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.