摘要
水电站厂房是将水能转换为电能的最终场所,是水利枢纽中主要建筑物之一,随着我国水电事业的蓬勃发展,水电站厂房的规模越来越大,重要性越来越突出,这对水电站厂房的结构设计提出了更高的要求。
水电站厂房上部空间较大,结构相对单薄,所以比较不同的厂房上部结构型式来确保厂房的安全运行是必要的。通过数值分析,对比各可行布置方案结构的静动力特性,特别是地震的作用。在满足机电设备布置的前提下,优选厂房上部结构型式、尺寸和结构措施,以满足厂房在控制地震工况下的结构强度和刚度要求。最后选定了厂房上部结构的最优结构型式。在选型过程中,主要进行以下工作:
1.建立了复杂厂坝整体结构的三维真实数值模型:模拟对象包括坝体、网架结构、上下游墙、楼板、风罩、整个流道、尾水管以及主要孔洞等。模型中,厂房上部结构分别选取上下游实体墙、上游墙体下游柱体、上下游柱体三种型式。
2.通过上述不同结构型式方案,分析在各方案下结构的自振特性:研究不同的厂房上部结构型式对结构自振频率及振型的影响,并综合几种计算结果对厂房结构进行了共振复核。
3.基于动静力分析,对各方案进行位移计算,研究各荷载在结构受力中发挥的作用,并且对比了不同厂房型式在各工况下关键部位的变位,同时对各方案进行应力分析。
4.在优化过程中,进行了6种优化措施的数值计算与对比分析,在大量的分析基础上,综合考虑其他方面的因素,找到了一种经济、有效、可行的方案。
本论文结合龙开口水电站工程实例,用有限元法对龙开口水电站厂房进行了结构计算,通过对比厂房上部结构型式,得出了一些有价值的结论,供同类工程参考,并对结构选型计算提出了合理的计算方法和建议。
The powerhouse of hydropower station is the final place where hydro energy is changed into electric energy and it is one of the main buildings in hydro project. With the flourishing development of hydropower enterprise in China, the scale of powerhouse is larger and larger, and meanwhile its importance becomes more and more outstanding. Accordingly, the higher request has been put forward for structural design of powerhouse.
The space of superstructure of powerhouse is large and the corresponding stiffness is low. So it's necessary to compare different styles of the superstructure to ensure the safety of powerhouse. Through numerical analysis, this paper compares the static and dynamic performance of each feasible structure style, especially in the presence of seismic action. Besides satisfying the requests of electromechanical equipment layout, this paper optimizes the style、dimension and measurement of the superstructure of hydropower house, in order to satisfy the requirements of the structure strength and stiffness of building under earthquake controlling condition. In the end of this paper, the optimization style of superstructure is suggested. The procedure of model selection is as follows:
1、A more realistic three-dimension model of the complex powerhouse structure is made, which includes dam body, frame structure, upstream and downstream wall, floor slab, wind cover, integral flow passage, all galleries, key holes, etc. The superstructure of powerhouse is also considered in three styles: the solid wall in upstream and downstream, the solid wall in upstream and column in downstream, the column in upstream and downstream.
2、The natural dynamic characteristic of powerhouse has been analyzed based on the schemes above, and the influence on the natural frequency and vibration model of structure caused by different superstructure style of powerhouse has been investigated, and meanwhile the resonance vibration of powerhouse structure between the different results has been rechecked.
3、The action of loads to the structure has been analyzed based on the static and dynamic force after calculating the deformations, and the deflections of critical parts of the powerhouse under every working condition have also been compared. The stresses under every condition are analyzed.
4、Six optimization measurements are numerical calculated and analyzed contrastively during the optimizing process. On the basis of a great deal of analysis, a feasible economic and available plan has been found.
Combined with LongKaikou hydropower project, the structure is calculated with finite element method. Through comparing styles of superstructure of powerhouse, this paper proposes some conclusions to serve as a reference for similar projects, and a reasonable calculated method and suggestions are given.
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