A large 20-story steel structure is planned for an officebuilding the Denver Metropolitan. The exploration program revealedthat foundation soil comprises of 25-foot clay with undrained shearstrength of 1,000 psf overlying a thick stiff clay shale with theundrained shear strength of 3,000 psf. To avoid construction noise,the architect selected 3-ft diameter drilled shaft foundation. Thedrilled shafts are socketed 15 feet in the stiff clay shale.Calculate:
a. The ultimate capacity of the drilled shaft.
b. Estimate the total structural dead load.
c. Estimate the office building life load.
d. At a factor of safety of 2,5, how many drilled shafts wouldbe required?
Note: When you suspect some missing information, please makereasonable assumption(s) and process with your solution. Clearlyshow why assumption(s) is needed.
