SSC JE Civil Engineering 25-Sep-2019 Shift 1 Solved Paper

For simply supported beams and girders of the span L where no lateral restraint to the compression flange is provided but each end of the beam is restrained against torsion, the effective ${\mathit{L}}_{\mathrm{LT}}$ for the lateral torsional buckling is given in Table
The effective length ${\mathit{L}}_{\mathrm{LT}}$ for lateral torsional buckling of simply supported beams Where, (D - overall depth of beam, L - length of span)
Hence, the effective length of lateral buckling for a simply supported beam under normal loading conditions, provided torsional restraint as fully restrained and warping restraint as both flanges fully restrained should be 0.7L.