固化黄土的三轴剪切试验及数值模拟

发布时间：2018-04-23 07:07

本文选题：固化黄土 + SH固化剂　；参考：《太原理工大学》2015年硕士论文

【摘要】：黄土由于环境、地质、以及自身原因，导致黄土区别于一般的黏性土，具有一般土所不具备的低强度、湿陷性和结构性等工程特性。黄土的强度问题一直困扰工程界，亟需一种切实有效的办法对黄土进行加固处理。所以研究固化黄土的剪切特性并确定其影响因素具有相当的学术意义。本文采用新型固化剂SH加固山西太原地区黄土，通过室内土工试验和有限元模拟，分析影响固化黄土抗剪强度的因素和规律，开展固化黄土强度的多元回归预测，主要研究成果如下：（1）不同固化剂掺量黄土的物理试验：液塑限和击实试验，得到各掺量固化黄土的液限、塑限含水率和塑性指数，以及含水率和干密度曲线。（2）黄土抗剪强度参数的影响因素，主要有干密度和含水率。黄土的抗剪强度随干密度的增大而增大，随含水率的增大而减小。得到不同含水率下黄土试样的应力应变曲线，为分析黄土的本构模型提供依据。（3）固化黄土抗剪强度参数的影响因素，主要有干密度、掺量和含水率。固化黄土的抗剪强度同样随干密度的增大而增大，随含水率的增大而减小，并随着固化剂掺量的增加而增加，得到了SH固化黄土的多因素线性回归方程。（4）分析脱水方式对SH固化黄土抗剪强度的影响，得出龄期对SH固化黄土的抗剪强度参数无影响的结论。（5）对比重塑黄土的抗剪强度参数与SH固化黄土的抗剪强度参数，得到SH固化剂的加固黄土的效果，并给出建议固化剂掺量。综合考虑影响SH固化黄土的各种因素，建议山西太原地区可以试验性采用SH固化剂加固黄土，较适宜的固化剂掺量为10%（质量分数）。且在工程中尽量提高压实度，并做好排水降水设施，以期达到良好的加固效果。（6）通过ANSYS有限元软件对固化黄土和黄土三轴试验的数值模拟，得到试样的变形的数值近似解，并与试验结果进行对比，，验证了用ANSYS分析固化黄土和黄土常规三轴试样的有效性。
[Abstract]:Loess is different from the general clay soil because of its environment, geology and its own reasons. It has the engineering characteristics of low strength, collapsibility and structure, which are not possessed by the common soil. The strength problem of loess has always troubled the engineering circle, and a practical and effective method is urgently needed to reinforce loess. Therefore, it is of great academic significance to study the shear characteristics of solidified loess and determine its influencing factors. In this paper, a new curing agent SH is used to reinforce loess in Taiyuan area of Shanxi Province. Through indoor geotechnical test and finite element simulation, the factors and laws affecting the shear strength of solidified loess are analyzed, and the multivariate regression prediction of the strength of solidified loess is carried out. The main findings are as follows: 1) physical test of loess with different content of curing agent: liquid plastic limit and compaction test, the liquid limit, plastic limit moisture content and plastic index, water content and dry density curve of each content of solidified loess are obtained. 2) the main factors affecting the shear strength parameters of loess are dry density and moisture content. The shear strength of loess increases with the increase of dry density and decreases with the increase of moisture content. The stress-strain curves of loess samples with different moisture content are obtained, which provides the basis for analyzing the constitutive model of loess. The main factors affecting the shear strength parameters of solidified loess are dry density, content and moisture content. The shear strength of solidified loess also increases with the increase of dry density, decreases with the increase of moisture content, and increases with the increase of the content of curing agent. The multifactor linear regression equation of SH solidified loess is obtained. 4) the influence of dehydration mode on the shear strength of SH solidified loess is analyzed, and the conclusion is drawn that the age has no effect on the shear strength parameter of SH solidified loess. 5) comparing the shear strength parameters of remolded loess with that of SH solidified loess, the effect of SH curing agent on reinforcing loess is obtained, and the recommended content of solidifying agent is given. Considering all kinds of factors affecting SH solidified loess, it is suggested that SH curing agent can be used to reinforce loess in Taiyuan, Shanxi Province, and the suitable amount of solidifying agent is 10 (mass fraction). In addition, the compaction degree is raised as far as possible, and the drainage and precipitation facilities are done well in order to achieve good reinforcement effect. (6) through the numerical simulation of the triaxial test of solidified loess and loess by ANSYS finite element software, the numerical approximate solution of the deformation of the specimen is obtained, and compared with the test results, the validity of the conventional triaxial test of solidified loess and loess is verified by using ANSYS.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU444;TU411

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