Rev. 5-1-88

MASS DIAGRAM EXPLANATION

203-R-036

A mass diagram representing excavation quantities is shown on the plans. This mass diagram is a graphical representation of the algebraic summation of earthwork and was developed for purposes of studying questions of excavations and direction of haul. The basic properties of the mass diagram are as follows:

The ordinate at a given point represents the cumulative cubic meterage (cubic yardage) to that point. The ordinate represents a cut if it is above the axis or a fill if it is below the axis.

The difference in the lengths of 2 ordinates is equal to the cubic meterage (cubic yardage) between the 2 stations (tenths of stations) at which the ordinates are erected.

Ascending lines represent cut, and descending lines represent fill.

Maximum and minimum points of ordinates on the mass diagram occur where the grade line intersects the existing ground profile. Stations where the grade line changes from a cut section to a fill section correspond to a point of maximum ordinate. Stations (Tenths of stations) where the grade line changes from a fill section to a cut section will correspond to a point of minimum ordinate.

The loops which are convex upward indicate that the haul from cut to fill shall be in one direction, left to right. Loops which are concave upward indicate that the haul shall be in the opposite direction.

Cuts and fills are equal or balanced between 2 points where a horizontal line intersects the mass diagram. Such points are called balance points.

Haul along the profile is represented by area in the mass diagram. The amount of haul or overhaul may be determined by measuring the proper areas.