非达西渗流理论及其工程应用

发布时间：2018-03-11 06:14

本文选题：非达西渗流　切入点：土石坝　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前,渗流问题的工程应用基本采用线性达西定律,但是地下水在多孔介质中的实际流动受各种因素综合影响,流动比较复杂,渗流运动实际呈非线性。许多的试验资料和监测资料也证实了存在很多偏离线性达西渗流的现象。因此,若仍然运用线性达西渗流定律,使计算得到的水头分布和渗流量都存在很大误差,对渗流运动的描述与实际情况存在差异,并且渗流运动在工程各个领域普遍存在,许多工程事故都是由渗流破坏引起的,特别在某些特殊的情况下对工程的安全具有很大的影响。因此,对偏离达西渗流现象的研究具有重要且深远的意义。本论文通过对渗流基本理论分析,且以渗流力学的基本原理为基础对非达西渗流开展了如下工作:(1)渗流基本原理概述。分别对达西定律及非达西渗流理论进行了概述,分析产生非达西渗流的原因,并对渗流分析方法、渗流数值计算原理、达西渗流基本微分方程推导等作了总结介绍。(2)分析产生非达西渗流的原因,针对渗流运动方程的非线性特性,结合土石坝渗流实际情况,采用流动势的形式推导了同时考虑重力和惯性力的非达西渗流微分方程,并用有限体积法对该方程进行离散求解。(3)采用FORTRAN语言编写计算程序,利用ANSYS软件对研究对象进行实体建模,将单元节点信息导入SP程序的前处理模块并生成单元拓扑关系文件,调用程序进行计算并通过TECPLOT软件输出计算结果。(4)参照前人的研究及实验结果,对方程的合理性和准确性进行验证。(5)以实际工程为例,采用非达西渗流的SP程序进行数值模拟,并将达西渗流模拟计算结果与非达西渗流模拟计算结果做对比分析。由此得出,采用非达西渗流计算,自由液面会有所升高,大坝下游的溢点出也会稍微上升,水力坡降会增大,坝基处更加明显,并且随着上游水头的增加,水力坡降增幅加大,本文非达西渗流公式所计算渗透流量有所减少,非达西渗流的现象更加的明显。
[Abstract]:At present, the engineering application of seepage problem basically adopts the linear Darcy law, but the actual flow of groundwater in porous media is affected by various factors, and the flow is quite complex. The seepage movement is actually nonlinear. Many experimental and monitoring data confirm that there are many deviations from the linear Darcy seepage. Therefore, if the linear Darcy seepage law is still applied, The calculated water head distribution and seepage discharge have great errors, the description of seepage movement is different from the actual situation, and seepage movement is common in all fields of engineering, and many engineering accidents are caused by seepage failure. Especially under some special circumstances, it has great influence on the safety of engineering. Therefore, the study of deviation from Darcy seepage phenomenon is of great and far-reaching significance. And based on the basic principles of seepage mechanics, the following work is carried out on non-Darcy seepage: 1) the basic principle of seepage is summarized. Darcy's law and non-Darcy seepage theory are summarized respectively, and the causes of non-Darcy seepage are analyzed. The analysis method of seepage, the principle of seepage numerical calculation and the derivation of basic differential equation of Darcy seepage are summarized and introduced. According to the actual seepage situation of earth-rock dam, the differential equation of non-Darcy seepage considering gravity and inertial force is derived by using the form of flow potential, and the equation is solved discretely by finite volume method. The calculation program is compiled by FORTRAN language. The research object is modeled by ANSYS software, the unit node information is imported into the preprocessing module of SP program and the unit topological relation file is generated. According to the previous research and experimental results, the rationality and accuracy of the equation are verified. (5) taking the actual engineering as an example, the non-Darcy seepage SP program is used to carry out numerical simulation. The results of Darcy seepage simulation and non-Darcy seepage simulation are compared and analyzed. It is concluded that the free liquid surface will be increased and the overflow point will rise slightly after using non-Darcy seepage calculation. The hydraulic slope will increase, the dam foundation will become more obvious, and with the increase of upstream water head, the increase of hydraulic gradient will increase, the seepage flow calculated by the non-Darcy seepage formula in this paper will be reduced, and the phenomenon of non-Darcy seepage will be more obvious.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O357.3

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