EARTHWORK 



213 



long, the volume is TpjfgX 2,025 = 1,2 15 cu. yd., and this number 

 is written in column 4 (6) opposite Sta. 129. 



The computation for the other stations is made in a similar 

 way. It will be observed that the sections at Sta. 126 and 

 Sta. 127 are three-level sections, and that in this case there 

 are no minus areas. 



The sum of the numbers in column 4 (6) is 4,927 cu. yd.; 

 the prismoidal correction, which is figured according to the 

 formula for C under the heading Three-Level Section, is 54 

 cu. yd.; the final volume between Sta. 126 and Sta. 129, is, 

 therefore, 4,927-54 = 4,873 cu. yd. 



Side-Hill Work. When both the cut and the fill occur in the 

 same section, as in Fig. 9, the areas, volumes, and their correc- 

 tions are determined for the fill and the cut separately. For 



I 



FIG. 9 



the purpose of calculating the prismoidal and curvature COK 

 rections, each part of the section, cut or fill, is considered as a 

 triangle and the formulas previously given are used. 



For calculating the areas, it is also frequently sufficient to 

 consider that the section in either fill or cut is triangular. This 

 is, however, not exact enough when the ground is very irregular. 

 In Fig. 9, the area of the fill would be taken as that of the 

 triangle mnp, while for determining the area of the cut the 

 method of irregular sections would be used. 



