Thermal Conductivity of Shanghai ⑤1 Silty Clay

Abstract:

A series of tests were carried out with the heat probe method by thermal properties analyzer to investigate the thermal conductivity of shanghai ⑤1 layer silty clay, the most common type in the metro tunnel engineering. The test results show that the thermal conductivity of saturated silty clay decreases with the void ratio. When the water contents drop down gradually from saturated value to dry value, the soil sample shrinks evidently first and then its thermal conductivity increases. While the water contents drop down near the plasticity limit, the volumetric shrinkage becomes stable and the thermal conductivity reaches its maximum value. After the peak, the thermal conductivity decreases with water contents. Finally, some existing empirical formulas were introduced to fit the test data, and their fitness was verified.

Key words:silty clay; thermal conductivity; water content; void ratio