软土地基水闸渗流分析研究

发布时间：2018-06-06 08:53

本文选题：软土地基 + 天然闸基　；参考：《扬州大学》2014年硕士论文

【摘要】：本文借助三维有限元软件ABAQUS和相关数学理论,对天然闸基、预制桩复合闸基和灌注桩闸基的渗流场进行分析研究,同时深入分析三种闸基对渗流场的影响,最后对降雨入渗时渗流场与应力场的耦合作用进行研究。全文主要研究内容如下： (1)阐述渗流的基本概念,介绍渗流场有限元数值分析的基本原理和稳定渗流场的变分原理,确定渗流场的初始条件和边界条件,引进大型有限元软件ABAQUS,对其用于渗流场分析研究的可行性进行分析,研究渗透坡降的有限元计算方法。 (2)基于实际工程焦土港闸,建立天然软土地基和预制桩复合闸基渗流的三维有限元模型,分析其渗透水头、应力、位移和渗透坡降的分布,并对天然软土地基和预制桩复合闸基的各要素进行对比分析。 (3)基于实际工程丁楼闸,建立灌注桩闸基渗流的三维有限元模型,考虑灌注桩扰动区范围内渗透系数的三种变化模式,因此对灌注桩桩周特征位置的渗流进行分析研究。比较三种模式下渗透水头、应力、位移和渗透坡降的分布,分析灌注桩闸基区域和扰动区内的渗流特性。 (4)考虑上部结构荷载的影响,建立闸基在不同荷载作用下的有限元模型,分析天然闸基和预制桩复合闸基各特征点的渗透水头、应力、位移和渗透坡降。并且对影响较大的参数进行了拟合,找出相应的变化规律。对比两种闸基下渗透水头、应力、位移、坡降的变化曲线,计算预制桩闸基的消力池护坦防渗作用影响值,分析预制桩基础对渗流的影响。 (5)采用基质吸力—饱和度—渗透系数耦合模型和Mohr-Coulomb屈服准则,建立某水闸的渗流场与应力场耦合的三维有限元模型,分析研究72h内降雨入渗时两岸土体和闸基土体的应力、应变、饱和度、等效塑应变随时间的变化关系。
[Abstract]:In this paper, the seepage field of natural sluice foundation, prefabricated pile composite gate foundation and cast-in-place pile sluice foundation is analyzed with the help of three-dimensional finite element software ABAQUS and related mathematical theory. At the same time, the influence of three kinds of sluice foundation on seepage field is analyzed deeply. Finally, the coupling effect of seepage field and stress field during rainfall infiltration is studied. The main contents of this paper are as follows: 1) the basic concept of seepage flow is expounded, the basic principle of finite element numerical analysis of seepage field and the variational principle of steady seepage field are introduced, and the initial conditions and boundary conditions of seepage field are determined. A large-scale finite element software Abaqus was introduced to analyze the feasibility of the seepage field analysis and the finite element calculation method of seepage slope was studied. (2) based on the actual construction of the scorched earth sluice gate, a three-dimensional finite element model for seepage of natural soft soil foundation and prefabricated pile composite sluice foundation is established, and the distribution of seepage head, stress, displacement and seepage slope is analyzed. The factors of natural soft soil foundation and prefabricated pile composite gate foundation are compared and analyzed. 3) based on the practical construction of Tinglou sluice, a three-dimensional finite element model of foundation seepage of cast-in-place pile sluice is established. Considering the three modes of variation of permeability coefficient in the disturbance zone of cast-in-place pile, the percolation around characteristic position of cast-in-place pile is analyzed and studied. By comparing the distribution of seepage head, stress, displacement and seepage slope in three different modes, the percolation characteristics of foundation region and disturbed zone of cast-in-place pile are analyzed. Considering the influence of superstructure load, the finite element model of sluice foundation under different loads is established, and the seepage head, stress, displacement and seepage slope of each characteristic point of natural gate foundation and prefabricated pile composite gate foundation are analyzed. And the parameters which have a great influence are fitted to find out the corresponding law of change. By comparing the change curves of seepage head, stress, displacement and slope under the two kinds of sluice foundation, the influence value of anti-seepage effect of the stilling pool of prefabricated pile sluice foundation is calculated, and the influence of prefabricated pile foundation on seepage is analyzed. In this paper, the coupling model of matrix suction, saturation and permeability coefficient and Mohr-Coulomb yield criterion are used to establish a three-dimensional finite element model for coupling seepage field and stress field of a sluice. The stress of soil and sluice foundation soil under rainfall infiltration within 72 hours is analyzed and studied. The relationship between strain, saturation, equivalent plastic strain and time.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV66;TV223.4

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