昆明机场砂岩残积红土粒度成分试验研究

Experimental study on grain size composition of sandstone red residual soil in Kunming airport

昆明机场残积红土既是区域内重要的土地资源,又是各类工程建设的建筑地基,由于红土自身的团粒结构,所以红土在物理性质方面展现出和一般黏性土的差异性。本文针对昆明机场砂岩散粒红土开展了一系列粒度成分试验研究。采用不同浓度下的4种分散剂(六偏磷酸钠、硅酸钠、草酸钠、碳酸钠)对砂岩散粒红土的分散效果、最优浓度及相应的粒度成分特征值进行了试验研究。试验结果说明能使砂岩散粒红土达到最好分散效果的分散剂为浓度2.5%的硅酸钠,并对该分散剂作用下的结果相关性进行了分析。所获得的砂岩残积红土粒度成分试验研究成果,对红土系统深入研究及工程实践应用具有重大的指导意义。

The residual red soil in Kunming Changshui International Airport is not only an important resource in the region, but also a building ground for various types of construction works. Due to the agglomerate structure of the red clay itself, the red soil is different in physical properties from the common clayey soil. A series of particle size experiments were carried out on sandstone loose red soil in Kunming Changshui International Airport. The experiment reveals the dispersing effect, the optimal concentration and the corresponding particle size composition characteristic values of four dispersing agents including sodium hexametaphosphate, sodium silicate, sodium oxalate, sodium carbonate in sandstone loose red clay at different concentrations. The experimental results show that the dispersant with the best dispersant effect is 2.5% sodium silicate, and the correlation between loose red clay and sodium silicate was analyzed. The obtained experimental result of the particle size composition of red residual clay is significant to guide the further study and engineering practice.