Field Compaction

RET 565
BUILDING TECHNOLOGIES AND
INFRASTRUCTURES

FIELD COMPACTION

Prepared By:
Muhammad Arkam Bin Che Munaaim
SRM0069/08, 771224-07-5147
www.arkamonline.com

COMPACTION-DEFINITION

Soil: The part of the earth's surface consisting of humus and
disintegrated rock, Material in the top layer of the surface of
the earth in which plants can grow (especially with reference
to its quality or use)
Compaction: An increase in the density of something.


Thus, SOIL COMPACTION is the process to increase the soil
(ground) density in order to make use the ground surface for
development, ie, building, road, etc.
The volume of void space is reduced by applying high loads over a
small area to force the air out of an unsaturated soil mass.


In other words, soil compaction is defined as the method of
mechanically increasing the density of soil. In construction, this is
a significant part of the building process. If performed
improperly, settlement of the soil could occur and result in
unnecessary maintenance costs or structure failure. Almost all
types of building sites and construction projects utilize mechanical
compaction techniques.

COMPACTION-WHY COMPACT?
There are five principle reasons to compact soil:
- Increases load-bearing capacity
- Prevents soil settlement and frost damage
- Provides stability
- Reduces water seepage, swelling and contraction
- Reduces settling of soil

COMPACTION-TYPES OF COMPACTION
There are four types of compaction effort on soil or
asphalt:

-Vibration (Vibratory Force Compaction)
-Impact (Vibratory Force Compaction)
-Kneading (Static Compaction)
-Pressure (Static Compaction)

COMPACTION-SIGNIFICANT

To construct ROAD, highway, expressway, runway, railway,
plantations, etc.

COMPACTION-SIGNIFICANT

Building constructions, drainage, embankment, external
services, etc.

COMPACTION-SOIL TYPES

Sand, silt, and clay are the basic types of soil. Most soils are made up of a
combination of the three. The texture of the soil, how it looks and feels, depends
upon the amount of each one in that particular soil. The type of soil varies from
place to place on our planet and can even vary from one place to another in our
own backyard.


Every soil type behaves differently with respect to maximum
density and optimum moisture.
Soil types are commonly classified by grain size, determined by
passing the soil through a series of sieves to screen or separate
the different grain sizes.
Soils found in nature are almost always a combination of soil
types. A well-graded soil consists of a wide range of particle
sizes with the smaller particles filling voids between larger
particles.

The are three basic soil groups:

Cohesive
Granular
Organic


Cohesive soils
Cohesive soils have the smallest particles. Clay has a particle
size range of .00004quot; to .002quot;. Silt ranges from .0002quot; to
.003quot;. Clay is used in embankment fills and retaining pond beds.

Characteristics
Cohesive soils are dense and tightly bound together by molecular
attraction. They are plastic when wet and can be molded, but
become very hard when dry. Proper water content, evenly
distributed, is critical for proper compaction. Cohesive soils
usually require a force such as impact or pressure. Silt has a
noticeably lower cohesion than clay. However, silt is still heavily
reliant on water content.

Granular soils
Granular soils range in particle size from .003quot; to .08quot; (sand)
and .08quot; to 1.0quot; (fine to medium gravel). Granular soils are
known for their water-draining properties.

Characteristics
Sand and gravel obtain maximum density in either a fully dry or
saturated state. Testing curves are relatively flat so density can
be obtained regardless of water content.


THE BEST PROPERTY
FOR SOIL COMPACTION

COMPACTION-METHOD
BASIC PRINCIPLES:

Preliminaries
Site Clearing & Demolition Works
Stripping Of Topsoil
Soil Sampling
Trial Embankment
Excavation Of Cut/Fill Area
Filling/Backfilling Materials
Replacement Of Unsuitable Materials
Backfilling To Unsuitable Area
Embankment Filling
Rock Blasting
Rock Filled Embankment
Sub Grade

BASIC PRINCIPLES OF FIELD
COMPACTION
METHOD- Preliminaries

ROAD ONLY Stripping Of Topsoil
Soil Sampling
Trial Embankment
1) Survey: Existing ground level, setting Replacement Of Unsuitable Materials
out of centre lines and road reserved, cut
Embankment Filling
and fill area, invert level and direction of Rock Blasting
water path. Rock Filled Embankment
Sub Grade
2) Submission of any approvals required.
Temporary road diversion if required.
Submit localized environmental mitigation
5) Where crossing of
measures.
watercourses, install temporary
3) Routes of transportation, temporary steel pipe to divert water flow.
access, modes of transport, frequency and
6) Use machinery fitted with
mode of filling identified.
silencer to reduce noise level if
4) Provide adequate plant and equipment necessary.
to carry out all activities.

COMPACTION

Soil Sampling
Trial Embankment
1) Setting out of contract limit, ROW and Replacement Of Unsuitable Materials
centre line carried out by licensed surveyor.
Embankment Filling
2) Approval from local authorities on Rock Blasting
machineries to be used.
Sub Grade
3) Determine status of land acquisition
5) Secure, establish and make a
and confirmed.
proper temporary access.
4) Liaise with local authorities and give
6) Provide sufficient temporary
notice to vacate buildings on TOL land prior
earth drain where necessary to
to commence activity.
avoid water ponding.
5) Public services and utilities identified
7) Confine the demolition within
and protected where necessary.
site, control dust and noise
6) Determine the status of termination of pollution arising from the work
connection and temporary activity.

COMPACTION

Soil Sampling
Trial Embankment
1) Identify topsoil's stockpile area outside Replacement Of Unsuitable Materials
the road reserve within ROW.
Embankment Filling
2) Maintain public access and provide Rock Blasting
alternative route where/ when necessary.
Sub Grade
3) Use suitable machinery to remove an
average depth of at least 100mm below
existing ground level.
5) Control activities to within
4) Liaise with local authorities and give the areas (zoning and
notice to vacate buildings on TOL land prior scheduling) to avoid unnecessary
to commence activity. prolonged exposure, to decrease
siltation in water courses and/ or
dust in dry condition.

COMPACTION

Soil Sampling
Trial Embankment
1) Samples of suitable imported backfill Replacement Of Unsuitable Materials
material shall be subjected to the following
Embankment Filling
tests ; Rock Blasting
i) Atterberg's Limit for Plastic Limit,
Sub Grade
Liquid Limit and Plastic Index.
ii) B.S. Heavy Compaction Test to
obtain the Proctor Value for maximum dry
density and optimum moisture content.
iii) CBR Value to determine the bearing
capacity in top sub grade layer.
iv) Sieve Analysis to determine soil
classification.

COMPACTION

Soil Sampling
Trial Embankment
1) The purpose of trial embankment fill is Replacement Of Unsuitable Materials
to confirm the degree of compaction
Embankment Filling
required in relation to loose depth and Rock Blasting
compaction equipment for various types Rock Filled Embankment
of soil and machinery used. Sub Grade

2) The specified machinery will be
directed to carry out specified number
of passes required on different loose
5) All these datas will be plotted
thickness of fill material followed by In
and analyzed for the relationship
Situ Field Density Test.
between loose depth thickness
3) Test Result will be recorded and the and number of passes required
test repeated for a different type of on different machinery used.
compaction equipment and imported
materials.

COMPACTION

Soil Sampling
Trial Embankment
Embankment Filling
1) Slopes, levels, and other control pegs
Rock Blasting
are available at cut areas to obtain the Rock Filled Embankment
required design profile. Sub Grade

2) Confirm acceptance of material for
embankment filling and/or backfilling
materials.

COMPACTION

Soil Sampling
Trial Embankment
1) Determine range of moisture content
Embankment Filling
to achieve the degree of compaction. Rock Blasting
2) Wet materials shall be spread and left Sub Grade
to dry. If the materials found too dry,
mix with water mechanically at
spreading areas.
3) Obtain approval before using hard
materials, rocks or boulders and discard
all materials deemed unsuitable.

COMPACTION

Soil Sampling
Trial Embankment
1) Carry out soil investigation by using Replacement Of Unsuitable Materials
Mackintosh Probe to the required depth/
Embankment Filling
penetration per blow. Rock Blasting
2) Carry out setting out and joint survey
Sub Grade
to demarcate limits and depth of
unsuitable material.
5) In presence of access pore
3) Carry out trial pits to determine soil water pressure, dewatering
classification using Alterberg 's limit or continuously and provide proper
by cone penetrometer test to confirm drainage to prevent ingress of
the recommended depth below the surface water runoff.
original ground level and method of
6) Excavate the unsuitable
backfill used.
material to the extent of
required depth and profiles.

COMPACTION

Soil Sampling
Trial Embankment
1) Upon completion of joint measurement Replacement Of Unsuitable Materials
for the excavation area, carry out
Embankment Filling
backfilling with granular material (sand). Rock Blasting
2) Sewn geotextile will be laid flat on the
Sub Grade
intended work area (if required).
3) If found that ground water level
develop above the 500mm sand
thickness. Further sand fill to attain
5) When backfilling at the edge
300mm clearance above standing water.
of ground having slope, cut the
4) Where ground water level is high, it slope edge into benches to
would be expected that seepage would approximately the same as the
effect the first layer of earth filling. Place fill level to obtain uniform
a slightly thicker first layer of sand fill. compaction over the fill area.

COMPACTION

Soil Sampling
Trial Embankment
1) Surface preparation to receive layer Replacement Of Unsuitable Materials
of fill. Area to be filled cleared from
Embankment Filling (1)
existing structures and services. Rock Blasting
2) Control deposition of earth fill,
Sub Grade
spread, levelled and compacted in layers
less than 300mm loose depth using 5) Secure a team for Field
suitable plants and equipments. Density Test to determine the
degree of compaction at any time.
3) Form embankment with suitable cross
Field Density Test shall be done
fall to avoid water ponding. While if the
using Sand Replacement Method (in
surface is too dry, provide water tanker
accordance with BS1377: Part 2) or
to control the moisture.
by Core Cutter Method. If the
4) Loose fill levels are controlled by density is below the requirements,
flagged top levels of fill to ensure further compaction will be carried
compacted fill thickness is achieved out.

COMPACTION

Soil Sampling
Trial Embankment
If the moisture content is high, fill materials Replacement Of Unsuitable Materials
will be scarified, dried and compacted for
Embankment Filling (2)
retesting.
Rock Blasting
If FDT passed - proceed to the next layer. Rock Filled Embankment
Sub Grade
If FDT failed - proceed with ratification and
retest.
5) Maintain existing and new
6) In presence of water ponding, remove and
drainage to ensure surface water run-off
scarify the top 100mm and blend it with the
in proper discharge.
new embankment fill, compact and continue
with normal backfilling. 6) When backfilling at edge of
embankment, each compacted layer to
7) If backfilling on slope against existing
be extended by 600mm and trim back to
embankment or on ground with existing
the required slope angle.
slope, excavate the foundation in horizontal
and vertical to form contiguous width in
benches and use the excavated material as fill
material for embankment.

COMPACTION

Soil Sampling
Trial Embankment
1) Carry out joint survey with consultant Replacement Of Unsuitable Materials
to determine the extent of rock
Embankment Filling
formation. Rock Blasting
2) Request permission from relevant
Sub Grade
authorities including the police to
monitor the blasting works.
3) Carry out the blasting work to the
required formation level.
4) Carry out joint survey to calculate the
quantities of blasted rock.

COMPACTION

Soil Sampling
Trial Embankment
1) Rock shall be defined as a material that Filling/Backfilling Materials
cannot be ripped by a drawnripper having Replacement Of Unsuitable Materials
weight of 20 tonnes with a nett horse power Backfilling To Unsuitable Area
not less than 200 brake. Embankment Filling
Rock Blasting
2) Rock fill embankment shall not more than Rock Filled Embankment
400mm so that it can be deposited in Sub Grade
horizontal layers, each not exceeding 500mm
in compacted depth and extending over the
full width of the embankment. 5) Place uniformly graded material
( 6mm - 150mm ) at least 300mm
3) Spread, level and compact using crawler
thick between the top 300mm of sub
tractor weighing not less than 15 tonnes.
grade and the rock fill.
4) Fill void using fine graded material and
6) Fill any void with blinded and
through blind uniformly before proceed to the
regulate the rock surface to
next layer.
formation levels

COMPACTION

Soil Sampling
Trial Embankment
1) Lay, spread and compact uniformly Filling/Backfilling Materials
the top 300mm and carry out FDT 95% Replacement Of Unsuitable Materials
maximum dry density (for cohesive soil)
Embankment Filling
or 100% maximum dry density (for Rock Blasting
cohesiveness soil) relative to Proctor Rock Filled Embankment
Sub Grade
Test (4.5 kg rammer) as per BS 1377.
2) If the compaction achieve below the
Wearing Course
requirement, scarify the surface, leave it
Tack Coat
to dry recompact and retest. If it is still
unpractical, remove the top sub grade Binder Course
layer and replace with suitable material
Prime Coat
and compact to the required density.
Sub grade
3) Tolerance for sub grade finish layer
Sand Blanding
shall be within + 10mm to 30mm of the
required gradient and level. Sub base

COMPACTION-MACHINERIES

Rammers deliver a high impact force ( high amplitude) making them an excellent
choice for cohesive and semi-cohesive soils. Frequency range is 500 to 750 blows
per minute. Rammers get compaction force from a small gasoline or diesel engine
powering a large piston set with two sets of springs. The rammer is inclined at a
forward angle to allow forward travel as the machine jumps. Rammers cover three
types of compaction: impact, vibration and kneading.


Vibratory plates are low amplitude and high frequency, designed to compact granular
soils and asphalt. Gasoline or diesel engines drive one or two eccentric weights at a
high speed to develop compaction force. The resulting vibrations cause forward
motion. The engine and handle are vibration-isolated from the vibrating plate. The
heavier the plate, the more compaction force it generates. Frequency range is usually
2500 vpm to 6000 vpm. Plates used for asphalt have a water tank and sprinkler
system to prevent asphalt from sticking to the bottom of the base plate. Vibration is
the one principal compaction effect.


Reversible Vibratory Plates
In addition to some of the standard vibratory plate features, reversible plates have two
eccentric weights that allow smooth transition for forward or reverse travel, plus
increased compaction force as the result of dual weights. Due to their weight and
force, reversible plates are ideal for semi-cohesive soils. A reversible is possible the
best compaction buy dollar for dollar. Unlike standard plates, the reversible forward
travel may be stopped and the machine will maintain its force for quot;spotquot; compaction.


Rollers
Rollers are available in several categories: walk-behind and ride-on, which
are available as smooth drum, padded drum, and rubber-tired models; and
are further divided into static and vibratory sub-categories.

COMPACTION & CLIMATE
Although compaction may not change the water content of a soil, the
maximum density obtainable does depend on the amount of water
present in the soil mass.
Because the individual particles in a course grained soil are chemically
inert, there is a little interaction between the solid and liquid fraction of
a soil mass.
The effects of water in the deposit is largely through the formation of
capillary tensions, with result in the particles being tightly bound in a
matrix that resist rearrangement.
As a degree of saturation increases, the capillary forces are destroyed
and compaction energy becomes more effective in densifying the soil.
For most cases, the optimum water content yielding the greatest
density of the solid fraction (dry density) can be identified.
At water content at both below and above the optimum, the same
compaction effort in result lower soil density.


Source: Encyclopedia of Soil Science, R.Lal, William E Wolfe, Ohio State
University, Columbus, Ohio, USA, 2006


Example of Test Results:

Example of Test Results:

OPTIMUM MOISTURE CONTENT

Since the Moisture Content, W is much depending on the
weight of water, Wd, it is obvious that the climate condition
will effect the quality of compaction in any area of
compaction.
It is important to know the Optimum Moisture Content for the
soil so that the energy used for saturation process is also at
optimum and resulting in the quality of compaction works.
There will be some amount of moisture needed in compaction
process, the compaction is not recommended to be done
either in a too dry or too wet condition to achieve the good
and quality compacting results.

The response of soil to moisture is very important, as the soil must
carry the load year-round. Rain, for example, may transform soil into a
plastic state or even into a liquid. In this state, soil has very little or no
load-bearing ability.

COMPACTION: CONCLUSION
Soil Compaction is very critical for any development. Failure to
make sure the effectiveness of an entire process may cause disaster
in future.
Generally there are 13 steps on doing compaction based on
Malaysia’s methods and technologies. These steps must be carried
out professionally according to the highest specifications and
international standards that available without compromise.
Developers, consultants, local authorities and the contractor must
aware the bad consequences that probably happen if neglecting any
aspect in the process and should be responsible to the scope of
works that delegated to them by the users.
Hopefully this short presentation will benefits to the viewers in
understanding the basic principles in Soil Compaction theory that
can be useful in their career.
THANK YOU… Muhammad Arkam B Che Munaaim
30 March 2009, USM, PENANG.

Field Compaction

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