--> //initializations

--> Q=2000 //KN (concentrated load)
 Q  = 

   2000.


--> z=6 //m (depth)
 z  = 

   6.


--> r1=0 //m (horizontal distance)
 r1  = 

   0.


--> r2=5 //m (horizontal distance)
 r2  = 

   5.


--> //calculations

--> nz1=((3*Q)/(2*%pi*(z^2)))*(1/(1+(r1/z)^2))^(5/2) //(vertical stress at point at P)
 nz1  = 

   26.525824


--> nz2=((3*Q)/(2*%pi*(z^2)))*(1/(1+(r2/z)^2))^(5/2) //(vertical stress at point at R)
 nz2  = 

   7.0974206


--> //results

--> printf('vertical stress at point P=%f',nz1)//KN/m^2
vertical stress at point P=26.525824
--> printf('vertical stress at point R=%f',nz2)//KN/m^2
vertical stress at point R=7.097421