EARTHWORK 



219 



Let v = volume of any prismoid in cut; 



a = area of its end section nearest to A ; 

 a' = area of its end section most remote from A ; 

 m = distance from A to middle section of prismoid; 

 / = length of prismoid, in feet; 



# = distance from center of gravity of this prismoid to 

 point A. 



I a'-a 



Then, x = m+~X 



6 a'+a 



The overhaul of this prismoid from its position in the cut 

 to the point A will therefore be, since overhaul is reckoned 

 in stations, 



vx v ( I a'-a" 



By this formula, the overhaul for each prismoid of the cut 

 is computed for the transportation of this material to the 

 point A. In a similar manner, the overhaul for the trans- 

 portation of each prismoid to its position in the fill BLND 

 from the point B is found. The sum of the overhauls for all 

 the prismoids of the cut and fill is the desired total overhaul. 



If a part of the cut, for example MZO, is hauled in one direc- 

 tion, and the remainder MZC in the other, the overhaul for 

 each part of the cut must be computed separately. 



EXAMPLE. Let CM KA in the preceding illustration represent 

 the cut for which the computations on pages 210 and 211 are 

 shown, C being Sta. 126 and A Sta. 129. Let, also, the length 

 of free haul be 600 ft., B being Sta. 135, and let the volumes 

 and end areas of the prismoids beyond Sta. 135 be as follows: 



Sum = 4,367 



