【摘要】：以硫酸鹽漬土為研究對象,從理論上建立了凍結溫度以上未相變含水率與溫度的關系,并通過室內試驗測試了硫酸鹽土體及對應溶液中鹽晶體初始析出溫度和硫酸鹽漬土未相變含水率在不同溫度環(huán)境下的變化。從土體降溫溫度曲線、不同溫度下核磁共振信號強度分析了溫度對未相變含水率的影響。研究結果表明:在特定降溫速率下,十水硫酸鈉晶體析出存在滯后性,初始析出溫度均低于其飽和濃度所對應的溫度,并隨著初始含鹽量的減小,初始析出溫度大幅度降低,且與土體比較,溶液中鹽晶體易于析出;土體中十水硫酸鈉晶體的析出造成含水率的減小明顯大于溶液中晶體的析出引起的減小,且隨著溫度遞降,未相變含水率遞減;凍結溫度以下,高含鹽量的硫酸鹽漬土未凍含水率與溫度呈指數(shù)規(guī)律減小,-10℃以下,其含水率不再變化。對于低含鹽量硫酸鹽漬土,凍結溫度以下其未凍含水率隨溫度降低同樣按指數(shù)規(guī)律減小,且隨著含鹽量的增加,土體的含水率有所增加。
[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，

本文編號：2291361