杭州软土固化优化研究

发布时间：2018-07-25 12:13

【摘要】：杭州地区分布有大片软土地基,其中绝大部分含水量较高,且含有一定量的有机质。与此同时,这些软土表现出一些共有的工程特性,如压缩性高,承载力低,渗透性小等。为了使这些地基的各项工程指标满足实际需求,常需对其进行固化处理。传统水泥土、石灰土的固化方法对不同软土的处理缺乏针对性,不同区域的土体固化效果差异较大。因此有必要针对杭州地区软土的特点,研发出适宜的固化剂或添加剂产品,并给出方便快捷的固化方案优选策略,从而达到集约型处理的目的。为此,本文主要开展了如下工作： (1)针对杭州软土高含水量和高有机质含量的特点,深入分析了土体含水量与有机质对固化效果的影响机制,在此基础上综合考虑固化效果、材料价格、取材与施工的便利性等因素,确定采用水泥、生石膏、生石灰、碳酸钠这四种固化材料改良软土性质。 (2)将响应面法引入添加剂配方的研究中,在掺入水泥的基础上,以不同龄期的固化土无侧限抗压强度为响应值,以生石膏、生石灰、碳酸钠三种添加成分的掺入比为影响因子,通过方差分析、单因子效应分析、交互作用分析及机理分析,最终完成了水泥系添加剂CX-13配方的确定。 (3)将响应面法引入固化方案的优化研究中,以不同龄期下固化土无侧限抗压强度为响应值,以土有机质含量、初始含水量、水泥掺入比、CX-13掺入比为四个影响因子,构建不同龄期下固化土的强度量化模型。根据所得固化土强度量化模型深入分析影响因子间的交互作用规律,并从机理上对其进行了剖析。 (4)将拉格朗日乘数法引入固化方案的优化分析中,并以算例的形式阐述了具体的实施步骤。通过对单一水泥固化和水泥与CX-13联合固化进行对比试验,进一步说明了添加剂CX-13在实际软土固化处理中的经济适用性。
[Abstract]:There is a large area of soft soil foundation in Hangzhou area, most of which have high water content and contain a certain amount of organic matter. At the same time, these soft soils show some common engineering characteristics, such as high compressibility, low bearing capacity, low permeability and so on. In order to meet the actual requirements of these foundation engineering indexes, it is often necessary to solidify them. The solidification methods of traditional cement soil and lime soil have little pertinence to the treatment of different soft soil, and the solidification effect of different regions is quite different. Therefore, it is necessary to develop suitable hardener or additive products according to the characteristics of soft soil in Hangzhou area, and give the convenient and quick strategy of optimal selection of curing scheme, so as to achieve the purpose of intensive treatment. Therefore, the main work of this paper is as follows: (1) according to the characteristics of high moisture content and high organic matter content in Hangzhou soft soil, the influence mechanism of soil moisture content and organic matter on solidification effect is deeply analyzed. On this basis, the factors such as solidification effect, material price, material selection and construction convenience are considered synthetically, and cement, raw gypsum and quicklime are adopted. The four solidified materials, sodium carbonate, are used to improve the properties of soft soil. (2) the response surface method is introduced into the study of additive formulation. Based on the addition of cement, the unconfined compressive strength of the solidified soil of different ages is taken as the response value, and the gypsum is used as raw gypsum. The mixing ratio of lime and sodium carbonate was the influence factor, which was analyzed by variance analysis, single factor effect analysis, interaction analysis and mechanism analysis. Finally, the CX-13 formula of cement additive was determined. (3) the response surface method was introduced into the optimization study of curing scheme. The unconfined compressive strength of solidified soil under different ages was taken as the response value, the content of soil organic matter and the initial water content were taken as the response value. The cement blending ratio (CX-13) is four influencing factors, and the strength quantification model of solidified soil at different ages is constructed. According to the quantitative model of the strength of solidified soil, the interaction law among the influencing factors is deeply analyzed, and the mechanism is analyzed. (4) the Lagrange multiplier method is introduced into the optimization analysis of solidification scheme. And the concrete implementation steps are expounded in the form of an example. The economic applicability of additive CX-13 in the curing treatment of soft soil is further explained by comparing the single cement solidification and cement / CX-13 curing.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU447

【参考文献】