基于荆江河段粘性弃土固化利用的土体特性研究

Study on Soil Characteristics Based on Solidification Reutilization of Cohesive Spoil from Jingjiang River Segment

为了对荆江河段护岸弃土实现再利用,将其固化处理后制备成水工材料,需对弃土的特性进行分析。以粘性弃土为样本,通过对其进行pH值测定、化学成分分析、矿物组成分析和颗粒级配分析,为固化材料的选择和配制提供依据。分析结果表明:粘性弃土的pH值为7.67,不适合选择离子类土壤固化剂;粘性弃土中SiO_2、Al_2O_3含量比较高,其他物质及有机质含量较少,固化材料需能提供有效的OH根离子,促使活性SiO_2、Al_2O_3溶蚀,从而提高火山灰反应的速度;粘性弃土中粘性矿物比重低,土样活性较差,固化材料中需添加一定量的碱性激发剂激活黏土中矿物的活性;依据化学成分和矿物组成的测定结果,同时考虑到固化制品的水稳性能,适合选择无机类土壤固化剂;粘性弃土的粒径分布范围窄,土的级配不良,固化材料中需要添加一定量粗骨料。

In order to realize the reuse of the spoil from Jingjiang River segment, it was feasible to get the preparation of material for water project through solidification treatment of the spoil, the characteristics of the spoil needed to be researched. Taking cohesive spoil as a sample, the analysis of the p H, chemical composition, mineral composition and particle size distribution were carried out to provide the basis for the selection and matching of the solidified materials. The results showed that：（1） the cohesive spoil＇s p H was 7.67, which was not suitable for selecting ion soil consolidating additive;（2） the total content of SiO_2、Al_2O_3 was higher. The other substances and organic matter content was less. The consolidating material must be able to provide effective OH-and promote the dissolution of active SiO_2、Al_2O_3, so as to improve the speed of the ash reaction;（3） the proportion of clay mineral was low, so the activity of the soil sample was poor. A certain amount of alkali activator was needed to activate the activity of the clay minerals;（4） according to the determination results of chemical composition and mineral composition, at the same time, considering the water stability performance of the solidified products, it was suitable to choose inorganic soil consolidating additive;（5） the cohesive spoil had a narrow particle size distribution range, and the particle size mainly concentrated in the 0.002~0.05 mm, and the cohesive spoil is a poorly graded soil. So it needed to add a certain amount of coarse aggregate to the solidified materials.