Factors Effecting Seismic Design of Water Towers

The behavior of a water tower under seismic forces depends essentially on the natural period of vibration of the tower, nature of the foundation soil and other factors. The elasticity of the foundation soil can be neglected for hard soils like rock, but for soft soils, theories developed by Terzhaghi, T. K. Hsieh, Salvadori and Heer give different values for periods of vibration for the same earthquake force. Therefore, this factor must be investigated. The stresses in the columns and bracing rods are little influenced by the sizes of the different components of the tower if the stiffness of the tower is maintained constant. The size of columns, number of panels, initial tension, and the diameter of the bracing rods will seriously affect the stresses in the columns and braces due to an earthquake force.