含细粒土夹层粗颗粒硫酸盐渍土盐胀实验分析

The Salt Expansion Experimental Analysis on Coarse-Grained Sulphate Salty Soil in Fine-grained Soil Interlayer

为研究含细粒夹层粗颗粒硫酸盐渍土经多次冻融循环后的盐胀特性,对取自甘肃河西走廊地区敦煌飞机场某天然料场的粗颗粒盐渍土进行了室内多次冻融循环盐胀实验。结果表明：含细粒土层与不含细粒土层的硫酸盐渍土的盐胀主要集中在-5-15℃,在这个温度区间盐胀量变化较小;随着温度的升高,盐胀量有所减少,升温过程中盐胀减少量约为降温过程中盐胀增加量的0.5倍左右,但最终都趋于一个大于零的稳定值。含细粒土夹层粗颗粒硫酸盐渍土的盐胀量大于不含细粒土夹层的盐渍土,且前者盐胀量是后者盐胀量的1.5倍左右。

In order to research on the salt expansion characteristics of coarse-grained sulphate salty soil in finegrained soil interlayer after several freeze-thaw cycles,several salt expansion experiments indoor under freeze-thaw cycles on the coarse-grained salty soil from some borrow area of Dunhuang airport in Hexi corridor area of Gansu are conducted.The experiment indicates that the salt expansion of sulphate salty soil in soil interlayer with or without fine grains mainly concentrates upon the temperature range between 15℃and-5℃,which has smaller changes in salt expansion amount.The salt expansion amount gets lesser with the rise of temperature.The decreasing amount of salt expansion in the rise of temperature is about 0.5times than the increasing amount of salt expansion in the fall of temperature.However the multiples tends to become stable constants which is above zero eventually.The salt expansion amount of coarse-grained sulphate salty soil in fine-grained soil interlayer is about 1.5times than the salt expansion amount of salty soil in soil interlayer without fine grains.