摘要:Thermal conductivity of soil is a basic physical property related to heat conduction, and also is one of parameters widely applied in geotechnical engineering. The effect of gradation on the thermal conductivity of fused quartz was analyzed by thermal needle tests. The different particle size with the same uniformity coefficient (Cu = 3.2) and different uniformity coefficient for the same particle size (0.10~1.00 mm) were considered in this study. It shows that the thermal conductivity of fused quartz decreases with the decreasing of the mean particle size and with the increasing of the porosity. Simple modified methods to estimate the value of thermal conductivity are proposed, and had been demonstrated successfully by conducting fused quartz, carbonate sand and Ottawa sand.