【作者】 王国辉；

【导师】 柴军瑞；

【作者基本信息】 西安理工大学 ， 水工结构工程， 2009， 硕士

【摘要】 地震激励作用下,坝库系统安全问题关系到人民生命财产、国民经济的发展；而解决这一问题的关键技术之一,就是比较完备的流固动力耦合理论。但坝库相互作用问题是极其复杂的多学科交叉课题,无论在理论分析还是数值计算方面都存在缺陷和不足。所以有必要对这一课题进行深入的研究。本文对流固耦合相互作用的机理进行初步研究,推导了流固耦合矩阵并编写相应程序,通过算例分析了坝库系统相互作用。水体虽然在地震初期对坝体的运动有一定阻尼作用,减小了坝体的运动,这对提高坝体的抗震性能是有益的,但它延长了坝体振动时间,并对坝体后期运动有一定作用。通过建立三维坝库系统流固耦合模型,对比分析了流固动力耦合模型和附加质量模型在进行坝体动力特性和地震响应计算时的区别。附加质量模型夸大了水体的动力影响,相对于流固耦合模型偏于保守；另外,研究了水体压缩性对坝体动力特性的影响,研究表明：库水可以降低坝体自振频率,并且随着水位的加深降低的幅度更为明显,水体压缩性也可以降低坝体自振频率,其下降值大于不可压缩库水模型。可压缩库水模型和不可压缩库水模型计算的坝体振型有较大区别,在实际应用中不能相互替代。作为工程应用,本文以某双曲拱坝工程为例,采用前述流体-固体动力耦合分析方法对其进行动力特性和地震响应分析。结果表明,考虑库水可压缩性后,将十分明显地降低拱坝的应力反应,尤其对抗震安全起控制作用的部位降低更为明显；不可压缩库水模型夸大了拱坝抗震关键部位的应力反应,对于工程设计会导致偏于安全的结果。考虑库水可压缩性后计算量略有增大,但更能真实的反应水体对坝体的影响,因此建议采用可压缩库水模型求解坝库相互作用问题。更多还原

【Abstract】 The safety of dam-reservoir system is related to the people’s life and even the development of the national economy under the earthquake stimulates. And solving this problem one of the key technologies is more complete fluid-structure dynamic coupling theory. But dam-reservoir interaction is a very complex multi-disciplinary subject, both in theoretical analysis and numerical calculations are flawed and inadequate. So, the deep rearch should be made on this subjuct.In this paper, deep rearch has been made on the principle of the fluid and solid interaction; deducing solid-fluid interaction matrix and compiling the corresponding procedures which is verified right by the corresponding example. And we find that:the water can minish the movement of the dam, which is benefit for improving the capability of the dam to resist the quake, but it prolong the time of the dam’s libration.Through the establishment of three-dimensional dam-reservoir interaction system model, a comparative analysis of fluid-dynamic coupling model and the additional mass model has been made on dam dynamic properties and seimic response. It makes out that additional mass model exaggerate the influence of compressible water and is conservative compared to the fluid-solid dynamic coupling model. In additional, researching the influence of the compressibility of the water on the dam dynamic properties, it educes water can reduce the natural frequency of dam and the lower rate is more obvious with the water level deepening. Compressibility of the water can also reduce the natural frequency of dam and the decrease was greater than the value of the incompressible water model. The compressible water model and incompressible water model have greater difference in practical applications and can not substitute for each other.As the project application, Based on a hyperbolic arch dam project, using aforementioned fluid-solid dynamic coupling theory analyse the dam’s dynamic properties and seimic response. The results show that:considering the compressibility of water, it will obviously reduce the stress response of the dam, especially on the part of the seismic safety control. Incompressible water model exaggerated the seismic stress response of the dam which will lead to security for the design of the arch dam. Considering the compressibility of water, the computation load increase slightly, but real reflect the influence that the water to the dam. Therefore, it suggests that using the compressible water model for solving water dam interaction problem.更多还原