砂黏土混合物的工程特性及其路用改性

发布时间：2018-01-10 22:01

本文关键词：砂-黏土混合物的工程特性及其路用改性　出处：《东南大学》2015年硕士论文　论文类型：学位论文

【摘要】：吹填造陆是解决土地资源紧缺和加快港口码头建设的重要途径。吹填形成的土体类型可能是单一的高含水率淤泥,也可能是砂-黏土混合物,取决于原泥土层与吹填工艺。目前,关于高含水率淤泥的基本工程特性已经开展了大量的研究,而针对砂-黏土混合物的研究相对较少。深入开展砂-黏土混合物基本工程性质的研究,能够为吹填形成的砂-黏土混合物地基沉降分析和计算奠定基础。本文以江苏交通运输科技项目《吹填土应用于临海高等级公路路基及港区关键技术研究》为课题依托,以赣榆港区吹填造陆地基沉降分析与控制为研究背景,在室内开展了一系列的实验,研究了砂-黏土混合物的基本工程特性；同时基于该混合物用作路用底基层材料时不能满足规范要求这一具体工况,通过实验开展了一系列的路用改性技术研究。主要研究内容和成果如下：(1)砂-黏土混合物液限wL与黏土含量和矿物组成密切相关：基于实验结果提出了考虑黏土含量和矿物组成影响的液限综合表达式：(2)常用于评价纯黏土压缩性状的归一化指标e/eL和孔隙指数Iv亦能够拓展运用在砂-黏土混合物中,以此指标能够建立其与荷载之间特定的关系式；但是纯黏土与砂-黏土混合物归一化压缩特性存在差异性,本质原因在于混合物在荷载作用下形成了砂骨架：骨架形成之前,混合物压缩特性由黏土控制,表现出似黏土性状,而在骨架形成之后,其压缩特性由砂颗粒控制而非黏土：当e/eL位于0.40-0.42之间时,混合物的压缩性状发生明显改变：最后针对对于不同黏土含量以及黏土矿物(高岭石和蒙脱石)比例的砂-黏土混合物,给出了一种预测砂骨架开始形成的方法；(3)常用于评价纯黏土渗透特性的归一化指标e/eL亦能够运用在砂-黏土混合物中,以此指标能够建立其与渗透系数k之间的非线性关系,不同于纯黏土的线性关系；本文基于室内试验数据提出了一种预测纯黏土和砂-黏土混合物渗透系数的经验公式：(4)通过无侧限抗压、劈裂抗压以及抗压回弹模量等实验,评价了砂-黏土混合物改性处理后的力学性能；同时基于击实实验、水稳实验以及干缩实验等结果,明确了改性土的路用性能。结果表明：在纯水泥、水泥钢渣复合物以及水泥MK复合物三种改性剂中,水泥+MK复合材料的改性处理效果最好。
[Abstract]:Filling land is an important way to solve the shortage of land resources and accelerate the construction of port wharf. The type of soil formed by blowing filling may be a single high moisture content silt or a mixture of sand and clay. At present, a lot of research has been done on the basic engineering characteristics of high moisture content silt. However, the research on sand clay mixture is relatively few. The basic engineering properties of sand clay mixture are studied in depth. It can lay a foundation for the foundation settlement analysis and calculation of sand clay mixture formed by blowing fill. This paper takes Jiangsu transportation science and technology project < study of key technology applied to roadbed and port area of high grade highway near sea by blowing fill soil " The question depends on. Based on the analysis and control of land base subsidence in Ganyu Port area, a series of experiments were carried out in the laboratory to study the basic engineering characteristics of sand clay mixture. At the same time, based on the concrete condition that the mixture can not meet the requirements of the specification when it is used as the base material for road use. A series of road modification techniques were studied through experiments. The main research contents and results are as follows: 1). The liquid limit (WL) of sand clay mixture is closely related to the clay content and mineral composition. Based on the experimental results, a comprehensive expression of liquid limit considering the influence of clay content and mineral composition is proposed. The normalized index E / eL and the porosity index I _ v, which are commonly used to evaluate the compression properties of pure clay, can also be extended to sand and clay mixtures. This index can establish a specific relationship between the load and its relationship; But there is a difference between pure clay and sand clay mixture normalized compression characteristics, the essential reason is that the mixture formed sand skeleton under load: before the formation of skeleton, the mixture compression characteristics are controlled by clay. After the formation of the skeleton, the compression property of the clay is controlled by sand particles rather than clay: when er / eL is between 0.40-0.42. The compression behavior of the mixture changed obviously: finally, the sand clay mixture with different clay content and ratio of clay minerals (kaolinite and montmorillonite) was targeted. A method for predicting the formation of sand skeleton is presented. (3) the normalized index er / eL, which is often used to evaluate the permeability of pure clay, can also be used in sand-clay mixture, and the nonlinear relationship between it and permeability coefficient k can be established. The linear relationship is different from that of pure clay. In this paper, an empirical formula of predicting permeability coefficient of pure clay and sand clay mixture is presented based on laboratory test data. The mechanical properties of the modified sand clay mixture were evaluated. At the same time, based on the results of compaction test, water stability test and dry shrinkage test, the road performance of the modified soil was determined. The results showed that: in the pure cement, cement steel slag composite and cement MK composite three modifiers. The modification effect of cement MK composite is the best.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U414

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