A semicircular symmetrical three hinge arch has a span of 20m. The arch sustains a load of 45kN/m on the left half of the span.

Determine.

(1) The horizontal thrust

(2) The moment, radial shear and normal thrust at a section 6m from the left hand support

(3) Draw B.M.D.

Note: Since the arch is symmetrical

$\therefore h=10m$ (in circular arch)