【摘要】 为探讨硫酸钠盐渍土产生盐胀与冻胀的机理,研究了硫酸钠盐溶液在温度变化时的盐胀和冻胀的特征和规律性.针对不同浓度的硫酸钠盐溶液,在不同温度下的体积变化进行了观测.通过试验,定量分析了不同浓度的硫酸钠盐溶液在温度降低过程中,其盐胀率在一定的温度范围内随温度的变化规律;尤其是在负温区间,不同浓度的硫酸钠盐溶液冻胀率随着温度的变化规律.试验表明,硫酸钠盐溶液的盐胀必须具备一定的浓度条件,否则无结晶盐析出,无盐胀产生,并且低于这个浓度的所有盐溶液随着温度的降低将一直处于冷缩状态,直到冻胀产生.比较了不同浓度溶液的盐水比和结晶盐的盐水比,不同浓度的盐溶液其体积膨胀率(盐胀率与冻胀率之和)不同,硫酸钠盐具有一定的抑制冻胀的作用.更多还原

【Abstract】 At different concentrations and temperatures,the characteristics and rules of the salt expansion and frost heave of sodium sulphate solution were studied for revealing their forming mechanism. The relationship between salt heave rate and temperature,especially at the temperatures below freezing point,is analyzed quantificationally based on a lot of experiments. In a certain temperature range,the salt heave rates of different solution concentrations increase gradually with lowering temperature. In the temperature range below freezing point,the frost heave rate of salt solution increases rapidly with the decrease of temperature. The frost heave rate is relatively smaller for the larger concentration salt solution,and the salt expansion rate is much smaller than the frost heave rate. The experiment shows that the salt heaves of sodium sulphate solution must have a certain concentration (initial concentration);below which,no salt segregates out and no salt heave forms. When the salt solution is smaller than the initial concentration,it will keep in cold contract with temperature decreasing until frost heaving occurs. As the temperature reaches -16℃,the salt expansion and frost heave rate of salt solution is different for different concentrations and it will decrease with increasing concentration. Therefore,the sodium salt can restrain the frost heave to some extent.更多还原