SEISMIC ANALYSIS OF RC ELEVATED WATER TANK IN DIFFERENT SEISMIC ZONES

Elevated water tanks are becomes most vital life line structures in earthquake prone areas. These structure are generally used to store the liquids in containers which are placed at the top end of assisting systems (staging's) and are most effected by seismic forces during earthquakes. They are very important in water supply, fire-frightening systems and also in many industrial use to store water. At the time of earthquake, damage to these tanks creates so many problems like interruption in drinking water supply, creates uncontrollable flames when damage to tank with flammable fluids in industries. So therefore these elevated water tanks must remain in working condition even after the earthquake. Due to this reason, a very large studies carried on seismic behavior of tanks at different conditions. In this, we are going to analyze the tank under seismic forces with the variations of different seismic zones and shape of containers e.g. rectangular tank and circular tank with constant staging height. In this paper, analysis is carried according with IS 1893-1984 (i.e. single lumped mass method) and IS 1893-2002 (i.e. two mass model method), by changing seismic zone and soil type i.e. hard rock and soft soil. Analysis is carried out for two different tank fill conditions i.e. full and empty tank conditions. Seismic forces acting on the tank are evaluated by the response spectrum method by changing response spectrum value (R), by using the software STADD PRO. Seismic response such as nodal displacement, base shear, base moment, shear force& bending moment are evaluated and compared.