02200 earth( revised )

Division 02 - Site work Section 02200 - Earthwork1 Part 1: General1 01 SummaryThe work covered by this Section consists of providing all tools, labour, equipment and materials, and performing all operations in connection with excavation and backfilling for structures, pavements, and utility service lines related to building construction.

1 01 01 Section Includes

01.0 Preparation of subgrade and subbase/base course for structures.

02.0 Preparation of subgrade and subbase/base course for pavements.

03.0 Preparing of subgrade and subbase/base course for utilities.

04.0 Excavation and backfilling for structures.

05.0 Excavation and backfilling for pavements.

06.0 Excavation and backfilling of pits and trenches for utility lines including buried mechanical and electrical appurtenances.

1 01 04 Related Sections

02500 Paving and surfacing

02660 Water Distribution

02700 Sewerage and Drainage

02900 Landscaping

03300 Cast-In-Place Concrete

1 02 References1 02 01 Applicable Standards

1 02 01 04 USA Standards

1 02 01 04 01 American Society for Testing and Material (ASTM)

ASTM C 88: 90 Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate.

ASTM C 131: 96 Standard Test Method for Resistance to Degradation of Small Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine.

ASTM C 136: 89 Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

ASTM C 535: 84 Standard Test Method for Resistance to degradation of Large Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine.

Earth work | Division 02 - Site work 1

ASTM D 422: 84 Standard Test Method for Particle-Size Analysis of Soils

ASTM D .653: 90 Standard Terminology Relating to Soil, Rock, and Contained Fluids

ASTM D 1140: 92 Standard Test Method for Amount of Material in soils finer than the 0,075 mm Sieve

ASTM D 1194: 87 Standard Test Methods for Bearing Capacity of Soil for Static Load and Spread Footings

ASTM D 1556: 90 Standard Test Method for Density of Soil in Place by the Sand-Cone Method

ASTM D 1557: 91 Standard Test Method for Moisture-Density Relations of Soils and Soil-Aggregate Mixtures using 4,54 kg Rammer and 457 mm Drop

ASTM D 1883: 94 Standard Test Method for California Bearing Ratio of Laboratory-Compacted Soils

ASTM D 2167: 84 Standard Test Method for Density and Unit Weight of Soil in Place by the Rubber Balloon Method

ASTM D 2216: 92 Standard Method for Laboratory Determination of Water (Moisture) Content of Soil, Rock, and Aggregate Mixtures

ASTM D 2419: 79 Standard Test Method for Sand Equivalent Value of Soils and Fine Aggregate

ASTM D 2487: 85 Standard Test Method for Classification of Soils for Engineering Purposes

ASTM D 2488: 84 Standard Practice for Description and Identification of Soils

ASTM D 2922: 91 Standard Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods

ASTM D 3017: 88 Standard Test Method for Water Content of Soil and Rock in Place by Nuclear Methods

ASTM D 4318: 95 Standard Test Method for Liquid Limit, Plastic Limit, and Plasticity Index of Soils

ASTM D 4253: 93 Standard Test Methods for Maximum Index Density of Soils Using a Vibratory Table

ASTM D 4254: 91 Standard Test Methods for Minimum Index Density of Soils and Calculation of Relative Density

1 02 Codes

BS 6031: 81 Code of practice for earthworks

BS 8000-1: 89 Code of practice for excavation and filling


1 03 Definitions1 03 01 Technical Terms

Backfilling - spaces from excavation being refilled will be referred to as backfilling.

Base course - a layer of specified or selected granular material of planned thickness constructed on the or subbase for the purpose of serving one or more functions such as distributing load, providing drainage etc.

Borrow material - material obtained from sources other than from site excavation. This is a reference to the source of supply and not to the characteristics of the material.

California Bearing Ratio (CBR) - the ratio of the force per unit area required to penetrate a soil mass with a circular piston.

Cohesion - that property of material that tends to make its particles stick together.

Cohesionless soil - a soil that when unconfined has little or no strength when air-dried and that has little or no cohesion when submerged. Sand is a cohesionless soil.

Cohesive soil - a soil that when unconfined has considerable strength when air-dried and that has significant cohesion when submerged.

Compaction - the artificial densification of a soil by means of mechanical manipulation (e.g. rolling, tamping, vibration, or other means). The percent compaction is defined as the ratio, in percent, of the as-compacted field dry density to the laboratory maximum dry density.

Excavation - (a) the act of taking out material (e.g. soil); (b) the materials taken out; (c) the cavity remaining after materials have been taken out.

Embankment - a raised earth structure on which the roadway pavement structure (granular subbase/base course, asphalt concrete). is placed. When finally placed and graded it will be act as a subgrade.

Embankment material - see fill material.

Fill material - soil material being placed upon the surface of an existing ground resulting in a higher construction will be referred to as fill. (In road construction often designated as preparation of embankment)

Grading - (a) construction of the earthwork portion of a road. (b) Planning or smoothing the surface of parts of ground by means of motor-driven adjustable steel blade (grader).

Ground surfaces - see subgrade.

Ground water - that parts of the subsurface water that is in the saturated zone.

Natural water (Moisture) content - as determined by ASTM D 2216.


Optimum moisture content - the water content at which a soil can be compacted to a maximum dry unit by a given compaction effort. Determined by the ASTM standard specified to determine the maximum dry density for relative compaction.

Organic clay - a clay with a high organic content.

Peat - a naturally occurring highly organic substance derived from plant materials

Plasticity - the property of a soil or rock which allows it to be deformed beyond the point of recovery without cracking or appreciable volume change.

Plasticity index - the range of water content over which a soil behaves plastically. Numerically, it is the difference between the liquid limit and the plastic limit.

Plastic limit - (a) the water content corresponding to an arbitrary limit between the plastic and the semi-solid states of consistency of a soil. (b) The water content at which a soil will just begin to crumble when rolled into a thread approximately 3,2 mm in diameter.

Relative density- as defined by ASTM D 4253 and D 4254.

Roadbed - the graded portion of a road, upon which the granular subbase/base course is being placed. The top of the subgrade or embankment.

Rock - natural solid mineral matter occurring in large masses or fragments.

Sand equivalent - a measure of the amount of silt or clay contamination in fine aggregate as determined by test.

Soil classification - the arrangement of soils in classes according to their physical properties. There are several systems of soil classifications.

Subbase course - the layer or layers of specified or selected granular material of designated thickness placed on a subgrade to support a granular base course.

Subgrade - the undisturbed soil prepared to support a structure or a pavement system. The subgrade, if not adequate, may be improved by (a) the incorporation of stabilizers, (b) any course or courses of granular material placed on the subgrade or by (c) an asphaltic subbase (roadbase) on the subgrade. If the subgrade is of adequate quality or is improved by one of the methods described under (a) (b) (c), it may serve as subbase course.

Topsoil - surface soil, usually containing organic matter.

1 03 02 Abbreviations

Q.C. Quality Control

1 05 SubmittalsIn compliance with conditions of contract, the following shall be submitted thirty (30) days before earthworks are scheduled to commence.


1 05 04 Quality Control Submittals

01.0 Documented experience of Contractor’s sites engineer(s) and operator(s).

02.0 Records and reports of Contractor’s Source Q.C.

03.0 Records and reports of Contractor’s Field Q.C.

04.0 Records and reports of Contractor’s Internal Q.C.

05.0 Records and reports of External (third-party) Q.C.

06.0 Chemical analysis of earthfill

1 05 06 Other Submittals

01.0 Records and reports of contractor’s major equipment.

1 06 Quality AssuranceSampling, testing and checking procedures shall be recorded on a daily basis (i.e. indicating day, month, year) including corrective actions taken by the Contractor if necessary. Reports and records shall be available for assessment to the Engineer not later than three (3) days after testing and checking. Reports and records shall be established in a manner to ensure traceability. Arrangements shall be made in Contractor’s work schedule and time allowed for testing and checking as indicated.

1 06 01 Qualifications

Contractor’s site engineer responsible for earthwork shall have at least five (5) years of documented experience in this field, shall be familiar with the referenced standards, and shall have successfully completed work similar in material, design, and extent to that work indicated for the project.

Contractor’s operators shall be skilled and familiar with all work and equipment and shall have at least three (3) years of documented experience.

1 06 04 Quality Control

1 06 04 01 Internal Quality Control

Contractor’s Internal Q.C. shall include but not be limited to the following:

Checking supplier’s test certificates to conform compliance with specifications and standards prior to first delivery. Checking supplier’s delivery tickets to comply with supply order .Checking correct storage of fill and backfill and aggregates for subbase and base course at least every week. Checking maintenance of equipment to comply with manufacturer’s instructions at least every month.

Field Q.C. as specified in ref. 3 04.

Source Q.C. as specified in ref. 1 06 04 03.

1 06 04 02 External Quality Control

The Contractor shall employ and pay for a qualified independent geotechnical testing laboratory/Agency which will supervise Quality Control procedures carried out by the Contractor and perform its own sampling, testing and inspection services during earthwork operations in accordance with indicated standards and specifications.


The laboratory/Agency shall be approved by the Engineer.

All checking procedures and tests performed by the laboratory/Agency shall be properly documented and submitted to the Engineer within three (3) days after checking and testing.

1 06 04 03 Source Quality Control

01.0 Testing imported fill in accordance with ASTM D 2487 and ASTM D 1557 for every 500 m3

02.0 Testing subbase and base course material in accordance with ASTM C 136, ASTM C 131, ASTM D 4318, ASTM D 1557, and ASTM C 88 for every 500 m3

1 07 Delivery, Storage, and Handling 1 07 01 Packing and Shipping

For transport only equipment suitable for the location and type of work shall be used and maintained in proper working condition and in charge of skilled and competent operators.

1 07 02 Storage and Protection

Topsoil shall be removed by stripping and carefully stockpiled for re-use unless otherwise specified.

Granular subbase- and base course material shall be stored and handled in a manner that excludes degradation and segregation and avoid contamination.

1 08 Project and Site ConditionsIf a subsurface investigation has been provided to the Contractor, the Owner will not be responsible for interpretations or conclusions drawn from this data by the Contractor.

The Contractor at his option may perform additional investigations or exploratory operations.

The Contractor shall locate existing underground utilities in areas of excavation.

If utilities or structures are indicated to remain in place, adequate means of support and protection during earthwork operations shall be provided.

When uncharted or incorrectly charted piping or other utilities are encountered during excavation, the utility owner shall be consulted immediately for directions.

Damaged utilities or structures shall be repaired to the satisfaction of the utility owner or paid the cost, which may result from any of the Contractor’s operations during the period of contract.

Existing utility serving facilities occupied by the Owner shall not be interrupted during occupied hours, except when permitted in writing by the Engineer and when acceptable temporary utilities have been provided.

1 08 02 Environmental Requirements

Dust on and near work and on and near all off-site borrow areas shall be controlled by use of all means necessary if such dust is caused by the contractor’s operations during performance of the work.

Necessary precautions shall be taken to prevent pollution of ground with fuel, oil, chemicals or other harmful materials.


Before commencing any excavation, trees, plants, shrubs, hedges etc. to be retained, protected and/or preserved shall be identified and marked.

Excavation by hand shall be performed within dripline of trees and plants to be retained.

Root systems shall be protected from dry-out or damage to the greatest extent possible. Exposed roots shall be covered with burlap and maintained in moist condition.


2 Part 2: Products2 01 Materials2 01 01 Material to be Excavated

Unclassified as indicated hereinafter.

2 01 01 01 Classified Excavation

2 01 01 01 01 Top Soil

01.0 The top layer of soil which contains besides organic matters mineral elements in adequate quantity to act as a nutrient medium for vegetation when watered.

2 01 01 01 02 Easily Loosened Excavation

01.0 Easily loosened excavation will be non-cohesive sand; sand-gravel mixes, and gravels containing less than 15% of clay and shall not contain more than 30% (by weight) of stones of gradation exceeding 63 mm and shall not contain any single stone exceeding 0,01 m3 in volume.

2 01 01 01 03 Moderately Loosened Excavation

01.0 Moderately loosened excavation will be mixture of sand, gravel, and clay containing more than 15% (by weight) of clay as well as all cohesive soil with a water content classifying the soil as soft plastic. Stones shall be not exceed portions given under ref. 2 01 01 01 02.

2 01 01 01 04 Excavation Loosened with Difficulties

01.0 Excavation ref. 2 01 01 01 02 and ref. 2 01 01 01 03 containing more than 30% by weight of stones exceeding a gradation of 63 mm up to a volume of 0,01 m3. Also included are all cohesive soils with low moisture content.

2 01 01 01 05 Rock Excavation for Pits and Trenches

01.0 Rock excavation for pits and trenches will be defined as material that cannot be excavated with a track-mounted power excavator.

2 01 01 01 06 Rock Excavation for Open Excavation

01.0 Rock excavation for open excavation will be defined as material that cannot be dislodged and excavated with modern track-mounted, heavy-duty excavating equipment without drilling, blasting, or ripping.

2 01 01 02 Unclassified Excavation

All excavation regardless of type, nature, composition, or conditions of the materials encountered.

2 01 01 03 Unclassified Excavation Except for Rock.

All excavation regardless of type, nature, composition or conditions of the material encountered, except for rock acc. to 2 01 01 01 05 or 2 01 01 01 06.


2 01 02 Excavated Material to be Filled and Backfilled

2 01 02 01 General

Material to be filled and backfilled shall be free from roots, organic matter, trash, debris and other deleterious material and shall be excavated and stockpiled as necessary for the appropriate type of fill and backfill or disposed off site if unsatisfactory or directed by the Engineer.

2 01 02 02 Satisfactory Material (Selected Material)

01.0 Satisfactory soil materials are defined as those complying with ASTM D 2487 soil classification groups GW, GP, GM, SM, SW, SP unless otherwise specified and subject to approval by the Engineer.

2 01 02 03 Unsatisfactory Material

01.0 Unsatisfactory soil materials are defined as those complying with ASTM D 2487 soil classification groups GC, SC, ML, MH, CL, CH, OL, OH, PT unless otherwise specified and subject to approval by the Engineer.

2 01 02 04 Earth Fill

01.0 Soil material free of clay, rock, or gravel larger than 75 mm in any dimension, debris, waste, or any other deleterious material.

2 01 02 05 Earthfill under Landscaped Areas

01.0 The top 50 cm of earth fill below topsoil shall be obtained from a source approved by the Engineer and shall be free of any stones larger than 50 mm in any direction, concrete, bricks, debris, or any other deleterious matter and shall act as a source of plant nutrients and moisture.

02.0 Earth fill shall have a pH-value 6,5 - 8,50 and the total soluble salts content in a saturated soil extract shall not exceed 1,500 ppm. The Exchangeable Sodium Percentage (E.S.P.) shall not be greater than 10%.

03.0 The Contractor shall provide the Engineer with a chemical and physical analysis prior to delivery and filling.

2 01 03 Imported Backfill and Fill

2 01 03 01 General

No imported materials shall be delivered to the site until the proposed source and material tests have been accepted in writing by the Engineer.

Final acceptance will be based on tests made on samples of materials taken from the completed and compacted layer.

If tests indicate that the material does not meet specification requirements, material placement shall be terminated until corrective measures are taken. Material, which does not conform to the specification requirements and is placed in the Work, shall be removed and replaced.


2 01 03 02 Satisfactory Material

See ref. 2 01 02 02

2 01 03 03 Unsatisfactory Material

See ref. 2 01 02 03

2 01 03 04 Earth fill

See ref. 2 01 02 04

2 01 03 05 Earth fill under Landscaped Areas

See ref. 2 01 02 05

2 01 03 06 Granular Subbase Course Material

Material shall consist of hard, durable particles or fragments of stone or gravel, free from dirt, clay balls organic matters, and any other deleterious material, screened or crushed to required size and grading.

Granular subbase course material shall be central plant mixed and shall produce a uniform mixture with the correct moisture content and shall conform to the following physical requirements:

01.0 Sand Equivalent when tested in compliance with ASTM D 2419: min. 25

02.0 Loss of abrasion when tested in compliance with ASTM C 131: max. 50

03.0 Plasticity Index when tested in compliance with ASTM D 4318: max. 10

04.0 Material shall conform to the following gradation:

Sieve Designation Percentage by Weight

75 mm 100

50 mm 90 -100

4,75 mm 35 - 70

0,0075 mm 0 - 15

The grading is based on aggregates of uniform specific gravity and the percentage passing the various sieves are subject to correction by the Engineer when aggregates of varying specific gravity are used.

2 01 03 07 Granular Base Course Material

Material shall consist of hard, durable particles or fragments of stone or gravel, free from dirt, clay balls organic matters, and any other deleterious material, screened or crushed to required size and grading.

Granular base course material shall be central plant mixed and shall produce a uniform mixture with the correct moisture content and shall conform to the following physical requirements:

01.0 Sand Equivalent when tested in compliance with ASTM D 2419: min. 50

02.0 Loss of abrasion when tested in compliance with ASTM C 131: max.50


03.0 Plasticity Index when tested in compliance with ASTM D 4318: max. 6

04.0 Loss of Sodium Sulfate when tested in compliance with ASTM C 88: max. 10%

05.0 Loss of Magnesium Sulfate when tested in compliance with ASTM C 88: max. 12%

06.0 Material shall conform to the following gradation:

Sieve Designation Percentage by Weight

37, 5 mm 100

25 mm 60 - 100

19 mm 55 - 85

4,75 mm 35 - 60

2,00 mm 25 - 50

0,425 mm 15 - 30

0,075 mm 8 - 15

The grading is based on aggregates of uniform specific gravity, and the percentage passing the various sieves are subject to correction by the Engineer when aggregates of varying specific gravities are used.

2 01 03 08 Granular Drainage Fill under Slabs-on-Grade

01.0 Capillary water barrier under slabs-on-grade shall consist of clean crushed nonporous rock, crushed or uncrushed gravel. The maximum particle size shall be 37,5 mm and no more then 2% (by weight) shall pass the 4,75 mm size sieve.


3 Part 3: Execution3 01 General ExaminationAll natural ground surfaces upon which foundations and embankments are to be constructed shall be checked for unsuitable material.

Areas where unsuitable material has been found and removed shall be approved by the Engineer prior to placing concrete or any filling or backfilling.

3 02 General PreparationStakes, control survey points, and benchmarks shall be established and maintained during construction by the Contractor.

Positions and levels of existing utility lines shall be located and marked according to information obtained from utility owners.

3 03 Excavation, Filling, Backfilling and Compaction3 03 01 General

3 03 01 01 Excavation

Contractor’s schedule of work shall ensure that no excavation is left in an exposed condition for a period of more than thirty (30) days unless otherwise specified or directed by the Engineer

Excavation shall be performed to lines, levels, dimensions, and depths indicated on Drawings and/or as directed by the Engineer

Excavation shall be extended to a sufficient distance from walls and footings to allow for placing and removal of forms, installation of services, and for inspections, except where concrete is authorized to be placed directly against excavated surfaces.

All suitable and acceptable excavated material shall be used as backfill, fill or subgrade preparation and shall be stockpiled at locations approved by the Engineer. Stockpiles shall be placed, graded and shaped for proper drainage.

Material which is unnecessarily wasted, disposed off, or otherwise misused shall be replaced at Contractor’s expense.

Sides of excavations shall be sloped as necessary to protect workmen. Where sloping is not possible because of space restrictions or stability of material excavated, sides shall be shored and braced.

Sides and slopes of excavation shall be maintained in safe condition until completion of backfilling regardless of time period excavations will be open.

On rock surfaces, only excavation methods that will leave the bottom of an excavation in a solid and unshattered condition shall be used.

Sloped surfaces shall be cut into rough steps or benches to provide a satisfactory bond.

Overdepth excavation of unsatisfactory material below lines and levels indicated shall be as directed by Engineer.


3 03 01 02 Preparation of Subgrade/Ground Surface Preparation

All debris, unsatisfactory soil material, and other deleterious material shall be removed from the ground surface prior to placing any fill, backfill or concrete. When the existing ground surface has a density less than specified hereinafter for particular areas, the ground surface shall be scarified, pulverized, moisture-conditioned to optimum moisture content and compacted to required depth and percentage of maximum density as indicated.

When the subgrade is part fill and part excavation or natural ground, the excavated or natural ground portion shall be scarified to a depth of 300 mm and compacted as specified for the adjacent fill.

Where soil has been softened or eroded by flooding or during unfavorable weather, all damaged areas shall be removed, backfilled, filled, and compacted.

Subgrade outside building lines shall be graded within limits of construction between points where elevations are indicated or between such points and existing grades.

Finished grading shall be free from irregular surface changes and within the following tolerances:

01.0 unpaved and landscaped areas to receive topsoil shall be finished within not more than 30 mm above or below required subgrade elevations.

02.0 under slabs on grade, finished grading shall be smooth and even, free of voids, compacted as specified, with finished surface not more than 13 mm above or below required subgrade elevation.

03.0 under pavements, finished grading shall be graded to line and cross-section, with finished surface not more than 30 mm above or below required subgrade elevation. Surface smoothness of finished surface shall be 13 mm in 3 m.

3 03 01 03 Backfilling and Filling

Tentative acceptance of the source of delivery of imported fill and backfill will be based on an inspection of the source by the Engineer and certified test results submitted by the contractor.

Backfill and fill shall not be placed, spread and compacted during unfavorable weather conditions. Operations shall not begin until moisture content is satisfactory and approved by the Engineer.

Backfill and fill shall be placed in layers not more than 200 mm in compacted thickness for material compacted by heavy compaction equipment and not more than 100 mm for areas where mechanical tampers are used unless otherwise specified.

Surfaces to receive fill shall be scarified to a depth of at least 150-mm before the filling operation begins.

Backfill and fill shall be placed to required elevation, for each area classification listed below, using materials specified in Part 2: Products of this Section as follows:

01.0 under unpaved and landscaped areas earth fill ref. 2 01 02 04.

02.0 under landscaped areas,

* 02.1 for the top 50 cm earth fill ref. 2 01 02 04 if suitable.

* 02.2 for the top 50 cm ref. 2 01 03 05


03.0 under paved areas,

* 03.1 satisfactory material ref. 2 01 02 02.

* 03.2 granular subbase/base course material ref. 2 01 03 06/2 01 03 07.

04.0 under structural elements, concrete of same class as structure.

05.0 under slabs on grade,

* 05.1 satisfactory material ref. 2 01 02 02.

* 05.2 granular drainage fill ref. 2 01 03 08 of indicated thickness.

3 03 01 04 Compaction

Where layers of soil material have to be moisture conditioned before compaction, water shall be applied in minimum quantities as necessary to prevent free water from appearing on surface during or subsequent to compaction operations.

When fill and backfill, embankment, or subgrade has been tested and approved, the Contractor shall proceed with construction. However, if placement of concrete or the next layer is delayed, compaction testing shall be repeated. If test results indicate that the layer does not meet specified density, regardless of previous test results, the Contractor shall scarify and recompact the material to meet the required density.

Each layer of backfill and fill shall be compacted, providing minimum percentage of maximum density specified for each area classification as listed below in accordance with ASTM D 1557 unless otherwise specified:

01.0 Under slabs on grade and pavement, top 300 mm and each layer of backfill or fill at 95% maximum density.

02.0 Under unpaved and landscaped areas, each layer of backfill or fill at 90% maximum density except top 100 mm for landscaped areas.

3 03 01 05 Equipment

Compaction equipment shall be of suitable type and adequate to obtain the densities specified and shall be dedicated for the sole purpose of compaction. Material hauling or placing equipment shall not be considered as compaction equipment.

Where rollers cannot operate, compaction shall be obtained by using mechanical tampers. However, hand operated equipment shall be capable of achieving the specified densities.

Compaction equipment shall be operated in strict accordance with manufacturer’s instructions and recommendations. If inadequate densities are obtained, larger and /or different types shall be provided by the Contractor.

Hand tampers shall weigh not less than nine (9) kilograms and have a tamping face not larger than 225 cm2.

Equipment for applying water shall be of a type and quality adequate for the work and shall be equipped with a distributor bar or other approved device to assure uniform application.


All equipment shall be maintained in such a condition that it will deliver manufacturer’s rated results.

3 03 01 06 Disposal

Excavation that exceeds the volume that is required as backfill, fill, or subgrade preparation shall be disposed off site.

No material shall be disposed off in a manner, which impairs adjacent properties.

3 03 02 Excavation, Backfilling and Compaction for Structures


The ground surface of excavation shall not be disturbed.

Excavation to final grade shall be made by hand just before concrete is placed. The ground surface shall be trimmed to leave a solid base to receive other work.

Excavation shall be to elevations and dimensions within a tolerance of 30 mm.

Overdepth excavation below foundations as directed by the Engineer shall be backfilled with the same class of concrete designated for the foundation and shall be placed monolithically with the foundation. Unauthorized over excavation shall be backfilled as stated above without additional payment.

3 03 02 02 Backfilling

Backfill shall not be placed against new structures until they have developed sufficient strength to withstand the filling operation.

Backfill shall be spread equally around all sides of the structure.


See ref. 3 03 01 04

3 03 03 Excavation, Backfilling and Compaction for Utility Lines


Trenches shall be excavated to uniform width to provide ample working space and a minimum of 20 cm clearance on both sides of pipes and conduits.

Trenches and conduits shall be excavated to depth as indicated or required to establish indicated slopes, invert elevations, and to support bottom of pipe or conduit on undisturbed soil.

Excavation shall be to elevations and dimensions within a tolerance of 30 mm.

Unless otherwise specified or directed by the Engineer, a strip of minimum 600 mm width shall be kept free from any loads at the upper edge of the trench.

Where rock is encountered, trenches shall be excavated 15 cm below required elevation and backfilled with a 15 cm layer of base course material ref. 2 01 03 07 prior to installation of pipe.

3 03 03 02 Backfilling

01.0 Backfilling of trenches shall only start when inspection, testing, approval, and recording of locations of utility lines have been performed.


02.0 After pipes have been bedded, satisfactory material ref. 2 01 02 02 shall be backfilled up to an elevation of 300 mm above top of the pipe and compacted by mechanical tampers, providing minimum percentage of maximum density specified for each area classification as listed under ref. 3 03 01 04.

03.0 Then, trenches shall be backfilled in layers to required elevation, for each area classification as listed under ref. 3 03 01 03.

04.0 For correction of unauthorized or overdepth excavation base course material ref. 2 01 03 07 shall be used.

05.0 Where pipes and conduits pass under structural elements not deeper than one (1) m, trenches shall be backfilled with concrete unless otherwise indicated.

06.0 For pipe bedding and concrete haunching see relevant Sections


See ref. 3 03 01 04

3 03 04 Excavation, Backfilling and Compaction for Pavement


See ref. 3 03 01 01

3 03 04 02 Fill and Backfilling

Each layer of embankment shall be uniform as to material, density and moisture content prior to beginning compaction.

Top 300 mm of subgrade shall be constructed of satisfactory material ref. 2 01 02 02.

Stones or rock fragments larger than 75 mm in any direction will not be permitted in the top 150 mm of subgrade.

When embankments are to be placed on natural slopes steeper than 3 to 1, horizontal benches shall be constructed into the slope with sufficient depth to accommodate earthwork operations.

3 03 04 03 Granular Subbase/Base Course

No subbase or base course shall be placed on the subgrade until the subgrade has been approved by the Engineer.

Before starting subbase or base course operations, the Engineer may direct the contractor to construct a trial length to determine adequacy of contractor’s equipment, loose depth necessary to obtain the compacted layer thickness, correct moisture content, and number of passes required to obtain the specified density.

Subbase and base course shall be spread and placed to required thickness with self-propelled spreading equipment which will give the required uniform layer and specified tolerances after compaction.

Immediately after spreading, the course shall be compacted to specified density. Both static and vibratory rollers are allowed for compacting.


Any moisture loss during spreading finished grading and compaction shall be replaced with applications of water to maintain the proper moisture content.

Edges and end slopes shall be trimmed to conform to lines, levels and dimensions shown on the drawings or otherwise specified.

After final compaction, the surface shall be dampened and trimmed, either placing the trimmed material into the next lane or wasting it on the shoulder. Then a final pass shall be made with the roller.


01.0 Cohesive subgrades shall be compacted to minimum 95% density for the top 300 mm and minimum 90% for all fill areas below the top 300 mm when tested in accordance with ASTM D 1557. The water content for compaction of cohesive soils shall be selected to provide the highest remolded strength consistent with expansion considerations.

02.0 Cohesionless subgrades shall be compacted to 100% density for the top 300 mm and minimum 95% below this for all fill areas when tested in accordance with ASTM D 1557.

3 03 05 Excavation, Filling, Backfilling and Compaction for Landscaped or Unpaved Areas


See ref. 3 03 01 01

3 03 05 02 Backfilling and Filling

01.0 Areas to receive topsoil in which the top layer of soil material has become compacted by hauling or other operations and activities of the contractor, the soil shall be scarified to a depth of at least 100 mm and finally graded to required elevations.


See ref. 3 03 01 04.

3 03 06 Dewatering

All excavation shall be performed so that the area of the site and the area surrounding the site and affecting operations at the site will be continuously drained. Water shall not be permitted to accumulate in crawl-space areas and the excavation. The excavations shall be drained by pumping or other satisfactory methods.

At all time during construction, pumps, well points, sumps, suction and discharge lines, and other dewatering system components necessary to convey water away from excavation shall be provided and maintained by the contractor.

3 04 Field Quality ControlThe following checks and tests will be required unless otherwise specified:


3 04 01 For Backfill and Fill

01.0 Visual inspection of backfill prior to placing to determine unsatisfactory material.

02.0 Visual inspection of each delivery of imported material prior to placing to determine unsatisfactory material.

03.0 Checking supplier’s delivery ticket of each delivery for completeness and compliance with supply order for imported material.

04.0 One test for classification of soil according to ASTM D 2487 for every 1000 m2 for every completed layer.

05.0 One test of field density according to ASTM D 1556 or ASTM D 2167 as appropriate for every 500 m2 for every completed layer but not less than one test per day for each type of material placed.

3 04 02 For Subbase and Base Course

01.0 Visual Inspection of each delivery prior to placing to determine unsatisfactory material.

02.0 Checking supplier’s delivery ticket of each delivery for completeness and compliance with supply order and specification

03.0 One test of gradation of material for each 500 m2 completed subbase/base course in accordance with ASTM C 136 or AASHTO T 27.

04.0 One test of field density according to ASTM D 1556 or ASTM D 2167 as appropriate for each 500 m2 for every completed layer but not less than one test per day.

05.0 One test to determine the plasticity index according to ASTM D 4318 for every 500 m2 completed layer.

06.0 Thickness of layer for every 500 m2 for each completed layer to conform with drawings and specification.

3 04 03 For Subgrade

01.0 Field density according to ASTM D 1556 or ASTM D 2167 as appropriate for every 500 m2.

02.0 Bearing capacity of soil on which foundations will be placed, for each strata at least one test in accordance with ASTM D 1194.

03.0 Visual inspection of each subgrade and comparison with related tested subgrade. All required tests may be performed in conjunction with a laboratory/Agency employed by the Contractor and approved by the Engineer.

3 07 Protection The Contractor shall maintain all backfilling and filling at the specified levels and ensure that the surfaces are in a satisfactory condition during Contract. Any settlement after backfilling shall be corrected with the


same class of material. If such settlements indicate -in the opinion of the Engineer- poor backfilling, the Contractor shall re-excavate to the required depth and backfill and fill again to required standards and specifications.

During excavation and filling, the Contractor shall protect all work from erosion.

Where completed compacted areas are disturbed by subsequent construction operations or adverse weather; the surface shall be scarified, reshaped and compacted to required density prior to further construction.

Subbase and base course shall be protected from traffic, overload vehicles, other Contractor’s operations and other detriments.


4 Part 4: Method of Measurement 4 01 GeneralThe quantities to be paid will be measured in place or will be determined from drawings as directed by the Engineer.

Excavation and backfill are measured geometrically according to the dimensions on the drawings. Any excess excavation and back filling are not considered as part of measurement.

Excavation will be net as the void which is to be occupied by the permanent construction with no allowance for working space or other additions.

The volume of rock excavation will include the minimum undercutting of subgrade as specified.

The volume of unsuitable material excavated will be measured separately from other excavation work.

Disposal of material arising from excavation will be measured as equal as to the volume measured as excavation or as part thereof.

4 02 Units of MeasurementExcavation will be measured in cubic meter (m3) stating the starting level and indicating the depth in successive stages.

Trench excavation will be measured in cubic meter (m3).

Disposal of material will be measured by cubic meter (m3).

Filling will be measured by cubic meter (m3) as equal to the void to be filled.

Subbase and base course will be measured in cubic meter (m3) computed from each typical section as shown on the drawings and multiplied by the measured length.


5 Part 5: Basis of Payment5 01 GeneralPayment will be in full compensation for excavation, hauling and placing materials, for compaction including all labour, plant, equipment, tools, traffic control, certifying and testing, quality assurance, and all other operations to perform the work, including but not limited to the following ancillary works. (Ref. 5 02)

Material, which is unnecessarily wasted, disposed off site, or otherwise misused, shall be placed at Contractor’s expense.

No payment will be made for quantities resulting from oversized or unauthorized excavation or any other unauthorized operation.

Drilling, blasting, or ripping performed to increase production and not necessary to permit excavation of material encountered will not be classified and paid for as rock.

Material or work, which does not conform to specification requirements, shall be removed and replaced on Contractor’s expense.

5 02 Ancillary Works to be Included in the Unit Price Rates01.0 Excavation in all kinds of soil, unless otherwise noticed.

02.0 Holding and supporting sides of excavation.

03.0 Removing existing foundation.

04.0 Disposal of excess material in authorized tips.

05.0 Level and compact bottom of excavation.

06.0 Subgrade preparation will be considered as part of excavation and not to be paid for as an extra.

07.0 Contracting an independent laboratory/Agency to perform the external quality control.

08.0 Investigations and exploratory operations performed by the Contractor.

09.0 Stockpiling any excavation material for later re-use on site.

10.0 Dewatering the site and areas adjacent to the site.

11.0 Plain concrete arises due to excess excavation depth.

12.0 All tests made on compacted soil.

13.0 Manual and mechanical compaction and watering.


6 Annex: Tables and Figures6 01 Tables6 01 01 Angles of slope

Table 1: Guidance on steepest angles of slope for different soils

Type of ground Angle of slope from theHorizontal as shown in

Figure 1 and 2Dry site Degrees

Wet site degrees

Clay:soft 1.2m to 3m depth of cutClay:firm 1.2m to 3m depth of cutClay:stiff 1.2m to 3m

Peat:soft non-fibrous

Peat:firm non-fibrous

Peat:firm fibrous

Peat:stiff fibrous

30 to 45

35 to 45

40 to 45

10 to 20

20 to 25

25 to 35

NOTE 1. Approximate equivalents of the angle given in this table, expressed as the relationship between the rise of a slope and the horizontal measurements are:

5 deg=1 in 11 20 deg=1 in 2.8 35 deg=1 in 1.4deg=1 in 5.8 25 deg=1 in 2.2 40 deg=1 in 1.2

15 deg=1 in 3.7 30 deg=1 in 1.7 45 deg=1 in 1

NOTE 2. The angles of slope are guide figures and are subject to:

(a) Temporary conditions (usually not more than 14 days).(b) experience on the site;(c) Water seepage affecting the stability of slopes. Ground water

flow towards the slope may be intercepted to prevent it entering the trench by the use of cut off drains or Lowered by rising well points.

The erosion and slumping of sand and silt slopes can be minimized by weighting with a layer of well-graded

Sand and gravel to act as a filter.


6 02 Figures

Fig. 1: Battered Trench


Fig. 2: Structure Excavation


Fig. 3: Edges of Excavation


Fig. 4: Barrier for vehicles


Fig. 5: Trench Excavation


02200 earth( revised )

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