2. Planning for Earthwork
Construction
Every construction project is a unique
undertaking. Therefore, planning is undertakenundertaking. Therefore, planning is undertaken
to understand the problems and to develop
courses of action.
3. Planning
Understand project objectives and requirements
Define work elements
Develop safe construction methods and avoid hazards
Improve efficiency Improve efficiency
Coordinate and integrate activities
Develop accurate schedules
Respond to future changes
Provide a yardstick for monitoring and controlling
execution of project activities
4. Planning Earthwork Construction
Review the Contract Documents
Study the plans
Plan the Work
Perform quantity take-off
Determine costs
5. Variables related to the work:
The quantities involved, basically volume or weight
The haul distances
The grades for all segments of the hauls
The work hazards The work hazards
Various contractual and legal restraints
6. Typical constraints:
Contract requirements described in the drawings and
technical specifications, completion dates, etc.
Legal requirements (OSHA, licensing, environmental
control)control)
Physical and/or environmental limits of the job
Fabrication and material storage
Sequencing of construction operations (traffic control)
Climatic conditions that limit when certain activities
can be performed, such as paving or stabilization
7. Planning Earthwork Construction
A site visit is strongly recommended to relate the
physical site characteristics to the work details.
8. Safety
In 2002 there were 1,181 highway construction work
zone fatalities in the United States
Safety should be a part of all construction planning
9. Earthwork Planning
Quantity Survey The process of calculating the
quantity of materials required to build a project
Mass Excavation The requirement to excavate Mass Excavation The requirement to excavate
substantial volumes of material, usually at
considerable depth or over a large area
Structural Excavation Excavation undertaken in
support of structural element construction, usually
involves removing materials from a limited area
11. Graphical Presentation of
Earthwork
Plan View A construction drawing representing the
horizontal alignment of the work
Profile view A construction drawing depicting a
vertical plane cut through the centerline of the workvertical plane cut through the centerline of the work
Cross Section View A construction drawing
depicting a vertical section of earthwork at right angles
to the centerline of the work
Cross Sections Earthwork drawings created by
combining the project design with field measurements
of existing conditions
15. Cross Sections Existing Elevations Shown
as Dashed Lines
Proposed Elevations Shown
as Solid Lines
16. Earthwork Quantities
End-Area Determination
Digitizing Tablet
Planimeter
Trapezoidal Computations A2 2’ Trapezoidal Computations
Average End Area
Volume = (A1 + A2) X L
2 27
A1
A2
2’
2
1
2
1
3’
2’
2’
100 ft
17. Stripping
The upper layer of organic material that must be
removed before beginning an excavation or
embankment
18. Net Volume
The volumes from fill cross sections represent
Compacted volume, expressed as Compacted Cubic
Yards (ccy)
The volume of cut sections represent in situ volume,
the volume in its natural state is expressed as Bank
Cubic Yards (bcy)
If cut and fill volumes are to be combined, they must
be converted into compatible volumes
21. Mass Diagram
Cumulative Quantities of materials
Average haul distances
Indicates the types of equipment that should be
considered for accomplishing the workconsidered for accomplishing the work
26. Using the Mass Diagram
Balance Lines A horizontal line of specific length
that intersects the mass diagram in two places
1000
0
-500
-1000
500
1000
1+00 2+00 3+00 4+00 5+00 6+00 7+00 8+00
V
O
L
U
M
E
C
C
Y
S TATIONS
FILL CUT
CUT FILL
30. Average Grade
Average Grade Percent = Change in Elevation * 100
Grade affects equipment efficiency and production rates.
Average Grade Percent = Change in Elevation * 100
Average Haul Distance
May be estimated from the profile view.
31. Two Balance Lines on a Mass
Diagram
Note that opposing
points are in balance.points are in balance.
Total cut = total fill
From point to point.
32. Spread Production
Spread A group (or crew) of construction machines
that work together to accomplish a specific
construction task such as excavating, hauling, and
compacting materialcompacting material
34. Pricing Earthwork Operations
The cost of earthwork operations will vary with the kind of soil or rock
encountered and the methods used to excavate, haul, and place the
material in its final deposition
It is usually not too difficult to compute the volume of earth or rock to
be movedbe moved
Estimating the cost of actually performing the work depends on both a
careful study of the project plans and a diligent site investigation
How much material must be moved?
What equipment is required? And daily cost of the equipment?
What is the estimated daily production of the crew?
35. AGTEK is one of the leading software tools for managing earthwork.
See: http://www.agtek.com/
