Investigation of Thermal Conductivity and Prediction Model of Mucky Silty Clay

Abstract

The thermal conductivity of soil is an important parameter that determines the geothermal properties of geotechnical engineering structures. In this research, a series of thermal needle tests were conducted to investigate the effects of water content, dry density, degree of saturation, and porosity on the thermal conductivity of mucky silty clay. Three models were used to predict the thermal conductivity of mucky silty clay in Nanjing, China. The results indicate that the critical water content of 25% can be attained by mucky silty clay, while its thermal conductivity is related linearly and exponentially to dry density and degree of saturation, respectively. Similarly, thermal conductivity is exponentially related to porosity. A modified predictive model of mucky silty clay that considers its high water content was established based on a parallel-series mixed model. By comparing it with three classic models and three sets of measured data from three sites in Nanjing, it is demonstrated that the modified predictive model can accurately estimate the thermal conductivity of mucky silty clay. This research contributes to a more comprehensive understanding of the heat transfer mechanism in mucky silty clay and provides thermal parameters for the design of geothermal-related structures in such soils.