论文部分内容阅读
通过控制恒温恒湿箱的温湿度工作参数,实现饱和膨胀土在不同脱湿速率条件下的状态变化,借助收缩试验和非饱和三轴试验,研究脱湿速率对膨胀土收缩特性、强度特性与持水特性的影响规律。试验结果表明,膨胀土的收缩系数随脱湿速率的减小而变大,并先呈现线性脱湿过程,后呈现非线性脱湿特征;在相同含水率条件下,膨胀土的吸附强度亦随脱湿速率的减小而增大,尤在含水率和围压较低时更趋明显。结合吸附强度与吸力关系的乘幂函数表达式,利用收缩系数和吸附强度反算出不同脱湿速率下的膨胀土“双线性”土水特征曲线,发现不同脱湿速率时曲线下降段接近平行趋势,脱湿速率越小,膨胀土的进气值越大,相同含水率时的吸力越高。
By controlling the temperature and humidity operating parameters of the constant temperature and humidity box, the state changes of the saturated expansive soil under different dehumidification rates are achieved. By means of the shrinkage test and the unsaturated triaxial test, the effects of the dehumidification rate on the shrinkage characteristics, Influence of water holding capacity. The experimental results show that the shrinkage coefficient of expansive soil becomes larger with the decrease of desorption rate, and presents the process of linear desorption first, and then shows the characteristics of non-linear desorption. Under the same moisture content, the adsorption strength of expansive soil Decreasing the rate of desiccation increases, especially when the moisture content and confining pressure is more obvious. Combined with the exponential function of the relationship between adsorption strength and suction, the characteristic curve of expansive soil “bilinear ” under different dehumidification rates was calculated by using shrinkage coefficient and adsorption strength. Close to the parallel trend, the smaller the rate of dehumidification, the larger the value of expansive soil intake, the higher the suction of the same moisture content.