General Construction In Steel – Code of Practice
2007 Edition

According to IS 800:2007, the acceptable steel materials include all varieties of structural steel that comply with the relevant clauses of the standard. Specifically, steel must conform to IS 2062 prior to usage, which encompasses hot rolled medium and high tensile steels. Common grades include Fe 410, Fe 410W, Fe 510, and Fe 510W, ensuring standardized mechanical properties and quality for structural applications.

IS 800:2007 stipulates that lateral torsional buckling (LTB) checks are unnecessary for bending about the minor axis, for circular hollow or solid sections, and when the lateral torsional buckling parameter (ALT) is below 0.4 during major axis bending. The effective length for LTB is defined by the spacing between lateral supports; it equals the segment length for typical loads or 1.2 times that length when loads cause destabilizing effects. Lateral restraints can include web or flange cleats, bearing stiffeners, end frames, or fixed walls. Design strength depends on whether beams are laterally supported or unsupported, with unsupported beams governed by LTB strength requirements.

IS 800 prescribes strict erection tolerances to ensure structural accuracy: the maximum deviation between adjacent columns must not exceed 5 mm; column location deviation in multi-storey buildings should be within 0.0035 times the total storey height divided by the square root of the number of stories; inclination tolerances for single-storey columns are limited to 0.0035 times the column height; tension members must not deviate more than 3 mm along any axis. Straightness tolerances for columns and beams between lateral restraints are set at 0.001 times the length for solid sections and 0.002 times for hollow sections.

For bolted connections, IS 800 mandates the use of high-strength friction grip bolts in slip-critical joints where no slip is allowed under service loads. For connections subjected to impact or vibration, either high-strength friction grip bolts or ordinary bolts with locking devices must be used. Welded connections require a lap length at least four times the plate thickness, with weld lengths along each edge not less than half the batten plate depth. Welds should be distributed so that at least one-third of the weld length is at each end, with the weld continuing along adjacent edges for at least the minimum lap length. Design forces in bolts and welds must satisfy strength criteria as per the standard.

IS 800:2007 integrates seismic design by specifying criteria for various steel frame systems, including Ordinary and Special Concentrically Braced Frames, Eccentrically Braced Frames, and Ordinary and Special Moment Resisting Frames. Clauses 12.7 to 12.11 provide detailing requirements focused on ductility and energy dissipation under seismic loads. The standard references IS 1893 (Part 1) for seismic loading calculations and emphasizes appropriate detailing of connections and column bases to enhance seismic resilience.