SSC JE Civil Engineering 29-Oct-2020 Shift 1 Paper

The Indian Code IS 800 has adopted multiple column curves, which are based on Perry-Robertson approach. Theses curves are called buckling curve and these are classified into four categories (namely curve a,b,c,d ) based on

fcd

fy

and λ, where
fcd is the design compressive strength
fy is the yield strength
λ is the non-dimensional slenderness ratio, which is given as
λ=√

fy

fcr

fcr is the Euler's Buckling stress
These buckling curves are shown below: It is clear from the above figure that for a given value of non-dimensional slenderness ratio, λ , the buckling curve ‘a’ has maximum value of

fcd

fy

ratio and hence, has maximum axial compressive stress by keeping constant fy and λ constant and buckling curve ‘d’ has minimum axial compressive stress.