连坝泄水建筑物仿真分析及洪水演进数值模拟

发布时间：2018-06-03 14:53

本文选题：梯级水库 + 泄水建筑物　；参考：《郑州大学》2017年硕士论文

【摘要】：梯级水库群具有相互联系相互制约的关系,一旦上游水库失事,将会对下游梯级水库造成严重的影响。石漫滩水库与田岗水库是淮河上游洪河支流滚河上的两座连坝挡水建筑物,石漫滩水库拦河坝为全断面碾压混凝土重力坝,田岗水库为均质土坝,坝顶不能溢流。坝体的应力应变性能是评价重力坝安全性的重要指标,研究基本荷载作用下重力坝的应力变化规律,评价工程结构安全性,对研究汛期非常洪水来临时石漫滩水库洪水下泄到田岗水库对大坝造成的威胁具有非常重要的意义。本文根据碾压混凝土重力坝的工作特点和有限单元法应力分析的基本理论,运用ANSYS Workbench软件进行有限元分析,建立了石漫滩重力坝三维溢流坝段和非溢流坝段仿真模型,并对其进行了应力分析;研究了石漫滩水库洪水过程下的泄洪规律与下游河道非恒定流的洪水演进,运用求解圣·维南方程组的矩形网格差分法建立了数学模型,使用MATLAB语言对洪水演进过程进行了数值模拟,其主要研究结论如下:(1)坝体静力分析采用超单元剖分技术自动生成八结点六面体单元,在设计洪水位、校核洪水位、平坝顶水位三种计算工况下非溢流坝和溢流坝的应力分布均符合一般规律,即坝体最大压应力出现在坝趾,最大拉应力(最小压应力)出现在坝踵,且随着上游水位的升高,应力值增大。(2)非溢流坝段在三种计算工况下的坝踵垂直正应力,其拉应力区范围均小于坝体宽度的7%,满足规范要求;溢流坝段在设计洪水位和校核洪水位工况下坝踵垂直正应力拉应力区范围也小于规范规定的数值,但溢流坝段在平坝顶洪水位工况下的坝踵垂直正应力拉应力区范围达到7.49%,不满足规范要求。(3)根据石漫滩水库的泄洪规则,运用MATLAB编程,采用四次迭代,求出下泄洪水过程线作为河道洪水演进的初始条件,建立差分格式的圣·维南方程组数学模型,计算了每一时刻各断面上流量及洪水水位等因素曲线。(4)运用工程实例,对洪水演进模型进行了验证,分析表明模拟值与实测值结果具有较好的适用性。
[Abstract]:The cascade reservoir group has the relationship of interrelation and mutual restriction. Once the upstream reservoir is wrecked, it will have serious influence on the downstream cascade reservoir. Shimantan reservoir and Tiangang reservoir are two dam-retaining structures on the tributary of Huai River. The dam of Shimantan reservoir is a full-section roller compacted concrete gravity dam, and Tiangang reservoir is a homogeneous earth dam, the top of the dam can not be overflowing. The stress-strain behavior of dam body is an important index to evaluate the safety of gravity dam. The stress variation law of gravity dam under basic load is studied and the safety of engineering structure is evaluated. It is of great significance to study the threat to the dam caused by the flood discharge from the Shimantan reservoir to the Tiangang reservoir when the flood season is coming. According to the working characteristics of RCC gravity dam and the basic theory of finite element method stress analysis, the simulation model of 3D overflow dam and non-overflow dam section of Shimantan gravity dam is established by using ANSYS Workbench software. The stress analysis was carried out, the flood discharge law of Shimantan reservoir and the flood routing of unsteady flow in the downstream river were studied, and the mathematical model was established by using the rectangular grid difference method to solve the equations of Saint Venan. The numerical simulation of flood routing process is carried out by using MATLAB language. The main conclusions are as follows: 1) the static analysis of the dam body automatically generates eight node hexahedron elements by using the technique of superelement dissection. The flood level is designed and checked. The stress distribution of the non-spillway dam and the spillway dam under three calculating conditions of the top water level of the horizontal dam accords with the general law, that is, the maximum compressive stress of the dam body appears at the toe of the dam, the maximum tensile stress (the minimum compressive stress) appears at the dam heel, and with the rising of the upstream water level, the maximum tensile stress appears at the dam heel. The vertical normal stress of the dam heel of the non-spillway dam section under three calculation conditions is smaller than that of the dam body width in the range of the tensile stress zone, which meets the requirements of the code. Under the conditions of design flood level and check flood water level, the range of vertical normal stress tensile stress zone of dam heel is also smaller than the value specified in the code. However, the range of vertical normal stress tensile stress zone of spillway section under the condition of horizontal dam top flood level reaches 7.49, which does not meet the requirements of the code. (3) according to the flood discharge rules of Shimantan reservoir, the MATLAB is used to program, and four iterations are adopted. As the initial condition of river flood routing, a mathematical model of Saint Venant equations with difference scheme is established, and the factor curves such as discharge and flood water level on each section at every moment are calculated. The model of flood routing is verified and the analysis shows that the simulated value and the measured value have good applicability.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV122

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