Some vital terms associated with calculation of volume in surveying
In this civil engineering video tutorial, you will get some vital information concerning calculation of volume in surveying.
Definition of Mass Diagram:
The mass diagram stands for a curve that is set on a base line (that demonstrates chainages of alignment) to bring the ordinates at any point as the algebraic sum of the volume of cutting and filling from the starting point up to that point.
The volume of cutting is taken as positive and that of filling is treated as negative. The mass diagram is created to allow exact allocation of excavated material and choosing perfect locations for borrowpits.
Definition of ‘lead’ and ‘lift’
Lead belongs to the horizontal distance through which the excavated soil from the borrowpit or cutting is transmitted to the adjacent place. The earth work is measured based on this distance.
The vertical distance through which the excavated soil from the borrowpit or from cutting is raised or transferred is called lift. At the time of calculating earth work, this factor should be taken into consideration.
Types of cross-section
Cross-sections are categorized as follow :-
1) Level 2) Two-level 3) Three-level 4) Side hill two-level 5) Multilevel
Constraints of the prismoidal formula
If the number of sections is odd, then the prismoidal formula can be used directly.
The formulas applied for volume calculation :-
The following two formulas are generally found :-
Trapezoidal Volume Formula
= (common distance / 2)(area of 1st section + area of last section + 2 x sum of the areas of other sections)
Prismoidal Volume Formula
= (common distance / 3) (area of 1st section + area of last section + 4 x sum of the areas of even sections + 2 x sum of areas of remaining odd sections)
When prismoidal correction should be used
Prismoidal correction should be used when the volume is computed with the trapezoidal formula. This correction should be deducted from the value procured by the trapezoidal formula.