非饱和土水力耦合模型及其数值实现
发布时间：2018-11-06 11:32
【摘要】：自然界广泛存在的土体,大多处于非饱和态。岩土工程师要面临大量的非饱和土的工程问题,通常认为利用饱和土力学的理论分析和处理非饱和土的问题是偏于安全的,但这些处理问题的方法,仍处于半理论、半经验的发展阶段。 如何采用更加客观科学的方法,对非饱和土的特性进行研究并加强与工程问题的衔接,是当前非饱和土力学发展中需要努力的方向之一。本文结合刘艳提出的固液气三相耦合的非饱和土本构模型框架,对非饱和土水力耦合模型及其数值实现方法进行了研究,探讨了模型应用于实际的可能性,具体内容如下： (1)结合实际情况,将固液气三相耦合的非饱和土本构模型中液相对固相的影响参数及液相的更新参数进行简化,并推导了适用于数值计算的非饱和土水力耦合模型。 (2)选用半隐式本构积分算法,推导得到了水力耦合的非饱和土的一致切线模量,运用FORTRAN语言开发本构模型计算的子程序,使其能向外输出切线刚度矩阵并用于有限元计算。利用本构子程序对已有试验进行模拟计算,将模型计算结果与已有试验结果进行对比,主要包括土体在等向固结、干湿循环以及三轴剪切等不同路径下的行为特性。 (3)基于固液耦合思想,引入非线性的土水特征曲线模型,对土水特征曲线进气值与体变的关系提出假设并应用于模型,详细推导并编程完成新的土水特征曲线模块下的数值计算更新,将模型计算结果与已有干湿循环试验结果对比,考察了新的土水特征曲线模型的适用性。 (4)运用UMAT子程序二次开发功能,将本构模型扩展到ABAQUS大型有限元分析软件中,对单个与多个单元的弹塑性问题进行分析。验证了本构模型从一点应力-应变关系到多单元实体响应的扩展效果。
[Abstract]:The soil mass, which exists widely in nature, is mostly in unsaturated state. Geotechnical engineers are faced with a large number of engineering problems of unsaturated soil. It is generally considered that it is safe to use the theory of saturated soil mechanics to analyze and deal with unsaturated soil, but the methods of dealing with these problems are still semi-theoretical. A semi-empirical stage of development. How to use more objective and scientific methods to study the characteristics of unsaturated soil and strengthen the connection with engineering problems is one of the directions in the development of unsaturated soil mechanics. In this paper, the hydraulic coupling model of unsaturated soil and its numerical realization method are studied, and the possibility of application of the model in practice is discussed, combined with the constitutive model of unsaturated soil proposed by Liu Yan, which is a three-phase solid-liquid-gas coupling model. The main contents are as follows: (1) in combination with the actual situation, the influence parameters of liquid to solid and the renewal parameters of liquid phase in the constitutive model of unsaturated soil with solid-liquid-gas coupling are simplified. The hydraulic coupling model of unsaturated soil is derived for numerical calculation. (2) using semi-implicit constitutive integral algorithm, the uniform tangent modulus of hydraulically coupled unsaturated soil is derived. The subprogram of constitutive model calculation is developed by using FORTRAN language, so that the tangent stiffness matrix can be outputted out and used in finite element calculation. The constitutive subroutine is used to simulate and calculate the existing tests. The results of the model calculation are compared with those of the existing tests, including the behavior characteristics of soils under different paths such as isotropic consolidation, dry and wet cycles and triaxial shear. (3) based on the idea of solid-liquid coupling, the nonlinear soil-water characteristic curve model is introduced, and the hypothesis of the relation between the air intake value of soil-water characteristic curve and the volume variation is proposed and applied to the model. The numerical calculation and updating of the new soil-water characteristic curve module are deduced and programmed in detail. The applicability of the new soil-water characteristic curve model is investigated by comparing the results of the model calculation with the existing dry and wet cycle test results. (4) by using the secondary development function of UMAT subroutine, the constitutive model is extended to ABAQUS large-scale finite element analysis software to analyze the elastoplastic problems of single and multiple elements. The expansion effect of the constitutive model from a stress-strain relation to a multi-element solid response is verified.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43
本文编号：2314146
[Abstract]:The soil mass, which exists widely in nature, is mostly in unsaturated state. Geotechnical engineers are faced with a large number of engineering problems of unsaturated soil. It is generally considered that it is safe to use the theory of saturated soil mechanics to analyze and deal with unsaturated soil, but the methods of dealing with these problems are still semi-theoretical. A semi-empirical stage of development. How to use more objective and scientific methods to study the characteristics of unsaturated soil and strengthen the connection with engineering problems is one of the directions in the development of unsaturated soil mechanics. In this paper, the hydraulic coupling model of unsaturated soil and its numerical realization method are studied, and the possibility of application of the model in practice is discussed, combined with the constitutive model of unsaturated soil proposed by Liu Yan, which is a three-phase solid-liquid-gas coupling model. The main contents are as follows: (1) in combination with the actual situation, the influence parameters of liquid to solid and the renewal parameters of liquid phase in the constitutive model of unsaturated soil with solid-liquid-gas coupling are simplified. The hydraulic coupling model of unsaturated soil is derived for numerical calculation. (2) using semi-implicit constitutive integral algorithm, the uniform tangent modulus of hydraulically coupled unsaturated soil is derived. The subprogram of constitutive model calculation is developed by using FORTRAN language, so that the tangent stiffness matrix can be outputted out and used in finite element calculation. The constitutive subroutine is used to simulate and calculate the existing tests. The results of the model calculation are compared with those of the existing tests, including the behavior characteristics of soils under different paths such as isotropic consolidation, dry and wet cycles and triaxial shear. (3) based on the idea of solid-liquid coupling, the nonlinear soil-water characteristic curve model is introduced, and the hypothesis of the relation between the air intake value of soil-water characteristic curve and the volume variation is proposed and applied to the model. The numerical calculation and updating of the new soil-water characteristic curve module are deduced and programmed in detail. The applicability of the new soil-water characteristic curve model is investigated by comparing the results of the model calculation with the existing dry and wet cycle test results. (4) by using the secondary development function of UMAT subroutine, the constitutive model is extended to ABAQUS large-scale finite element analysis software to analyze the elastoplastic problems of single and multiple elements. The expansion effect of the constitutive model from a stress-strain relation to a multi-element solid response is verified.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43
【参考文献】
相关期刊论文 前10条
1 赵成刚;张雪东;;非饱和土中功的表述以及有效应力与相分离原理的讨论[J];中国科学(E辑:技术科学);2008年09期
2 姚仰平;张丙印;朱俊高;;土的基本特性、本构关系及数值模拟研究综述[J];土木工程学报;2012年03期
3 陈正汉,周海清,DGFredlund;非饱和土的非线性模型及其应用[J];岩土工程学报;1999年05期
4 包承纲;詹良通;;非饱和土性状及其与工程问题的联系[J];岩土工程学报;2006年02期
5 赵成刚;;土力学的现状及其数值分析方法中某些问题的讨论[J];岩土力学;2006年08期
6 张玉军;;核废物地质处置模型试验近场热-水-应力耦合数值模拟[J];岩土力学;2007年12期
7 徐炎兵;韦昌富;李幻;陈辉;;非饱和土渗流与变形耦合问题的有限元分析[J];岩土力学;2009年05期
8 孙德安;;非饱和土的水力和力学特性及其弹塑性描述[J];岩土力学;2009年11期
9 赵成刚;蔡国庆;;非饱和土广义有效应力原理[J];岩土力学;2009年11期
10 龚晓南;;对岩土工程数值分析的几点思考[J];岩土力学;2011年02期
相关博士学位论文 前3条
1 刘艳;非饱和土的广义有效应力原理及其本构模型研究[D];北京交通大学;2010年
2 张雪东;土水特征曲线及其在非饱和土力学中应用的基本问题研究[D];北京交通大学;2010年
3 胡冉;非饱和土水力全耦合模型与数值模拟方法研究[D];武汉大学;2013年
，本文编号：2314146
本文链接：https://www.wllwen.com/kejilunwen/diqiudizhi/2314146.html
