CE 453 Lab #9Page 1/3
EARTHWORK/MASS DIAGRAM
PROBLEM:
Today we will use Eagle Point to create a Mass Diagram. You will also locate an area or areas where you may obtain fill (borrow) for your project. To do this, the team will determine the location and size of the borrow or waste areas using topographic and soils information (NRCS data – see MapInfo table: SOILS) and the location of the cut and fill areas. Room 220 has example DOT plans (bottom drawer) with sheets showing mass diagram information and plan and profile sheets with earthwork details. Refer also to the DOT manual for preparation of earthwork data in plans.
COMPLETION STEPS:
- Once you have your vertical alignment and cross sections developed, Eagle Point can easily prepare a table of cut, fill plus shrink, and mass ordinate values for the length of the project. Use the tutorial to complete the steps required to Manage Condition Tables and Run the project. You can then use the output option to show the Mass Diagram coordinates and graphics.
- Prepare a scaled drawing of the mass diagram. Export the data to Excel, and plot the mass diagram. You may do this in Eagle Point if you like. (warning, Eagle Point may plot the mass ordinates off the scale (fill) if you have a lot of fill (you probably do) and you would have to change the vertical scale on the drawings. Be aware if Eagle Point uses negative or positive for cut.
- Identify the freehaul distance balance lines on the mass diagram with a horizontal line in all loops that are at least as long as the freehaul distance. The length of the freehaul for this project is assumed to be 300 meters. I think it would be best to copy the excel or Eagle Point mass diagram image into Power Point, then use colored lines to indicate freehaul, overhaul, etc.
- Calculate the limit of profitable haul, LPH, (also referred to as limit of economic haul) and place LPH balance lines within all loops that are large enough to accommodate these balance lines. Several other balance lines shorter than the limit of profitable haul may be needed in your mass diagram. No balance line should be longer than the LPH as it is less expensive to find alternative resources than to pay the contractor for the longer distance hauls.
- Calculate the Overhaul in each loop
Calculate the length of the overhaul in each loop on the diagram in stations, assuming cost of excavation = $2.50/cubic meter, borrow = $3.50 per cubic meter and cost of overhaul = $7.00 per station (1000 meters) cubic meter. The average length of overhaul is determined by splitting the vertical distance between the freehaul distance (FHD) balance line and the LPH balance line (or other balance line in the loop) into two equal parts. At the midpoint, measure the horizontal distance between the left and right edge of the mass diagram curve in that loop. The average overhaul distance is this distance, in stations, minus the freehaul distance, in stations. Calculate the overhaul as
Overhaul (sta –cubic m) = Average overhaul distance (sta) * vertical difference between FH line and balance line (cubic m)
- Cross hatch or color-code overhaul, borrow and waste areas on the mass diagram.
Identify the amount of borrow and waste that may be present along the project. Indicate, by Station Number, where each segment of borrow or waste begins and ends. Find appropriate fill material by using the soils MapInfo layer (derived from NRCS data). Also consider that you are either going to remove a hill or create a lake with borrow. Use your CE 382 background and identify appropriate soil type for fills (recall AASHTO M-145 soil classification for highway subgrade)– consider erosion, and consider what you will do with the borrow pit if you create one. Use the MapInfo table/layer SOILS and the metadata file “soils metadata.pdf” found on the class FTP-download-MapInfo data folder. Select a borrow area with no more than about 25% clay content max (CLAYSURH). Note: if the soil has 0 clay, it probably means the table does not have data on clay for that polygon, so don’t specify that as your borrow area.
GRADING CONSIDERATIONS AND EXPECTED RESULTS
No written report
10%Sample screen shots from Eagle Point that shows the steps used to get your earthwork volumes, and screen shot showing you got the mass diagram graphics to show
10%Table of stations, end areas, earthwork volumes and mass ordinates that represent the final design.
30%Mass Diagram drawing (Power point 11x17)
a. Include the grade and ground profile above the mass diagram (use same horizontal scale)
b. Identify freehaul, overhaul and balance point station
c. Indicate borrow and waste areas
20%Calculation of overhaul on mass diagram
a. Calculate the length of profitable haul
- Present overhaul calculations for each sub area and total overhaul volume in station cubic yards
- Indicate information (overhaul, borrow, waste) in tables on the mass diagram with appropriate referencing of tables to balance lines (e.g., which data goes with each line) See a set of DOT plans and the DOT design manual to see how earthwork data is displayed on a set of plans
30%Identification of borrow or waste sites with location from centerline, dimensions and calculations of potential overhaul. (Put the location and footprint of your borrow area on a plan view, Power Point 11x17)
Up to 30% penalty for poor presentation, style or grammar