of the wicking geotextiles in the coarse-grained soils increased with the increasing initial water contents but decreased with the increasing fine contents; 3) with the increase in freezing-thawing cycles, the maximum LVWHs of the wicking geotextiles in coarse-grained soils demonstrated a two-stage decline (first decreasing rapidly, then slowing down) before stabilizing at a constant value. Based on the microstructures, the mechanisms by which the initial water contents, fine contents, and freezing-thawing cycles affected the wicking performance were qualitatively analyzed and discussed. This study contributes to frost heave prevention of coarse-grained soils in cold regions.