Mechanical and osmotic consolidation of geosynthetic clay liners: a laboratory study

Abstract

This study aims to assess the effect of pore water salinity (sodium chloride (NaCL) solution) on the consolidation behaviour of GCLs (geosynthetic clay liners) using one-dimensional oedometer test apparatus. The experiments include two testing conditions: (1) an investigation of mechanical consolidation of GCL specimens saturated with water having different salinity levels, and (2) an investigation of the effect of pore water salinity on the volume change of GCL specimens under different constant vertical stress levels (i.e. osmotic consolidation). The mechanical consolidation test results indicated that the compression and swelling indices decrease as the liquid salinity increases, whereas an elastic hysteresis volume change behaviour was observed in the osmotic consolidation test results. The results of this study also show that the compression and swelling indices, and the hydraulic conductivity of a GCL specimen are almost reversible when it is subjected to an osmotic cycle.