Term 3, 2021
CVEN9723 DESIGN OF
CONSTRUCTION OPERATIONS
Earthwork Planning
Instructor: Dr X Shen
Date: 14 September 2021
Dr X Shen©2021
OUTLINE
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Introduction
Soil Volume-Change Characteristics
Earthwork Quantity Take-off
Innovations in Earthmoving
Construction Teaching Lab
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Earthmoving Construction
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(Courtesy: Glenden Australia)
What’s Earthmoving?
Earthmoving is the process of moving soil or
rock from one location to another and
processing it so that it meets construction
requirements of location, elevation, density,
moisture content, etc.
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Typical Earthmoving Operations
Haul, Loaded
Return, Empty
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Soil Volume-Change Characteristics
Soil Conditions
– Bank: natural state before disturbance
• Referred to as: “in-place” or “in-situ”
• Unit: bank cubic meter (BCM)
– Loose: material that has been excavated or
loaded
• Unit: loose cubic meter (LCM)
– Compacted: material after compaction
• Unit: compacted cubic meter (CCM)
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Soil Volume-Change Characteristics
1 BCM
Bank
1.25 LCM
Loose
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0.9 CCM
Compacted
(Courtesy: Nunnally 2011)
Load Factor
A conversion factor to simplify the
conversion of loose volume to bank volume
Load factor =
Weight/loose unit volume
Weight/bank unit volume
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Shrinkage Factor
A factor used for the conversion of bank
volume to compacted volume
Weight/bank unit volume
Shrinkage factor =
Weight/compacted unit volume
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Soil Volume-Change Characteristics
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(Courtesy: Nunnally 2011)
Earthmoving Operations
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Earthmoving Estimate
Cycle Time for Transporting Material
– Loading Time
– Traveling Time (haul, loaded)
– Unloading Time
– Returning Time (empty)
The time required for each element should
be determined for cost estimate
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Earthmoving Estimate
Production Rate
– The number of units of work produced by a
unit of equipment or a person in a specified
unit of time, e.g. m3/hour
Efficient Factor
– A machine or a worker may work only 45 min
in an hour
– Actual production rate is 0.75 of maximum
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Earthmoving Estimate
• Production rates are crucial to estimate
the time and cost of the projects
• The total project time is determined by
dividing the total quantity of work by the
production rate
• Cost of labour and equipment can be
determined by multiplying the total time by
the hourly rate of labour and equipment
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Estimation Procedures
Step 1: Quantity of Work
Step 2: Cycle Time
Step 3: Production Rate
Step 4: Project Time
Step 5: Total Cost
Step 6: Unit Cost
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Example 1
A total 120 m3 of clay has to be transported to a job
site 15 km away using a 10 m3 dump truck.
A tractor loader is used to load the truck at a rate of
80 m3/hour. The travel times for haul and return of
the truck are 32 minutes and 25 minutes,
respectively. It takes 3 minutes to dump the load.
The cost of the truck is $ 42 /hour, the truck driver is
$ 28 /hour. The cost of the loader is $ 55 /hour, the
loader operator is $ 32 /hour. The average working
time is 45 minutes in one hour.
Determine the total time, total cost, and the cost/unit
of transporting the clay.
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Productivity Improvement?
• How to improve the loading efficiency?
• What is the difference using labour or a
loader for loading?
• How to match the number of the loader
and the haul trucks?
No. of Trucks =
Total Cycle Time
Load Time
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Example 2
Using the data in Example 1, determine the
economical number of trucks such that the
load time and transport time balance.
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Productivity Improvement?
What if there are 2
loaders and 10
trucks? How to
estimate the
project cost?
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(Courtesy: CYCLONE Simulation)
Earthwork Quantity Take-off
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(Courtesy: Donaldson Garrett)
Earthwork Quantity Take-off
• When planning or estimating an
earthmoving project, it is often necessary to
estimate the volume of material to be
excavated or placed (Cut vs. Fill)
• Quantity take-off is a detailed
measurement of earthwork volume to
complete a construction project
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Earthwork Quantity Take-off
• Contractors are paid for the volume of
excavation
• Earthwork can
be roughly
estimated by
counting the
number of
truckloads
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(Courtesy: CAT)
Pit Excavations
Small, relatively deep excavations
Volume = Horizontal area × Average depth
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(Courtesy: FictionU)
Pit Excavations
Calculation
– Step 1: Divide the horizontal area into a
convenient set of rectangles, triangles, or
circular segments
– Step 2: Determine the total area as the sum of
the segment areas
– Step 3: Calculate the average depth
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Example 3
Estimate the volume of excavation required for the
basement. Values shown at each corner are
depths of excavation.
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(Courtesy: Nunnally 2011)
Trench Excavations
Usually constructed for utility lines
Volume = Cross-sectional area × Length
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(Courtesy: Joyceroad)
Example 4
Find the volume of excavation required for a trench
0.92 m wide, 1.83 m deep, and 152 m long.
Assume that the
trench sides will be
approximately vertical.
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(Courtesy: ecmweb)
Large Areas
Dividing the area into a grid indicating the
depth of excavation or fill at each grid
intersection
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(Courtesy: wplinternational)
Large Areas
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(Courtesy: CAT)
Large Areas
Average Depth
– Assign the depth at each corner or segment
intersection a weight according to its location
• Interior points: Weight of four
• Exterior points at the intersection of two
segments: Weight of two
• Corner point: Weight of one
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Large Areas
Average Depth
=
Sum of products of depth × Weight
Sum of weight
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Example 5
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Mass Diagram
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(Courtesy: ugpti.org)
Mass Diagram
• A continuous curve representing the
accumulated volume of earthwork plotted
against the linear profile of a roadway or
airfield
• Prepared by highway and airfield
designers
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Mass Diagram
• Used to assist in selecting an alignment
which minimizes the earthwork required to
construct the facility while meeting
established limits of roadway grade and
curvature
• Very useful for construction manager
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Example 6
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(Courtesy: Nunnally 2011)
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(Courtesy: Nunnally 2011)
Innovations in Earthmoving
Komatsu - Autonomous Haulage System
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(Courtesy: aerometrex)
Aerial Innovation
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(Courtesy: THIESS)
UAV Resources at UNSW
Multirotor UAVs
DJI Phantom 3 Professional
Vulcan Heavy Lift Octocopter
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Weight: 1.28 Kg
Sensor: 12MP Camera
Flight time: 20 min
No. of Propellers: 4
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Weight: 14 Kg
Sensors: LiDAR/Infrared Cam
Flight time: 1 Hour
No. of Propellers: 8
UAV Resources at UNSW
Fixed Wing UAVs
SenseFly eBee RTK
SenseFly swinglet CAM
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Weight: 0.73 kg
Sensor: 12MP RGB & NIR Cams
Flight time: 40 min
Wingspan: 0.96 m
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Weight: 0.5 kg
Sensors: 12 MP Camera
Flight time: 30 min
Wingspan: 0.8 m
Case Study – Narrabeen Beach, NSW
Home waypoint
Flight path of UAV
Orthomosaic of site
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(Courtesy: Max Stannard 2014)
Point Cloud input into AutoCAD Civil 3D
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(Courtesy: Max Stannard 2014)
TIN volume surface
1m x 1m grid
volume surface
10m x 10m grid
volume surface
Cut - Purple
Fill - Orange
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(Courtesy: Max Stannard 2014)
Station = 200
(1,4)
Cut
Fill
Net
(1,3)
Cut
Fill
Net
(1,2)
Cut
Fill
Net
(1,1)
Cut
Fill
Net
(2,4)
-339.03 Cut
3377.87 Fill
3038.84 Net
(2,3)
-369.58 Cut
6150.42 Fill
5780.84 Net
(2,2)
-767.39 Cut
2571.26 Fill
1803.87 Net
(2,1)
-16886.4 Cut
0 Fill
-16886.4 Net
(3,4)
-80.1 Cut
9110.38 Fill
9030.28 Net
(3,3)
-0.3 Cut
8612.65 Fill
8612.35 Net
(3,2)
-4340.94 Cut
1405.93 Fill
-2935.01 Net
(3,1)
-12902.5 Cut
0 Fill
-12902.5 Net
(4,4)
0 Cut
7323.39 Fill
7323.39 Net
(4,3)
-3925.35 Cut
2952.51 Fill
-972.84 Net
(4,2)
-12883.9 Cut
0 Fill
-12883.9 Net
(4,1)
-5207.85 Cut
290.47 Fill
-4917.38 Net
(5,4)
-1483.51 Cut
4078.89 Fill
2595.38 Net
(5,3)
-10798 Cut
4.7 Fill
-10793.3 Net
(5,2)
-2737.64 Cut
680.51 Fill
-2057.13 Net
(5,1)
-8.68 Cut
4463.59 Fill
4454.91 Net
-805.97
2998.13
2192.16
-489.57
2881.72
2392.15
-0.14
6717.91
6717.77
Earthwork
Planning
Cut - Purple
Fill - Orange
-0.29
10447.92
10447.63
Station = 0
Alignment
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(Courtesy: Max Stannard 2014)
Questions?
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