To re-utilize the solidified spoil in bank protection construction of Jingjiang River reach, the characteristics of the spoil should be analyzed. Taking cohesive spoil as an example, the measurement of pH, analysis of chemical composition, min-eral composition and particle size distribution were carried out to provide the basis for the selection and preparation of the solidi-fied materials. The results show that pH of cohesive spoil is 7. 67 and it doesn′t suit to use the ion soil consolidating additive;the total content of the four elements ( SiO2、Al2 O3、CaO、Fe2 O3 ) reaches 90%, of which the content of SiO2 and Al2 O3 is higher;the content of other substances and organic matter is less;the consolidating material should be able to provide effective OH- to pro-mote the dissolution of the active SiO2 and Al2 O3 and accelerate tephra reaction; The ratio of clay to non-clay minerals in the spoil is in a low proportion of about 3:7, so the activity of the soil sample is poor. A certain amount of alkali activator is needed to activate the activity of the clay minerals. According to the results of chemical and mineral composition measurement and by consideration of the water stability of the solidified products, the inorganic soil consolidating additive is suitable;The particle size of cohesive spoil distributions in a small range, mainly between 0. 002 to 0. 05 mm, so the cohesive spoil is a poorly graded one and a certain amount of coarse aggregate needs to be added.%为了实现荆江河段护岸弃土再利用,拟将其固化处理后制备成水工材料,故需对弃土的特性进行分析。以黏性弃土为样本,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：①黏性弃土的pH值为7.67,不适合选择离子类土壤固化剂。②黏性弃土中SiO2、Al2 O3含量比较高,其中SiO2、Al2 O3、CaO、Fe2 O3四种组分含量之和达到90%,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SiO2、Al2 O3溶蚀,从而提高火山灰反应的速度。③黏性弃土中黏性矿物与非黏性矿物相比约为3/7,黏性矿物比重低,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。④黏性弃土的粒径分布范围窄,主要集中于0.002~0.05 mm之间,土的级配不良,固化材料中需要添加一定量粗骨料。
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