ContentsLiterature review...................................................................................................................................1

Terminology...........................................................................................................................................2

Characteristic of Mass Haul Diagram.....................................................................................................3

Example of mass haul calculation..........................................................................................................4

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Literature reviewMass haul diagram is a significant part in anyway projects that involves earthworks.

It is a summarized form of soil embankments and excavations for the entire project. It is also extremely useful tool in the earthwork design process, to evaluate design process and balancing points (zero mass ordinate), and to calculate haul.

The mass haul diagram or curve is drawn in accordance to the calculation of earthwork volumes and its ordinates that describes cumulative volume at specific points along the center line. A simple way to understand mass haul diagram is to imagine a truck that’s moves along the length of the projects in the direction of increasing stations. As the truck moves between two stations, the cut volumes between these stations are added to the truck and fill volumes (adjusted for the compaction factor) are removed from the truck. The volume of soil in the truck at a particular station is the mass ordinate. Volumes of cut (excavation) and fill (embankment) are treated as positive and negative, respectively. Compensation can be made as necessary, for shrinkage or bulking of the excavated material when placed finally in an embankment.

Using mass haul diagram we can determine:

The distances over which cut (excavation) and fill (Embankment) will balance. Volume of soil to be moved and the direction of movement. Areas where soil may have to be borrowed or wasted and the volumes involved. The best policy to adopt to achieve the most economic use of plan.

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TerminologyHaul: The number of work involved in an earthwork project is not totally reflected by the (cut) excavation and (fill) embankment volumes alone. Two balanced projects with similar excavation volumes, but significantly different lengths, differ so much in the amount of work required to move the excavated soil to its final place in the embankment. The effort required to transport the excavated soil is quantified as haul. Haul is measured in units of cubic m3/km, which is defined as the amount of work required to move 1 m3 of excavated soil a km.

Free haul distance: is the specified distance wherein an excavated material will be hauled without additional cost.

Overhaul: is the authorized hauling in excess of the free haul distance and beyond balance points.

Waste Material: Occasionally, excess excavated soil not necessary to construct the roadway embankment is obtained. Consequently, waste areas must be obtained or embankment slopes must be flattened, so that excess soil can be disposed.

Borrow Material: in some occasion, the existing profile grade cannot be adjusted, or there may be insufficient excavation soil available to balance the earthwork.

Excavation (cut): the soil volume that is removed to obtain the desired earth grade cross section. The cut slope catch point for each cut section is normally set at a fixed distance from the bottom of the ditch.

Embankment (fill): Excavated soil that is placed and compacted to obtain the desired earth grade cross section.

Topsoil: Top soil is the layer of nutrient rich soil that is removed, stored, and placed over the surface of all disturbed areas for vegetation purposes.

Shrinkage or swell factor: 1m3 of excavation on amount will not always occupies 1 m³ of space in the fill, so some adjusting is required. Shrinkage and swell factor are stated as “percentage of shrinkage” or “percentage of swell”, which symbolize the percent volume change between cut and fill.

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Characteristic of Mass Haul Diagram

Figure 1

1. The ordinate at any station along the curve in mass haul diagram represent the soil volume accumulation to that point.

2. The maximum ordinate (+) shows a change from cut to fill as one continues along the centre-line from a randomly assumed origin. The minimum ordinate (-) shows a change from fill to cut. These maximum and minimum points may not certainly coincide with the apparent points of transition as shown by the profile section; this based on whether or not there are side-hill transition as shown by the profile section;

3. A rising curve at any point shows an excess of cut (excavation) volume over embankment material at this point. A falling curve indicates the opposite.

4. A steeply rising or falling curve indicates heavy cuts (excavation) or fills (embankment). Flat curves show that the accumulated soil volume is small.

5. The shapes of the loops show the direction of haul. A convex loop indicates that the haul from cut to fill is to be from left to right, while a concave loop shows that the haul is to be from right to left.

6. Since the ordinates of a curve are plotted from cuts (excavation) volumes and adjusted fills (embankment) volumes, then any line parallel to the base line which cuts off a loop intersects the curve at two points between which the amount of cut is equal to the fill. Such a line is called a balancing line and the intersection points are called ' balancing points '.

7. The area between a balance line and the mass-haul curve is a measure of the haul between the balance points. If this area is divided by the maximum ordinate between the balance line and curve, the value attained is the average distance that

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the cut soil must be hauled in order to make the fill. This distance can also be calculated by drawing a horizontal line through the mid-point of this maximum ordinate until it intersects the loop at two points; the length of this line is very close to the average haul distance when the shape of the loop is smooth.

8. Balance lines need not be continuous; the vertical break between any two balance lines merely indicates unbalanced earthwork between two adjacent points of termination of the lines. Adjacent balance lines should never overlap, as this means using the same part of the mass-diagram twice.

Example of mass haul calculation

Chainage/Station

CentreHeight

(m)

Volume (m3) ShrinkageConstant

CorrectedVolume

AccumulatedvolumeCut Fill

1000 F1.22 01040 0 230 -230 -2301100 C1.52 480 0.90 +430 +2001200 C3.96 2560 0.90 +2300 +25001300 C4.12 4560 0.90 +4100 +66001400 C2.74 3940 0.90 +3550 +101501500 0 950 0.90 +850 +110001600 F3.05 1350 -1350 +96501700 F4.27 4010 -4010 +56401780 F4.72 4600 -4600 +10401820 F4.72 BRIDGE 0 +10401900 F3.51 4130 -4130 -30902000 F1.22 2370 -2370 -54602035 0 60 -60 -55202100 C1.98 510 0.90 +460 -50602200 C3.96 3180 0.90 +2860 -22002300 C3.66 4055 0.90 +3650 +14502400 C2.44 3860 0.90 +3470 +49202500 C0.61 1320 0.90 +1190 +61102530 0 100 0.90 +90 +62002600 F1.07 350 -350 +58502700 F1.52 1230 -1230 +46202800 0 420 -420 +42002900 C1.68 1080 0.89 +960 +51603000 C3.66 3720 0.89 +3320 +8480

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TOTAL COST OF EARTHWORK

Freehaul prices in freehaul distance

= freehaul volume x freehaul distance x freehaul prices

Overhaul prices in freehaul distance

= overhaul volume x freehaul distance x freehaul prices

Overhaul prices in overhaul distance

= overhaul volume x (average overhaul distance – freehaul distance) x overhaul prices

Borrow prices = borrow volume x borrow prices

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