題組內容

3.The pile has a circular cross section 1 ft in diameter and its modulus of elasticity is E=2×106 psi. A downward force F=480 kip is applied to the top of the pile. The resisting force on the bottom of the pile is negligible in comparison to the axial frictional force on its lateral surface. Assume that the frictional force is uniformly distributed, determine

(c) the change in length of the pile. (10%)