约束方式对蜗壳初始保压缝隙形成机理的影响分析  

Influences of boundary conditions on the initial gap of preloading water-filled spiral case

作　　者：郭涛[1] 张立翔[1] 李世杰 Guo Tao;Zhang Lixiang;Li Shijie(Department of Engineering Mechanics,Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming 650500,China;POWERCHINA Kunming Engineering Corporation Limited,Kunming 650051,China)

机构地区：[1]昆明理工大学,建筑工程学院工程力学系,昆明650500 [2]中国电建集团昆明勘测设计研究院有限公司,昆明650051

出　　处：《农业工程学报》2020年第8期40-47,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(51309128,51969009);教育部高等学校博士学科点专项科研基金(优先发展领域)资助项目(20135314130002);昆明理工大学人才启动资助项目(KKSY201306052)。

摘　　要：准确掌握初始保压缝隙的开度值和形成机理,是保压蜗壳结构研究的基础和重点之一。而初始保压缝隙主要随保压水头和边界条件的不同而改变,因此充压浇筑阶段钢蜗壳的约束方式是必须考虑的重要因素。该研究从保压结构施工工艺出发,基于充水保压蜗壳全仿真算法,构造出施工阶段的初始保压缝隙,探讨了不同支承形式(连续式和离散式)和支墩与钢衬之间的接触滑移对初始缝隙形成机理的影响。结果表明,初始保压缝隙具有非均匀和局部非张开特性,其中蜗壳腰部附近缝隙开度最大,其次是蜗壳顶部,底部最小。支承形式和接触滑移对缝隙的构成存在较大影响,虽然规律基本一致,但数值上差别较大。是否考虑接触对蜗壳腰部的缝隙开度影响最大,尤其在蜗壳的进口段,最大相差达1.8倍,主要是由于滑移增强了蜗壳水平方向的扭转变形,导致侧向位移增大。通过与原型监测结果对比验证了算法的准确性,同时也说明考虑支墩与钢衬之间的接触更加接近真实情况。The structure of preloading filling spiral case can take full advantage of the strength of steel, lower stress of outside concrete, reduce the ratio of reinforcement and make the structure of the spiral case safe, reliable. Hydraulic structure of preloading filling spiral case has been widely applied due to its excellent advantage in the strength of steel, low stress of concrete outside, and the low ratio of reinforcement with safety and reliability. In view of the complex shape of the spiral case, it is impossible to exactly ensure that all parts work under the ideal situation of design load, and the deformation cannot all inflation at the same time. Moreover, the action of axial force from the bulkhead under internal pressure has also posed a significant influence on spiral case deformation in the construction process of a constant internal pressure spiral case. Therefore, the initial gap of spiral case usually presents local closed and non-uniform conditions. It is necessary to explore the initial non-uniform gap and contact behavior, in order to approaching an ideal situation of no gap, no energy transfers between spiral case and surrounding concrete. The accurate evaluation of initial non-uniform gap is also a prerequisite of solution algorithm for preloading structure of water-filled spiral case. However, the constraint way on the construction phase needs to be considered because the initial gap value varies with the preloading water head and boundary conditions in the specific application sites. In this paper, a modified simulation algorithm based on the construction process is proposed to study the preloading water-filled spiral case of NZD project. The results show that the proposed method can effectively simulate the initial gap with non-uniform and local closed condition that caused by the asymmetrical structure of spiral case. The variation of initial gap strongly depends on the radial deformation of spiral case. Compared with the simplified method, this modified algorithm considers the gap and contac

关 键 词：水工结构 充水保压蜗壳 离散式支承 连续式支承 接触 初始保压缝隙 

分 类 号：TV31[水利工程—水工结构工程] TV731