Hydraulic and Thermal Conductivities of Kaolin-Silica Mixtures Under Different Consolidation Stresses

Abstract

Stable backfill materials for the heat sensitive structures of buried power cables, hot water pipes, and gas pipelines are suggested to have low permeability and high heat transfer characteristics. Hydraulic and thermal conductivities of backfill materials or clay liners are important parameters in proper design and construction of geotechnical structures involved with heat transfers. In this study, to investigate optimal natural backfill or liner materials, thermal and hydraulic conductivities of Kaolin-Silica mixtures were examined based on the results from laboratory tests under different consolidation conditions. From the experiment results, the thermal conductivity increases while hydraulic conductivity decreases with increasing density during consolidation process. Backfill materials with high Kaolin content under low consolidation stress were desirable materials for burrier of heat sensitive structures.