2010 Volume 32 Issue 2 Pages 87-96
In this paper, we examine how the thermal conductivity estimated on line-source theory is affected by geothermal gradient, where we discuss it through a numerical simulation referring the real data obtained at Yumoto, Fukushima, Japan.
The thermal conductivity of layer estimated though thermal response test is usually apparent thermal conductivity and the estimate of apparent thermal conductivity is affected by the underground conditions such as groundwater flow and geothermal gradient. Then, we have calculated the apparent thermal conductivity using a simulator on FEM, where we changed the geothermal gradients and conditions for approximation of thermal response curves. It has been revealed that the estimated thermal conductivities have different trends depending on the thermal response curve used for estimation such as circulation test or recovery test, and heating or cooling. It has also been revealed that the difference between actual thermal conductivity and its estimates has been 7.3 in maximum to the actual thermal conductivity in case of Yumoto, where the thermal gradient is 0.106 /m.
