Development of a simplified method for hydrodynamic pressures in wall corners and roof in liquid storage tanks

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Liquid Storage Tanks (LST's) are used for storage of drinking water, various industrial liquids such asLiquified Natural Gas (LNG), oil, petroleum, as well as in the treatment of pulp and paper product wastes aswell as other industrial wastes. The stored materials could also be toxic or flammable, so keeping the tanksfunctional and preventing them from damages during and after an earthquake event is important in the designprocess. Currently, simplified analytical methods are adopted by design codes in North America for the designof these tanks. However such methods are only acceptable in tanks with certain aspect ratios where sloshingwaves are linear. For tanks in which non-linearity occurs, the method loses its accuracy. In a design case,reliable prediction of the forces on the roof and required freeboard is important to prevent failure of the tanks.Some previous studies show that the hydrodynamic pressure due to the sloshing of the liquid at the sharp tankcorners can be up to three times higher compared to other locations. This pressure can cause significant damageto the tanks. In the current project, partially filled tanks with and without a roof are excited on a seismicshaking table. For tanks with a roof, the data is obtained through pressure sensors that are placed at variouslocations on the tank and collecting the pressure data to find the associated pressures at each senor location. Forroofless tanks, the sloshing height is the parameter of interest. The simulations are also recorded in the form ofvideo clips for further investigation of the free surface. For the simulations, the OpenFOAM which is aComputational Fluid Dynamics (CFD) program is used to generate excitations. The results of numerical andexperimental study are used to develop a simplified procedure to calculate the sloshing heights and roofpressures near the tank corners.