Critical appraisal on steel water tank design using recent and past I. S codes

IS: 800 code is the basic code for general construction in steel structures and the prime document for any structural design and has influence on many other codes governing the design of other special steel structures. IS:800–1984, furnished provisions, for designing the structures, mainly, by “Working Stress Method”. Realizing the necessity to update the standard to the state of the art of the steel construction technology and economy, the current revision of the standard (IS:800–2007) was undertaken. Earlier codes are silent in respect of design with respect to fatigue, corrosion, earthquake and durability etc, whereas in the present code careful revisions have been incorporated. In particular new code has advocated the design aspects with respect to fatigue, corrosion, earthquake and durability etc which place predominant role because of rattling forces created due to earthquake. The new code furnishes provisions, for designing the structures, mainly, by “Limit State Method of Design”. An attempt here is made to explain the basic differences in the IS codes – old (IS:800–1984)4 and revised(IS:800–2007). To reinforce the effect of the additional parameters included in the revised version, a steel elevated water tank is designed, using both the codes separately, and a conclusion is arrived at based on the sizes f the designed members. (For brevity the detailed design calculation are not given here.) An elevated water tank has been chosen because the structure involves the design of all type of members – struts, ties, columns, base plates and girder.