EARTHWORKS

EARTHWORKS
1. Definition
2. Classification of materials
3. Bulking
4. Mass diagram
5. Earthmoving equipment
6. Compaction
7. Soil stabilization
8. Rock breaking
 Earthmoving Materials &
Operations
Nunnally Chapter 2
INTRODUCTION

2. EARTHMOVING – process of moving

soil or rock from one location to
another and processing it (if needed) to
meet construction requirements i.t.o.
1. Location
2. Elevation
3. Density
4. Moisture content
1m³ of in-situ soil 1,25m³ of loose soil 0,9m³ of compacted soil
EARTHWORKS activities include:
• Excavation
• Loading
• Hauling (transporting)
• Placing (dumping/spreading)
• Compacting
• Grading
• Finishing
Efficient management of the earthmoving
process requires:

1. Accurate estimating of quantities - ?

2. Job conditions: type soil/rock to be
excavated, size etc. – Geo-tech report
3. Proper selection of equipment – efficiency &
profitability.
– Most important: ability to perform the work
thus maximizing the profit or return on the
investment produced by the equipment
4. Competent job management
Soil characteristics:
1. Trafficability – ability to support the
weight of vehicles under repeated
traffic – examples?
2. Loadability – measure of the
difficulty in excavating & loading of
the soil – examples?
Column layout – foundation excavations
Trafficability of soil?
Trafficability of soil?
Trafficability of soil?
Trafficability of soil?
3. SOIL IDENTIFICATION & CLASSIFICATION
Soil considered to consist of 5 fundamental
material types:
1. Gravel – 6-75mm dia.
2. Sand – smaller than 0.7mm dia.
3. Silt – particles up to 0.02mm dia.
4. Clay – particles smaller than 0.002mm dia.
5. Organic material – particles 3-6mm dia.
(organic material - ?)
Soil classification systems:
•  AASHTO – American Association of State
Highway and Transportation Officials – applies to South
African industry
• AASHO - American Association of State Highway
Officials
1. Liquid limit: water content at which the soil will
start to flow when subjected to shaking test
2. Plastic limit: moisture content in % at which the
soil will begin to crumble

Geo-Technical Engineer to issue Geo-Tech

Report of soil classification
(when coming into contention? At pre-tender
stage)
 Site classifications based on soil reactivity
Stable, non-reactive. Most sand and rock sites. Little or no ground
Class A movement likely as a result of moisture changes.

Slightly reactive clay sites. May experience slight ground

Class S movement as a result of moisture changes.

Moderately reactive clay or silt sites. May experience moderate

Class M ground movement as a result of moisture changes.

Highly reactive clay sites. May experience a high amount of ground

Class H movement as a result of moisture changes.

Extremely reactive sites. May experience extreme amounts of

Class E ground movement as a result of moisture changes.

Problem sites The ability of the soil to evenly bear a load is

very poor. Sites may be classified as 'Class P' as a result of mine
subsidence, landslip, collapse activity or coastal erosion. Ground
Class P
movement as a result of moisture changes may be very severe. If you
are building on a Class P site you will need to consult a structural
engineer.
Self study: Field identification of soil – refer Table 2, p. 14

4. SOIL VOLUME-CHANGE CHARACTERISTICS:

BULKING (p.17)
3 Principal conditions or states in which material may
exist:
1. Bank – material in its natural state before disturbance
i.e. “in situ” material
2. Loose – material that has been excavated or loaded
3. Compacted – material after compaction

SWELL: excavated soil increases in volume

because of grains loosening during
excavation and air filling the voids created
(See example 2, p. 17)
SHRINKAGE: as soil is compacted, air is forced
out of the soil’s void spaces, as a result the soil
will occupy less volume than it did under the
bank/loose condition (See example 2, p. 17)
5. SPOIL BANKS
• when planning/estimating, it is necessary to determine
the size of the pile that will be created by dumping the
excavated material
• if the pile is long in relation to the width: spoil bank
(triangular cross section)
• if the material is dumped from a fixed position: spoil pile
(conical shape)

6. ESTIMATING EARTHWORK VOLUME

• When planning/estimating, it is necessary to estimate the
volume of material to be excavated or placed as fill
Loadability of soil?
Loadability of soil?
Loadability of rock?
 Loadability of rock?

Further processing required?

Loadability?
Loadability of soil?
2.5 Loose spoil banks - dumped by loader
Loose spoil banks - dumped by loader
Procedure to be followed can be divided into 3
principal categories:
1. Pit excavation – small/deep example
bases/foundations. See example 6
2. Trench excavation – utility lines. See example 7
3. Excavation of large areas (Bulk excavations).
See example 8

7. THE MASS DIAGRAM (Cut-to-fill)

• a continuous curve, representing the accumulated
volume of earthwork plotted against the linear profile of a
roadway/airfield
• diagrams prepared by highway designers to assist in
selecting an alignment which minimizes the earthwork
required to construct the facility while meeting
established limits of roadway grade/curvature
• does not form part of the contractor’s tendering
documents
Bulk excavation?
Bulk excavation?
2.7FillCut-to-fill (Bulk excavation)
Cut-to-fill

Fill to create elevated surface

Cut
2.7 Cut-to-fill (Bulk excavation)

Earthmoving – the process of moving soil or

rock from 1 location to another and processing
it to meet requirements i.t.o.
• Location
• Elevation
Characteristics:
1. The vertical coordinate of the mass diagram
corresponding to any location on the roadway profile,
represents the cumulative earthwork volume from the
origin to that point
2. Within a cut: curve rises from left to right
3. Within a fill: curve rises falls from left to right
4. A peak on the curve, represents a point where the
earthwork changes from cut to fill
5. A valley (low point) on the curve, represents a point
where the earthwork changes from fill to cut
6. Where a horizontal line intersects
the curve at two or more points, the
accumulated volumes at these
points are equal – balance line
Using the mass diagram - information that can
be provided/helpful to the CM & QS:

1. The length & direction of haul within a

balanced section
2. The average length of haul for a balanced
section
3. The location & amount of borrow (material
hauled in from a borrow pit) and waste
(material hauled away to a dump site) for the
project
 Excavating & Lifting
Nunnally Chapter 3 – EARTHMOVING EQUIPMENT
1. INTRODUCTION
Excavator: power-driven digging machine designed to
excavate below grade - See page 27
1. Hydraulic excavators
2. Cable-operated crane-shovel family
Dozers, loaders and scrapers can also serve as
excavators
Advantages of hydraulic excavators over cable-operated
machines:
• faster cycle time
• higher bucket penetrating force
• more precise digging
• easier operator control
Excavator: excavating/loading
3.1 Excavator
Excavator used for pipe laying
 Ramp to basement: Entrance and exit point

Sun Arena basement, Menlyn Maine: 483,650m³ excavation

Ramp to basement: Entrance and exit point
Ramp to basement: Entrance and exit point
Excavators consist of 3 major assemblies:
1. Carrier or mounting
2. Revolving super-structure containing the
power units
(see figures 2 & 3)
3. Front-end assembly

Carriers available in: (See figure 2)

• Crawler: provides excellent on-site mobility in
areas with low trafficability; used for trenching
and rock excavation
• Truck: provides better mobility between sites;
less stable
• Wheel mountings: as for truck above
Carrier / mounting Revolving superstructure Front end assembly
Crawler-type carrier
2. HYDRAULIC EXCAVATORS
Hydraulic excavator with hoe front end – hydraulic
hoe or hydraulic excavator-backhoe designed to
excavate below grade i.e. by pulling the dipper
back toward the machine – See figure 3
• The backhoe widely used for trenching, laying
pipe bedding, pipe laying, pulling trench shields
and backfilling
• Best measure of production is the length of
trench excavated per unit of time – important:
choose correct dipper width with or without side
cutters
• Self study pages 28-29
3. SHOVELS
The hydraulic shovel also called a front shovel or hydraulic
excavator-front shovel – See figures 6, 7 & 8
It digs with a combination of crowding force and breakout
force
Crowding force: generated by the stick cylinder, acts at
the bucket edge on a tangent to the arc of the radius
from point A
Breakout force: generated by the bucket cylinder and acts
at the bucket edge on a tangent to the arc of the radius
through point B
• Self study pages 30-31
4. DRAGLINES

• Versatile with the longest reach for digging/dumping

• Can dig from above machine level as well as significant
depths below in soft to medium-hard material
• Bucket teeth and weight produce digging action as the
drag cable pulls the bucket across the ground surface
• Digging is controlled by the position at which the drag
chain is attached to the bucket – see figure 1 page 34
• The higher the point of attachment, the greater the angle
at which the bucket enters the soil
• During hoisting and swinging, material is retained inside
the bucket by the tension dump cable
• When tension on the drag cable is released, tension is
released from the dump cable, allowing the bucket to
dump
* Self study pages 33-35
Batching plant: Dragline?
 Batching plant
Cement silo’s

Stone aggregate Sand aggregate

Batching plant utilizing a drag line system
5. CLAMSHELLS
1. When the crane-shovel is equipped with a crane boom
and clamshell bucket, is becomes an excavator
known as a clamshell
2. Capable of excavating deep but lacks the positive
digging action and precise lateral control of the
shovel and backhoe
3. Used for vertical excavation (shafts), footings and
unloading bulk material from trains, ships
4. Moving bulk material from stockpiles to bins, hoppers
or haul units (trucks)
* Self study pages 35-36
Water environment - Harbour
6. TRENCHING
Trenching done by using backhoes and excavators –
greater demand for installing utility systems with
minimum open excavations: trenching machines and
plows, thus the development of
Trenchless technology:
1. Pipe jacking: forcing pipe horizontally through the soil (See
figure 18)
2. Horizontal earth boring: horizontal hole is created
mechanically/hydraulically with the pipe to be installed serving as
the casing for the hole (See figure 20)
3. Micro-tunneling: similar to conventional tunneling except for
size & use; usually intended for services/utilities, tunnels are
small; tunnel liner is used instead of pipe itself
* Self study: pages 36-40
Trenching
Trenching
Pipe jacking
Culvert jacking (Pre-cast concrete element)
Culvert jacking
Microtunneling
Microtunneling
7. CRANES
1. Primarily for lifting, lowering & transporting loads
2. Loads moved horizontally by swinging/traveling
3. Mobile cranes: major factor for controlling the load
that may be safely lifted, is its operating radius: the
horizontal distance from the center of rotation to the hook
4. Other factors:
4.1 position of the boom in relation to the carrier,
whether or not stabilizers are used to
increase the effective base
4.2 amount of counterweight
4.3 condition of the supporting surface
HEAVY LIFT CRANES: Cranes intended for
heavy lifting usually crawler-mounted lattice-
boom (lifting ability of up to 600 tons and a
113m reach)
 Mobile crane:
Important – Operating radius
and stabiliser arms

Stabilisers
TOWER CRANES
• Another type of specialist crane
• Widely used on building sites because of its
wide operating radius and almost unlimited
height restriction
• Types: (See figure 29)
1. Horizontal jib – swings over the structure
2. Luffing boom – ability to operate in areas of
restricted horizontal clearance not suitable for
horizontal jib type cranes with their fixed jibs and
counterweights
3. Articulated jib – ability to reposition their
hinged jibs to convert excess hook reach into
added hook height; can be operated in either the
horizontal or luffed position
TOWER CRANES
• Refer to figure 31: Self-raising tower crane mast
 CONVERT

Hinged
Rail mounted tower crane
Rail mounted tower crane
Rail mounting for tower crane
Static mounted tower crane
Static mounted tower crane
Static mounted tower crane
“Types” of tower crane by method of
mounting include:
1. Static (fixed mount)
2. Rail-mounted
3. Mobile
4. Climbing

Tower crane capacity depends on:

1. Operating radius
2. Amount of counterweight
3. Mounting used
 Loading & Hauling
Nunnally Chapter 4 – EARTHMOVING EQUIPMENT
1. Read pages 49-54
2. DOZERS – See figure 6 (Read pages 56-57)
• A tractor with a front-mounted earthmoving blade
known as a dozer or bull-dozer
• Moves earth by lowering the blade and cutting until a
full blade load of material is obtained; moves it to the
required position; unloading by lifting the blade over
the spoil pile or pushing the load over a cliff or in to a
hopper
• Wheel/crawler dozers available
• Used in rough terrain and or low trafficability
Dozer blades – see figure 9 page 57
1. straight 2. angle-blade 3. universal 4. cushion
Dozer blade adjustments: 1. tilting 2. pitching 3. angling
3. LOADERS
• A tractor equipped with a front-end bucket: called
a loader or front-end loader or bucket loader
• Wheel or track (crawler) loaders available
• Used for:
1. Excavating soft to medium-hard material
2. Loading hoppers and haul units
3. Stockpiling material
4. Backfilling ditches
5. Moving construction materials such as
concrete etc.
Wheel loaders: excellent mobility, capable of
over-the-road movement up to 45km/h
Track loaders: capable of steeper grades and side
slopes but work slower than wheel loaders over
long haul distances
4.3 Loader
4.3 Loader-Excavator
Loadability of material/boulders?
9,6m face

NGL

5,1m deep
3. Loaders – Backhoe “TLB”
TLB: TRACTOR LOADER BACKACTOR/HOE
 3. Continue
SKID STEER LOADERS (“Bobcat”) – See figure 13 page 61
Small wheel loader having rigid axles
• Steers by breaking with the wheels or tracks on one side
while applying power to the other side
• Small in size but highly productive & versatile
MATERIAL HANDLERS – See figure 15 page 62
• Also called rough terrain forklifts
• Referred to as “Tele-Handler” (Telescopic handler)
• Lift capacity of 4 tons
• Reach capacity of 12m
Skid steer loader: “Bobcat”
“Bobcat” or skid steer or Bobcat skid steer?
4.2 Skid steer loader
Telescopic-Handler
Telescopic-Handler
4. SCRAPERS (not to be confused with a grader)
Scrapers are capable of:
1. Excavating – e.g. cutting levels of sports fields
2. Hauling – quantity ?
3. Dumping material over medium-to long haul distances
 It excavates by lowering the front edge of its bowl
into the soil

5. TRUCKS AND WAGONS

Because hauling forms such a major part of earthmoving,
other than dozers, loaders etc., hauling equipment
include
• trucks,
• wagons,
• conveyor belts
• trains
Scraper
?
 VIDEOS
• Liebherr 630 EC-H40
tower crane assembly
• San Marco self raising
crane
https://www.youtube.com/watch?v=xdnwyenTY70

https://www.youtube.com/watch?v=hxNfR4sYgTk&t=53s