不同压力条件下罗布泊地区天然亚氯盐渍土盐-冻胀试验研究

摘要

To study the frost heaving ratio changes with moisture content and pressure of natural sub-chlorine saline soil after freezing and thawing cycle.Natural sub chlorine saline soil in Lop Nur area was se-lected to conduct freeze-thaw cycle test.The experimental results showed that the accumulation of salt and frost force gradually increased with the increasing of freezing thawing times.Under the same dry density and when the moisture content of the soil sample was the optimal,the tired salt heaving ratio reached the maximum value.The change of moisture content had significant effects on salt-frost heaving ratio.Differ-ent frost heaving and salt dry density moisture content of soil sample rate decreased with increasing pres-sure.External pressure of sub chlorine saline soil salt and frost phenomenon had obvious inhibitory effect, and the larger salt and frost heaving ratio occurrence cycle shifted to an earlier date than that without pres-sure.When the pressure was 50.00 kPa,the maximum salt expansion rate decreased to 85.5%,but when the pressure was 66.00 kPa,it did not completely eliminate the salt-frost heaving.%研究天然亚氯盐渍土冻融循环后盐-冻胀率随含水率和压力变化规律,选取罗布泊地区天然亚氯盐渍土,进行冻融循环试验.结果表明,累加盐-冻胀率随冻融次数的递增逐渐增大.在干密度相同的情况下,试验土样的含水率为最优含水率时,其累加盐-冻胀率达到最大值;含水率的变化对盐-冻胀率的影响显著.不同干密度不同含水率土样的盐-冻胀率随压力的增大而减小.外界压力对亚氯盐渍土盐-冻胀现象有明显的抑制作用,且较大的盐-冻胀率的出现周期较无压有所提前.当压力为50.00 kPa时,最大盐-冻胀率减少85.5%,但当压力为66.00 kPa时并不能完全消除盐-冻胀的产生.