硫酸盐渍土定量增湿盐胀特性试验

Salt-heaving characteristics of sulphate saline soil under quantitative humidifying

为了分析硫酸盐渍土在定量增湿条件下的盐胀特性,设计制作了定量增湿盐胀试验装置,通过室内试验得到不同含盐量、不同干密度和不同上覆荷载条件下重塑硫酸盐渍土的定量增湿盐胀曲线。研究结果表明：含盐量越高增湿盐胀变形越大,盐渍土的剧烈盐胀含水量上限在11%-16%之间;干密度越大增湿盐胀越大,干密度每增加0.1g/cm^3,总盐胀率增加1.1%-2.9%;上覆荷载越大盐胀越小,在0-25kPa范围内,上覆荷载每增加10kPa,土样盐胀率减小约3.6%,25-50kPa的上覆荷载将盐胀率抑制在2.1%左右。试验结果的综合分析表明：机场换填宜用细颗粒非盐渍土,慎用细颗粒弱盐渍土,建议换填深度取0.75-2m;依据土基工作含水量与剧烈盐胀含水量上限的对比,建议将盐渍土土基处理分成2类。

To analyze the characteristics of salt-heaving of sulphate saline soil under quantitative humidifying, an equipment for quantitative humidifying salt-heaving was made. The curves of quantitative humidifying salt expansion under different dry densities, different salt contents, and different loads were gotten. Experimental results indicate that： the salt expansion increases with the increase of the salinity, and the moisture toplimit of severe salt expansion is between 11% and 16~; the salt expansion increases with the increase of dry density, and when dry density increases every 0. 1 g/cm3 , the total salt expansion rate increases 1.1% to 2.9 M; the salt expansion decreases with the increase of load, and within the range of 0 to 25 kPa, when the load increases every 10 kPa, the total salt expansion rate decreases 3.6 ~, but when the load changes from 25 to 50 kPa , the total salt expansion rate is about 2.1%. Comprehensive analysis of experimental results show that： in the replacement of airdrome construction engineering it＇s appropriate to adopt thin plain soil, and thin grain slight saline soil should be adopted cautiously, and the depth of replacement should be controlled within the range of 0. 75 to 2 meter; based on the contrast between the moisture content in work condition and the moisture toplimit Of severe salt expansion, the ground treatment of saline soil should be divided into two types. 7 figs, 11 refs.