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SECTION TABLE OF CONTENTS

DIVISION 31 - EARTHWORK

SECTION 31 00 00

EARTHWORK

PART 1 GENERAL

1.1 CRITERIA FOR BIDDING

1.2 REFERENCES

1.3 DEFINITIONS

1.3.1 Satisfactory Materials

1.3.1.1 Satisfactory Materials for Engineered Fill (0 to 1.1 meter depth)

1.3.1.2 Satisfactory Materials for Engineered Fill (below 1.1 meter depth)

1.3.2 Unsatisfactory Materials

1.3.3 Cohesionless and Cohesive Materials

1.3.4 Degree of Compaction

1.3.5 Topsoil

1.3.6 Hard/Unyielding Materials

1.3.7 Rock

1.3.8 Unstable Material

1.3.9 Select Granular Material

1.3.9.1 General Requirements

1.3.9.2 California Bearing Ratio Values

1.3.10 Initial Backfill Material

1.3.11 Expansive Soils

1.3.12 Nonfrost Susceptible (NFS) Material

1.3.13 Pile Supported Structure

1.4 SYSTEM DESCRIPTION

1.4.1 Classification of Excavation

1.4.2 Blasting

1.4.3 Dewatering Work Plan

1.5 SUBMITTALS

PART 2 PRODUCTS

2.1 REQUIREMENTS FOR OFFSITE SOILS

2.2 BURIED WARNING AND IDENTIFICATION TAPE

2.2.1 Warning Tape for Metallic Piping

2.2.2 Detectable Warning Tape for Non-Metallic Piping

2.3 DETECTION WIRE FOR NON-METALLIC PIPING

2.4 CAPILLARY WATER BARRIER

2.5 PIPE CASING

2.5.1 Casing Pipe

2.5.2 Casing Spacers and End Seals

2.6 STRUCTURAL BACKFILL

PART 3 EXECUTION

3.1 STRIPPING OF TOPSOIL

3.2 GENERAL EXCAVATION

3.2.1 Ditches, Gutters, and Channel Changes

SECTION 31 00 00 Page 1

3.2.2 Drainage Structures

3.2.3 Drainage

3.2.4 Dewatering

3.2.5 Trench Excavation Requirements

3.2.5.1 Bottom Preparation

3.2.5.2 Removal of Unyielding Material

3.2.5.3 Removal of Unstable Material

3.2.5.4 Excavation for Appurtenances

3.2.5.5 Jacking, Boring, and Tunneling

3.2.6 Underground Utilities

3.2.7 Structural Excavation

3.3 SELECTION OF BORROW MATERIAL

3.4 OPENING AND DRAINAGE OF EXCAVATION AND BORROW PITS

3.5 SHORING

3.5.1 General Requirements

3.5.2 Geotechnical Engineer

3.6 GRADING AREAS

3.7 FINAL GRADE OF SURFACES TO SUPPORT CONCRETE

3.8 GROUND SURFACE PREPARATION

3.8.1 General Requirements

3.8.2 Frozen Material

3.9 UTILIZATION OF EXCAVATED MATERIALS

3.10 BURIED TAPE AND DETECTION WIRE

3.10.1 Buried Warning and Identification Tape

3.10.2 Buried Detection Wire

3.11 BACKFILLING AND COMPACTION

3.11.1 Engineered Fill Compaction Requirements

3.11.2 Trench Backfill

3.11.2.1 Replacement of Unyielding Material

3.11.2.2 Replacement of Unstable Material

3.11.2.3 Bedding and Initial Backfill

3.11.2.4 Final Backfill

3.11.3 Backfill for Appurtenances

3.12 SPECIAL REQUIREMENTS

3.12.1 Water Lines

3.12.2 Sanitary Sewer Lines

3.12.3 Storm Drainage Lines

3.12.4 Electrical Distribution System

3.12.5 Heat Distribution System

3.12.6 Pipeline Casing

3.12.6.1 Bore Holes

3.12.6.2 Cleaning

3.12.6.3 Casing Spacers and End Seals

3.13 EMBANKMENTS

3.13.1 Earth Embankments

3.13.2 Rock Embankments

3.14 SUBGRADE PREPARATION

3.14.1 Construction

3.14.2 Compaction

3.14.2.1 Subgrade for Pavements

3.14.2.2 Subgrade for Shoulders

3.15 Structural Backfill Material

3.16 SHOULDER CONSTRUCTION

3.17 FINISHING

3.17.1 Subgrade and Embankments

3.17.2 Capillary Water Barrier

3.17.3 Grading Around Structures

3.18 PLACING TOPSOIL

3.19 TESTING

SECTION 31 00 00 Page 2

3.19.1 Fill and Backfill Material Gradation

3.19.2 In-Place Densities

3.19.3 Moisture Contents

3.19.4 Optimum Moisture and Laboratory Maximum Density

3.19.5 Tolerance Tests for Subgrades

3.19.6 Displacement of Sewers

3.20 DISPOSITION OF SURPLUS MATERIAL

-- End of Section Table of Contents --

SECTION 31 00 00 Page 3

SECTION 31 00 00

EARTHWORK

PART 1 GENERAL

1.1 CRITERIA FOR BIDDING

Base bids on the following criteria:

a. Surface elevations are as indicated.

b. Pipes or other artificial obstructions, except those indicated, will not be encountered.

c. Ground water elevations indicated by the boring log were those existing at the time subsurface investigations were made and do not necessarily represent ground water elevation at the time of construction.

d. Material character is indicated by the boring logs.

1.2 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS

(AASHTO)

AASHTO T 180 (2010) Standard Method of Test for Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm (18-in.) Drop

AASHTO T 224 (2010) Standard Method of Test for Correction for Coarse Particles in the Soil Compaction Test

AMERICAN WELDING SOCIETY (AWS)

AWS D1.1/D1.1M (2010; Errata 2010) Structural Welding Code - Steel

ASTM INTERNATIONAL (ASTM)

ASTM A139/A139M (2004; R 2010) Standard Specification for Electric-Fusion (ARC)-Welded Steel Pipe (NPS 4 and over)

ASTM A252 (2010) Standard Specification for Welded and Seamless Steel Pipe Piles

ASTM C136 (2006) Standard Test Method for Sieve

SECTION 31 00 00 Page 4

Analysis of Fine and Coarse Aggregates

ASTM C33/C33M (2011a) Standard Specification for Concrete Aggregates

ASTM D1140 (2000; R 2006) Amount of Material in Soils Finer than the No. 200 (75-micrometer) Sieve

ASTM D1556 (2007) Density and Unit Weight of Soil in Place by the Sand-Cone Method

ASTM D1557 (2009) Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3) (2700 kN-m/m3)

ASTM D1883 (2007e2) CBR (California Bearing Ratio) of Laboratory-Compacted Soils

ASTM D2167 (2008) Density and Unit Weight of Soil in Place by the Rubber Balloon Method

ASTM D2434 (1968; R 2006) Permeability of Granular Soils (Constant Head)

ASTM D2487 (2011) Soils for Engineering Purposes (Unified Soil Classification System)

ASTM D2937 (2010) Density of Soil in Place by the Drive-Cylinder Method

ASTM D422 (1963; R 2007) Particle-Size Analysis of Soils

ASTM D4318 (2010) Liquid Limit, Plastic Limit, and Plasticity Index of Soils

ASTM D698 (2007e1) Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/cu. ft. (600 kN-m/cu. m.))

KOREAN INDUSTRIAL STANDARDS (KS)

KS F 2302 (2002; 2007) Test Method for Particle Size Distribution of Soils

KS F 2303 (2000; 2010) Test Method for Liquid Limit and Plastic Limit of Soils

KS F 2309 (2009) Testing Method for Amount of Material in Passing Standard Sieve 75Mm in Soils

KS F 2311 (2001; 2006) Test Method for Soil Density By The Sand Replacement Method

KS F 2312 (2001; 2006) Test Method for Soil

SECTION 31 00 00 Page 5

Compaction Using A Rammer

KS F 2320 (2000; 2010) Testing Method for The California Bearing Ratio of Soils

KS F 2322 (2000; 2010) Test Methods for Permeability of Saturated Soils

KS F 2324 (2006) Method of Classification of Soils for Engineering Purposes

KS F 2347 (2007) Testing Method for Density of Soil in Place By The Rubber-Ballon Method

KS F 2526 (2007) Concrete Aggregate

U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA)

EPA SW-846.3-3 (1999, Third Edition, Update III-A) Test Methods for Evaluating Solid Waste:

Physical/Chemical Methods

1.3 DEFINITIONS

1.3.1 Satisfactory Materials

Satisfactory materials comprise any materials classified by ASTM D2487 as

GW, GP, GM, GP-GM, GW-GM, GC, GP-GC, GM-GC, SW, SP, SM, SW-SM, SC, SW-SC,

SP-SM, and SP-SC, . Satisfactory materials for grading comprise stones less than 200 mm (8 inches), except for fill material for pavements and railroads which comprise stones less than 75 mm (3 inches) in any dimension.

1.3.1.1 Satisfactory Materials for Engineered Fill (0 to 1.1 meter depth)

The upper 1.1 meters of engineered fill shall consists of satisfactory materials conforming to Unified Soil Classifications GW, GP, GM, GC, SW, SP, SM and SC, classified by ASTM D2487 or KS F 2324. The material shall be free from trash, waste, debris, chemical contamination, roots, and other organic matter, or stones larger than 75 mm (3 inches) in any dimensions.

The amount of material by weight retained on the 1-inch sieve shall be limited to no more than 15%. In addition, when more than 25% of the satisfactory material passes the No. 40 sieve, that portion passing the No.

40 sieve shall have a plasticity index not greater than 10 as determined by ASTM D4318 or KS F 2303.

1.3.1.2 Satisfactory Materials for Engineered Fill (below 1.1 meter depth)

The engineered fill layers below a depth of 1.1 meters shall consists of satisfactory materials conforming to Unified Soil Classifications GW, GP, GM, GC, SW, SP, SM, SC, ML and CL, classified by ASTM D2487 or KS F 2324.

The material shall be free from trash, waste, debris, chemical contamination, roots, and other organic matter, or rocks larger than 150 mm (6 inches) in any dimensions. The amount of material by weight retained on the 1-inch sieve shall be limited to no more than 20%. In addition, when more than 25% of the satisfactory material passes the No. 40 sieve, that portion passing the No. 40 sieve shall have a plasticity index not greater than 30 as determined by ASTM D4318 or KS F 2303.

SECTION 31 00 00 Page 6

1.3.2 Unsatisfactory Materials

Materials which do not comply with the requirements for satisfactory materials are unsatisfactory. Unsatisfactory materials also include man-made fills; trash; refuse; backfills from previous construction; and material classified as satisfactory which contains root and other organic matter or frozen material. Notify the Contracting Officer when encountering any contaminated materials.

1.3.3 Cohesionless and Cohesive Materials

Cohesionless materials include materials classified in ASTM D2487 or KS F 2324 as GW, GP, SW, and SP. Cohesive materials include materials classified as GC, SC, ML, CL, MH, and CH. Materials classified as GM and SM will be identified as cohesionless only when the fines are nonplastic.

Perform testing, required for classifying materials, in accordance with ASTM D4318 or KS F 2303;, ASTM C136; ASTM D422 or KS F 2302; and ASTM D1140 or KS F 2309.

1.3.4 Degree of Compaction

Degree of compaction required, except as noted in the second sentence, is expressed as a percentage of the maximum density obtained by the test procedure presented in ASTM D1557 or KS F 2312 abbreviated as a percent of laboratory maximum density. Since ASTM D1557 or KS F 2312 applies only to soils that have 30 percent or less by weight of their particles retained on the 19.0 mm (3/4 inch) sieve, express the degree of compaction for material having more than 30 percent by weight of their particles retained on the

19.0 mm (3/4 inch) sieve as a percentage of the maximum density in accordance with AASHTO T 180 and corrected with AASHTO T 224. To maintain the same percentage of coarse material, use the "remove and replace" procedure as described in NOTE 8 of Paragraph 7.2 in AASHTO T 180.

1.3.5 Topsoil

Material suitable for topsoils is defined as: Natural, friable soil representative of productive, well-drained soils in the area, free of subsoil, stumps, rocks larger than 25 mm (1 inch) diameter, brush, weeds, toxic substances, and other material detrimental to plant growth. Amend topsoil pH range to obtain a pH of 5.5 to 7.

1.3.6 Hard/Unyielding Materials

Hard/Unyielding materials comprise weathered rock, dense consolidated deposits, or conglomerate materials which are not included in the definition of "rock" with stones greater than 75 mm (3 inches) in any dimension or as defined by the pipe manufacturer, whichever is smaller.

These materials usually require the use of heavy excavation equipment, ripper teeth, or jack hammers for removal.

1.3.7 Rock

Solid homogeneous interlocking crystalline material with firmly cemented, laminated, or foliated masses or conglomerate deposits, neither of which can be removed without systematic drilling and blasting, drilling and the use of expansion jacks or feather wedges, or the use of backhoe-mounted pneumatic hole punchers or rock breakers; also large boulders, buried masonry, or concrete other than pavement exceeding 0.375 cubic meter (1/2 cubic yard) in volume. Removal of hard material will not be considered

SECTION 31 00 00 Page 7 rock excavation because of intermittent drilling and blasting that is performed merely to increase production.

1.3.8 Unstable Material

Unstable materials are too wet to properly support the utility pipe, conduit, or appurtenant structure.

1.3.9 Select Granular Material

1.3.9.1 General Requirements

Select granular material consist of materials classified as GW, GP, SW, or SP by ASTM D2487 or KS F 2324 where indicated. The liquid limit of such material must not exceed 35 percent when tested in accordance with ASTM D4318 or KS F 2303. The plasticity index must not be greater than 12 percent when tested in accordance with ASTM D4318 or KS F 2303, and not more than 35 percent by weight may be finer than 75 micrometers (No. 200) sieve when tested in accordance with ASTM D1140. Provide a minimum coefficient of permeability of 0.01 mm per second (0.002 feet per minute) when tested in accordance with ASTM D2434 or KS F 2322.

1.3.9.2 California Bearing Ratio Values

Bearing Ratio: At 2.5 mm (0.1 inch) penetration, provide a bearing ratio of 100 percent at 95 percent ASTM D1557 or KS F 2312 maximum density as determined in accordance with ASTM D1883 or KS F 2320 for a laboratory soaking period of not less than 4 days. Conform the combined material to the following sieve analysis:

Sieve Size Percent Passing by Weight

63 mm (2.5 inches) 100

4.75 mm (No. 4) 40 - 85

2.00 mm (No. 10) 20 - 80

425 micrometers (No. 40) 10 - 60 75 micrometers (No. 200) 5 - 25

1.3.10 Initial Backfill Material

Initial backfill consists of select granular material or satisfactory materials free from rocks 75 mm (3 inches) or larger in any dimension or free from rocks of such size as recommended by the pipe manufacturer, whichever is smaller. When the pipe is coated or wrapped for corrosion protection, free the initial backfill material of stones larger than 75 mm (3 inches) in any dimension or as recommended by the pipe manufacturer, whichever is smaller.

1.3.11 Expansive Soils

Expansive soils are defined as soils that have a plasticity index equal to or greater than 35 when tested in accordance with ASTM D4318 or KS F 2303.

1.3.12 Nonfrost Susceptible (NFS) Material

Nonfrost susceptible material are a uniformly graded washed sand with a maximum particle size of 6 mm (1/4 inch) and less than 5 percent passing the

0.075 mm (No. 200) size sieve, and with not more than 3 percent by weight

SECTION 31 00 00 Page 8 finer than 0.02 mm (No. 635) grain size.

1.3.13 Pile Supported Structure

As used herein, a structure where both the foundation and floor slab are pile supported.

1.4 SYSTEM DESCRIPTION

Subsurface soil boring logs are shown on the drawings. The subsoil investigation report and samples of materials taken from subsurface investigations may be examined at US Army Corps of Engineers, Far East District. These data represent the best subsurface information available;

however, variations may exist in the subsurface between boring locations.

1.4.1 Classification of Excavation

Finish the specified excavation on a unclassified basis regardless of the material encountered.

1.4.2 Blasting

Blasting will not be permitted.

1.4.3 Dewatering Work Plan

Submit procedures for accomplishing dewatering work.

1.5 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Shoring; G

Dewatering Work Plan; G

Submit 15 days prior to starting work.

SD-03 Product Data

Utilization of Excavated Materials; G Opening of any Excavation or Borrow Pit Shoulder Construction

Procedure and location for disposal of unused satisfactory material. Proposed source of borrow material. Notification of encountering rock in the project. Advance notice on the opening of excavation or borrow areas. Advance notice on shoulder construction for rigid pavements.

Structural Backfill; G Nonfrost Susceptible (NFS) Material; G

SECTION 31 00 00 Page 9

SD-06 Test Reports

Testing; G Borrow Site Testing; G

Within 24 hours of conclusion of physical tests, 5 copies of test results, including calibration curves and results of calibration tests. Results of testing at the borrow site.

SD-07 Certificates

Testing

Qualifications of the Corps validated commercial testing laboratory or the Contractor's validated testing facilities.

PART 2 PRODUCTS

2.1 REQUIREMENTS FOR OFFSITE SOILS

Offsite soils brought in for use as backfill shall be tested for Total Petroleum Hydrocarbons (TPH) and Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX). Backfill shall contain less than 100 parts per million (ppm) TPH, less than 1 ppm Benzene, less than 20 ppm Toluene, less than 50 ppm Ethyl Benzene, and less than 15 ppm Xylene. Determine TPH concentrations by using EPA SW-846.3-3 Method 8015. Determine BTEX concentrations by using EPA SW-846.3-3 Method 8021 or 8260

Provide borrow site testing for TPH and BTEX from composite samples of soil collected from the borrow site, with the composite samples being representative of the soil to be acquired for the project. Surface samples shall be obtained by excavating a minimum of 200 mm (8 inches) from the surface. For borrow sites 8093 square meter(2 acres) or less, 1 composite sample shall be collected from the site for analysis. For borrow sites larger than 8093 square meter(2 acres), 1 sample for each additional 8093 square meter(2 acres) increment shall be collected. For borrow excavations deeper than 2 meters (6 feet), the above sampling protocol shall be repeated again with every 2 meter(6 feet) increase in depth.

For each prospective borrow site, the contractor shall submit to the Contracting Officer a Borrow Site Environmental Assessment Report which documents that borrow soil from the site is not contaminated. The Borrow Site Environmental Assessment Report shall include the following: general site description and environmental condition; location information and map;

historic and current land use; photographs; any known contaminant spills in the area; any on-site or adjacent facilities which pose risks of contaminating the borrow fill; procedures for soil sample collection and collection locations; and the laboratory testing procedures and resulting analytical data. The report shall have a cover sheet that is signed by the contractor, which attests and certifies the suitability of the fill material. Soil from a particular borrow site shall not be brought onsite until this report has been approved by the Contracting Officer.

2.2 BURIED WARNING AND IDENTIFICATION TAPE

Provide metallic core or metallic-faced, acid- and alkali-resistant, polyethylene plastic warning tape manufactured specifically for warning and identification of buried utility lines. Provide tape on rolls, 75 mm (3 inches) minimum width, color coded as specified below for the intended

SECTION 31 00 00 Page 10 utility with warning and identification imprinted in bold black letters continuously over the entire tape length. Warning and identification to read, "CAUTION, BURIED (intended service) LINE BELOW" or similar wording.

Provide permanent color and printing, unaffected by moisture or soil.

Warning Tape Color Codes

Red: Electric Yellow: Oil; Dangerous Materials Orange: Telephone and Other

Communications Blue: Water Systems Green: Sewer Systems White: Steam Systems Gray: Compressed Air

2.2.1 Warning Tape for Metallic Piping

Provide acid and alkali-resistant polyethylene plastic tape conforming to the width, color, and printing requirements specified above, with a minimum thickness of 0.08 mm (0.003 inch) and a minimum strength of 10.3 MPa (1,500 psi) lengthwise, and 8.6 MPa (1,250 psi) crosswise, with a maximum 350 percent elongation.

2.2.2 Detectable Warning Tape for Non-Metallic Piping

Provide polyethylene plastic tape conforming to the width, color, and printing requirements specified above, with a minimum thickness of 0.10 mm (0.004 inch), and a minimum strength of 10.3 MPa (1,500 psi) lengthwise and

8.6 MPa (1,250 psi) crosswise. Manufacture tape with integral wires, foil backing, or other means of enabling detection by a metal detector when tape is buried up to 920 mm (3 feet) deep. Encase metallic element of the tape in a protective jacket or provide with other means of corrosion protection.

2.3 DETECTION WIRE FOR NON-METALLIC PIPING

Insulate a single strand, solid copper detection wire with a minimum of 2 mm (No. 12 AWG).

2.4 CAPILLARY WATER BARRIER

Provide capillary water barrier of clean, poorly graded crushed rock, crushed gravel, or uncrushed gravel placed beneath a building slab with or without a vapor barrier to cut off the capillary flow of pore water to the area immediately below. Conform to ASTM C33/C33M or KS F 2526 for fine aggregate grading with a maximum of 3 percent by weight passing ASTM D1140 or KS F 2309, 75 micrometers (No. 200) sieve, or37.5 mm (1-1/2 inch) and no more than 2 percent by weight passing the 4.75 mm (No. 4) size sieve.

2.5 PIPE CASING

2.5.1 Casing Pipe

ASTM A139/A139M, Grade B, or ASTM A252, Grade 2, smooth wall pipe. Match casing size to the outside diameter and wall thickness as indicated on Drawing. Protective coating is not required on casing pipe.

SECTION 31 00 00 Page 11

2.5.2 Casing Spacers and End Seals

Casing spacers shall be PSI Model C8GN-2 for carrier pipes up to 600 mm (24-inch) diameters and Model C12GN2 for larger pipe sizes as manufactured by Pipeline Seal and Insulator, Inc., Houston, TX or approved equal.

End Seal shall be PSI Model S or W as manufactured by Pipeline Seal and Insulator, Inc., Houston, TX or approved equal.

2.6 STRUCTURAL BACKFILL

Structural backfill is a well-graded sand and gravel mixture that is further classified as nonfrost susceptible material. Structural backfill consists of sand, gravel, crushed gravel, or crushed rock composed of hard, tough and durable particles, and shall be reasonable well-graded within the limits given below. Structural backfill shall be placed and compacted in maximum 150 mm (6 inches) loose lifts to achieve a uniform compaction of at least 100 percent of laboratory maximum density.

Sieve Designation, mm (inch) Percent Finer by Weight

40 mm (1-1/2 inches) 100 13 mm (1/2 inch) 48-100 10 mm (3/8 inch) 42-84

4.75 mm (No. 4) 28-58

2.00 mm (No. 10) 15-40

0.425 mm (No. 40) 4-19

0.075 mm (No. 200) 0-4

PART 3 EXECUTION

3.1 STRIPPING OF TOPSOIL

Where indicated or directed, strip topsoil to a depth of 100 mm (4 inches).

Spread topsoil on areas already graded and prepared for topsoil, or transported and deposited in stockpiles convenient to areas that are to receive application of the topsoil later, or at locations indicated or specified. Keep topsoil separate from other excavated materials, brush, litter, objectionable weeds, roots, stones larger than 50 mm (2 inches) in diameter, and other materials that would interfere with planting and maintenance operations. Stockpile in locations indicated any surplus of topsoil from excavations and gradings.

3.2 GENERAL EXCAVATION

Perform excavation of every type of material encountered within the limits of the project to the lines, grades, and elevations indicated and as specified. Perform the grading in accordance with the typical sections shown and the tolerances specified in paragraph FINISHING. Transport satisfactory excavated materials and place in fill or embankment within the limits of the work. Excavate unsatisfactory materials encountered within the limits of the work below grade and replace with satisfactory materials as directed. Include such excavated material and the satisfactory material ordered as replacement in excavation. Dispose surplus satisfactory excavated material not required for fill or embankment in areas approved for surplus material storage or designated waste areas. Dispose unsatisfactory excavated material in designated waste or spoil areas.

During construction, perform excavation and fill in a manner and sequence that will provide proper drainage at all times. Excavate material required

SECTION 31 00 00 Page 12 for fill or embankment in excess of that produced by excavation within the grading limits from the borrow areas indicated or from other approved areas selected by the Contractor as specified.

3.2.1 Ditches, Gutters, and Channel Changes

Finish excavation of ditches, gutters, and channel changes by cutting accurately to the cross sections, grades, and elevations shown on Drawing .

Do not excavate ditches and gutters below grades shown. Backfill the excessive open ditch or gutter excavation with satisfactory, thoroughly compacted, material or with suitable stone or cobble to grades shown.

Dispose excavated material as shown or as directed, except in no case allow material be deposited a maximum 1 meter (4 feet) from edge of a ditch.

Maintain excavations free from detrimental quantities of leaves, brush, sticks, trash, and other debris until final acceptance of the work.

3.2.2 Drainage Structures

Make excavations to the lines, grades, and elevations shown, or as directed. Provide trenches and foundation pits of sufficient size to permit the placement and removal of forms for the full length and width of structure footings and foundations as shown. Clean rock or other hard foundation material of loose debris and cut to a firm, level, stepped, or serrated surface. Remove loose disintegrated rock and thin strata. Do not disturb the bottom of the excavation when concrete or masonry is to be placed in an excavated area. Do not excavate to the final grade level until just before the concrete or masonry is to be placed. Where pile foundations are to be used, stop the excavation of each pit at an elevation 300 mm (1 foot) above the base of the footing, as specified, before piles are driven. After the pile driving has been completed, remove loose and displaced material and complete excavation, leaving a smooth, solid, undisturbed surface to receive the concrete or masonry.

3.2.3 Drainage

Provide for the collection and disposal of surface and subsurface water encountered during construction. Completely drain construction site during periods of construction to keep soil materials sufficiently dry. Construct storm drainage features (ponds/basins) at the earliest stages of site development, and throughout construction grade the construction area to provide positive surface water runoff away from the construction activity or provide temporary ditches, swales, and other drainage features and equipment as required to maintain dry soils. When unsuitable working platforms for equipment operation and unsuitable soil support for subsequent construction features develop, remove unsuitable material and provide new soil material as specified herein. It is the responsibility of the Contractor to assess the soil and ground water conditions presented by the plans and specifications and to employ necessary measures to permit construction to proceed.

3.2.4 Dewatering

Control groundwater flowing toward or into excavations to prevent sloughing of excavation slopes and walls, boils, uplift and heave in the excavation and to eliminate interference with orderly progress of construction. Do not permit French drains, sumps, ditches or trenches within 0.9 m of the foundation of any structure, except with specific written approval, and after specific contractual provisions for restoration of the foundation area have been made. Take control measures by the time the excavation

SECTION 31 00 00 Page 13 reaches the water level in order to maintain the integrity of the in situ material. While the excavation is open, maintain the water level continuously, at least 0.9 m (3 feet) below the working level. Operate dewatering system continuously until construction work below existing water levels is complete. Submit performance records weekly.

3.2.5 Trench Excavation Requirements

Excavate the trench as recommended by the manufacturer of the pipe to be installed. Slope trench walls below the top of the pipe, or make vertical, and of such width as recommended in the manufacturer's printed installation manual. Provide vertical trench walls where no manufacturer's printed installation manual is available. Shore trench walls more than 1.5 meters (5 feet) high, cut back to a stable slope, or provide with equivalent means of protection for employees who may be exposed to moving ground or cave

in. Shore vertical trench walls more than 1.5 meters (5 feet) high.

Excavate trench walls which are cut back to at least the angle of repose of the soil. Give special attention to slopes which may be adversely affected by weather or moisture content. Do not exceed the trench width below the pipe top of 600 mm (24 inches) plus pipe outside diameter (O.D.) for pipes of less than 600 mm (24 inches) inside diameter, and do not exceed 900 mm (36 inches) plus pipe outside diameter for sizes larger than 600 mm (24 inches) inside diameter. Where recommended trench widths are exceeded, provide redesign, stronger pipe, or special installation procedures by the Contractor. The Contractor is responsible for the cost of redesign, stronger pipe, or special installation procedures without any additional cost to the Government.

3.2.5.1 Bottom Preparation

Grade the bottoms of trenches accurately to provide uniform bearing and support for the bottom quadrant of each section of the pipe. Excavate bell holes to the necessary size at each joint or coupling to eliminate point bearing. Remove stones of 75 mm (3 inches) or greater in any dimension, or as recommended by the pipe manufacturer, whichever is smaller, to avoid point bearing.

3.2.5.2 Removal of Unyielding Material

Where overdepth is not indicated and unyielding material is encountered in the bottom of the trench, remove such material 100 mm (4 inches) below the required grade and replaced with suitable materials as provided in paragraph BACKFILLING AND COMPACTION.

3.2.5.3 Removal of Unstable Material

Where unstable material is encountered in the bottom of the trench, remove such material to the depth directed and replace it to the proper grade with select granular material as provided in paragraph BACKFILLING AND COMPACTION. When removal of unstable material is required due to the Contractor's fault or neglect in performing the work, the Contractor is responsible for excavating the resulting material and replacing it without additional cost to the Government.

3.2.5.4 Excavation for Appurtenances

Provide excavation for manholes, catch-basins, inlets, or similar structures of sufficient size to permit the placement and removal of forms for the full length and width of structure footings and foundations as

SECTION 31 00 00 Page 14 shown. Clean rock or loose debris and cut to a firm surface either level, stepped, or serrated, as shown or as directed. Remove loose disintegrated rock and thin strata. Specify removal of unstable material. When concrete or masonry is to be placed in an excavated area, take special care not to disturb the bottom of the excavation. Do not excavate to the final grade level until just before the concrete or masonry is to be placed.

3.2.5.5 Jacking, Boring, and Tunneling

Unless otherwise indicated, provide excavation by open cut except that sections of a trench may be jacked, bored, or tunneled if, in the opinion of the Contracting Officer, the pipe, cable, or duct can be safely and properly installed and backfill can be properly compacted in such sections.

3.2.6 Underground Utilities

The Contractor is responsible for movement of construction machinery and equipment over pipes and utilities during construction. Excavation made with power-driven equipment is not permitted within 600 mm (2 feet) of known Government-owned utility or subsurface construction. For work immediately adjacent to or for excavations exposing a utility or other buried obstruction, excavate by hand. Start hand excavation on each side of the indicated obstruction and continue until the obstruction is uncovered or until clearance for the new grade is assured. Support uncovered lines or other existing work affected by the contract excavation until approval for backfill is granted by the Contracting Officer. Report damage to utility lines or subsurface construction immediately to the Contracting Officer.

3.2.7 Structural Excavation

Ensure that footing subgrades have been inspected and approved by the Contracting Officer prior to concrete placement. Excavate to bottom of pile cap prior to placing or driving piles, unless authorized otherwise by the Contracting Officer. Backfill and compact over excavations and changes in grade due to pile driving operations to 95 percent of ASTM D698 maximum density.

3.3 SELECTION OF BORROW MATERIAL

Select borrow material to meet the requirements and conditions of the particular fill or embankment for which it is to be used. Obtain borrow material from the borrow areas. Unless otherwise provided in the contract, the Contractor is responsible for obtaining the right to procure material, pay royalties and other charges involved, and bear the expense of developing the sources, including rights-of-way for hauling from the owners. Borrow material from approved sources on Government-controlled land may be obtained without payment of royalties. Unless specifically provided, do not obtain borrow within the limits of the project site without prior written approval. Consider necessary clearing, grubbing, and satisfactory drainage of borrow pits and the disposal of debris thereon related operations to the borrow excavation.

3.4 OPENING AND DRAINAGE OF EXCAVATION AND BORROW PITS

Notify the Contracting Officer sufficiently in advance of the opening of any excavation or borrow pit to permit elevations and measurements of the undisturbed ground surface to be taken. Except as otherwise permitted, excavate borrow pits and other excavation areas providing adequate

SECTION 31 00 00 Page 15 drainage. Transport overburden and other spoil material to designated spoil areas or otherwise dispose of as directed. Provide neatly trimmed and drained borrow pits after the excavation is completed. Ensure that excavation of any area, operation of borrow pits, or dumping of spoil material results in minimum detrimental effects on natural environmental conditions.

3.5 SHORING

3.5.1 General Requirements

Submit a Shoring and Sheeting plan for approval 15 days prior to starting work. Submit drawings and calculations, certified by a registered professional engineer, describing the methods for shoring and sheeting of excavations. Finish shoring, including sheet piling, and install as necessary to protect workmen, banks, adjacent paving, structures, and utilities. Remove shoring, bracing, and sheeting as excavations are backfilled, in a manner to prevent caving.

3.5.2 Geotechnical Engineer

Hire a Professional Geotechnical Engineer to provide inspection of excavations and soil/groundwater conditions throughout construction. The Geotechnical Engineer is responsible for performing pre-construction and periodic site visits throughout construction to assess site conditions.

The Geotechnical Engineer is responsible for updating the excavation, sheeting and dewatering plans as construction progresses to reflect changing conditions and submit an updated plan if necessary. Submit a monthly written report, informing the Contractor and Contracting Officer of the status of the plan and an accounting of the Contractor's adherence to the plan addressing any present or potential problems. The Contracting Officer is responsible for arranging meetings with the Geotechnical Engineer at any time throughout the contract duration.

3.6 GRADING AREAS

Where indicated, divide work into grading areas within which satisfactory excavated material will be placed in embankments, fills, and required backfills. Do not haul satisfactory material excavated in one grading area to another grading area except when so directed in writing. Place and grade stockpiles of satisfactory, unsatisfactory, and wasted materials as specified. Keep stockpiles in a neat and well drained condition, giving due consideration to drainage at all times. Clear, grub, and seal by rubber-tired equipment, the ground surface at stockpile locations;

separately stockpile excavated satisfactory and unsatisfactory materials.

Protect stockpiles of satisfactory materials from contamination which may destroy the quality and fitness of the stockpiled material. If the Contractor fails to protect the stockpiles, and any material becomes unsatisfactory, remove and replace such material with satisfactory material from approved sources.

3.7 FINAL GRADE OF SURFACES TO SUPPORT CONCRETE

Do not excavate to final grade until just before concrete is to be placed.

For pile foundations, stop the excavation at an elevation of from 150 to 300 mm (6 to 12 inches) above the bottom of the footing before driving piles. After pile driving has been completed, complete the remainder of the excavation to the elevations shown. Only use excavation methods that will leave the foundation rock in a solid and unshattered condition.

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Roughen the level surfaces, and cut the sloped surfaces, as indicated, into rough steps or benches to provide a satisfactory bond. Protect shales from slaking and all surfaces from erosion resulting from ponding or water flow.

3.8 GROUND SURFACE PREPARATION

3.8.1 General Requirements

Remove and replace unsatisfactory material with satisfactory materials, as directed by the Contracting Officer, in surfaces to receive fill or in excavated areas. Scarify the surface to a depth of 150 mm (6 inches) before the fill is started. Plow, step, bench, or break up sloped surfaces steeper than 1 vertical to 4 horizontal so that the fill material will bond with the existing material. When subgrades are less than the specified density, break up the ground surface to a minimum depth of 150 mm (6 inches), pulverizing, and compacting to the specified density. When the subgrade is part fill and part excavation or natural ground, scarify the excavated or natural ground portion to a depth of 300 mm (12 inches) and compact it as specified for the adjacent fill.

3.8.2 Frozen Material

Do not place material on surfaces that are muddy, frozen, or contain frost. Finish compaction by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, or other approved equipment well suited to the soil being compacted. Moisten material as necessary to provide the moisture content that will readily facilitate obtaining the specified compaction with the equipment used.

3.9 UTILIZATION OF EXCAVATED MATERIALS

Dispose unsatisfactory materials removing from excavations into designated waste disposal or spoil areas. Use satisfactory material removed from excavations, insofar as practicable, in the construction of fills, embankments, subgrades, shoulders, bedding (as backfill), and for similar purposes. Do not waste any satisfactory excavated material without specific written authorization. Dispose of satisfactory material, authorized to be wasted, in designated areas approved for surplus material storage or designated waste areas as directed. Clear and grub newly designated waste areas on Government-controlled land before disposal of waste material thereon. Stockpile and use coarse rock from excavations for constructing slopes or embankments adjacent to streams, or sides and bottoms of channels and for protecting against erosion. Do not dispose excavated material to obstruct the flow of any stream, endanger a partly finished structure, impair the efficiency or appearance of any structure, or be detrimental to the completed work in any way.

3.10 BURIED TAPE AND DETECTION WIRE

3.10.1 Buried Warning and Identification Tape

Provide buried utility lines with utility identification tape. Bury tape 300 mm (12 inches) below finished grade; under pavements and slabs, bury tape 150 mm (6 inches) below top of subgrade.

3.10.2 Buried Detection Wire

Bury detection wire directly above non-metallic piping at a distance not to exceed 300 mm (12 inches) above the top of pipe. Extend the wire

SECTION 31 00 00 Page 17 continuously and unbroken, from manhole to manhole. Terminate the ends of the wire inside the manholes at each end of the pipe, with a minimum of 0.9 m (3 feet) of wire, coiled, remaining accessible in each manhole. Furnish insulated wire over it's entire length. Install wires at manholes between the top of the corbel and the frame, and extend up through the chimney seal between the frame and the chimney seal. For force mains, terminate the wire in the valve pit at the pump station end of the pipe.

3.11 BACKFILLING AND COMPACTION

Place backfill adjacent to any and all types of structures, and compact to at least 90 percent laboratory maximum density for cohesive materials or 95 percent laboratory maximum density for cohesionless materials, to prevent wedging action or eccentric loading upon or against the structure. Prepare ground surface on which backfill is to be placed and provide compaction requirements for backfill materials in conformance with the applicable portions of paragraphs GROUND SURFACE PREPARATION. Finish compaction by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment.

3.11.1 Engineered Fill Compaction Requirements

The engineered fill shall be placed in loose lifts no greater than 300 mm for the fill depth below 1.1 meters from the final fill grade, and remaining fill height shall be placed in loose lifts no greater than 200

mm. Each loose lift shall be compacted to achieve a uniform compaction.

After compaction, each lift layer shall attain not less than the percentage of maximum density specified below. The testing of density shall be carried out in accordance with the procedure described in ASTM D 1557.

Compact to at least 90 percent laboratory maximum density for cohesive materials or 95 percent laboratory maximum density for cohesionless materials.

3.11.2 Trench Backfill

Backfill trenches to the grade shown. Do not backfill the trench until all specified tests are performed.

3.11.2.1 Replacement of Unyielding Material

Replace unyielding material removed from the bottom of the trench with select granular material or initial backfill material.

3.11.2.2 Replacement of Unstable Material

Replace unstable material removed from the bottom of the trench or excavation with select granular material placed in layers not exceeding 150 mm (6 inches) loose thickness.

3.11.2.3 Bedding and Initial Backfill

Provide bedding of the type and thickness shown. Place initial backfill material and compact it with approved tampers to a height of at least 300 mm (1 foot) above the utility pipe or conduit. Bring up the backfill evenly on both sides of the pipe for the full length of the pipe. Take care to ensure thorough compaction of the fill under the haunches of the pipe.

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3.11.2.4 Final Backfill

Fill the remainder of the trench, except for special materials for roadways, railroads and airfields, with satisfactory material. Place backfill material and compact as follows:

a. Roadways: Place backfill up to the required elevation as specified. Do not permit water flooding or jetting methods of compaction.

b. Sidewalks, Turfed or Seeded Areas and Miscellaneous Areas: Deposit backfill in layers of a maximum of 300 mm (12 inches) loose thickness, and compact it to 85 percent maximum density for cohesive soils and 90 percent maximum density for cohesionless soils. Do not permit compaction by water flooding or jetting. Apply this requirement to all other areas not specifically designated above.

3.11.3 Backfill for Appurtenances

After the manhole, catchbasin, inlet, or similar structure has been constructed and the concrete has been allowed to cure for 7 days, place backfill in such a manner that the structure is not be damaged by the shock of falling earth. Deposit the backfill material, compact it as specified for final backfill, and bring up the backfill evenly on all sides of the structure to prevent eccentric loading and excessive stress.

3.12 SPECIAL REQUIREMENTS

Special requirements for both excavation and backfill relating to the specific utilities are as follows:

3.12.1 Water Lines

Excavate trenches to a depth that provides a minimum cover of 1.10 meters (43 inches) from the existing ground surface, or from the indicated finished grade, whichever is lower, to the top of the pipe. Domestic water lines will have an additional 150 mm (6 inches) of cover or 1.25 meters (49 inches). Fire water lines will have an additional 300 mm (12 inches) of cover or 1.40 meters (55 inches) from finished surface level.

3.12.2 Sanitary Sewer Lines

Excavate trenches to a depth that provides a minimum cover of 1.10 meters (43 inches) from the existing ground surface, or from the indicated finished grade, whichever is lower, to the top of the pipe.

3.12.3 Storm Drainage Lines

Excavate trenches to a depth that provides a minimum cover as indicated on the drawings.

3.12.4 Electrical Distribution System

Provide a minimum cover as indicated on the drawings from the finished grade to direct burial cable and conduit or duct line, unless otherwise indicated.

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3.12.5 Heat Distribution System

Free initial backfill material of stones larger than 6.3 mm (1/4 inch) in any dimension.

3.12.6 Pipeline Casing

Provide each new pipeline casing, where indicated or specified and to the lengths and dimensions as required, complete and suitable for use with the new piped utility as indicated. Install pipeline casing by dry boring and jacking method as follows:

3.12.6.1 Bore Holes

Mechanically bore holes and case through the soil with a cutting head on a continuous auger mounted inside the casing pipe. Weld lengths of pipe together in accordance with AWS D1.1/D1.1M. Do not use water or other fluids in connection with the boring operation.

3.12.6.2 Cleaning

Clean inside of the pipeline casing of dirt, weld splatters, and other foreign matter which would interfere with insertion of the piped utilities by attaching a pipe cleaning plug to the boring rig and passing it through the pipe.

3.12.6.3 Casing Spacers and End Seals

Provide Casing Spacers and End Seals per manufacturers recommendations.

Provided printed manufactures installation instruction to the Contracting Officer for approval before the commencement of installation.

3.13 EMBANKMENTS

3.13.1 Earth Embankments

Construct earth embankments from satisfactory materials free of organic or frozen material and rocks with any dimension greater than 75 mm (3 inches).

Place the material in successive horizontal layers of loose material not more than 300 mm (12 inches) in depth. Spread each layer uniformly on a soil surface that has been moistened or aerated as necessary, and scarified or otherwise broken up so that the fill will bond with the surface on which it is placed. After spreading, plow, disk, or otherwise brake up each layer; moisten or aerate as necessary; thoroughly mix; and compact to at least 90 percent laboratory maximum density for cohesive materials or 95 percent laboratory maximum density for cohesionless materials. Compaction requirements for the upper portion of earth embankments forming subgrade for pavements are identical with those requirements specified in paragraph SUBGRADE PREPARATION. Finish compaction by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment. Allowable moisture content of a lift of soil after compaction shall be within 2 percent (+/-2%) of the optimum moisture content as determined by ASTM D698.

3.13.2 Rock Embankments

Construct rock embankments from material classified as rock excavation, as defined above, placed in successive horizontal layers of loose material not more than 200 mm (8 inches) in depth. Do not use pieces of rock larger

SECTION 31 00 00 Page 20 than 100 mm (4 inches) in the greatest dimension. Spread each layer of material uniformly, completely saturate, and compact . Adequately bond each successive layer of material to the material on which it is placed.

Finish compaction with vibratory compactors weighing at least 10 metric tons (11 tons), heavy rubber-tired rollers weighing at least 10metric tons (11 tons), or steel-wheeled rollers weighing at least 10 metric tons (11 tons). Do not use rock excavation as fill material for the construction of pavements. In embankments on which pavements are to be constructed, do not use rock above a point 900 mm (36 inches) below the surface of the pavement.

3.14 SUBGRADE PREPARATION

3.14.1 Construction

Shape subgrade to line, grade, and cross section, and compact as specified. Include plowing, disking, and any moistening or aerating required to obtain specified compaction for this operation. Remove soft or otherwise unsatisfactory material and replace with satisfactory excavated material or other approved material as directed. Excavate rock encountered in the cut section to a depth of 150 mm (6 inches) below finished grade for the subgrade. Bring up low areas resulting from removal of unsatisfactory material or excavation of rock to required grade with satisfactory materials, and shape the entire subgrade to line, grade, and cross section and compact as specified. After rolling, the surface of the subgrade for roadways shall not show deviations greater than 13 mm (1/2 inch) when tested with a 4 m (12-foot) straightedge applied both parallel and at right angles to the centerline of the area. Do not vary the elevation of the finish subgrade more than 15 mm (0.05 foot) from the established grade and cross section.

3.14.2 Compaction

Finish compaction by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment.

Except for paved areas and railroads, compact each layer of the embankment to at least 90 percent of laboratory maximum density.

3.14.2.1 Subgrade for Pavements

Compact subgrade for pavements to at least 90 percentage laboratory maximum density for cohesive materials or 95 percent laboratory maximum density for cohesionless materials. When more than one soil classification is present in the subgrade, thoroughly blend, reshape, and compact.

3.14.2.2 Subgrade for Shoulders

Compact…