水泥改良土抗剪强度试验研究

Experimental study on shear strength of cement improved soil

为获得濒水环境下水泥改良土抗剪强度设计参数,采用室内试验方法,研究水泥与土的质量比、压实度、含水量及养护龄期对水泥改良土抗剪强度的影响。结果表明:含水量、压实度、养护龄期相同时,水泥改良土的黏聚力、内摩擦角及抗剪强度随水泥与土的质量比的增大而增大;水泥与土的质量比、含水量、养护龄期相同时,随压实度的增大,水泥改良土的黏聚力、内摩擦角及抗剪强度线性增大,水泥与土的质量比为8.0%时,黏聚力平均增大3.4%,水泥与土的质量比为10%时,黏聚力平均增大2.1%;水泥与土的质量比、压实度和养护龄期相同时,水泥改良土的黏聚力、内摩擦角及抗剪强度随含水量的增大而减小,黏聚力变化较小,内摩擦角、抗剪强度变化较大;水泥与土的质量比、压实度和含水量相同时,水泥改良土的黏聚力、内摩擦角及抗剪强度随养护龄期的增大而增大,但增速放缓,养护28 d后内摩擦角基本不变,抗剪强度因黏聚力继续增大而增大。

To obtain design parameters for the shear strength of cement improved soil in a wetland environment,an indoor experimental method is employed to study the effects of the cement-to-soil mass ratio,compaction degree,moisture content,and curing age on the shear strength of cement improved soil.The results indicate that,with the same moisture content,compaction degree,and curing age,the cohesion,internal friction angle,and shear strength of the cement improved soil increase with the increase of the cement-to-soil mass ratio.When the cement-to-soil mass ratio,moisture content,and curing age remain constant,the cohesion,internal friction angle,and shear strength of the cement improved soil increase linearly with the increase of compaction degree.At a cement-to-soil mass ratio of 8.0%,the average cohesion increases by 3.4%,and at a cement-to-soil mass ratio of 10%,the average cohesion increases by 2.1%.With the cement-to-soil mass ratio,compaction degree,and curing age remaining constant,the cohesion,internal friction angle,and shear strength of the cement improved soil decrease with the increase of moisture content.The change in cohesion is small,while the changes in internal friction angle and shear strength are significant.When the cement-to-soil mass ratio,compaction degree,and moisture content are constant,the cohesion,internal friction angle,and shear strength of the cement-modified soil increase with the increase of curing age,but the rate of increase slows down.After 28 days of curing,the internal friction angle remains basically unchanged,while the shear strength increases due to the continued increase in cohesion.