13. (6 pts) Determine the bearing stress under the column due to an external load (P) and the dead load of the structure itself (Provide your calculation). The structure has the following information: The structure is subject to an 800-lb. vertical load. (P = 800 lbs.) Both column and footing are made of concrete. The density or unit weight of the concrete is 150 pcf. The column has a 4 in. by 4 in. cross-section and the height is 20 in. The footing has a 12 in. by 12 in. cross section and the height is 8 in. P Column (post) Concrete footing