硫酸盐渍土未相变含水率与温度关系研究
发布时间：2018-10-24 12:05
【摘要】：以硫酸盐渍土为研究对象,从理论上建立了冻结温度以上未相变含水率与温度的关系,并通过室内试验测试了硫酸盐土体及对应溶液中盐晶体初始析出温度和硫酸盐渍土未相变含水率在不同温度环境下的变化。从土体降温温度曲线、不同温度下核磁共振信号强度分析了温度对未相变含水率的影响。研究结果表明:在特定降温速率下,十水硫酸钠晶体析出存在滞后性,初始析出温度均低于其饱和浓度所对应的温度,并随着初始含盐量的减小,初始析出温度大幅度降低,且与土体比较,溶液中盐晶体易于析出;土体中十水硫酸钠晶体的析出造成含水率的减小明显大于溶液中晶体的析出引起的减小,且随着温度递降,未相变含水率递减;冻结温度以下,高含盐量的硫酸盐渍土未冻含水率与温度呈指数规律减小,-10℃以下,其含水率不再变化。对于低含盐量硫酸盐渍土,冻结温度以下其未冻含水率随温度降低同样按指数规律减小,且随着含盐量的增加,土体的含水率有所增加。
[Abstract]:Taking sulphuric acid saline soil as the research object, the relationship between moisture content and temperature above freezing temperature is established theoretically. The change of initial precipitation temperature of salt crystal and unphase-change moisture content of sulphate soil under different temperature conditions were also measured by laboratory tests. The effect of temperature on the moisture content of untransformed soil was analyzed by nuclear magnetic resonance (NMR) signal intensity at different temperatures. The results show that the precipitation temperature of sodium sulfate decahydrate crystal is lower than the temperature corresponding to its saturation concentration at a specific cooling rate, and the initial precipitation temperature decreases greatly with the decrease of the initial salt content. Compared with the soil mass, the salt crystal in the solution is easy to precipitate, and the precipitation of sodium sulfate decahydrate crystal in the soil results in the decrease of moisture content, which is obviously larger than that caused by the precipitation of the crystal in the solution, and the moisture content of the phase change does not decrease with the temperature decreasing. Under freezing temperature, the unfrozen moisture content and temperature of sulfate saline soil with high salt content decreased exponentially, but below -10 鈩，
本文编号：2291361
[Abstract]:Taking sulphuric acid saline soil as the research object, the relationship between moisture content and temperature above freezing temperature is established theoretically. The change of initial precipitation temperature of salt crystal and unphase-change moisture content of sulphate soil under different temperature conditions were also measured by laboratory tests. The effect of temperature on the moisture content of untransformed soil was analyzed by nuclear magnetic resonance (NMR) signal intensity at different temperatures. The results show that the precipitation temperature of sodium sulfate decahydrate crystal is lower than the temperature corresponding to its saturation concentration at a specific cooling rate, and the initial precipitation temperature decreases greatly with the decrease of the initial salt content. Compared with the soil mass, the salt crystal in the solution is easy to precipitate, and the precipitation of sodium sulfate decahydrate crystal in the soil results in the decrease of moisture content, which is obviously larger than that caused by the precipitation of the crystal in the solution, and the moisture content of the phase change does not decrease with the temperature decreasing. Under freezing temperature, the unfrozen moisture content and temperature of sulfate saline soil with high salt content decreased exponentially, but below -10 鈩，
本文编号：2291361
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