两种类型吹填场区地基土的次固结特性试验研究  

Properties of secondary consolidation of two types of dredger fill sites

作　　者：雷华阳[1,2] 陈丽[1] 丁小冬[1] 郑刚[1,2] 康景文 

机构地区：[1]天津大学土木工程系,天津300072 [2]天津大学滨海土木工程结构与安全教育部重点实验室,天津300072 [3]中国建筑西南勘察设计研究院有限公司,四川成都610081

出　　处：《岩土工程学报》2013年第S1期90-96,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51078262);同济大学岩土及地下工程教育部重点实验室开放研究基金项目(KLE-TJGE-B1101);天津市软土特性与工程环境重点实验室开放课题基金项目(2011SCEEKL003)

摘　　要：利用单向固结仪,对天津滨海中心渔港地区真空预压处理后和未处理两种类型吹填场地的地基土进行一系列一维压缩次固结试验,获得应变、应力、孔隙比和时间关系,对比分析其次固结特性及其影响因素。结果表明:随着荷载的增大,次固结系数Ca先增大后减小,其中已处理土样Ca增长幅度很小,增长了14%;未处理土样Ca则大幅增长了11倍;次固结系数随含水率增大呈上凹形非线性增长,与压缩指数呈良好的线性关系,随时间的增加均呈对数下降趋势。次固结特性受土样高度和排水条件影响明显。所提出的适用于吹填场地基土特性的次固结系数模型及变形预测方法简便实用。通过与试验结果的比较,表明基于该模型计算的Ca值和次固结变形量均拟合较好,能够较好地模拟吹填场地基土的变形特性。By use of the unidirectional oedometer apparatus,a series of 1-D compression secondary consolidation tests on soil samples in two kinds of dredger fill sites are done.The relationship among stress,strain,void ratio and time is obtained,and the characteristics of the secondary consolidation and its influencing factors are compared.The results show that the secondary consolidation coefficient first increases with the increase of load and then decreases.In contrast,the value in unprocessed site is more than that in processed site.It also increases with the increases of moisture content,and the relationship curve is a concave.It keeps a linear increase with the compression index,at the same time,it keeps a logarithmic downtrend with the increasing time.The characteristics of the secondary consolidation are obviously influenced by the height and the drainage condition of soil samples.Based on the results,a simple and practical secondary consolidation coefficient model and deformation forecast method,which are suitable for the characteristics of dredger fill sites,are proposed.Compared with the experimenta;results,the proposed model can be employed to predict the deformation characteristics of the dredger fill sites.

关 键 词：吹填场地 次固结特性 次固结系数 沉降预测 

分 类 号：TU411[建筑科学—岩土工程]