混合坝插入式接头的抗震性能研究

发布时间：2019-07-01 18:16

【摘要】：混合坝是指中间溢流坝段采用混凝土坝,两侧挡水坝段为土石坝的混合坝型。这种坝型可以充分利用地形条件,而且工程造价也比较经济。但是混凝土刚度较大,土石坝筑坝材料刚度相对较小,刚度的差别将导致混凝土坝与土石坝的接合面处变形差别大和应力分布不均匀。在地震过程中接头部位的混凝土坝和土石坝具有不同的振动行为。因此,接头部位容易出现相对沉降和张拉裂缝,是坝体结构的薄弱部位,必须处置妥当。观音岩水电站位于云南省丽金沙江中游河段,电站采用混合坝构成挡水建筑物,混凝土坝与土石坝的结合部位采用插入式接头,接头处高度71m。工程处于高烈度地震区,在地震荷载作甩下接头部位容易出现错动位移和张拉裂缝,是大坝的薄弱部位,接头部位的安全关系到工程全局。本文以此工程为背景,对其三种插入接头方案进行永久变形计算分析。主要内容如下： (1)接触面的试验研究、本构模型和数值模拟三方面的理论。国内外接触面试验研究的现状,详细分析了常见接触单元类型的特性,总结了数值计算中接触单元常用的本构模型。 (2)建立了观音岩水电站三维有限元模型,接触单元采用有厚度Goodman单元,考虑了超余应力和嵌入位移对接触单元本构模型的影响,编制了大坝永久变形有限元计算程序。 (3)对观音岩混合坝插入段直角接头方案、转角接头方案、修圆接头方案进行了有限元分析。对计算结果进行了详细的对比分析,结果表明：从接触面震后法向位移看,修圆接头方案位移相对较大,直角接头方案次之,转角接头方案位移相对较小；从接触面震后切向位移看,修圆接头方案相对较大,转角接头方案次之,直角接头方案位移相对较小。
[Abstract]:The mixed dam refers to the concrete dam used in the middle overflow dam section and the mixed dam type in which the water retaining dam section on both sides is the earth-rock dam. This kind of dam type can make full use of topographic conditions, and the project cost is also relatively economical. However, the stiffness of concrete is large and the material stiffness of earth-rock dam is relatively small. The difference of stiffness will lead to the large deformation difference and uneven stress distribution between concrete dam and earth-rock dam. During the earthquake, the concrete dam and the earth-rock dam have different vibration behavior. Therefore, the relative settlement and tension cracks are easy to appear in the joint, which is the weak part of the dam structure and must be disposed of properly. Guanyinyan Hydropower Station is located in the middle reaches of the Lisha River in Yunnan Province. the power station adopts mixed dam to form a water retaining structure. The joint of concrete dam and earth-rock dam adopts plug-in joint, and the joint height is 71 m. The project is located in the high intensity seismic area, and the dislocation displacement and tension cracks are easy to appear in the joint under seismic load, which is the weak part of the dam, and the safety of the joint is related to the overall situation of the project. Based on the background of the project, the permanent deformation of the three insertion joint schemes is calculated and analyzed in this paper. The main contents are as follows: (1) the experimental study of contact surface, the theory of constitutive model and numerical simulation. The present situation of contact surface test research at home and abroad is carried out. The characteristics of common contact element types are analyzed in detail, and the common Constitutive models of contact element in numerical calculation are summarized. (2) the three-dimensional finite element model of Guanyinyan Hydropower Station is established. Goodman element with thickness is used in the contact element, and the influence of superstress and embedded displacement on the constitutive model of the contact element is taken into account, and the finite element calculation program of dam permanent deformation is compiled. (3) the finite element analysis of right angle joint, corner joint and round joint of Guanyinyan mixed dam is carried out. The calculated results are compared and analyzed in detail, the results show that from the normal displacement of the contact surface after earthquake, the displacement of the repair round joint scheme is relatively large, the right angle joint scheme is the second, and the angular joint scheme displacement is relatively small; from the contact surface tangential displacement after the earthquake, the repair circular joint scheme is relatively large, the corner joint scheme is the second, and the right angle joint scheme displacement is relatively small.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV64;TV312

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