考虑水体质量双槽式渡槽结构地震反应研究

发布时间：2018-06-16 10:10

本文选题：双槽式渡槽 + 流固耦合　；参考：《兰州交通大学》2014年硕士论文

【摘要】：我国水资源总量丰富但人均占有量不足且时空分布极不平衡，这导致我国部分地区严重缺水。为了解决我国水资源分布不均的现状，，我国修建了一系列跨地区、跨流域、长距离的水资源调配工程。在这些大型输水调水工程中，渡槽作为一种交叉联系水工建筑物，得到了广泛应用。随着输水流量的不断增大，传统的单槽式渡槽已不能满足实际工程的需要，作为一种新型的渡槽结构型式，多槽式渡槽在南水北调工程中被广泛应用。典型的双槽并联渡槽有双洎河渡槽和m:河渡槽，三槽并联渡槽有漕河渡槽。由于槽墩之上的槽体与槽体内水体荷载特别巨大，这些渡槽是典型的“头重脚轻”结构，在地震作用下，这些结构型式极不利于抗震。在地震作用下，渡槽会发生剧烈振动，槽壳中的水体也会相应的产生一定晃动，水体的晃动作用越是剧烈，水体与渡槽结构的耦合效果越强，这是一种复杂的流体与结构的相互作用问题。但是目前的水工抗震规范却没有提及有关渡槽流固耦合的设计方法及原则，因此有必要将流固耦合的研究理论与渡槽相结合，研究大型渡槽结构在地震作用下的动力反应。本文以南水北调工程双洎河双槽式渡槽为例，用大型有限元软件ANSYS建立了考虑水体作用的三维动力分析模型，计算了该渡槽在不同水体作用下的自振特性。计算结果表明：渡槽的自振频率随着槽内水体质量的增加而降低，水体增加的越多，频率下降的越多，水体的存在延长了结构的自振周期；槽内是否有水，对双洎河渡槽的主振型影响不大。采用时程分析法从动位移和动应力两方面计算了渡槽在不同地震波作用下的动力响应。计算结果表明：在不同地震波激励下，渡槽结构的横向位移和应力都随着槽内水位的增加而增大，这是由于槽壳内水体的质量增加了上部结构的重量，使作用在结构上的地震力加大的缘故；在大型渡槽的动力分析中，必须考虑槽内水体质量的影响，建立合理的动力分析模型。
[Abstract]:The total amount of water resources in China is abundant, but the per capita water resources are insufficient and the spatial and temporal distribution is very unbalanced, which leads to serious water shortage in some areas of China. In order to solve the problem of uneven distribution of water resources in China, a series of water resources allocation projects across regions, across basins and over long distances have been built. In these large-scale water transfer projects, aqueduct is widely used as a kind of intersecting hydraulic structure. As a new type of aqueduct, multi-channel aqueduct is widely used in South-to-North Water transfer Project. The typical parallel aqueduct has double Ji River aqueduct and m: River aqueduct, while the three parallel aqueduct has Caohe Aqueduct. These aqueducts are typical "top-heavy" structures because of the huge loads on the trough body and the water body above the trough pier. Under the earthquake action, these structural types are extremely unfavorable to the earthquake resistance. Under the earthquake action, the aqueduct will vibrate violently, and the water body in the tank shell will also produce certain sloshing. The more intense the sloshing action, the stronger the coupling effect between the water body and the aqueduct structure. This is a complex interaction between fluid and structure. However, the design methods and principles of fluid-solid coupling of aqueduct are not mentioned in the current seismic code, so it is necessary to combine the research theory of fluid-solid coupling with the aqueduct to study the dynamic response of large aqueduct structures under earthquake. Taking the Shuangji River double-channel aqueduct of the South-to-North Water transfer Project as an example, a three-dimensional dynamic analysis model considering the effect of water body is established by using the large-scale finite element software ANSYS, and the natural vibration characteristics of the aqueduct under different water bodies are calculated. The results show that the natural vibration frequency of the aqueduct decreases with the increase of the water quality in the aqueduct, the more the water body increases, the more the frequency decreases, and the existence of the water body prolongs the natural vibration period of the structure, and whether there is water in the aqueduct, It has little effect on the main mode of Shuangji River aqueduct. The dynamic response of aqueduct under different seismic waves was calculated by time-history analysis from two aspects of dynamic displacement and dynamic stress. The results show that the transverse displacement and stress of aqueduct structure increase with the increase of water level in the aqueduct under the excitation of different seismic waves, which is due to the increase of the weight of the superstructure by the mass of the water body in the tank shell. In the dynamic analysis of large aqueduct, the influence of water quality in the aqueduct must be considered, and a reasonable dynamic analysis model must be established.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV672.3;TV312

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