28 ft 40 ft Problem 2 (30 points) A 68-ft long pre-stressed concrete pile with square cross section (14 inch) is driven the soil profile shown in Fig. 2. a) Compute the ultimate compressive load that can be carried by that pile and side friction loads). b) If the water table goes up to the ground surface, determine the change pile ultimate axial capacity. Pre-stressed Square pile A Medium Stiff Clay S₁ = 1500 psf y= 110 pcf Water Table Medium dense Sand 4 = 35° y= 110 pcf N60=28 Fig. 2