Aconcentrated vertical laod of 6000 lbf is applied at the ground suface most nearly what is the increase in the vertical pressure 3.5 ft below the surface and 4 ft away from a point directly below the concentrated load?
(a) 29 lbf/ft^2
(b) 36 lbf/ft^2
(c) 41 lbf/ft^2
(d) 58 lbf/ft^2

the correct answer is option A

Explanation:

given,

Load = 6000 lbf            

depth = 3.5 ft                                      

distance from the load = 4 ft                  

vertical stress =

                        =

                        = 28.96 lbf/ft²                      

                        = 29 lbf/ft²              

hence, the correct answer is option A