SEISMIC RESPONSE OF ELEVATED WATER TANK-1

Abstract

Elevated water tanks are important components of water supply systems, particularly in areas where reliable water storage and distribution are required. Due to their considerable height, mass distribution, and supporting structure, elevated water tanks are vulnerable to lateral forces generated during earthquakes. The movement of water inside the tank can produce a sloshing effect, which increases the dynamic load and may affect the stability of the supporting structure. Therefore, understanding the seismic behaviour of elevated water tanks is essential for improving their safety and structural performance. This project presents a physical model of an elevated water tank to study its response under simulated earthquake loading. The model consists of a water tank supported on a structural frame with X-bracing, mounted on a manually or motor-operated shake table. The model is subjected to controlled lateral movement to simulate earthquake forces. The water inside the tank demonstrates the sloshing effect and its influence on the movement and stability of the structure. Different structural conditions, particularly with and without bracing, can be observed and compared. The study focuses on parameters such as lateral movement, tank tilting, structural stability, and the effectiveness of bracing and base isolation in reducing earthquakeinduced movement. The observations indicate that a properly braced supporting frame provides greater resistance to lateral forces and reduces excessive movement and tilting of the tank. Rubber pads used as an optional base-isolation arrangement can further help in reducing the transmission of vibrations to the structure. The project provides a simple and practical demonstration of the principles of earthquakeresistant design of elevated water tanks. It helps in understanding the interaction between structural response and water sloshing during seismic loading and highlights the importance of adequate bracing, stable foundations, and suitable structural design for safer water storage systems in earthquakeprone areas.