超高镶嵌面板堆石坝应力变形特性研究

发布时间：2018-05-06 23:37

本文选题：镶嵌面板堆石坝 + 高模量区　；参考：《西安理工大学》2017年硕士论文

【摘要】：随着我国水电事业的发展,修建超高(300m级)混凝土面板堆石坝已成为一种必然趋势。300m级超高面板堆石坝建设的关键难题是堆石体变形控制与面板防裂,大量的研究成果表明,坝高从200 m增加到300 m时,坝体变形几乎增加了 1倍,坝体变形必然会导致面板出现不同程度的裂缝,严重危害大坝安全。因此,对常规面板堆石坝体型进行优化设计,提出镶嵌面板堆石坝的设计思路,对300m级超高面板堆石坝的建设具有重要的意义。本文采用有限元中点增量法对镶嵌面板堆石坝的应力变形特性进行了深入研究,在此基础上对镶嵌面板堆石坝高模量区设计的方案进行了优化,基于正交试验法对高模量区邓肯-张E-B模型参数进行了敏感性分析,具体研究内容及主要结论如下:(1)针对300 m级超高面板堆石坝建设的关键难题,本文通过在面板坝上游底部位置设置坝踵混凝土结构,减短面板斜长,来改善面板的应力状态;通过在上游中部位置设置高模量区,减小堆石体变形,进一步提出了镶嵌面板堆石坝新坝型的设计思路。(2)在自重和水荷载作用下,模拟了常规面板坝、镶嵌面板坝和设置高模量区的镶嵌面板坝施工过程和蓄水过程,系统的研究了上述三种形式面板堆石坝应力变形特性。计算结果表明,设置坝踵混凝土结构和高模量区能够有效改善坝体及面板的应力变形,设置高模量区的镶嵌面板坝对改善坝体及面板的应力变形效果最佳,为后续的研究奠定基础。(3)对超高镶嵌面板堆石坝设计时,在尽可能改善坝体及面板应力变形前提下,采用数值计算的方法对高模量区起始高程及高度进行优化研究,探讨了高模量区对镶嵌面板堆石坝应力变形的影响。计算结果表明,相比较其它方案,当高模量区起始高程为最大坝高的23%且高度为最大坝高的38%时,坝体及面板的应力变形改善效果最为明显。(4)以高模量区邓肯-张E-B模型参数为研究对象,基于正交试验法对其进行了敏感性分析,对正交试验各方案的有限元计算结果进行极差和方差对比分析。计算结果表明,参数Kb对坝体沉降υ3,面板挠度w和顺坡向应力σ三个指标敏感性高,影响显著,其次为参数φ和m ;参数K、n、Rf及Δφ对上述三个指标敏感性低,影响不显著。本文的研究成果可为面板堆石坝改善面板应力状态,减小堆石体变形提供参考应用价值,为相对较为准确、快捷、符合工程实际地确定堆石体本构模型参数提供了一种思路,对300 m级超高面板堆石坝建设具有借鉴意义。
[Abstract]:With the development of hydropower industry in our country, it has become an inevitable trend to build a concrete face rockfill dam with 300m) concrete face rockfill dam. The key problems in the construction of 300m super-high face rockfill dam are the deformation control of rockfill body and crack prevention of concrete face slab. A large number of research results show that, When the height of the dam increases from 200 m to 300 m, the deformation of the dam body almost doubles. The deformation of the dam body will inevitably lead to cracks in the face slab, which will seriously endanger the safety of the dam. Therefore, it is of great significance for the construction of 300m super-high face rockfill dam to optimize the shape design of the conventional face rockfill dam and put forward the design idea of the inlaid face rockfill dam. In this paper, the stress and deformation characteristics of the inlaid face rockfill dam are studied by using the midpoint increment method of finite element method, and the design scheme of the high modulus zone of the inlaid face rockfill dam is optimized. Based on the orthogonal test method, the sensitivity of Duncan-Zhang E-B model parameters in high modulus region is analyzed. The specific research contents and main conclusions are as follows: 1) aiming at the key problems in the construction of 300m super-high face rockfill dam, In this paper, the stress state of the slab is improved by setting the concrete structure at the bottom of the dam upstream to reduce the inclined length of the face slab, and the deformation of the rockfill is reduced by setting the high modulus zone in the middle part of the face slab. Furthermore, the design idea of the new type of inlaid face rockfill dam is put forward. Under the action of deadweight and water load, the construction process and the water storage process of the conventional face slab dam, the inlaid face slab dam and the inlaid face slab dam with high modulus are simulated. The stress and deformation characteristics of the above three types of face rockfill dams are systematically studied. The calculation results show that the stress and deformation of dam body and face slab can be effectively improved by setting concrete structure and high modulus zone of dam heel, and the stress and deformation effect of dam body and face slab can be improved by setting inlaid face slab dam with high modulus region. In order to lay a foundation for the further study, the initial height and height of high modulus region are optimized by numerical method under the premise of improving the stress and deformation of dam body and face slab in the design of super-high inlaid face rockfill dam. The influence of high modulus region on stress and deformation of face rockfill dam is discussed. The results show that compared with other schemes, when the initial height of the high modulus region is 23% of the maximum dam height and the height is 38 times the maximum dam height, The improvement effect of stress and deformation of dam body and face slab is most obvious. (4) taking the parameters of Duncan-Zhang E-B model in high modulus region as the research object, the sensitivity analysis of the dam body and face slab is carried out based on the orthogonal test method. The range and variance of the finite element calculation results of each scheme of orthogonal test are compared and analyzed. The calculated results show that the parameter Kb has a high sensitivity to the three indexes of dam settlement v 3, face deflection w and stress 蟽 in the direction of slope direction, followed by the parameters 蠁 and m, and the parameters Knn Rf and 螖蠁 have low sensitivity to the above three indexes, but the effect is not significant. The research results in this paper can provide a reference value for improving the stress state of the face slab and reducing the deformation of the rockfill, and provide a way of thinking for determining the constitutive model parameters of the rockfill body relatively accurately, quickly and in accordance with the engineering practice. It can be used for reference in the construction of 300m super high face rockfill dam.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV641.43

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