矿粉固化剂处理盐渍吹填土地基效果研究

研究目的:曹妃甸吹填土含有大量细颗粒成分,且含盐量高,常规地基处理方法达不到强度和变形要求,化学固化方式处理该地区盐渍吹填土具有较大的优势。本文以10%矿粉作为固化剂主剂,硅酸钠、生石灰和石膏粉作为添加剂,分别进行单掺、双掺和三掺添加剂固化后的强度试验,分析盐渍吹填土在不同掺入材料、配比及不同期龄下的无侧限抗压强度变化规律。研究结论:(1)矿粉固化剂能大大提高曹妃甸盐渍吹填土的无侧限抗压强度,其中生石灰对矿粉固化盐渍吹填土的固化效果影响最大;(2)10%的矿粉+1.0%的生石灰+0.8%的硅酸钠+1.5%的石膏粉,是矿粉固化剂的最优配比方案,该配比固化土试样7 d无侧限抗压强度达到了2007 k Pa,28 d无侧限抗压强度增至3370 k Pa,完全能满足铁路地基强度要求;(3)该研究成果可为曹妃甸及其他滨海盐渍化吹填土地区铁路地基固化工程提供指导和理论依据。

Research on the Effect of Mineral Powder Curing Agent on Reinforcing Saline Dredger Fill Foundation

Research purposes:Caofeidian dredger fill contains a large number of fine particles,and has high salt content.Conventional foundation treatment methods can not meet the requirements of strength and deformation.Chemical solidification method has great advantages in treating saline dredger fill in this area.In this paper,10%mineral powder is used as the main curing agent,sodium silicate,quicklime and gypsum powder are used as additives.Strength tests of saline dredger fill solidified with single,double and three additives are carried out respectively.The changing rules of unconfined compressive strength of saline dredger fill under different mixing materials,ratios and ages are analyzed.Research conclusions:(1)The unconfined compressive strength of Caofeidian saline dredger fill can be greatly improved by the mineral powder curing agent,among which quicklime has the greatest influence on the solidifying effect of the mineral powder solidifying saline dredger fill.(2)10%mineral powder+1.0%quicklime+0.8%sodium silicate+1.5%gypsum powder is the optimum proportion of the mineral powder curing agent.The 7-day unconfined compressive strength of the solidified soil sample reaches 2007 kPa,and the 28-day unconfined compressive strength increases to 3370 k Pa,which fully meets the requirements of foundation strength.(3)The research results can provide guidance and theoretical basis for railway foundation consolidation projects in Caofeidian and other coastal saline dredger fill areas.