Earthworks

All civil engineering project involve some form of ...

Earthmoving

Earthmoving involves...

Removal of soil or rocks for foundations, handling of spoils, or importing these to build embankments

Failures during and after construction require ....

Careful consideration of earthworks

Earthworks and its considerations depend on ...

The scope

In dams, earthworks relates to ...

Slope stabilization and remediation

2 Things essential to earthworks

1. The ability to model the job in terms of soil properties
2. Selection of the correct construction method

The 5 steps of earthworks in building construction

1. Remove topsoil
2. Setting out
3. Excavation and compaction
4. Shoring
5. Backfilling around foundation

In earthworks during building construction there is a need to plan for ...

Quantities, program, resources, regulatory framework

The 5 steps of earthworks in civil projects

1. Setting out
2. Remove topsoil
3. Cuts and fills to formation levels
4. Subgrade preparation and drainage
5. Lay sub-base

In earthworks during civil projects there is a need to plan for ...

Quantities, program, resources including plant, materials and disposal, regulatory framework

The design objective of safety and economical solution are achieved by ....

1. Minimal in-service settlement
2. Optimising cuts and fills, minimize cost of borrowing and disposing spoils
3. Improving and reusing existing materials

Contractors execute earthworks to ....

specifications, method or end-product based

Method basic specifications tend to be ...

Prescriptive in terms of materials and equipment

End product specifications define the ...

Characteristics of the earthworks, allowing the contractor to be flexible with materials and methods

Giving contractors flexibility is ...

Attractive, but can be risky

Resident engineers have ...

Challenging tasks to conform to the specifications

The 4 categories of machinery used in earthworks (each has variations based on capacity and manufacturer)

1. Excavators and loaders
2. Earth transporters
3. Bulldozers and graders
4. Compactors

Excavators have capability to ...

Scoop or scrape soil, rock or loose materials

Excavators and loaders can be further classified in terms of ...

Support, boom, depth of dig, capacity

3 Types of excavators and loaders

1. Backacters
2. Draglines
3. Loading shovels
4. Backhoe

Selectors of transporters must consider ....

1. Ground conditions
2. Capacity
3. Access conditions

3 Types of transporters

1. Swivel dumper
2. Dump truck
3. Dipper truck
4. Scrapers

Bulldozers can be ....

Crawler or wheel-mounted

Similarities between bulldozers and graders include ...

Trim excavations, spread or push spoils

Compaction is necessary of soil before work because ...

Soil is porous and will swells when disturbed if exposed to moisture

Compaction method depends on ...

Soil type and moisture content

3 Types of compactors

1. Smooth roller
2. Sheepfoot roller
3. Pneumatic tyre
4. Grid

Loose volume equation

Bank volume * swell factor

Volume of soil taken per cycle equation

Volume of bucket * loading capacity

Number of cycles to load a truck equation

Volume of truck/volume of backacters per cycle

Bank volume is calculated by ...

The prismoidal method

Bank volume equation

Chain interval/2 ((A0 + An) + 4(A1 + A3 + ...) + 2(A2 + A4 + ...))

A = Area

Time to excavate and load truck equation

Positioning time of truck + time to load one truck

Time to load one truck equation

Number of cycles to load truck * (1/cycles per hour output)

Time to complete works equation

(Volume of soil * time to excavate one truck)/time to excavate and load one truck