Annular Tuned Liquid Dampers for Elevated Tanks

高架储水箱广泛应用于供水设施中。这些储罐暴露在广泛的地震危险中，并与建筑环境的其他部门相互作用。对高架储罐抗震性能的研究很少。地震对储罐的破坏会导致饮用水和用水短缺以及无法控制的火灾等意想不到的事件。由于这些原因，从工程的角度来看，这种结构在构造和功能上都是特殊的，必须进行抗震施工。在本项目中，将研究环形调谐液体阻尼器（ATLD）的效率，以加强高架储罐抵御地震荷载的能力。调谐液体阻尼器（TLD）是一个部分填充的水箱，用作减振器，以减少结构的动态运动。结构在外部动载荷作用下的振动引起TLD内部液体的晃动运动。液体运动通过将晃动运动的固有频率调整为结构的固有频率，使惯性力与外部动力近似反相，从而减小结构的运动。由于tld比其他传统阻尼器件具有许多优点，因此tld的使用有所增加。它们易于安装在现有结构上，维护成本低，运行成本低。建议的环形TLD可以很容易地安装在高架的储罐轴上，而不会干扰其他机械装置或限制进入储罐。虽然TLD结构简单，但TLD内部的液体晃动运动具有高度非线性和复杂性。由于液固相互作用和晃动波的复杂动力学行为，对其行为的准确预测是迫切需要的。本研究的重点是利用先进的数值程序研究在高架储罐中应用的ATLDs的行为。

Elevated water storage tanks are extensively used in water supply facilities. These tanks are exposed to a wide range of seismic hazards and interaction with other sectors of built environment. Very few investigations have been carried out on the seismic resistance of elevated tanks. Earthquake damages to the tanks can cause unwanted events such as shortage of drinking and utilizing water and uncontrolled fires.Due to these reasons, this type of structure which is special in construction and in function from engineering point of view must be constructed to be resistant against earthquakes. In this project, the efficiency of an annular tuned liquid damper (ATLD) will be investigated in order to strengthen the elevated tanks against seismic loads. A tuned liquid damper (TLD) is a partially filled, water tank used as a vibration absorber in order to decrease the dynamic motion of a structure. The vibration of the structure under an external dynamic load causes sloshing motion of the liquid inside the TLD. By tuning the natural frequency of the sloshing motion to the natural frequency of the structure, the liquid motion imparts inertia forces approximately anti-phase to the external dynamic force, thereby reducing structural motion. The use of TLDs has increased due to their many advantages over other conventional damping devices. They are easy to install on existing structures, and need low maintenance and low operating costs. The proposed annular TLD can be easily installed in an elevated tank shaft without disturbing other mechanical devices or limiting the access to the reservoir. Although the construction of a TLD is simple, the liquid sloshing motion inside the TLD is characterized by a highly non-linear and complex nature. Due to the complex dynamic behavior of liquid-structure interaction and sloshing waves, the accurate prediction of their behavior is highly desired. The focus of this study is to investigate the behaviour of ATLDs for the application in elevated tanks using an advanced numerical program.