天津地区人工冻土力学特性试验及其工程应用

发布时间：2018-05-06 10:30

本文选题：人工冻结法 + 单轴抗压强度　；参考：《天津大学》2014年硕士论文

【摘要】：随着天津地区地铁建设的大规模推进,人工冻结法在盾构进出洞及联络通道开挖工程中的应用得到广泛应用。但是针对天津地区不同土质的人工冻土目前缺乏系统的试验研究,相关设计施工都是参照上海地区的规范和经验,不可避免的造成了一定的安全隐患和经济浪费。本文结合天津地铁5、6号线联络通道的建设,对天津市市区范围内土层分布做了充分的调研,选取不同区域钻孔,取样基本包含了天津市所有的土层和土质情况,通过室内冻土实验对人工冻土的强度特性开展研究。第一章总结了人工冻结法在城市地铁联络通道工程中的应用概况,对人工冻土单轴抗压强度特性、三轴抗剪强度特性、抗折强度特性以及冻结法联络通道开挖数值模拟的国内外研究现状进行了调研,指出了本文研究的主要内容。第二章开展了人工冻土单轴抗压强度特性试验研究,给出不同温度、不同土质、不同含水量、不同含盐量等条件下的单轴抗压强度变化规律,对天津地区人工冻土的单轴无侧限抗压强度进行了系统的分析研究。第三章进行了人工冻土三轴抗剪强度特性试验研究,得到了不同土质、不同温度、不同含水量、不同含盐量下的强度指标,为后文数值模拟的参数选取提供依据。第四章开展了人工冻土抗折强度特性试验研究,给出不同温度、不同含水量下的抗折强度变化规律。实验采用新型试验设备,弥补了国内外对该领域研究不足的空白,所得试验结果可为天津地区地下冻土工程的设计提供依据。第五章针对实际工程建立了ABAQUS二维有限元模型来模拟施工过程,模型参数的选取及结果对比分析以上文试验研究结果为依据,从而使得数值模拟更加接近实际。
[Abstract]:With the development of subway construction in Tianjin area, artificial freezing method has been widely used in shield tunnel excavation. However, the artificial frozen soil of different soil quality in Tianjin is lack of systematic experimental research at present, and the related design and construction are all referring to the code and experience of Shanghai area, which inevitably leads to a certain safety hidden trouble and economic waste. In this paper, based on the construction of Tianjin Metro Line 5, 6, the distribution of soil layer in Tianjin urban area is investigated fully. Different regions are selected to drill holes. The sampling basically includes all soil layers and soil quality in Tianjin. The strength characteristics of artificial frozen soil were studied by indoor frozen soil experiment. The first chapter summarizes the application of artificial freezing method in urban subway communication channel engineering. The uniaxial compressive strength and triaxial shear strength of artificial frozen soil are analyzed. The characteristics of flexural strength and the current situation of numerical simulation of freezing contact channel excavation are investigated and the main contents of this paper are pointed out. In the second chapter, the uniaxial compressive strength of artificial frozen soil is studied, and the variation of uniaxial compressive strength under different temperature, different soil quality, different water content and different salt content is given. The uniaxial unconfined compressive strength of artificial frozen soil in Tianjin is studied systematically. In chapter 3, the experimental study on triaxial shear strength of artificial frozen soil is carried out, and the strength indexes of different soil quality, different temperature, different moisture content and different salt content are obtained, which provides the basis for the parameter selection of the later numerical simulation. In chapter 4, the experimental study on the flexural strength characteristics of artificial frozen soil is carried out, and the variation law of the flexural strength under different temperature and different moisture content is given. A new type of test equipment is used to make up for the lack of research in this field at home and abroad. The experimental results can provide a basis for the design of underground frozen soil engineering in Tianjin. In the fifth chapter, the ABAQUS two-dimensional finite element model is established to simulate the construction process. The selection of model parameters and the comparison of the results are based on the above experimental results, so that the numerical simulation is closer to reality.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU445

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