大型抽水蓄能电站不同楼板结构形式的动力特性研究

Dynamic Characteristic Study on Different Types of Floor in Large Pumped Storage Hydropower Station

为研究不同结构形式下楼板振动特性的差异,在保证混凝土方量一致的前提下,设置板梁结构、厚板加圈梁结构和纯厚板结构三种形式,建立厂房三维有限元模型进行动力分析。结果表明,纯厚板结构的高阶自振频率高于板梁结构,而板梁结构略高于厚板加圈梁结构;在转轮叶片数频率及其两倍频率的脉动压力作用下,增加楼板厚度和板下增设梁系对绝大部分区域的楼板抗振是有利的,但三种楼板结构的振幅大致处于同一水平,不同结构形式有其抗振相对较强和相对较弱的部位,不存在绝对的最优方案。因此,实际工程中应综合考虑结构静力刚度、施工难度和管线布置等因素选择具体的楼板结构形式。

In order to analyze the vibration characteristics of different types of floor, beam slab, thick slab with ring beam and thick slab structure are proposed in condition of the same concrete volume. And then three dimensional finite element of powerhouse is established to analyze its dynamic characteristics. The results show that high order frequencies of thick slab structure are higher than that of beam slab structure, and the results of beam slab structure are a little larger than that of thick slab with ring beam structure; under the pulsation pressure with frequency of runner blade numbers and two times of runner blade numbers, thickening floor or adding beams can benefit the anti vibration performance for most regions; the vibration amplitudes of three types of floor are almost on the same level; there are relatively good anti vibration regions and bad regions in each type of floor, the absolutely best floor type does not exist. In practice project, the floor type can be determined by taking into account of static stiffness, construction difficulty, layout of pipes and wires.