Q$4$: The single$-$span bridge illustrated in the following figure is going to be founded on shallow $6m6m$ footings, embedded at a depth equal to $Df=2m.$ The structural analysis of the bridge resulted in a maximum axial force on the bridge's piers under serviceability conditions equal to $P=10MN.$ The site investigation revealed a rather heterogeneous soil profile under the bridge, consisting of loose sand in the area of the left abutment, and of medium$-$to$-$dense sand in the area of the right abutment, featuring the compressibility parameters noted on the figure. Ignoring the shear resistance developing at the wall$-$soil interface, calculate: a$)$ the maximum uniform settlement of the critical pier, and b$)$ the angular distortion of the bridge's foundation. Are these values tolerable?