EARTHWORK 



221 



The numbers in the sixth column are the sums of the corre- 

 sponding numbers in the fourth and fifth columns; each of these 

 numbers in the sixth column is the distance from the point A, 

 to the center of gravity of the corresponding prismoid. 



Finally, the overhaul for each prismoid is the product of. the 

 volume in the third column by the distance x in the sixth 

 column. These products are written in the seventh column; 

 but, since the distance x is expressed in feet, and the allowance 

 is Ic. per cu. yd. per sta., each product is divided by 100 before 

 writing it in the seventh column. The sum of the numbers 

 in the seventh column is 6,247; the overhaul for the cut is 

 therefore the equivalent of 6,247 cu. yd. overhauled one station. 



2. For the Fill. The total volume of the cut is 4,873 cu. yd. 

 Since the shrinkage is 10 %, the volume of this material when 

 placed in the embankment will be 4,873 487 = 4,386 cu. yd. 

 Since the volume of the embankment between Sta. 135 and 

 Sta. 137 is 4,367 cu. yd., the embankment made from the cut 

 practically ends at Sta. 137. Therefore, the point D, may be 

 taken as Sta. 137. 



The computation of overhaul for fill between Sta. 135, or B, 

 and the center of gravity of each prismoid is now computed 

 exactly as in the case of the cut. The results are as follows: 



Sum = 4,257 

 The sum of all the values of ^- is 6,247+4,257=10,504. 



This is the equivalent of 10,504 cu. yd. overhauled one station. 

 At the rate of Ic. per cu. yd. per sta., the allowance for over- 

 haul will be .01 X 10,504 = $105.04. 



