312000 earthwork.pdf

F5W61608 USPFO Warehouse Ohio Army National Guard Rev. 0 Defense Supply Center Columbus, Ohio 30 January 2009 Bid Final

EARTHWORK 312000 - 1

SECTION 312000 – EARTHWORK

PART 1 - GENERAL

1.1 SCOPE OF WORK

A. Earthwork shall consist of all work required to construct the earth grade to the lines, grade, and cross sections called for on the Contract Drawings and Specifications.

Earthwork shall consist of but is not limited to excavation, removal, and satisfactory disposal of all materials, except as specified under Section 311000 Clearing and Grubbing, for the construction of sub-grade, sub-base, entrances, drainage structures, pavement, curb and gutter, storm sewer, water lines, sanitary sewer, and incidental work;

and the removal and satisfactory disposal of unstable and unsuitable materials and the replacement with satisfactory materials where required. All costs for obtaining materials from an off-site borrow area, a site for dumping waste materials, and the hauling of materials to and from these areas shall be the responsibility of the CONTRACTOR and shall be included in the Lump Sum Contract Price. This includes erosion control as described in item 3.10 of this Section. CONTRACTOR shall pay for all permits required under this Specification.

1.2 STANDARD SPECIFICATIONS

A. All work, installations, procedures, materials, and testing of the work performed under this Section shall conform to the Construction and Material Specifications adopted January 1, 2008 by the Ohio Department of Transportation (herein referred to as the Standard Specifications), except as modified by this Specification.

1.3 WARRANTY

A. The CONTRACTOR shall warrant all construction associated with the CONTRACT to be free from defects for a period of one (1) year from the date of final acceptance by the

OWNER.

1.4 CONTRACTORS ORGANIZATION

A. The CONTRACTOR shall have a competent supervisor on the site during the progress of the work who shall act for the CONTRACTOR in all matters concerning the work. He shall have the authority to receive directions and to act upon directions from the OWNER.

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1.5 RELATED WORK

A. Refer to Specification Section 311000 - Clearing and Grubbing.

1.6 RELATED DOCUMENTS

A. Drawings and General Provisions of the Contract, including General and Supplementary Conditions and Division - 1 Specification Sections apply to work of this section.

1.7 SUBMITTALS

A. Topsoil and/or fill materials obtained from a borrow source off the site shall be approved by the GEOTECHNICAL ENGINEER prior to moving the topsoil or fill materials to the jobsite. The OWNER will employ a GEOTECHNICAL ENGINEER to observe and test excavations and compacted fill. Upon completion of this work and as a condition of its acceptance, deliver to the ARCHITECT a written report from the Geotechnical Engineer certifying that the compaction requirements have been obtained including the in-place soil density test reports.

1.8 PAYMENT

A. All work required under this section shall be included in the Lump Sum Contract Price.

PART 2 – PRODUCTS

2.1 TOPSOIL

A. Topsoil shall be relatively free from large roots, sticks, weeds, brush, or stones larger than 1 inch in diameter or other litter and waste products. It shall be a loamy mixture having at least 90% passing the No. 10 sieve. A sample, free from extraneous materials, shall comply with the following requirements:

B. It shall contain not less than 12% nor more than 35% clay as determined in accordance with AASHTO T- 88.

C. The sand content shall not exceed 55% as determined in accordance with AASHTO T- 88.

D. The pH of the sample shall not be lower than 5.0 nor higher than 8.0. The pH shall be determined with an acceptable pH meter, on the portion of the sample passing No. 10 sieve, in accordance with the "Suggested Methods of Tests for Hydrogen Ion Concentration (pH) of Soils" included in the procedures for Testing Soils issued December 1964 by the American Society for Testing Materials.

2.2 FILL AND BACKFILL MATERIALS

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A. Earth Fill Materials

1. Earth fill shall be constructed of materials that will compact and develop stability satisfactory to the GEOTECHNICAL ENGINEER. No sod, frozen material, organics, contaminated, or any material which by decay or otherwise might cause settlement shall be placed or allowed to be utilized as earth fill.

2. No rocks, stones, or broken concrete more than four (4) inches in largest dimensions shall be permitted within a vertical distance of 24 inches form the surface of the finished earth grade. In areas exterior to structural construction no stones, rocks, broken concrete, etc. will be allowed in the filled area larger than two

(2) inches in diameter. Rock shall not exceed 15% of the fill material volume.

3. Earth fill materials may be obtained from excavations on site provided it is approved by the GEOTECHNICAL ENGINEER. If approved earth fill materials obtained from the excavation of this site are insufficient to complete the fill areas to the grades as required by the Construction Drawings, the CONTRACTOR shall obtain necessary earth fill materials from an off-site source of supply.

B. Granular Backfill for Sanitary Sewer, Water mains, and Storm Sewers

1. Granular backfills for sanitary sewers, Water mains, and storm sewers shall be crushed gravel or crushed stone according to the following gradation:

Sieve Size Percent Passing

1 1/2

in. 1 in. 1/2" No. 4 No. 16

No.

100 95+/-5 75+/-15 43+/-13 25+/-15 8+/-4

C. Granular Backfill for Utilities

1. Granular backfill for utilities except as those specified in Article 2.1.2 above shall be fine aggregate (sand) according to the following gradation:

Sieve Size Percent Passing

No. 4 No.

No.

100 95+/-5 8+/-4

2.3 LAWNS

A. See Section 329200 for finish lawn surfaces.

PART 3 – EXECUTION

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3.1 NOTIFICATION OF START OF EARTHWORK

A. The CONTRACTOR shall notify the ARCHITECT and GEOTECHNICAL ENGINEER at least 48 hours in advance of the start of the grading and/or excavation operations.

Samples of on-site and off-site borrow materials must be provided to the GEOTECHNICAL ENGINEER at least 4 days in advance of using the material to allow time to complete laboratory moisture density tests.

3.2 EXCAVATION SAFETY

A. Excavation shall be properly supported in accordance with the requirements of the Occupational Safety and Health Administration (O.S.H.A.) and all state and local agencies governing safety and health on the work site. The support of all excavations shall be provided by the CONTRACTOR at no additional expense to the OWNER.

3.3 STRIPPING TOPSOIL

A. All topsoil shall be removed from area of construction. Under no circumstances shall new construction obtain its structural support from topsoil. If the GEOTECHNICAL ENGINEER determines the removed material is suitable for reuse later, it may be stockpiled, if unsuitable, the CONTRACTOR shall remove the material from the jobsite.

3.4 SITE SUBGRADE PREPARATION

A. After the topsoil is removed to the satisfaction of the GEOTECHNICAL ENGINEER, and further excavation is not required, the site subgrade shall be proofrolled with proper compaction equipment to determine zones of excessively soft, wet, disturbed, or otherwise unsuitable soils. Prior to placing fill over the natural soils, the subgrade shall be scarified to a minimum depth of six (6) inches and compacted in accordance with this specification. This “Site Subgrade Preparation” work may be waived if in the opinion of the GEOTECHNICAL ENGINEER this procedure appears to be detrimental or unnecessary.

3.5 GENERAL EXCAVATION

A. Excavation shall consist of the satisfactory removal and disposal of all materials taken from within the limits of the work contracted, meaning the material lying between the original ground line as shown on the Constructed Drawings regardless of whether the original ground line is exposed to air or is covered by water. Excavation below existing ground line to enable any required construction or removal is included. It is distinctly understood that any reference to earth, rock, silt, debris, or other materials on the Construction Drawings or in the SPECIFICATIONS is solely for the OWNER'S information and shall not be taken as an indications of classified excavations or other quantity of earth, rock, silt, debris, or other material encountered.

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3.6 EXCAVATION FOR PROPOSED BUILDING FOUNDATIONS

A. The CONTRACTOR shall completely remove all existing fill and trapped topsoil within the proposed building footprint plus a minimum of 5 feet beyond to expose firm, stable, natural soil deposits. Once the building footprint area is properly undercut, the natural soil subgrade shall be proof-rolled with a fully loaded tandem-axle dump-truck (or equivalent) to identify potential soft, yielding subgrade areas. The soft areas should be undercut to firm, stable conditions or otherwise remediated prior to placing controlled fill to design grade. Dark brown, stained natural soils can remain in place provided they are firm and stable when proof-rolled. The fill must be replaced according to paragraph 3.8 of this section.

3.7 EXCAVATION FOR PROPOSED PAVEMENT AREAS

A. The CONTRACTOR shall completely remove all existing fill and trapped topsoil under all proposed pavement areas to a minimum depth of two (2) feet below finished subgrade elevation. Once the pavement area is properly undercut, the natural soil subgrade shall be proof-rolled with a fully loaded tandem-axle dump-truck (or equivalent) to identify potential soft, yielding subgrade areas. The soft areas should be undercut to firm, stable conditions or otherwise remediated prior to placing controlled fill to design grade. Dark brown, stained natural soils can remain in place provided they are firm and stable when proof-rolled. The fill must be replaced according to paragraph 3.8 of this section.

3.8 PLACING CONTROLLED EARTH FILL AND BACKFILL

A. Controlled cohesive earthwork materials for foundation, pavement support, or other structures shall be placed in layers not exceeding eight (8) inches in depth, properly moistened to within three (3) percent (wet or dry) of the optimum moisture content and compacted to a dry density of not less than 98% of the Standard Proctor maximum dry density of the material as established by AASHTO T99 (Method A or C) or ASTM D698.

Controlled cohesive earthwork materials placed in planned landscaped areas shall be placed in layers not exceeding eight (8) inches in depth, properly moistened to within three (3) percent (wet or dry) of the optimum moisture content and compacted to a dry density of not less than 90% of the standard Proctor maximum dry density of the material as established by AASHTO T99 (Method A or C) or ASTM D698.

B. Compacting equipment and compacting operations shall be coordinated with the rate of placing controlled earthfill so that the required density is obtained. The GEOTECHNICAL ENGINEER shall perform a sufficient number of tests to establish that materials are placed in conformance with the Contract Drawings and Specifications.

3.9 TOPSOIL PLACEMENT

A. All areas disturbed by grading and construction operations, but not covered by structures, pavement, or trees, shall be covered with a minimum of four (4) inches of topsoil. After

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all excavated areas have been backfilled, the CONTRACTOR shall grade the areas disturbed by construction which changed the contour, allowing for and providing a four (4) inch minimum thickness of approved topsoil. All areas shall be graded to the elevations and contours as indicated by the Construction Drawings. The topsoil surface shall be trimmed and raked to true lines free from unsightly variations, humps, ridges, or depressions. The ground shall be sloped to provided positive drainage away from all buildings. Finish grading shall be left in a condition for grass seeding.

3.10 EROSION CONTROL

A. The CONTRACTOR shall provide erosion control in accordance with the drawings, in any area the CONTRACTOR deems necessary to prevent erosion during construction, in any area which shows signs of erosion, or as directed by the ENGINEER. The CONTRACTOR may use an erosion control method of his choice in any given area unless such a method has failed earlier at that location or a method has been specified on the drawings. The ENGINEER shall determine whether or not any specific erosion control method is successful.

B. The CONTRACTOR shall be responsible for obtaining and following the requirements of an IEPA NPDES storm water permit for construction activity for this project.

3.11 JOB CONDITIONS

A. The CONTRACTOR shall conduct earthwork operations in a manner that will limit dust, noise, and other nuisances. If necessary, water shall be applied to the soil to limit dust, etc. All earthwork operations shall be conducted in accordance with local government regulations.

3.12 LAWNS

A. See Section 329200 for finish lawn surfaces.

END OF SECTION 312000