A strip load of considerable length and 1.5 m width transmits a pressure of 150 kN/m2 to the underlying soil. Verify the maximum principal stress at 0.75 m depth below the footing, if the point lies
(i) Directly below the centre of the footing, and
(ii) Directly below the edge of the footing. What is the absolute maximum shear stress and where does it happen ?