Analysis and Design of Large Size Elevated Compartmental Water Tank

Abstract

Water is the elixir of life. Hence the importance of water retaining is obvious, especially in the present scenario when water is becoming a scarce commodity.

For storing water and its distribution, Water tanks are largely used. For achieving the required head, elevated storage tanks are used. Liquid storage tanks are commonly used in industries for storing chemicals, petroleum products, etc. and for storing water in public water distribution systems. Water supply is also essential for controlling fires that may occur during earthquakes, which cause a great deal of damage and loss of lives. Therefore, elevated water tanks should remain functional in the post-earthquake period to ensure water supply is available in earthquake-affected regions.

In general water tanks are mainly classified as elevated water tank and ground supported water tank, i.e. E.S.R (Elevated Storage Reservoir) and G.S.R (Ground Storage Reservoir). As per special requirements, like storing more than two types of liquid or extra storage to make live supply for maintenance work, different compartments are required in a tank. It is economical to construct large size storage tank with two or multi compartments, compared to two or more separate storage tanks.

An attempt has been made to visualize the clear understanding regarding the behaviour of the multi compartmental tank during earthquake and importance of considering the hydrodynamic pressure using draft code IS4 1893 (part-2). And the work includes analysis and design of compartmental tank with parametric study considering different configuration and shape.

The effect of hydrodynamic pressure on compartmental tank is calculated as per draft code IS4 1893 (part-2). Also the variation of base shear and overturning moment for different number of compartments are presented graphically.

Dynamic analysis has been carried out for all compartmental tanks using SAP 2000 software. Also the variation of time period and base shear are presented graphically for Rectangular as well as Circular compartmental tanks.