| dc.description.abstract | Thermal probe method is one of the ways to measure thermal conductivity which are applied comprehensively in laboratory and in-situ measurement for the complete rationale and convenience in uses. In this article, some factors, including the clearance between the thermal probe and drilled hole, type of thermal grease, and the relative size of the specimen, that influence the quality of thermal conductivity measurement with thermal probe are investigated. Standard measuring procedures by the implementation of test result and statistical analysis are prepared.
The experimental result showed that method with thermal probe directly buried inside the specimen delivers the best result. However, the value of thermal conductivity will be dropped 3%~7% with the traditional drilled hole, and the variability of result would dominate as the clearance increased. Reducing the clearance and repeating measurement are suggested in order to obtain the more accurate test results.
On the suggestions for the thermal grease uses, voltage input value and relative size of the specimen, experimental result shows that using thermal grease with 3W/mK, keeping the value of voltage input at 9~15Volt, and the aspect ratio of the specimen up to 12.5, delivers the stable and accurate test value.
For the geotechnical materials, the thermal conductivity has the best correlation with P-wave velocity in artificial rocks. As for isotropic rocks, the P-wave velocity can reflect the quantity of the rock porosity, but may produce oversized erroneous in rock with rich quartz content and porous. Thus the P-wave velocity waves might cooperate with rock-forming minerals to establish the relationship between thermal conductivity and P-wave velocity. However, in transversely isotropic rock, the wave velocity and thermal conductivity vary with the inclined angle of the bedding plane. Further research on the relationship between thermal conductivity and P-wave velocity is suggested. | en_US |