不同养护龄期下水泥掺入比对水泥土直剪特性的影响  

Effects of Mixing Ratio on Direct Shear Characteristics of Cement-Soil under Different Curing Ages

作　　者：陈利宏 杜军 唐灵敏 熊勃 姚嘉敏 CHEN Lihong;DU Jun;TANG Lingmin;XIONG Bo;YAO Jiamin(China Construction Fifth Engineering Bureau Co.,Ltd.Zhuhai 519000,China;Guangdong Huagu Engineering Cooperation Limited Guangzhou 510010,China;Department of Civil Engineering,Shanghai University Shanghai 200444,China)

机构地区：[1]中国建筑第五工程局有限公司,广东珠海519000 [2]广东华固工程有限公司,广州510010 [3]上海大学土木工程系,上海200444

出　　处：《广东土木与建筑》2022年第5期35-39,共5页Guangdong Architecture Civil Engineering

基　　金：国家自然科学基金项目(51678352)。

摘　　要：为了研究水泥掺入比与养护龄期对水泥土剪切特性的影响,针对珠海地区淤泥水泥土,通过36组直剪试验,定量分析了水泥掺入比(aw=13%、20%、25%、30%)、养护龄期(t=7、14、28 d)、竖向应力(σ=100、200、300 kPa)对水泥土抗剪强度以及剪胀特性的影响规律。试验结果表明:相同养护龄期(t=28 d)及竖向应力(σ=100 kPa),水泥掺入比为20%、25%、30%时的水泥土抗剪强度较13%时分别提高了40.69%、88.79%和116.33%;掺入比为13%的土样在剪切过程中未出现峰值剪切应力,掺入比分别为20%、25%、30%的土样在剪切过程中有趋于脆性破坏的现象;增长养护龄期可以提高水泥土抗剪强度,两者之间存在指数相关性;随着水泥掺入比和养护龄期的增大,水泥土体变表现出膨胀趋势,但随着竖向应力水平的提高,这种膨胀趋势逐渐减弱;水泥土的黏聚力c和摩擦角φ随着水泥掺入比与养护龄期的增加而表现出递增趋势。In order to study the influence of cement mixing ratio and curing age on the shear properties of cement-soil,36 groups of direct shear tests were carried out on the silt cement-soil in Zhuhai area.The effects of cement mixing ratio(a_(w)=13%,20%,25%,30%),curing age(t=7,14,28 d)and vertical stress(σ=100,200,300 kPa)on the shear strength and dilatancy characteristics of cement-soil were quantitatively analyzed.The test results show that under the same curing age(t=28 d)and vertical stress(σ=100 kPa),the shear strength of cement-soil with 20%,25%and 30%cement content is 40.69%,88.79%and 116.33%higher than that of cement-soil with 13%.The soil samples with the incorporation ratio of 13%had no peak shear strength in the shear process,and the soil samples with the incorporation ratios of 20%,25%and 30%had brittle failure in the shear process.Increasing the curing age can improve the shear strength of cement-soil,and there is an exponential correlation between them.With the increase of cement mixing ratio and curing age,the cement-soil shows an expansion trend,but with the increase of vertical stress level,the expansion trend is gradually weakened.The cohesion c and friction angleφof cement-soil increased with the increase of cement mixing ratio and curing age.

关 键 词：水泥加固土 水泥掺入比 养护龄期 抗剪强度 

分 类 号：TU447[建筑科学—岩土工程]