SSC JE Civil Engineering 23-Mar-2021 Shift 1 Paper

Concept:
Extra widening of road is given by,
${\mathrm{W}}_{\mathrm{e}}={\mathrm{W}}_{\mathrm{m}}+{\mathrm{W}}_{\mathrm{ps}}$
$\mathrm{W}=\mathrm{n}{\mathrm{l}}^{2}2\mathrm{R}+\frac{\mathrm{V}}{9.5\sqrt{\overline{\mathrm{R}}}}$
${\mathrm{W}}_{\mathrm{e}}$ = where, ${\mathrm{W}}_{\mathrm{m}}$ = mechanical widening
${\mathrm{W}}_{\mathrm{ps}}$ = psychological widening
n = No. of lanes
l = length of wheel base
R= radius of curve
V= velocity of vehicle (kmph)
Calculation:
Given,
n = 2
l = 5 m
R = 250 m
V = 70 km/h
${\mathrm{W}}_{\mathrm{m}}$ = 2× ( $5^2$ ) / (2 × 250) = 0.1 m