洞庭湖区软土固结特性研究

发布时间：2018-08-26 06:46

【摘要】：收集了洞庭湖区软土的相关资料、针对洞庭湖区的地质进行了详细的研究与分析。在室内对洞庭湖区原状土进行了基本土工试验,得到了土样的基本物理力学参数,经过回归分析,得到了不同物理力学参数与含水率的相关性表达式。通过研究可得洞庭湖区的软土具有高含水率、低强度的特性,土质较为细,软淤泥成分比较多。对GDS高级固结仪进行了详细的阐述,针对固结仪的工作原理,构成系统、操作方式及优缺点等进行分析和介绍。利用GDS高级固结系统对洞庭湖软土进行了分级加载固结试验,根据排水方式的不同,先后进行了竖向排水固结试验与径向排水固结试验,分析了不同排水条件下试样的孔隙比、压缩系数、压缩模量及固结系数。根据试验结果分析了在不同控制条件下土样的固结变形特性。对连续加载固结试验进行了系统的研究,对洞庭湖区软土进行了等应变速率与等荷载速率固结试验,并且与分级加载固结试验进行了比较。对比分析了在加载方式与排水方式不同的条件下土样的固结特性,发现在不同固结条件下,当土样中有效应力相同时,土样表现出相同的力学性状。对软土的非线性渗透模型与非线性压缩模型进行了分析,通过上述试验结果,得到了洞庭湖区软土非线性压缩模型与非线性渗透模型的参数。综合考虑了土体固结过程中压缩系数、渗透系数的非线性变化,建立了饱和软土的一维非线性固结模型,得到了方程的解析解,对结果进行了比较分析。
[Abstract]:The relevant data of soft soil in Dongting Lake region are collected, and the geology of Dongting Lake area is studied and analyzed in detail. The basic geotechnical tests of the undisturbed soil in Dongting Lake region were carried out in the laboratory, and the basic physical and mechanical parameters of the soil samples were obtained. Through regression analysis, the correlation expressions between different physical and mechanical parameters and moisture content were obtained. It can be found that the soft soil in Dongting Lake area has high moisture content and low strength, the soil quality is fine and the composition of soft silt is more. In this paper, the advanced consolidation instrument of GDS is described in detail, and the working principle, composing system, operating mode, advantages and disadvantages of the instrument are analyzed and introduced. By using GDS advanced consolidation system, the soft soil in Dongting Lake was subjected to graded loading consolidation test. According to the different drainage methods, vertical drainage consolidation test and radial drainage consolidation test were carried out successively, and the porosity ratio of the sample under different drainage conditions was analyzed. Compression coefficient, compression modulus and consolidation coefficient. According to the experimental results, the consolidation deformation characteristics of soil samples under different control conditions are analyzed. The continuous loading consolidation test was studied systematically, and the iso-strain rate and equal load rate consolidation tests of soft soil in Dongting Lake region were carried out, and the results were compared with those of graded loading consolidation test. The consolidation characteristics of soil samples under different loading and drainage conditions are compared and analyzed. It is found that under different consolidation conditions the soil samples exhibit the same mechanical properties when the effective stress in the soil samples is the same. The nonlinear permeability model and nonlinear compression model of soft soil are analyzed. The parameters of nonlinear compression model and nonlinear permeability model of soft soil in Dongting Lake region are obtained through the above experimental results. Taking into account the nonlinear variation of compressibility and permeability coefficient in the process of soil consolidation, the one-dimensional nonlinear consolidation model of saturated soft soil is established, and the analytical solution of the equation is obtained, and the results are compared and analyzed.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU447

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