Amd 01 W9128F25B0005 Spec 31 00 00.pdf

Lower Brule N. Ecosystem Restoration Proj. Element 1 Big Bend Dam BB00106

SECTION TABLE OF CONTENTS

DIVISION 31 - EARTHWORK

SECTION 31 00 00

EARTHWORK

PART 1 GENERAL

1.1 REFERENCES

1.2 DEFINITIONS

1.2.1 Satisfactory Materials

1.2.2 Unsatisfactory Materials

1.2.3 Cohesionless and Cohesive Materials

1.2.4 Degree of Compaction

1.2.5 Topsoil

1.2.6 Hard/Unyielding Materials

1.2.7 Stone

1.2.8 Unstable Material

1.3 SUBMITTALS

1.4 SUBSURFACE DATA

1.5 CLASSIFICATION OF EXCAVATION

1.5.1 Common Excavation

1.6 DEWATERING WORK PLAN

PART 2 PRODUCTS

2.1 REQUIREMENTS FOR OFFSITE SOILS

2.2 SELECT GRANULAR MATERIAL

2.2.1 General Requirements

2.3 INITIAL BACKFILL MATERIAL

2.4 DETECTION WIRE FOR NON-METALLIC PIPING

2.5 MATERIAL FOR RIPRAP

2.5.1 Stone

2.5.2 Geotextile

PART 3 EXECUTION

3.1 EARTHWORK NOTIFICATION

3.2 STRIPPING OF TOPSOIL

3.3 EXCAVATION

3.3.1 Ditches

3.3.2 Excavation For Structures

3.3.3 Excavation and Trenching For Utilities

3.3.3.1 Bottom Preparation

3.3.4 Dewatering

3.4 GROUND SURFACE PREPARATION

3.4.1 General Requirements

3.4.2 Frozen Material

3.5 EMBANKMENTS

3.5.1 Earth Embankments

3.6 BACKFILLING FOR UTILITIES

3.6.1 Utility Trench Backfill

SECTION 31 00 00 Page 1

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3.6.1.1 Bedding and Initial Backfill

3.6.1.2 Final Backfill

3.6.2 Backfill for Appurtenances

3.7 SOIL BORROW AND WASTE

3.7.1 Borrow

3.7.2 Waste

3.8 SUBGRADE PREPARATION

3.8.1 Proof Rolling

3.8.2 Construction

3.8.3 Compaction

3.8.3.1 Subgrade for Pavements

3.8.3.2 Subgrade for Shoulders

3.9 SHOULDER CONSTRUCTION

3.10 FINISHING

3.10.1 Embankments

3.11 PLACING TOPSOIL

3.12 RIPRAP CONSTRUCTION

3.12.1 Stone Placement

3.13 BURIED TAPE AND DETECTION WIRE

3.13.1 Buried Detection Wire

3.14 TESTING

3.14.1 Borrow Material Classification

3.14.2 In-Place Densities

3.14.2.1 Embankment

3.15 DISPOSITION OF SURPLUS MATERIAL

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SECTION 31 00 00 Page 2

SECTION 31 00 00

EARTHWORK

PART 1 GENERAL

1.1 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 (2001; R 2004) Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and an 457-mm (18-in) Drop

AASHTO T 224 (2001; R 2004) Correction for Coarse Particles in the Soil Compaction Test

ASTM INTERNATIONAL (ASTM)

ASTM C 136 (2006) Sieve Analysis of Fine and Coarse Aggregates

ASTM D 422 (1963; R 2007) Particle-Size Analysis of Soils

ASTM D 1140 (2000) Amount of Material in Soils Finer than the No. 200 (75-micrometer) Sieve

ASTM D 1556 (2007) Density and Unit Weight of Soil in Place by the Sand-Cone Method

ASTM D 1557 (2007) Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/cu. ft. (2,700 kN-m/cu.m.))

ASTM D 2321 (2008) Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications

ASTM D 2487 (2006e1) Soils for Engineering Purposes (Unified Soil Classification System)

ASTM D 2774 (2008) Underground Installation of Thermoplastic Pressure Piping

ASTM D 4318 (2005) Liquid Limit, Plastic Limit, and Plasticity Index of Soils

SECTION 31 00 00 Page 3

U.S. ARMY CORPS OF ENGINEERS (USACE)

EM 385-1-1 (2008) Safety -- Safety and Health Requirements

U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA)

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

Physical/Chemical Methods; Third Edition;

Final Update III-A

EPA 600/4-79/020 (1983) Methods for Chemical Analysis of Water and Wastes

1.2 DEFINITIONS

1.2.1 Satisfactory Materials

Satisfactory materials shall comprise any materials classified by ASTM D 2487 as GC, SC, CL, ML, CL-ML, CH, and MH. Unless otherwise specified, satisfactory materials for earthwork shall not contain stones greater than 3 inches in any dimension. Random material indicated on the bid schedule and other locations is referring to the clay fill material.

1.2.2 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. The Contracting Officer shall be notified of any contaminated materials. Otherwise satisfactory material which is unsuitable due to excess moisture content will not be classified as unsatisfactory material unless it can not be dried by manipulation, aeration, or blending with other materials satisfactorily as determined by the Contracting Officer's Representative.

1.2.3 Cohesionless and Cohesive Materials

Cohesionless materials include materials classified in ASTM D 2487 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. Testing required for classifying materials shall be in accordance with ASTM D 4318 , ASTM C 136 , ASTM D 422 , and ASTM D 1140 .

1.2.4 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 D 1557 abbreviated as a percent of laboratory maximum density. Since ASTM D 1557 applies only to soils that have 30 percent or less by weight of their particles retained on the 3/4 inch sieve, the degree of compaction for material having more than 30 percent by weight of their particles retained on the 3/4 inch sieve shall be expressed as a percentage of the maximum density in accordance with AASHTO T 180 Method D and corrected with AASHTO T 224 . To maintain the same percentage of coarse material, the "remove and replace" procedure as

SECTION 31 00 00 Page 4 described in the NOTE 8 in Paragraph 7.2 of AASHTO T 180 shall be used.

1.2.5 Topsoil

Topsoil is defined as: Natural, friable soil representative of productive, well-drained soils in the area, free of subsoil, stumps, rocks larger than one inch diameter, brush, weeds, toxic substances, and other material detrimental to plant growth.

1.2.6 Hard/Unyielding Materials

Weathered rock, dense consolidated deposits, or conglomerate materials which are not included in the definition of "rock" with stones greater than 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.

1.2.7 Stone

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 1/2 cubic yard in volume. Removal of hard material will not be considered rock excavation because of intermittent drilling and blasting that is performed merely to increase production.

1.2.8 Unstable Material

Unstable material shall consist of materials too wet to properly support the utility pipe, conduit, or appurtenant structure.

1.3 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. The following shall be submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Shoring and Sheeting Plan; G-AO

Dewatering Work Plan; G-AO

Submit 15 days prior to starting work.

Earthwork Notification

Advance notice on the opening of excavation or borrow areas.

Source of Borrow Material; G-AO

Breakwater Construction Work Plan; G-AO

SECTION 31 00 00 Page 5

SD-06 Test Reports

Borrow Site Testing: G-AO

Within 24 hours of conclusion of physical tests, 2 copies of test results, including calibration curves and results of calibration tests. Results of testing at the borrow site.

Testing

SD-07 Certificates

Testing; G-AO

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

1.4 SUBSURFACE DATA

A subsurface investigation was not performed. A subsurface investigation of the Grassrope borrow area was performed and is included as an attachement to this specification.

1.5 CLASSIFICATION OF EXCAVATION

No consideration will be given to the nature of the materials, and all excavation will be designated as unclassified excavation.

1.5.1 Common Excavation

Common excavation shall include the satisfactory removal and disposal of all materials not classified as rock excavation.

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1.6 DEWATERING WORK PLAN

Submit procedures for accomplishing dewatering work for the beach area culvert pipes prior to the start of Construction Activities.

1.7 BREAKWATER CONSTRUCTION WORK PLAN

Submit procedures as stated in the drawings for accomplishing breakwater construction including placement of all materials shown on the typical breakwater cross section, and the cofferdaming and dewatering of the box culvert areas prior to the start of Construction Activities. Also identify haul routes and construction equipment planned for use on the various construction activities.

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PART 2 PRODUCTS

2.1 REQUIREMENTS FOR OFFSITE SOILS

Soils from borrow areas outside Government property for use as embankment or backfill shall be tested for TPH, BTEX and full TCLP including ignitability, corrosivity and reactivity. Backfill shall contain less

SECTION 31 00 00 Page 6 than 100 parts per million (ppm) of total petroleum hydrocarbons (TPH) and less than 10 ppm of the sum of Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX) and shall not fail the TCPL test. TPH concentrations shall be determined by using EPA 600/4-79/020 Method 418.1. BTEX concentrations shall be determined by using EPA SW-846.3-3a Method 5030/8020. TCLP shall be performed in accordance with EPA SW-846.3-3a Method 1311. Provide Borrow Site Testing for TPH, BTEX and TCLP from a composite sample of material from the borrow site, with at least one test from each borrow site. Material shall not be brought on site until tests have been approved by the Contracting Officer.

2.2 SELECT GRANULAR MATERIAL

2.2.1 General Requirements

Select granular material shall consist of materials classified as GW, GP, SW, SP, by ASTM D 2487 where indicated. The maximum allowable aggregate size shall be 1/2 inch, unless otherwise indicated or recommended by the pipe manufacturer. The liquid limit of such material shall not exceed 35 percent when tested in accordance with ASTM D 4318 . The plasticity index shall not be greater than 12 percent when tested in accordance with ASTM D 4318 , and not more than 35 percent by weight shall be finer than No. 200 sieve when tested in accordance with ASTM D 1140 .

2.3 INITIAL BACKFILL MATERIAL

Initial backfill shall consist of select granular material or satisfactory materials free from rocks 1/2 inch or larger in any dimension unless otherwise indicated or recommended by the pipe manufacturer. Material locally referred to as "Squeegee" or "Pea Gravel" shall not be used.

2.4 DETECTION WIRE FOR NON-METALLIC PIPING

Detection wire shall be 12 AWG single strand, solid copper with a 30-mil (min.) polyethylene jacket suitable for direct bury.

2.5 MATERIAL FOR RIPRAP

2.5.1 Stone

Stone fragments sufficiently durable to ensure permanence in the structure and the environment in which it is to be used. Stone fragments shall be free from cracks, seams, and other defects that would increase the risk of deterioration from natural causes. The size of the fragments shall be such that no individual fragment exceeds a weight of 150 pounds and that no more than 10 percent of the mixture, by weight, consists of fragments weighing 2 pounds or less each. Specific gravity of the rock shall be a minimum of 2.50. The inclusion of more than of a trace (5 percent) quantities of dirt, sand, clay, and rock fines will not be permitted.

Other requirements for the Stone (riprap and spalls) can be found in Spec Section 35 31 19.

2.5.2 Geotextile

Geotextile shall conform to the requirements for geotextile in Spec Section 31 05 19.

SECTION 31 00 00 Page 7

PART 3 EXECUTION

3.1 EARTHWORK NOTIFICATION

The Contractor shall notify the Contracting Officer sufficiently in advance of beginning excavation and filling to permit elevations and measurements to be taken of the undisturbed ground surface at the project site and borrow and waste areas The Contractor is required to notify the Contracting Officer no less than 5 business days in advance of any ground disturbing activity to ensure that a cultural monitor may be on-site. No ground disturbing activity shall be performed until 5 business days after notice is given or as directed by the Contracting Officer. The cultural monitors shall be coordinated by the U.S. Army Corps of Engineers and shall be of no cost to the Contractor.

3.2 STRIPPING OF TOPSOIL

Topsoil shall be stripped to a depth of 4 inches from all areas to be excavated or filled. Stripped topsoil shall be spread 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. Topsoil shall be kept separate from other excavated materials, brush, litter, objectionable weeds, roots, stones larger than 2 inches in diameter, and other materials that would interfere with planting and maintenance operations. .

3.3 EXCAVATION

The Contractor shall perform excavation of every type of material encountered within the limits of the project to the lines, grades, and elevations indicated and as specified. Excavation shall conform to the requirements in EM 385-1-1 . Grading shall be in conformity with the drawings and the tolerances specified in paragraph FINISHING.

Satisfactory excavated materials shall be transported to and placed in fill or embankment within the limits of the work. Unsatisfactory materials encountered within the limits of the work shall be excavated below grade and replaced with satisfactory materials as directed.

Unsatisfactory excavated material shall be disposed of in designated waste or spoil areas. During construction, excavation and fill shall be performed in a manner and sequence that will provide proper drainage at all times. Excavated material shall not 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

3.3.1 Ditches

Excavation of ditches shall be accomplished by cutting accurately to the cross sections, grades, and elevations shown. Ditches shall not be excavated below grades shown. Excessive open ditch excavation shall be backfilled with thoroughly compacted satisfactory material or with suitable stone or cobble to grades shown. Material excavated shall not be deposited less than 4 feet from the edge of a ditch. The Contractor shall maintain excavations free from detrimental quantities of leaves, brush, sticks, trash, and other debris until final acceptance of the work.

3.3.2 Excavation For Structures

Trenches and foundation pits shall be of sufficient size to permit the placement and removal of forms for the full length and width of structure

SECTION 31 00 00 Page 8 footings and foundations as shown. 3.3.3 Excavation and Trenching For Utilities

Trenches shall be excavated in a manner that will prevent collapse of excavation sides and protect persons working in the trench at all times.

The sides of the excavation may be vertical, sloping or benched as determined by qualified Contractor personnel. Suitable protective systems shall be used where a vertical trench wall must exceed the maximum allowable height or where slopes or benched slopes exceed the angle of repose of the soil. Special attention shall be given to slopes which may be adversely affected by weather or moisture content. Trenches shall be of adequate width and depth to install the utility. Care shall be taken not to overexcavate. Care shall be taken not to undermine or damage adjacent structures, pavements, sidewalks, utilities to remain. Existing utility pipes exposed by trench excavation shall be supported and braced as necessary to protect the pipe.

3.3.3.1 Bottom Preparation

The bottom of trenches shall be accurately graded to provide uniform bearing and support for pipe bedding.

3.3.4 Dewatering

Dewatering of the beach area shall be required before excavation and placement of the beach sand. The specifics the Contractor plans to include for this shall be included in the Breakwater Construction Work Plan.

3.4 GROUND SURFACE PREPARATION

3.4.1 General Requirements

Unsatisfactory material in surfaces to receive fill or in excavated areas shall be removed and replaced with satisfactory materials as directed by the Contracting Officer. The surface (other than underwater areas) shall be scarified to a depth of 6 inches before the fill is placed. Sloped surfaces steeper than 1 vertical to 4 horizontal shall be plowed, stepped, benched, or broken up so that the fill material will bond with the existing material.

3.4.2 Frozen Material

Material shall not be placed on surfaces that are muddy, frozen, or contain frost.

3.5 EMBANKMENTS

3.5.1 Earth Embankments

Earth embankments shall be constructed from satisfactory materials free of organic or frozen material and rocks with any dimension greater than 3 inches. The material shall be placed in successive horizontal layers of loose material and compacted. The earth embankments are zoned and consist of gravels and clay loam. The maximum allowable depth of loose material to be compacted shall be determined by the Contractor and approved by the Contracting Officer. The compaction procedures and lift thickness shall be such that the entire depth of the lift is compacted to at least the

SECTION 31 00 00 Page 9 minimum specified density. Each layer shall be spread 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, each layer shall be plowed, disked, or otherwise broken up; moistened or aerated as necessary; thoroughly mixed;

and compacted to at least 95 percent laboratory maximum density for cohesive materials.Compaction shall be accomplished by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment.

3.6 BACKFILLING FOR UTILITIES

3.6.1 Utility Trench Backfill

Trenches shall be backfilled to the grade shown. The trench shall be backfilled to 2 feet above the top of pipe prior to performing the required pressure tests. The joints and couplings shall be left uncovered during the pressure test.

3.6.1.1 Bedding and Initial Backfill

Unless otherwise indicated or specified, bedding and initial backfill shall be as specified below:

a. Concrete Pipe. Haunch and bedding material shall consist of select granular material. Haunch and outer bedding shall be compacted to at least 95 percent laboratory maximum density and shall be placed in layers not exceeding 6 inch loose thickness for compaction by hand-operated compactors and 8 inches for other than hand-operated machines. Middle bedding shall be loosely placed and uncompacted. After the pipe has been properly bedded, haunch material, at a moisture content that will facilitate compaction, shall be placed evenly along both sides of the pipe and each layer thoroughly compacted with mechanical tampers or rammers to the springline of the pipe. The haunch material shall be thoroughly compacted under the haunches of the pipe.

b. Pressure Plastic Pipe. Installation of embedment around pipe shall conform to ASTM D 2774 . Bedding, haunching and initial backfill shall be either Class IB, II or III material conforming to ASTM D 2321 . Compaction of embedment shall be as specified in

ASTM D 2321 .

3.6.1.2 Final Backfill

The remainder of the trench shall be filled with satisfactory material.

Backfill shall be deposited in layers of a maximum of 8 inch loose thickness, and compacted to 90 percent maximum density for cohesive soils and 95 percent maximum density for cohesionless soils. Compaction by water flooding or jetting will not be permitted. Compaction shall be accomplished by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment.

3.6.2 Backfill for Appurtenances

After the manhole, catchbasin, inlet, or similar structure has been constructed and the concrete has been allowed to cure for 3 days, backfill shall be placed in such a manner that the structure will not be damaged by

SECTION 31 00 00 Page 10 the shock of falling earth. The backfill material shall be deposited and compacted as specified for final backfill, and shall be brought up evenly on all sides of the structure to prevent eccentric loading and excessive stress.

3.7 SOIL BORROW AND WASTE

3.7.1 Borrow

Borrow material shall be selected to meet the requirements and conditions of the particular fill or embankment for which it is to be used. Material required for fill or embankment in excess of that produced by excavation within the grading limits shall be obtained from the borrow area shown on drawings. Unless specifically provided, no borrow shall be obtained within the limits of the project site without prior written approval.

Necessary clearing, grubbing, and satisfactory drainage of borrow pits and the disposal of debris thereon shall be considered related operations to the borrow excavation.

3.7.2 Waste

Soil disposed of in waste areas on Government property shall be graded to provide adequate drainage. Maximum slope in disposal area shall be 1V on 4H.

3.8 SUBGRADE PREPARATION

3.8.1 Proof Rolling

Proof rolling shall be done on an exposed subgrade free of surface water (wet conditions resulting from rainfall) which would promote degradation of an otherwise acceptable subgrade. Operate the roller in a systematic manner to ensure the number of passes over all areas, and at speeds between 2 1/2 to 3 1/2 mph. When proof rolling, one-half of the passes made with the roller shall be in a direction perpendicular to the other passes. Notify the Contracting Officer a minimum of 3 days prior to proof rolling. Proof rolling shall be performed in the presence of the Contracting Officer. Rutting or pumping of material shall be undercut [as directed by the Contracting Officer and replaced with fill and backfill material.

3.8.2 Construction

Subgrade shall be shaped to line, grade, and cross section, and compacted as specified. This operation shall include plowing, disking, and any moistening or aerating required to obtain specified compaction. Soft or otherwise unsatisfactory material shall be removed and replaced with satisfactory excavated material or other approved material as directed.

Rock encountered in the cut section shall be excavated to a depth of 6 inches below finished grade for the subgrade. Low areas resulting from removal of unsatisfactory material or excavation of rock shall be brought up to required grade with satisfactory materials, and the entire subgrade shall be shaped to line, grade, and cross section and compacted as specified. After rolling, the surface of the subgrade for roads and parking areas shall not show deviations greater than 1/2-inch when tested with a 12-foot straightedge applied both parallel and at right angles to the centerline of the area. The elevation of the finish subgrade shall not vary more than 0.05 foot from the established grade and cross section.

SECTION 31 00 00 Page 11

3.8.3 Compaction

Compaction shall be accomplished by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment.

3.8.3.1 Subgrade for Pavements

Compact top 6 inches of subgrade for pavements to at least 95% percent laboratory maximum density for cohesive materials or 95% percent laboratory density for cohesionless materials. [The top 6inches of subgrade shall be scarified, windrowed, thoroughly blended, reshaped, and compacted.

3.8.3.2 Subgrade for Shoulders

Subgrade for shoulders shall be compacted to at least 90 percentage laboratory maximum density for the depth below the surface of shoulder shown.

3.9 SHOULDER CONSTRUCTION

Shoulders shall be constructed as soon as possible after adjacent paving is complete, but in the case of rigid pavements, shoulders shall not be constructed until permission of the Contracting Officer has been obtained. The entire shoulder area shall be compacted to at least the percentage of maximum density as specified in paragraph SUBGRADE PREPARATION above, for specific ranges of depth below the surface of the shoulder. Compaction shall be accomplished by sheepsfoot rollers, pneumatic-tired rollers, steel-wheeled rollers, vibratory compactors, or other approved equipment. Shoulder construction shall be done in proper sequence in such a manner that adjacent ditches will be drained effectively and that no damage of any kind is done to the adjacent completed pavement. The completed shoulders shall be true to alignment and grade and shaped to drain in conformity with the cross section shown.

3.10 FINISHING

The surface of excavations, embankments, and subgrades shall be finished to a smooth and compact surface in accordance with the lines, grades, and cross sections or elevations shown. The degree of finish for graded areas shall be within 0.1 foot of the grades and elevations indicated except that the degree of finish for subgrades shall be specified in paragraph SUBGRADE PREPARATION. Ditches shall be finished in a manner that will result in effective drainage. The surface of areas to be turfed shall be finished to a smoothness suitable for the application of turfing materials. Settlement or washing that occurs in graded, topsoiled, or backfilled areas prior to acceptance of the work, shall be repaired and grades re-established to the required elevations and slopes.

3.10.1 Embankments

During construction, embankments and excavations shall be kept shaped and drained. Ditches and drains along subgrade shall be maintained to drain effectively at all times. The finished subgrade shall not be disturbed by traffic or other operation and shall be protected and maintained by the Contractor in a satisfactory condition until ballast, subbase, base, or pavement is placed. The storage or stockpiling of materials on the

SECTION 31 00 00 Page 12 finished subgrade will not be permitted. No subbase, base course, ballast, or pavement shall be laid until the subgrade has been checked and approved, and in no case shall subbase, base, surfacing, pavement, or ballast be placed on a muddy, spongy, or frozen subgrade.

3.11 PLACING TOPSOIL

On areas to receive topsoil, the compacted subgrade soil shall be scarified to a 2 inch depth for bonding of topsoil with subsoil. Topsoil then shall be spread evenly to a thickness of 4 inches and graded to the elevations and slopes shown. Topsoil shall not be spread when frozen or excessively wet or dry. Material required for topsoil in excess of that produced by excavation within the grading limits shall be obtained from the borrow area shown on the drawings.

3.12 RIPRAP CONSTRUCTION

Place riprap on geotextile in the areas indicated.

3.12.1 Stone Placement

Place stone for riprap on prepared geotextile to produce a well graded mass with the minimum practicable percentage of voids in conformance with lines and grades indicated. Place stone for spalls on existing river bed to produce a well graded mass with the minimum practicable percentage of voids in conformance with lines and grades indicated. Distribute larger stone fragments, with dimensions extending the full depth of the riprap throughout the entire mass and eliminate "pockets" of small stone fragments. Rearrange individual pieces by mechanical equipment or by hand as necessary to obtain the distribution of fragment sizes specified above.

3.13 BURIED TAPE AND DETECTION WIRE

3.13.1 Buried Detection Wire

Bury detection wire directly above non-metallic piping at a distance not to exceed 12 inches above the top of pipe. The wire shall extend continuously and unbroken, from manhole to manhole. The ends of the wire shall terminate inside the manholes at each end of the pipe, with a minimum of 3 feet of wire, coiled, remaining accessible in each manhole.

The wire shall remain insulated over it's entire length. The wire shall enter 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, the wire shall terminate in the valve pit at the pump station end of the pipe. Tracer wire shall be tested for continuity after placement of the first lift of backfill over wire.

3.14 TESTING

Testing shall be performed by an approved commercial testing laboratory or by the Contractor subject to approval. If the Contractor elects to establish testing facilities, no work requiring testing will be permitted until the Contractor's facilities have been inspected and approved by the Contracting Officer.

3.14.1 Borrow Material Classification

Satisfactory materials from borrow intended for embankment or backfill

SECTION 31 00 00 Page 13 shall be classified in accordance with ASTM D 2487 . Classification shall be made for each type material or source of material. One classification shall be made for each 1000 cubic yards of material.

3.14.2 In-Place Densities

Field in-place density shall be determined in accordance with ASTM D 1556 .

3.14.2.1 Embankment

One test per 4,000 square feet, or fraction thereof, of each lift of fill compacted by other than hand-operated machines. One test per 1,000 square feet, or fraction thereof, of each lift of fill compacted by hand-operated machines.

3.15 DISPOSITION OF SURPLUS MATERIAL

Brush, refuse, stumps, roots, and timber shall be removed from Government property.

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SECTION 31 00 00 Page 14