Question

The radius of relative stiffness is given by the characteristic equation of _______

(a) \(l=\{\frac{eh^3}{12(1-μ^2 ) k_s}\}^\frac{1}{4}\)

(b) \(l=\{\frac{eh^3}{12(1-μ^4 ) k_s}\}^\frac{1}{4}\)

(c) \(l=\{\frac{eh^3}{12(1-μ^2 ) k_s}\}^\frac{1}{2}\)

(d) \(l=\{\frac{eh^3}{12(1-μ^2 ) k_s}\}^\frac{1}{3}\)

I got this question by my college director while I was bunking the class.

The query is from Design of Rigid Pavements topic in section Design of Flexible & Rigid Pavement of Geotechnical Engineering II

Answer 1

Right choice is (a) \(l=\{\frac{eh^3}{12(1-μ^2 ) k_s}\}^\frac{1}{4}\)

To elaborate: The radius of relative stiffness is given by the characteristic equation of,

\(l=\{\frac{eh^3}{12(1-μ^2 ) k_s}\}^\frac{1}{4},\)

where, l=radius of relative stiffness

E=elasticity modulus

h=thickness of pavement

μ=Poisson’s ratio

ks=modulus of sub-grade reaction.