由灌溉引起的黄土湿陷过程中碳酸钙行为研究

BEHAVIORS OF CaCO_3 IN LOESS COLLAPSE CAUSED BY IRRIGATION

长期以来,有关黄土湿陷的研究一直忽视对碳酸钙行为的探讨。本研究利用扫描电子显微镜(SEM)和能谱分析(EDX)技术研究了黄土中碳酸钙的分布,通过室内模拟实验,探讨了由灌溉引起的黄土湿陷过程中碳酸钙的行为,初步得出以下结论:黄土颗粒间存在大量碳酸钙,在黄土湿陷过程中碳酸钙发生淋溶、移动损失,其中以移动损失为主,溶解损失相对较少。碳酸钙的移动损失量随透水量增加而增加,在下部土层发生聚集。

The study on loess collapsibility has long ignored role of CaCO3. With the aid of scanning electron microscope （SEM） and X-ray energy dispersive microanalysis （EDX or EDS） , CaCO3 distribution in loess was explored. Some indoor experiments were carried out to simulate loess collapse and study behaviors of CaCO3 in the process. Results show that between loess particles exists plenty of CaCO3 , which is easily leached with irrigation water and lost in the process. Its loss through movement is much greater than through leaching, and increasing with the percolation rate of irrigation water. Then CaCO3 accumulates in the subsoil layer.