温度对花岗岩和砂岩导热系数影响的试验研究

Testing study on temperature effect on thermal conductivity for granite and sandstone

为探讨温度对岩石导热系数的影响,在不同平均温度水平下(28～62℃),采用平板热流计法测试花岗岩和砂岩岩样的导热系数,并初步分析温度对花岗岩和砂岩导热系数的影响。试验结果表明,对试验所用的岩样而言,花岗岩导热系数随温度的升高而缓慢下降,两者之间存在负相关的线性关系,而砂岩导热系数随温度的升高变化很小。因此,在精确计算隧道围岩温度场和应力场的分布时,应考虑温度变化对岩石导热系数的影响以及由此引起的围岩应力场的变化。

In order to study the effect of temperature on thermal conductivity,the thermal conductivity tests for granite and sandstone samples are conducted at various temperature levels（28-62 ℃） by using plate heat flow meter apparatus.According to the test results,the effect of temperature on the thermal conductivity of granite and sandstone were preliminarily analyzed.The testing results show that the thermal conductivity of granite decreases slowly with increasing of temperature,and there is a negative linear relationship between the thermal conductivity of granite and temperature.Where as,the thermal conductivity of sandstone has no obvious change basically with a rise in temperature.So the influence of temperature on thermal conductivity and its induced change of stress field should be considered in accurate analysis of the distribution of stress field and temperature field in surrounding rock of tunnel.