field compaction

RET 565BUILDING TECHNOLOGIES AND INFRASTRUCTURES

FIELD COMPACTIONFIELD COMPACTION

Prepared By: 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

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-TYPES OF COMPACTION

COMPACTION- RISK

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

Characteristics Cohesive soils are dense and tightly bound together by molecularattraction. 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 soilsGranular soils range in particle size from .003" to .08" (sand) and .08" to 1.0" (fine to medium gravel). Granular soils are known for their water-draining properties.

CharacteristicsSand 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

METHOD-ROAD ONLY

BASIC PRINCIPLES OF FIELD COMPACTION


1) Survey: Existing ground level, setting out of centre lines and road reserved, cut and fill area, invert level and direction of water path.

2) Submission of any approvals required. Temporary road diversion if required. Submit localized environmental mitigation measures.

3) Routes of transportation, temporary access, modes of transport, frequency and mode of filling identified.

4) Provide adequate plant and equipment to carry out all activities.

5) Where crossing of watercourses, install temporary steel pipe to divert water flow.

6) Use machinery fitted with silencer to reduce noise level if necessary.

METHOD-ROAD ONLY



1) Setting out of contract limit, ROW and centre line carried out by licensed surveyor.

2) Approval from local authorities on machineries to be used.

3) Determine status of land acquisition and confirmed.

4) Liaise with local authorities and give notice to vacate buildings on TOL land prior to commence activity.

5) Public services and utilities identified and protected where necessary.

6) Determine the status of termination of connection and temporary

5) Secure, establish and make a proper temporary access.

6) Provide sufficient temporary earth drain where necessary to avoid water ponding.

7) Confine the demolition within site, control dust and noise pollution arising from the work activity.

METHOD-ROAD ONLY



1) Identify topsoil's stockpile area outside the road reserve within ROW.

2) Maintain public access and provide alternative route where/ when necessary.

3) Use suitable machinery to remove an average depth of at least 100mm below existing ground level.

4) Liaise with local authorities and give notice to vacate buildings on TOL land prior to commence activity.

5) Control activities to within the areas (zoning and scheduling) to avoid unnecessary prolonged exposure, to decrease siltation in water courses and/ or dust in dry condition.

METHOD-ROAD ONLY



1) Samples of suitable imported backfill material shall be subjected to the following tests ;

i) Atterberg's Limit for Plastic Limit, 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.

METHOD-ROAD ONLY



1) The purpose of trial embankment fill is to confirm the degree of compaction required in relation to loose depth and compaction equipment for various types of soil and machinery used.

2) The specified machinery will be directed to carry out specified number of passes required on different loose thickness of fill material followed by In Situ Field Density Test.

3) Test Result will be recorded and the test repeated for a different type of compaction equipment and imported materials.

5) All these datas will be plotted and analyzed for the relationship between loose depth thickness and number of passes required on different machinery used.

METHOD-ROAD ONLY



1) Slopes, levels, and other control pegs are available at cut areas to obtain the required design profile.

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

METHOD-ROAD ONLY



1) Determine range of moisture content to achieve the degree of compaction.

2) Wet materials shall be spread and left 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.

METHOD-ROAD ONLY



1) Carry out soil investigation by using Mackintosh Probe to the required depth/ penetration per blow.

2) Carry out setting out and joint survey to demarcate limits and depth of unsuitable material.

3) Carry out trial pits to determine soil classification using Alterberg 's limit or by cone penetrometer test to confirm the recommended depth below the original ground level and method of backfill used.

5) In presence of access pore water pressure, dewatering continuously and provide proper drainage to prevent ingress of surface water runoff.

6) Excavate the unsuitable material to the extent of required depth and profiles.

METHOD-ROAD ONLY



1) Upon completion of joint measurement for the excavation area, carry out backfilling with granular material (sand).

2) Sewn geotextile will be laid flat on the intended work area (if required).

3) If found that ground water leveldevelop above the 500mm sand thickness. Further sand fill to attain 300mm clearance above standing water.

4) Where ground water level is high, it would be expected that seepage would effect the first layer of earth filling. Place a slightly thicker first layer of sand fill.

5) When backfilling at the edge of ground having slope, cut the slope edge into benches to approximately the same as the fill level to obtain uniform compaction over the fill area.

METHOD-ROAD ONLY


� 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 (1)� Rock Blasting� Rock Filled Embankment� Sub Grade

1) Surface preparation to receive layer of fill. Area to be filled cleared from existing structures and services.

2) Control deposition of earth fill, spread, levelled and compacted in layers less than 300mm loose depth using suitable plants and equipments.

3) Form embankment with suitable cross fall to avoid water ponding. While if the surface is too dry, provide water tanker to control the moisture.

4) Loose fill levels are controlled by flagged top levels of fill to ensure compacted fill thickness is achieved

5) Secure a team for Field Density Test to determine the degree of compaction at any time. Field Density Test shall be done using Sand Replacement Method (in accordance with BS1377: Part 2) or by Core Cutter Method. If the density is below the requirements, further compaction will be carried out.

METHOD-ROAD ONLY


� 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 (2) � Rock Blasting� Rock Filled Embankment� Sub Grade

If the moisture content is high, fill materials

will be scarified, dried and compacted for retesting.

If FDT passed - proceed to the next layer.

If FDT failed - proceed with ratification and retest.

6) In presence of water ponding, remove and scarify the top 100mm and blend it with the new embankment fill, compact and continue with normal backfilling.

7) If backfilling on slope against existing embankment or on ground with existing slope, excavate the foundation in horizontal and vertical to form contiguous width in benches and use the excavated material as fill material for embankment.

5) Maintain existing and new drainage to ensure surface water run-off in proper discharge.

6) When backfilling at edge of embankment, each compacted layer to be extended by 600mm and trim back to the required slope angle.

METHOD-ROAD ONLY



1) Carry out joint survey with consultant to determine the extent of rock formation.

2) Request permission from relevant 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.

METHOD-ROAD ONLY



1) Rock shall be defined as a material that cannot be ripped by a drawnripper having weight of 20 tonnes with a nett horse power not less than 200 brake.

2) Rock fill embankment shall not more than 400mm so that it can be deposited in horizontal layers, each not exceeding 500mm in compacted depth and extending over the full width of the embankment.

3) Spread, level and compact using crawler tractor weighing not less than 15 tonnes.

4) Fill void using fine graded material and through blind uniformly before proceed to the next layer.

5) Place uniformly graded material ( 6mm - 150mm ) at least 300mm thick between the top 300mm of sub grade and the rock fill.

6) Fill any void with blinded and regulate the rock surface to formation levels

METHOD-ROAD ONLY



1) Lay, spread and compact uniformlythe top 300mm and carry out FDT 95% maximum dry density (for cohesive soil) or 100% maximum dry density (for cohesiveness soil) relative to Proctor Test (4.5 kg rammer) as per BS 1377.

2) If the compaction achieve below the requirement, scarify the surface, leave it to dry recompact and retest. If it is still unpractical, remove the top sub grade layer and replace with suitable material and compact to the required density.

3) Tolerance for sub grade finish layer shall be within + 10mm to 30mm of the required gradient and level. Sub base

Sub grade

Binder Course

Wearing Course

Sand Blanding

Prime Coat

Tack Coat

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 PlatesIn 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 "spot" compaction.


RollersRollers 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:

COMPACTION & CLIMATEExample 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: CONCLUSIONSoil 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 Munaaim30 March 2009, USM, PENANG.

field compaction

Technology

compactiondefinition

density of soil

compactionsoil types

type of soil

soil settlement

soil orasphalt

particular soil

basic types of soil