Revised Indian code for structural steel design in India

Abstract

The Indian code for structural steel design (IS 800) was revised in 2007 after a gap of 23 years. The paper describes the salient aspects of the revised code. The previous code was following the working stress method (WSM) whereas the revised code is based on the Limit State Method (LSM). The revised code was drafted incorporating the knowledge gained about the behaviour of members and systems over the years. Original research was carried out to arrive at suitable provisions, where required. The new code addresses the phenomena of shear lag in tension members and block shear failure in their connections. It tackles the effect of initial imperfections and residual stresses in compression members by advocating the use of multiple column strength curves. The flexural-torsional buckling of angle struts connected by one leg is taken care of by an equivalent slenderness approach. Provisions for the design of bearing type as well as friction type bolted and welded connections are also given. The use of semi-rigid connections is encouraged by guidelines to calculate the behaviour of standard beam-to-column connections. New sections on durability, fire resistance, fatigue and earthquake resistant design are detailing have been introduced and are briefly reviewed. The response of the industry to the new code is also looked into.