粉土持水性能的温度效应研究

开展3种不同温度作用下粉土的持水特征曲线（SWRC）试验，测量脱湿过程中土体的体积变化，修正体变对体积含水率的影响。试验结果表明，在减湿过程中粉土体积发生明显收缩，孔隙比由0.675降低到0.645左右，不同温度作用下的最终孔隙比相差仅为0.003，说明粉土的变形对温度不是很敏感；温度对粉土持水性能影响显著，粉土的进气值随着温度的升高而降低；基质吸力为50 kPa时，不同温度下粉土持水性能差异达到最大值，20 ℃、30 ℃、40 ℃时的体积含水率分别为0.397、0.361和0.338；粉土的体积含水率随温度越高逐渐减小，但彼此之间的差异随着温度升高而逐渐减弱。孔隙中水的物理特性以及水、气的赋存状态是不同温度下粉土持水性能存在差异的主要原因

Thewater holdingcapacityof siltunder temperature effect

The soil water retention curve (SWRC) tests under the three different temperatures are carried out. The volume shrinkage deformations also are measured at the same time to amendment miscount caused by volume change. The test result shows that the shrinkage is obvious in the drying process, the void ratio reduced to 0.645 from 0.675, but the difference of final void ratio under different temperatures is only 0.003; it is shown that the silt’s deformation is not sensitive to temperature. The water holding capacity is significant different under the action of different temperatures. The air-entry value is smaller when the temperature increased. The difference of water holding capacity reach maximum under the action of suction of 50 kPa. The water content is 0.397, 0.361 and 0.338 respectively under the temperatures of 20 ℃, 30 ℃, 40 ℃; but the difference is decreasing with the suction increased. The water physical properties, water and gas’s occurrence are changed under the different temperatures and it lead to the changing of the water holding capacity.