214 



EARTHWORK 



Suppose that the shoulder m, Fig. 9, of the slope is 8 ft. 

 from the center; that the fill begins at 2 ft. from the center, 

 and is a rock fill with a slope of 1:1, and that the slope stake 

 is 16.8ft. from the center. Then, mk = ck cm= 16.8 8.0 

 = 8.8 ft.; and, since the slope km-z-nk is 1:1, the vertical 

 distance nk of n below subgrade will also be 8.8 ft. The area 



of the fill, is, then, = 26.4 sq. ft. 



In determining the area of the cut, it will be observed that 



C6.2 

 the fraction for the point p is , that for t is ; and that 



C8 2 

 for v is '. The center depth is 1.3 ft., and the distance 



cq=\b is 10 ft. The notes for the entire section shown in 

 Fig. 9, will therefore be as given in the following table: 



The series of fractions will therefore be, considering only 

 the section of cut, 



1.3 

 



6.2 

 7.6 



8.2 

 18.2 



The double areas are as follows: 



Plus Areas Minus Areas 



2.6 6 2.3 



9.9 



1 12.8 

 82.0 



Sum = 207.3 



The desired area for cut is, therefore, JX (207.3 -62.3) 

 -72.5 sq. ft. 



