SECTION 02000.pdf

AUGER CAST PILES 9503

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DIVISION 02000

SECTION 02070 - SELECTIVE DEMOLITION

PART 1 - GENERAL

RELATED DOCUMENTS: Drawings and general provisions of Contract, including General Division 1 Specification Sections, apply to this Section.

SUMMARY: This Section includes, but is not limited to, the following:

Demolition and removal of selected site elements including site pavements and slabs-on-grade.

Disconnecting, capping or sealing, and abandoning or removing existing site utilities.

Demolition and removal of dumpster screen walls, slab-on-grade footings, and associated elements.

Demolition and removal of fencing.

Relocation of existing site utilities, including light poles.

Demolition and removal of existing underground concrete rubble. Refer to Specification Section 02200.

Demolition and removal of other above and below grade improvements to accommodate new construction.

Demolition and removal of existing trench drain.

Patching and repairing.

Demolition and removal of curb and gutter.

Related Sections: The following Sections contain requirements that relate to this Section:

Division 1 Section "Cutting and Repairing" for cutting and repairing procedures for selective demolition operations.

Division 2 Section "Site Clearing" for site clearing and removal of topsoil and vegetation.

Division 2 Section "Earthwork" for soil materials, excavating, backfilling, and site grading.

Division 2 Section “Landscape Work” for relocation of trees.

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DEFINITIONS:

Remove: Remove and legally dispose of items except those indicated to be reinstalled, salvaged, or to remain the Government’s property.

Existing to Remain: Protect construction indicated to remain against damage and soiling during selective demolition.

MATERIALS OWNERSHIP: Except for items or materials indicated to be reused, salvaged, reinstalled, or otherwise indicated to remain the Government’s property, demolished materials shall become the Contractor's property and shall be removed from the site with further disposition at the Contractor's option, unless otherwise indicated.

SUBMITTALS: Schedule indicating proposed sequence of operations for selective demolition work for review prior to start of work. Include coordination for shutoff, capping, and continuation of utility services as required.

Coordinate with adjacent facilities to permit continuing occupation of existing building and parking areas.

QUALITY ASSURANCE: Regulatory Requirements: Comply with hauling and disposal regulations of authorities having jurisdiction.

JOB CONDITIONS: Occupancy: Conduct selective demolition work in manner that will minimize need for disruption of adjacent Government’s normal operations. Provide minimum of 72 hours advance notice to Contracting Officer’s Representative of demolition activities that will affect adjacent occupied facilities.

Condition of Structures: The Government assumes no responsibility for actual condition of items or structures to be demolished.

Conditions existing at time of inspection for bidding purposes will be maintained by Government insofar as practicable.

Partial Demolition and Removal: Items indicated to be removed but of salvageable value to Contractor may be removed as work progresses. Transport salvaged items from site as they are removed.

Storage or sale of removed items on site will not be permitted.

Protections: Provide temporary barricades and other forms of protection to protect from injury due to selective demolition work.

Conduct operations to prevent damage to adjacent buildings, structures, sidewalks, pavements, and other facilities and to prevent injury or damage to persons or property.

Provide interior and exterior shoring, bracing, or support to prevent movement, settlement, or collapse

02372 - 3 of structure or element to be demolished and adjacent facilities or work to remain.

Remove protections at completion of work.

Damages: Promptly repair damages caused to adjacent facilities by demolition work.

Environmental Controls: Comply with governing regulations pertaining to environmental protection.

PART 2 – PRODUCTS: Not Applicable in this section.

PART 3 - EXECUTION

EXAMINATION: Verify that utilities have been disconnected and capped.

Survey existing conditions and correlate with requirements indicated to determine extent of selective demolition required.

When unanticipated mechanical, electrical, or structural elements that conflict with the intended function or design are encountered, investigate and measure the nature and extent of the conflict.

Promptly submit a written report to the Architect.

UTILITY SERVICES: Maintain existing utilities to remain in service and protect them against damage during selective demolition operations.

Do not interrupt existing utilities serving occupied or operating facilities, except when authorized in writing by Contracting Officer and authorities having jurisdiction. Provide temporary services during interruptions to existing utilities, as acceptable to Government.

Provide not less than 72 hours' notice to Contracting Officer if shutdown of service is required during changeover.

Utility Requirements: Locate, identify, disconnect, and seal or cap off indicated utility services.

Where utility services are required to be removed, relocated, or abandoned, provide bypass connections to maintain continuity of service to other used or occupied buildings before proceeding with selective demolition.

PREPARATION: General: Provide interior and exterior shoring, bracing, or support to preserve stability and prevent movement, settlement, or collapse of areas to be demolished.

Drain, purge, or otherwise remove, collect, and dispose of chemicals, gases, acids, or other dangerous materials before proceeding with selective demolition operations.

Conduct demolition operations and remove debris to ensure minimum interference with roads, streets, walks, and other adjacent occupied and used facilities.

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Do not close or obstruct streets, walks, or other adjacent occupied or used facilities without permission from Government. Provide alternate routes around closed or obstructed traffic ways if required by governing regulations.

Conduct demolition operations to prevent injury to people and damage to adjacent buildings and facilities to remain. Ensure safe passage of people around selective demolition area.

Erect temporary protection, such as walks and fences, as needed for protection.

Protect existing site improvements, appurtenances, and landscaping to remain.

DEMOLITION: General: Perform selective demolition work in a systematic manner. Use methods required to complete work within limitations of governing regulations and as follows:

Neatly cut openings and holes plumb, square, and true to dimensions required. Use cutting methods least likely to damage construction to remain or adjoining construction. To minimize disturbance of adjacent surfaces, use hand or small power tools designed for sawing or grinding, not hammering and chopping.

Cut or drill from the exposed or finished side into concealed surfaces to avoid marring existing finished surfaces.

Do not use cutting torches until work area is cleared of flammable materials. At concealed spaces, such as duct and pipe interiors, verify condition and contents of hidden space before starting flame-cutting operations.

Maintain portable fire-suppression devices during flame-cutting operations.

Maintain adequate ventilation when using cutting torches.

Remove decayed, vermin-infested, or unsuitable materials and promptly dispose of off-site.

Remove structural framing members and lower to ground by method suitable to avoid free fall and to prevent ground impact or dust generation.

Return elements of construction and surfaces to remain to condition existing before start of selective demolition operations.

Locate demolition equipment throughout structure and promptly remove debris to avoid imposing excessive loads on supporting walls, floors, or framing.

Demolish concrete and masonry in small sections. Cut concrete and masonry at junctures with construction to remain, using power-driven masonry saw or hand tools; do not use power-driven impact tools.

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Break up and remove concrete slabs on grade, footings, and foundations, unless otherwise shown to remain.

Completely fill below-grade areas and voids resulting from demolition work. Provide fill consisting of approved earth, gravel, or sand, free of trash and debris, stones over 6 inches in diameter, roots, or other organic matter and thoroughly compact to specified criteria per Section 02200.

DISPOSAL OF DEMOLISHED MATERIALS: Remove from building site debris, rubbish, and other materials resulting from demolition operations, unless otherwise acceptable to Contracting Officer.

Transport and legally dispose off site.

If hazardous materials are encountered during demolition operations, comply with applicable regulations, laws, and ordinances concerning removal, handling, and protection against exposure or environmental pollution.

Burning of removed materials is not permitted on project site.

PATCHING AND REPAIRING: Promptly patch and repair damaged surfaces caused to adjacent construction by selective demolition operations.

Patching is specified in Division 1 Section "Cutting and Repairing."

Where repairs to existing surfaces are required, patch to produce surfaces suitable for new materials.

END OF SECTION 02070

SECTION 02110 - SITE CLEARING

PART 1 - GENERAL

RELATED DOCUMENTS: Drawings and general provisions of Contract, including General and Division 1 Specification Sections, apply to this Section.

SUMMARY: This Section includes the following:

Removal of vegetation. Refer to Specification Section 02900 for relocation of existing trees.

Topsoil stripping.

Clearing and grubbing.

Removing existing above-grade and below-grade site improvements within construction limits.

Refer to Specification Section 02070.

PROJECT CONDITIONS: Traffic: Conduct site clearing operations to ensure minimum interference with roads, streets, walks, and other adjacent occupied or used facilities. Do not close or obstruct

02372 - 6 streets, walks or other occupied or used facilities without permission from Government and authorities having jurisdiction.

Protection of Existing Improvements: Provide protections necessary to prevent damage to existing improvements to remain in place.

Protect improvements on adjoining properties and on Government’s property.

Restore damaged improvements to their original condition, as acceptable to property owners.

EXISTING SERVICES: General: Indicated locations are approximate; determine exact locations and elevations of all utilities before commencing Work.

Place markers to indicate location of underground services. Identify locations on Project Record Documents.

PART 2 – PRODUCTS: Not applicable to this Section.

SITE CLEARING: General: Remove shrubs, grass and other vegetation, improvements, or obstructions as required to permit installation of new construction. Removal includes digging out and off-site disposing of stumps, roots, and other underground obstructions.

Refer to Specification Section 02070 for removal of existing site pavements and underground concrete rubble.

Topsoil: Topsoil is defined as friable clay loam surface soil found in a depth of not less than 4 inches.

Satisfactory topsoil is reasonably free of subsoil, clay lumps, stones, and other objects over 2 inches in diameter, and without weeds, roots, and other objectionable material.

Strip topsoil in a manner to prevent intermingling with underlying subsoil or other objectionable material. Remove heavy growths of grass before stripping.

Stockpile topsoil in storage piles in areas as directed. Construct storage piles to provide free drainage of surface water. Cover storage piles, if required, to prevent wind erosion.

Stripped topsoil, if approved by Landscape Architect, shall be used exclusively for finish grading.

Dispose of unsuitable topsoil same as specified for disposal of waste material.

Provide new topsoil as required to comply with Specification Section 02900.

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Clearing and Grubbing: Clear site of trees, shrubs and other vegetation, except for those indicated to remain.

Completely remove stumps, roots, and other debris protruding through ground surface.

Fill depressions caused by clearing and grubbing operations with satisfactory soil material, unless further excavation or earthwork is indicated.

Place fill material in horizontal layers not exceeding 6 inches loose depth, and thoroughly compact to specified criteria per Section 02200.

Removal of Improvements: Remove existing improvements as necessary to facilitate new construction.

DISPOSAL OF WASTE MATERIALS: Burning on Government’s Property: Burning is not permitted on Government’s property, unless Burning Permit is obtained.

Removal from Government’s Property: Remove waste materials and unsuitable topsoil from Government’s property and dispose of in lawful manner.

END OF SECTION 02110

SECTION 02200 - EARTHWORK

PART 1 - GENERAL

RELATED DOCUMENTS: Drawings and general provisions of Contract, including General and Division 1 Specification Sections, apply to this Section.

SUMMARY: This Section includes the following:

Preparing and grading subgrades for building slabs, walks, and pavements.

Preparing stabilized low volume change zone for support of building slabs and pavements.

Excavating and backfilling for underground mechanical and electrical utilities and buried site, mechanical, and electrical appurtenances.

Importing and placing required soil fill materials.

Backfilling of void created by removal of underground concrete rubble. Refer to Section

02070.

Related Sections: The following Sections contain requirements that relate to this Section.

Division 2 Section “Selective Demolition” for removal of underground concrete rubble.

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Division 2 Section "Site Clearing" for site stripping including removal of trees and vegetation.

Division 2 Section “Excavation, Trenching and Backfilling for Utilities”, for trenching and backfilling.

Division 2 Section "Landscape Work" for finish grading, including importing, placing and preparing topsoil for lawns and planting.

DEFINITIONS

Excavation: consists of removal of material encountered to subgrade elevations indicated, including removal of unacceptable existing fill materials beneath foundation bearing levels and slabs-on-grade.

All footings shall bear on acceptable underlying native soils and all unsuitable material shall be removed and disposed of.

Unauthorized excavation: consists of removal of materials beyond indicated subgrade elevations or dimensions without specific direction of Contracting Officer. Unauthorized excavation, as well as remedial work directed by Contracting Officer, shall be at Contractor's expense.

Under footings, fill unauthorized excavation by extending indicated bottom elevation of footing or base to excavation bottom, without altering required top elevation. Lean concrete fill may be used to bring elevations to proper position, when acceptable to Contracting Officer and Soil Testing Lab.

In locations other than those above, backfill and compact unauthorized excavations as specified for authorized excavations of same classification, unless otherwise directed by Contracting Officer.

Subgrade: The undisturbed earth or the compacted soil layer immediately below slabs, pavements, or topsoil materials.

Structure: Buildings, foundations, slabs, curbs, or other man-made stationary features occurring above or below ground surface.

Borrow: Soil material obtained off-site when sufficient approved soil material is not available from excavations.

SUBMITTALS: Test Reports: Submit the following reports directly to Contracting Officer’s Representative and Architect from the testing services, with copy to Contractor:

Test reports on fill and borrow material, including laboratory analysis.

Verification of suitability of each footing subgrade material, in accordance with specified requirements.

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Field reports; in-place soil density tests.

One optimum moisture-maximum density curve for each type of soil material.

Report of actual unconfined compressive strength and/or results of bearing tests.

QUALITY ASSURANCE: Codes and Standards: Perform earthwork and excavation work in compliance with applicable requirements of authorities having jurisdiction.

Testing and Inspection Service: Contractor shall employ and pay for a qualified independent geotechnical testing laboratory to classify proposed on-site fill and borrow soils to verify that soils comply with specified requirements and to perform soil testing and inspection service during earthwork operations.

Pre-installation Conference: Conduct conference at Project site

Before commencing earthwork, meet with the Contracting Officer’s Representative, Architect, Geotechnical Engineer, independent testing agency, and other concerned entities. Review earthwork procedures and responsibilities including testing and inspection procedures and requirements. Notify participants at least 3 working days prior to convening conference.

Record discussions and agreements and furnish a copy to each participant.

PROJECT CONDITIONS: Site Information: Data in subsurface investigation report was used for the basis of the design and is available to the Contractor for information only. Conditions are not intended as representations or warranties of accuracy or continuity between soil borings. It is expressly understood that neither Government nor Architect will be responsible for interpretations or conclusions drawn from this data by Contractor.

Additional test borings and other exploratory operations may be performed by the Contractor, at the Contractor's option; however, no change in the Contract Sum will be authorized for such additional exploration.

Existing Utilities: Locate existing utilities in areas of excavation work. If utilities are indicated to remain in place, provide adequate means of support and protection during earthwork operations.

Should uncharted, or incorrectly charted, piping or other utilities be encountered during excavation, consult utility owner immediately for directions. Cooperate with Government and utility companies in keeping respective services and facilities in operation. Repair damaged utilities to satisfaction of utility owner.

Do not interrupt existing utilities serving occupied facilities, except when permitted in writing by Contracting Officer and then only after acceptable temporary utility services have been provided.

Provide minimum of 48-hour notice to Contracting Officer and receive written notice to proceed before interrupting any utility.

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Use of Explosives: Use of explosives is not permitted.

Protection of Persons and Property: Barricade open excavations occurring as part of this work and post with warning lights and other appropriate barriers.

Operate warning lights as recommended by authorities having jurisdiction.

Protect structures, utilities, sidewalks, pavements, and other facilities from damage caused by settlement, lateral movement, undermining, washout, and other hazards created by earthwork operations.

PART 2 - PRODUCTS

SOIL MATERIALS: General: Obtain approved borrow soil materials from adjacent stockpiles when sufficient approved soil materials are not available from excavations.

Satisfactory soil materials for fill and backfill:

Clean excavated materials or approved borrow material free from organic material and debris.

Silty or sandy clay with a maximum liquid limit of 35% and plasticity index less than 15 but no less than 5.

Silty or clayey sand with a minimum 15% fines by dry weight passing #200 sieve.

ACCESSORIES: Warning Tape: Acid-and alki-resistant polyethylene film warning tape manufactured for marking and identifying underground utilities, 6 inches wide and 4 mils thick, continuously inscribed with a description of the utility.

PART 3 - EXECUTION

PREPARATION: Protect structures, utilities, sidewalks, pavements, and other facilities from damage caused by settlement, lateral movement, undermining, washout, and other hazards created by earthwork operations.

Protect subgrades and foundation soils against freezing temperatures or frost. Provide protective insulating materials as necessary.

Provide erosion control measures to prevent erosion or displacement of soils and discharge of soil-bearing water runoff or airborne dust to adjacent properties and walkways.

EXCAVATION: Excavation is unclassified and includes excavation to subgrade elevations indicated, regardless of character of materials and obstructions encountered.

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STABILITY OF EXCAVATIONS: General: Comply with local codes, ordinances, and requirements of agencies having jurisdiction.

Contractor shall obtain Digging Permit prior to commencing excavation.

All excavations shall be constructed and shored in accordance with OSHA requirements.

Slope sides of excavations to comply with local codes, ordinances, and requirements of agencies having jurisdiction. Shore and brace where sloping is not possible because of space restrictions or stability of material excavated. Maintain sides and slopes of excavations in safe condition until completion of backfilling.

Shoring and Bracing: Provide materials for shoring and bracing, such as sheet piling, uprights, stringers, and cross braces, in good serviceable condition. Maintain shoring and bracing in excavations regardless of time period excavations will be open. Extend shoring and bracing as excavation progresses.

DEWATERING: Dewatering methods shall be in accordance with state and/or local municipality practices.

Prevent surface water and subsurface or groundwater from flowing into excavations, from ponding on prepared subgrades, and from flooding project site and surrounding area.

Protect subgrades and foundation soils from softening and damage by rain or water accumulation.

Do not allow water to accumulate in excavations. Remove water to prevent softening of foundation bottoms, undercutting footings, and soil changes detrimental to stability of subgrades and foundations. Provide and maintain pumps, well points, sumps, suction and discharge lines, and other dewatering system components necessary to convey water away from excavations.

Establish and maintain temporary drainage ditches and other diversions outside excavation limits to convey rainwater and water removed from excavations to collecting or runoff areas. Do not use trench excavations as temporary drainage ditches.

STORAGE OF EXCAVATED MATERIALS: Stockpile excavated materials acceptable for backfill and fill where directed. Place, grade, and shape stockpiles for proper drainage. Cover, if required, to prevent wind-blown dust.

Locate and retain soil materials away from edge of excavations.

EXCAVATION FOR STRUCTURES: Conform to elevations and dimensions shown within a tolerance of plus or minus 0.10 foot, and extending a sufficient distance from footings and foundations to permit placing and removal of concrete formwork, installation of services, and other construction and for inspection.

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Excavations for footings and foundations: Do not disturb bottom of excavation. Excavate by hand to final grade just before concrete reinforcement is placed. Trim bottoms to required lines and grades to leave solid base to receive other work.

EXCAVATION FOR PAVEMENTS AND WALKS: Cut surface under pavements and walks to comply with elevations and grades as indicated.

COLD WEATHER PROTECTION: Protect excavation bottoms against freezing when atmospheric temperature is less than 35o F.

BACKFILL AND FILL: General: Place soil material in layers to required subgrade elevations, for each area classification listed below, using materials specified in this Section.

Under grassed areas, use satisfactory excavated or fill material. Provide topsoil, minimum depth 6", for finish grading as specified in Section 02900.

Under building slabs, use satisfactory fill material and stabilized low volume change zone.

Clean sand is unacceptable as a fill material.

Under pavements and walks, use satisfactory fill material and stabilized low volume change zone.

Under piping and conduit, use subbase materials where required over rock bearing surface and for correction of unauthorized excavation. Shape excavation bottom to fit bottom 90o of cylinder.

Backfill trenches with concrete where trench excavations pass within 18 inches of column or wall footings and that are carried below bottom of such footings or that pass under wall footings. Place concrete to level of bottom of adjacent footing.

Concrete is specified in Division 3.

Do not backfill trenches until tests and inspections have been made and backfilling is authorized by Contracting Officer. Use care in backfilling to avoid damage or displacement of pipe systems.

Provide 4-inch-thick concrete base slab support for piping or conduit 8 inches and smaller and less than 2'-6" below surface of roadways and pavements. After installation and testing of piping or conduit, provide minimum 4-inch-thick encasement (sides and top) of concrete prior to backfilling or placement of pavement subbase.

Utility trenches entering the structure from the exterior shall be plugged a minimum of 4 feet on each side of the exterior building foundation wall with compacted natural clay fill or low cement sand mix (2 sack) concrete as approved by Soil Testing Lab.

Backfill excavations as promptly as work permits, but not until completion of the following:

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Acceptance of construction below finish grade including, where applicable, waterproofing and perimeter insulations.

Inspection, testing, approval, and recording locations of underground utilities have been performed and recorded.

Removal of concrete formwork.

Removal of shoring and bracing, and backfilling of voids with satisfactory materials. Cut off temporary sheet piling driven below bottom of structures and remove in manner to prevent settlement of the structure or utilities, or leave in place if required.

Removal of trash and debris from excavation.

Install warning tape directly above utilities, 12 inches below finished grade, except 6 inches below pavements and slabs.

PLACEMENT AND COMPACTION: Ground Surface Preparation: Remove vegetation, debris, unsatisfactory soil materials, obstructions, and deleterious materials from ground surface prior to placement of fills.

Strip topsoil from construction areas as specified in Section 02110. Topsoil shall be used exclusively for finish grading.

Following topsoil removal, strip existing on-site fill material and miscellaneous debris from under building slabs on grade and pavements. A minimum of 18 inches of existing fill shall be removed and replaced with newly compacted fill under the building floor slab. Exact extent of existing fill material to be removed shall be determined by Soil Testing Lab.

Site preparation procedures shall be applied a minimum of one foot laterally beyond all edges of footing foundations or pavements for each foot of vertical fill required, or a minimum of five feet beyond the edge of building slabs on grade or pavements, whichever is greater.

Following completion of stripping and grading operations, and prior to any scarification, exposed subgrades shall be proofrolled with several passes, in mutually perpendicular directions, using rubber-tired heavy construction equipment weighing a minimum of 25 tons. Suitable proofrolling equipment would include such items as a fully loaded dump truck or scraper. Proofrolling operations shall be observed by qualified geotechnical personnel. Any area which cannot be satisfactorily densified in-place shall be removed and replaced with approved, properly compacted fill material.

All unsuitable materials, including materials that become soft and yielding during proofrolling operations, shall be removed and replaced with acceptable and properly compacted fill material.

Following completion of proofrolling activities and correction of all problem areas, exposed subgrades shall be scarified to a minimum depth of 6 inches, then adjusted in moisture content and compacted as herein specified.

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All fill materials shall be free from organic matter and debris and shall consist of approved materials acceptable to Soil Testing Lab. Fill materials shall have a liquid limit of less than 35%, a maximum Plasticity Index of 15, a minimum Plasticity Index of 5, and contain a minimum of 15% fines (material passing the #200 sieve).

All compacted fill shall be placed under controlled conditions and placed under observation of Soil Testing Lab representative.

Place backfill and fill materials in layers not more than 8 inches in loose depth for material compacted by heavy compaction equipment, and not more than 4 inches in loose depth for material compacted by hand-operated tampers.

Before compaction, moisten or aerate each layer as necessary to provide specified moisture content.

Compact each layer to required percentage of maximum dry density or relative dry density for each area classification. Do not place backfill or fill material on surfaces that are muddy, frozen, or contain frost or ice.

Place backfill and fill materials evenly adjacent to structures, piping, or conduit to required elevations.

Prevent wedging action of backfill against structures or displacement of piping or conduit by carrying material uniformly around structure, piping, or conduit to approximately same elevation in each lift.

COMPACTION AND MOISTURE CONTROL: General: Control soil compaction during construction providing minimum and maximum percentages of density specified for each area classification and moisture contents as indicated.

Compaction: Maximum dry density shall be as determined by state or municipality designation. Compaction for filling and backfill operations shall be as follows:

1. Fill under Footings: Minimum of 95% of maximum dry density.

2. Fill under Floor Slabs: Minimum of 92% of maximum dry density.

3. Fill under Pavements: Minimum of 95% of maximum dry density.

4. Non-Structural Fill and Backfill: Minimum of 85% of maximum dry density.

Moisture Content: Moisture content shall be controlled during construction based on an acceptable range of moisture content as determined by Modified Proctor, state or municipality designation. Moisture content shall be as follows:

1. Fat Clay, Lean Clay: Minimum of 2% above optimum moisture content.

(CH, CL, MH)

2. Silts, Clayey Sand, Sandy Clay: 2% to + 2% of optimum moisture content.

(GM, GC, SM, SC, ML)

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3. Sands, Gravel: At workable moisture content.

(GM, GP,SW, SP)

Footing Foundations: Footings shall bear on underlying native soils.

All footing excavations shall be inspected by Soil Testing Lab to ensure that all existing fill is removed.

All bearing materials shall be evaluated by qualified geotechnical personnel at the time of foundation construction. Evaluation shall be accomplished by performing one test probe at each isolated foundation location and additional probes as determined by the testing agency along continuous footings.

Test probes shall extend a minimum of 3 feet below foundation bearing level or into underlying native soils. In-situ testing and testing of recovered samples from probes shall be performed as necessary to adequately evaluate bearing materials encountered.

Unsuitable existing fill and objectionable materials shall be removed and foundations shall be lowered to bear on approved, suitable material. Any over excavation required because of unsuitable soils shall extend laterally in all directions beyond the edges of the foundation, a minimum of 8 inches for each 12 inches of over excavated depth.

Care shall be taken to minimize wetting or drying of the exposed soil during foundation construction.

All loosened or disturbed material, or extremely wet or dry material, shall be removed from the foundation excavation prior to placing reinforcing steel and concrete.

Building Floor Slabs: Scarified subgrade and fill material below floor slabs, shall be adjusted in moisture content and compacted as specified.

All newly placed fill material beneath floor slabs shall consist of approved material, free from organic matter and debris. All fill shall be placed as soon as possible following scarifying procedures in order to minimize drying or excessive wetting of exposed subgrade soils.

Fill material used beneath floor slabs shall be as herein specified and shall be examined and approved by Soil Testing Lab prior to use. A stabilized low volume change zone shall be constructed beneath floor slabs as specified.

Pavements: Exposed subgrades shall be scarified and adjusted in moisture content and compacted as specified.

A stabilized low volume change zone shall be constructed beneath pavements as specified.

Moisture Control: Where subgrade or layer of soil material must be moisture conditioned before compaction, uniformly apply water to surface of subgrade or layer of soil material. Apply water in minimum quantity as necessary to prevent free water from appearing on surface during or subsequent to compaction operations.

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Remove and replace, or scarify and air dry, soil material that is too wet to permit compaction to specified density. Where soils become too dry, take appropriate measures to develop the minimum moisture level.

Soil material that has been removed because it is too wet to permit compaction may be stockpiled or spread and allowed to dry. Assist drying by discing, harrowing or pulverizing until moisture content is reduced to a satisfactory value.

Correct improperly compacted areas or lifts as directed by Contracting Officer if soil density tests indicate inadequate compaction.

BUILDING SLAB AND PAVEMENT STABILIZED SUBGRADE: General: Stabilized subgrade consists of placing stabilized materials, in layers to specified thickness, and compacting to specified density with proper moisture content, over subgrade surface supporting building slabs and pavements.

Stabilized Subgrade: A low volume change zone shall be constructed below floor slabs and pavements. Low volume change zone shall be a minimum of 12" thick, exclusive of any granular level course under floor slabs and a minimum of 9" thick under pavements.

Low volume change zone under floor slabs may be constructed of either imported low volume change fill materials acceptable to Soil Testing Lab or stabilized on-site cohesive soils.

Imported fill material used to develop low volume change zone shall consist of soils as specified and as acceptable to Soil Testing Lab. Limestone screenings may be used as approved by Soil Testing Lab.

Low volume change zone under pavements shall be constructed of stabilized in-place soils.

On-site soils shall be stabilized with hydrated lime. A minimum of 4% lime shall be used, based on the dry unit weight of the soil.

Stabilizing agent shall be completely and uniformly blended into site soils using mechanical mixers. Application procedures shall be performed in accordance with MDOT requirements.

Low volume change zone materials, including percentage of stabilization material, shall be approved by Soil Testing Lab. Provide written documentation of acceptability of low volume change materials from Soil Testing Lab.

The lift thickness, moisture content, and compaction of stabilized low volume change zone material shall be as specified for building floor slabs and pavements.

The stabilized low volume change zone under pavements and aprons shall extend a minimum distance of 1 foot beyond the edge of driveways, pavements, and aprons.

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GRADING: General: Uniformly grade areas within limits of grading under this section, including adjacent transition areas. Smooth finished surface within specified tolerances, compact with uniform levels or slopes between points where elevations are indicated or between such points and existing grades.

Grading Outside Building Lines: Grade areas adjacent to building lines to drain away from structures and to prevent ponding.

Finish surfaces free from irregular surface changes and as follows:

Lawn or Unpaved Areas: Finish areas to receive topsoil to within not more than 0.10 foot above or below required subgrade elevations.

Walks: Shape surface of areas under walks to line, grade, and cross-section, with finish surface not more than 0.10 foot above or below required subgrade elevation.

Pavements: Shape surface of areas under pavement to line, grade, and cross-section, with finish surface not more than ½ inch above or below required subgrade elevation.

Positive Drainage: Topsoil and fill material shall be sloped at a minimum grade of 5% for a minimum distance of 10 feet to provide positive drainage away from building foundations, slabs-on-grade, pavements and sidewalks.

Grading Surface of Fill under Building Slabs: Grade smooth and even, free of voids, compacted as specified, and to required elevation. Provide final grades within a tolerance of ½ inch when tested with a 10-foot straightedge.

Compaction: After grading, compact subgrade surfaces to the depth and indicated percentage of maximum density for each area classification.

TOPSOIL: Topsoil shall be stockpiled for re-use in finish grading if acceptable to Contracting Officer.

If quality or quantity of stockpiled topsoil is inadequate or insufficient, provide additional topsoil as required to provide a 6" minimum thickness over area within disturbed construction limits.

Provide new topsoil that is fertile, friable, natural loam, surface soil, free of subsoil, clay lumps, brush, weeds and other litter, and free of roots, stumps, stones larger than 2 inches in any dimension, and other extraneous or toxic matter harmful to plant growth.

Obtain topsoil from local sources or from areas having similar soil characteristics to that found at project site. Obtain topsoil only from naturally, well-drained sites where topsoil occurs in a depth of not less than 4 inches. Do not obtain from bogs or marshes.

FIELD QUALITY CONTROL: Quality Control Testing During Construction: Allow testing service to inspect and approve each subgrade and fill layer before further backfill or construction work is performed.

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Perform field density tests in accordance with state or municipality designation (sand cone method) or other state or municipality designation, as applicable.

Field density tests may also be performed by the nuclear method in accordance with state or municipality designation, providing that calibration curves are periodically checked and adjusted to correlate to tests performed using state or municipality designation. In conjunction with each density calibration check, check the calibration curves furnished with the moisture gages in accordance with state or municipality designation.

If field tests are performed using nuclear methods, make calibration checks of both density and moisture gages at beginning of work, on each different type of material encountered, and at intervals as directed by the Contracting Officer.

Footing Subgrade: For each strata of soil on which footings will be placed, perform at least one test to verify required design bearing capacities and perform test probes as specified. Subsequent verification and approval of each footing subgrade may be based on a visual comparison of each subgrade with related tested strata when acceptable to Contracting Officer and Soil Testing Lab.

Paved Areas and Building Slab Subgrade: Perform at least one field density test of subgrade for every 2,000 sq. ft. of paved area or building slab, but in no case fewer than three tests.

In each compacted fill layer, perform one field density test for every 2,000 sq. ft. of overlaying building slab or paved area, but in no case fewer than three tests.

Foundation Wall Backfill: Perform at least two field density tests at locations and elevations as directed.

If subgrade or fills that have been placed are below specified density, perform additional compaction and testing until specified density is obtained.

EROSION CONTROL: Provide erosion control methods in accordance with requirements of authorities having jurisdiction and as shown on the drawings.

MAINTENANCE: Maintenance Program: A regular maintenance program shall be implemented during the construction period to identify areas where water is standing adjacent to building foundations. These areas shall be repaired immediately to provide positive drainage away from the building.

Protection of Graded Areas: Protect newly graded areas from traffic and erosion. Keep free of trash and debris.

Repair and reestablish grades in settled, eroded, and rutted areas to specified tolerances.

Reconditioning Compacted Areas: Where completed compacted areas are disturbed by subsequent construction operations or adverse weather, scarify surface, reshape, and compact to required density prior to further construction.

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Settling: Where settling is measurable or observable at excavated areas during general project warranty period, remove surface (pavement, lawn, or other finish), add backfill material, compact, and replace surface treatment. Restore appearance, quality, and condition of surface or finish to match adjacent work, and eliminate evidence of restoration to greatest extent possible.

DISPOSAL OF EXCESS AND WASTE MATERIALS: Removal from Government’s Property:

Remove waste materials, including unacceptable excavated material, trash and debris, and legally dispose of it off Government’s property.

END OF SECTION 02200

SECTION 02372 - AUGER CAST PILES

PART 1 GENERAL

RELATED DOCUMENTS

Drawings and general provisions of Contract, including General and Division 1 Specification Sections, apply to this Section.

SUMMARY

This Section includes drilled, auger cast piles.

Extent of auger cast piles is shown on drawings, including locations, diameters of shafts, estimated bottom elevations, top elevations, and details of construction.

Division 2 Section “Earthwork” for excavation.

Division 3 Section “Cast-In-Place Concrete” for concrete and related materials.

Division 5 Section “Structural Steel” for anchor bolts.

SYSTEM DESCRIPTION

Auger cast pile system shall consist of auger cast piles, pile reinforcement, and anchor bolts as shown on Drawings.

Drawings are based on assumed elevation of bottom of auger cast pile. If required, pile diameter and length will be modified by Contracting Officer based on recommendation of Testing Agency.

Payment for auger cast pile system will be based on quantities determined by Testing Agency and unit prices stated in Bid Form.

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QUALITY ASSURANCE

Auger Cast Pile Installer Qualifications: Not less than three successfully completed contracts within the last 5 years with similar soil conditions, pile diameters, depths, and volumes to that contained in this Project. Submit satisfactory proof of compliance to Contracting Officer’s Representative before beginning Work.

Survey Work: Contractor shall employ, at his expense, a surveyor, registered in State in which Project is located, to perform surveys, layouts, and measurements for auger cast pile Work.

Record and maintain information log of each auger cast pile and cooperate with Testing Agency to provide data for required reports.

Upon completion of Work, before construction continues, surveyor shall provide reproducible Record Foundation Drawing, corrected to conform with conditions existing after construction.

Show following on Record Drawing:

Exact location and top elevation of all auger cast piles at same scale and orientation as Drawings.

Note all auger cast piles which do not meet specified tolerances.

Do not continue with foundation Work until Contracting Officer’s Representative has reviewed Record Drawing.

Testing Agency: Testing Agency will be independent testing laboratory employed by Contractor and approved by Contracting Officer.

Testing Agency is responsible for conducting, monitoring and reporting results of all tests required under this Section. Testing Agency has authority to reject materials not meeting Specifications.

Testing Agency shall observe all auger cast pile operations.

Responsibilities of Testing Agency:

Be present during all auger cast pile placement operations.

Keep Auger Cast Pile Log. Some data will be furnished by surveyor, but Testing Agency will complete log.

Confirm that each pile provides required capacity.

Confirm that each pile is at proper location.

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Be present during all pile load tests.

CODES AND STANDARDS

American Society for Testing and Materials (ASTM). Comply with the following:

ASTM A615, "Specification for Deformed and Plain Billet-Steel Bars for Concrete Reinforcement".

ASTM C33, "Specification for Concrete Aggregates".

ASTM C109, "Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or 50-mm Cube Specimens)".

ASTM C150, "Specification for Portland Cement".

ASTM C618, "Specification for Fly Ash and Raw or Calcined Natural Pizzolan for Use as a Mineral Admixture in Portland Cement Concrete".

ASTM C937, "Specification for Grout Fluidifier for Preplaced- Aggregate Concrete".

ASTM D1143, "Method of Testing Piles Under Static Axial Compressive Load".

SUBMITTALS

General: Submit the following in accordance with Conditions of Contract and Division 1 Specification Sections.

Satisfactory proof of installer qualifications.

Record Foundation Drawing.

Auger Cast Pile Log: Submit Auger Cast Pile Log for each pile within 2 working days after completion of pile. Surveyor to provide items marked (s) to Testing Agency for inclusion in log.

Include the following:

Design diameter.

Actual diameter. (s) Design elevation at bottom and top. (s) Actual elevation at bottom and top. (s) Design location of centerlines at top. (s) Actual location of centerlines at top. (s) Variation from plumb. (s) Starting and finishing times.

Total replacement time.

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Time required for each foot of penetration.

Grout mix design.

Pressure used during grouting procedure.

Volume of grout placed.

Results of soil tests, if any.

Any unusual conditions encountered.

Within 2 working days of day mortar cube testing is performed, submit to Contracting Officer’s Representative the following information:

Project name and location.

Contractor's name.

Testing Agency's name, address, and phone number.

Grout supplier.

Date of report.

Testing Agency technician's name (sampling and testing).

Location of pile(s).

Grout mix data (quantity and type):

Cement.

Fine aggregate.

Mineral filler.

Fluidifier.

Other admixtures.

Water.

Weather data:

Air temperatures.

Weather.

Wind speed.

Compressive test data (7 day and 28 day):

Cube number.

Age of mortar when tested.

Date and time of cube test.

Curing time (field and lab).

Compressive strength.

Dimensions shall be accurate to nearest 1/4 inch, except record elevations of pile bottoms shall be accurate to nearest inch.

Logs shall be prepared daily and jointly signed by Contractor, Testing Agency, and Surveyor.

Auger Cast Pile Load Tests: Testing Agency shall submit each test report within 2 working days of test.

Shop Drawings: Show all steel reinforcement, dowels, and anchor bolts cast in auger cast piles.

PROJECT CONDITIONS

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Site Information: Data in subsurface investigation report was used for the basis of the design and is available to the Contractor for information only. Conditions are not intended as representations or warranties of accuracy or continuity between soil borings. It is expressly understood that neither Government nor Architect will be held responsible for interpretations or conclusions drawn from this data by Contractor.

Additional test borings and other exploratory operations may be performed by the Contractor, at the Contractor’s option, however, no change in the Contract Sum will be authorized for such additional exploration.

Existing Utilities: Locate existing underground utilities by careful hand excavation before starting auger cast pile Work. If utilities are to remain in place, provide protection from damage during auger cast pile Work.

Should uncharted or incorrectly charted piping or other utilities be encountered during excavation, consult Contracting Officer’s Representative, immediately for directions as to procedure. Cooperate with Government, and public or private utility companies in keeping service and facilities in operation.

Do not interrupt existing utilities serving facilities occupied and used by Government and others, except when permitted in writing by Contracting Officer and only after acceptable temporary utility services have been provided.

SEQUENCING

Construct each auger cast pile continuously including placement of mortar and any steel reinforcement, dowels, or anchor bolts.

Do not interrupt sequence of operations for piles by weekends and holidays, or for any other reason, without approval of Contracting Officer.

UNIT PRICES

For purposes of bidding and measurement for payment, pile diameters, bottom elevations, top elevations, and reinforcement are shown on Drawings.

In Bid Form state:

Total number of pre-construction test piles upon which Bid is based.

Total number of structural piles upon which Bid is based.

Additional cost per lineal foot for installing more piling footage than indicated on Drawings.

Deducted cost per lineal foot for installing less piling footage than indicated on Drawings.

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Additional cost per test pile for each additional test pile required due to no fault of Contractor.

Deducted cost per test pile for each deleted test pile.

MATERIALS

Cement Grout:

Portland Cement: ASTM C150.

Pozzolan: ASTM C618, Class F.

Fluidifier: ASTM C937.

Water: Fresh, clean, and free from injurious amounts of sewage, oil, acid, alkali, salts, or organic matter.

Fine Aggregate: ASTM C33, fineness modulus between 1.30 and 2.10.

Steel Reinforcement: ASTM A615, Grade 60, continuous bars without splices.

CEMENT GROUT MIX DESIGN

Mortar shall consist of mixture of portland cement, fluidifier, fine aggregate, and water proportioned and mixed to produce mortar capable of maintaining solids in suspension without appreciable water gain, and which may be pumped without difficulty. Pozzolan may be used at piling contractor's option.

Materials shall be proportioned to have minimum 28-day strength of 4000 psi, ASTM C109.

Grout flow shall range between 15 and 35 seconds as measured by Flow Cone Method described in

ASTM D-939.

PART 3 - EXECUTION

INSPECTION

Examine…