两种高液限黏土的热导率

Thermal Conductivity of Two Kinds of High Liquid Limit Clay

通过对膨胀土、红黏土两种高液限黏性土进行热导率试验,结合砂土、粉质黏土等普通土进行对比分析后,选择经验公式法、边界法及理论模型法模拟其体积含水率-热导率的变化规律。研究发现:高液限黏土同普通土有很大的差异,反应含水率-热导率关系的θw-k曲线增长速率比普通土慢,模型拟合表明高液限黏土实测的θw-k曲线位于Wiener边界以内,由于土水作用较强,Kersten公式和Johansen模型的预测效果均不理想;EMT模型在低于某个临界含水率时的预测值与试验值偏差小,但超过临界含水率时,预测值就偏高;DEM模型的预测结果整体有较大的偏低。在此基础上,通过对Johansen模型中饱和度相关函数的分析,发现饱和度相关函数采用线性函数时比原模型的对数函数具有更高的精度。

Thermal conductivity of high liquid limit clay including expansive soil and red clay were measured at different volumetric water content. Three approaches,empirical equation,theoretical bound and theoretical model,were used to estimate the thermal conductivity after comparing with sand,silty clay and so on. The research shows that： high liquid limit clay has a great difference from the ordinary loam soil,the curve of the relationship between the rate of water cut and the thermal conductivity is slower than the ordinary soil. Model fitting result shows that the θw~ k curve of high liquid limit clay is located within the boundaries of Wiener. Due to the strong effect of soil water,the Kersten and Johansen models are not ideal. The predicted value of EMT model is close to the test value when the water content is smaller than the critical water content,but the predicted value is higher than the experimental value when the water content is higher than the critical water content. DEM model has a relatively low prediction results. On this basis,after the saturation correlation function in Johansen model is analyzed,it is found that the saturation correlation function uses a linear function has higher accuracy than the original model.