. Railroad construction. Theory and practice . should be dis-counted in about this propor-tion. Excavations in rock shouldbe increased in the properratio. In short, all excavationsshould be valued according to theamount of settled embankmentthat could be made from in the first column a listof the stations; in the secondcolumn,the number of cubicyardsof cut or fill between each stationand the preceding station; inthe third and fourth columns, the kind of material and the propershrinkage factor; in the fifth column, a repetition of the quan-tities in cubic yards, except that the excav
. Railroad construction. Theory and practice . should be dis-counted in about this propor-tion. Excavations in rock shouldbe increased in the properratio. In short, all excavationsshould be valued according to theamount of settled embankmentthat could be made from in the first column a listof the stations; in the secondcolumn,the number of cubicyardsof cut or fill between each stationand the preceding station; inthe third and fourth columns, the kind of material and the propershrinkage factor; in the fifth column, a repetition of the quan-tities in cubic yards, except that the excavations are dinnnished(or increased, in the case of rock) to the number of cubic yardsof settled embankment which may be made from them. Inthe sixth column place the algebraic sum of the quantities in thefifth column (calling cuts + and fills -) from the starting-point to the station considered. These algebraic sums at eachstation will be the ordinates, drawn to some scale, of the masscurve. The scale to be used will depend somewhat on whether. 118 RAILROAD CONSTRUCTION. §101. the work is heavy or light, but for ordinary cases a scale of5000 cubic yards per inch may be used. Drawing these ordi-nates to scale, a curve A, B, . . G may be obtained by joiningthe extremities of the ordinates. Sta. Yards] -/■! Material. Shrinkagefactor. Yards, reduced for shrinkai^e. Ordinate in mass curve. 46 + 70 0 47 48 4- 6049 + 1954- 1792+ 614 - 143 - 906 - 1985 - 1721 - 112+ 1774- 180 - 52 - 714- 2764- 1242+ 1302 Clayey soil - 10 per cent - 10 - 10 + 175+ 1613+ 553 - 143 - 906 - 1985 - 1721 - 112+ 283+ 289 - 52 - 71+ 249+ 1118+ 1172 + 175 + 17884 23414 2198 50 + 1292 51 - 693 52 - 2414 4- 30 - 2526 53 + 7054 Hard rock 4- 60 per cent+ 60 - 2243 - 1954 - 2006 4- 42 - 2077 555657 Clayey soil - 10 per cent - 10-- 10 - 1828 - 710+ 462 loi. Properties of the mass curve. 1. The curve will be rising while over cuts and falling whileover fills. 2. A tangent to the curve will be horizontal (as at B^ D,
Size: 980px × 2550px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorwebbwalt, bookcentury1900, bookdecade1900, bookyear1903
