洞庭湖区淤泥质土水泥土强度特性研究

发布时间：2018-09-14 18:15

【摘要】：本文以洞庭湖地区淤泥质土为原材料,利用水泥加固软土技术原理,通过室内试验,获得了满足工程需要的水泥土施工参数,为工程实践提供依据。本文主要的研究工作有:1、通过水泥土的混合均匀试验,研究了影响水泥土无侧限抗压强度的几个主要因素,获得了水泥土无侧限抗压强度随水泥掺入比、含水率、含砂率、水泥标号变化等而变化的规律;2通过开展水泥土三轴试验,对不同水泥掺入比、养护龄期和围压下水泥土的应力应变曲线进行研究,获得了水泥土强度随水泥掺入比、龄期和围压的变化规律。水泥土破坏型式为脆性破坏。3、以洞庭湖区某堤防工程为例,根据室内试验结果对其进行设计,现场载荷试验结果表明:本文提供的设计参数,可以指导工程实践,处理后的地基承载力满足要求。根据室内试验的结果研究分析,得出如下主要成果:1、当水泥掺入比在6%~16%时,淤泥质土水泥土的无侧限抗压强度随水泥掺入比大致呈线性增加,掺入比每增加1%,强度提高约56~87kPa。水泥掺入比小于10%时,水泥土强度增加较慢,随后增加较快,当水泥掺入比大于14%时,水泥土强度增加又趋缓。水泥掺入比对水泥土强度有显著性影响,其他因素无显著性影响。2、水泥土峰值强度随随水泥掺入比的增加而增大,水泥掺入比每增加3%,水泥土峰值强度增加值在60kPa~360kPa之间。在相同水泥掺入比时,水泥土峰值强度增加值随围压增加而增大,其值在170kPa~120kPa之间。水泥土应力峰值出现时,其应变值在2.1%~3.6%之间。3、围压对高龄期水泥土强度的影响要大于低龄期,水泥土桩在受压时其强度特性与周围土体提供的围压有关,提供的围压越大,越能发挥水泥土的强度特性。
[Abstract]:In this paper, the silt soil in Dongting Lake area is used as the raw material, and by using the technical principle of cement strengthening soft soil, through indoor test, the construction parameters of cement soil to meet the engineering needs are obtained, which provides the basis for engineering practice. The main research work in this paper is: 1. Through the mixed homogeneous test of cement-soil, several main factors affecting the unconfined compressive strength of cement-soil are studied, and the unconfined compressive strength of cement-soil is obtained with the ratio of cement to cement, moisture content and sand content. Through the triaxial test of cement soil, the stress-strain curves of cement with different cement ratio, curing age and confining pressure were studied, and the strength of cement soil with cement mixing ratio was obtained. Changes of age and confining pressure. The failure type of cement-soil is brittle failure. 3. Taking a dyke project in Dongting Lake area as an example, according to the results of indoor test, the field load test results show that the design parameters provided in this paper can guide the engineering practice. The bearing capacity of the treated foundation meets the requirements. According to the research and analysis of the results of laboratory tests, the following main results are obtained: 1: 1. When the ratio of cement to cement is between 6 and 16, the unconfined compressive strength of the cement soil increases linearly with the ratio of cement to cement, and the strength increases by 56 ~ 87 KPA with the increase of the ratio of cement to cement. When the ratio of cement to soil is less than 10, the strength of cement-soil increases slowly and then increases more quickly. When the ratio of cement to soil is greater than 14, the strength of cement-soil increases slowly. The ratio of cement to soil has a significant effect on the strength of cement-soil, but other factors have no significant effect. The peak strength of cement-soil increases with the increase of cement ratio. With the increase of cement ratio, the increase of peak strength of cement-soil is between 60kPa~360kPa. At the same cement ratio, the increase of peak strength of cement-soil increases with the increase of confining pressure, and its value is between 170kPa~120kPa. When the peak stress of cement soil appears, the strain value of cement soil is between 2.1% and 3.6%. The influence of confining pressure on cement soil strength at old age is greater than that at low age. The strength characteristic of cement soil pile under compression is related to the confining pressure provided by surrounding soil, and the larger the confining pressure is, The more the strength of cement soil can be developed.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43

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