Construction Specifications.pdf

NRCS – March 2009 250-1 KS –Big Caney Watershed District EWP, FRD 36-A and FRD 37

Construction Specification 250—Mobilization and Demobilization

1. Scope The work consists of the mobilization and demobilization of the contractor's forces and equipment necessary for performing the work required under the contract. It does not include mobilization and demobilization for specific items of work for which payment is provided elsewhere in the contract. Mobilization will not be considered as work in fulfilling the contract requirements for commencement of work.

2. Equipment and material Mobilization shall include all activities and associated costs for transportation of contractor's personnel, equipment, and operating supplies to the site; establishment of offices, buildings, and other necessary general facilities for the contractor's operations at the site; premiums paid for performance and payment bonds including coinsurance and reinsurance agreements as applicable;

and other items specified in section 4 of this specification.

Demobilization shall include all activities and costs for transportation of personnel, equipment, and supplies not required or included in the contract from the site. This includes the disassembly;

removal; and site cleanup of offices, buildings, and other facilities assembled on the site specifically for this contract.

This work includes mobilization and demobilization required by the contract at the time of award.

If additional mobilization and demobilization activities and costs are required during the performance of the contract as a result of changed, deleted, or added items of work for which the contractor is entitled to an adjustment in contract price, compensation for such costs will be included in the price adjustment for the item or items of work changed or added.

3. Measurement and payment Compensation for any item of work described in the contract (but not listed in the bid schedule) is included in the payment for the item of work to which it is made subsidiary. Such items (and the items to which they are made subsidiary) are identified in section 4 of this specification.

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4. Items of work and construction details Items of work to be performed in conformance with this specification and the construction details are:

Bid Item 1 - Mobilization and Demobilization

(1) This item shall consist of the mobilization and demobilization of the contractor's forces and equipment necessary for performing the work required under the contract.

It does not include mobilization and demobilization for specific items of work for which payment is provided elsewhere in the contract.

(2) Transportation of any materials incorporated into the permanent works shall not be considered a mobilization item.

(3) All roads, culverts, bridges, sidewalks, parking lots, fences, structures, etc., shall be protected from damage during the contract period. Road surfaces shall be protected from damages by equipment.

(4) Access shall be as shown on the drawings. If alternate routes are obtained by the contractor, they must be approved by the engineer or the inspector prior to use. All access routes shall be restored by the contractor to a condition equal to or better than the condition prior to the commencement of work under this contract.

(5) Payment for mobilization and demobilization will be made at the contract lump sum price for the item and will constitute full compensation for all labor, equipment, tools, and other items necessary and incidental to the completion of the work.

NRCS - March 2009 251-1

Construction Specification 251—Pollution Control

The work consists of installing measures or performing work to control erosion and minimize the production of sediment and other pollutants to water and air from construction activities.

2. Material All material furnished shall meet the requirements of the material specifications listed in section 8 of this specification.

3. Erosion and sediment control measures and works The measures and works shall include, but are not limited to, the following:

Seeding—Seeding to protect disturbed areas shall occur as soon as reasonably possible following completion of that earthwork activity.

Mulching—Mulching shall provide temporary protection of the soil surface from erosion.

Sediment filters—Straw bale filters or geotextile sediment fences trap sediment from areas of limited runoff. Sediment filters shall be properly anchored to prevent erosion under or around them. These filters are temporary and shall be removed and the area restored to its original condition when they are no longer required or when permanent measures are installed.

Other—Additional protection measures shall be as specified in section 8 of this specification or as required by federal, state, or local government.

4. Chemical pollution The contractor shall provide watertight tanks or barrels to dispose of chemical pollutants such as drained lubricating or transmission fluids.

Sanitary facilities such as chemical toilets or septic tanks shall not be located next to live streams, wells, or springs. They shall be located at a distance sufficient to prevent contamination of any water source. At the completion of construction activities, facilities shall be disposed of without causing pollution as specified in section 8 of this specification.

5. Air pollution The burning of brush or woody vegetation shall adhere to state and local regulations concerning open burning. Fire prevention measures shall be taken to prevent the start or spreading of wildfires that may result from project activities.

6. Maintenance, removal, and restoration All pollution control measures and temporary works shall be adequately maintained in a functional condition for the duration of the construction period. All temporary measures shall be removed and the site restored to near original condition, unless directed differently by the engineer.

NRCS - March 2009 251-2

7. Measurement and payment Compensation for any item of work described in the contract (but not listed in the bid schedule) is included in the payment for the item of work to which it is made subsidiary. Such items (and the items to which they are made subsidiary) are identified in section 8 of this specification.

8. Items of work and construction details Items of work to be performed in conformance with this specification and the construction details

Subsidiary Item - Pollution Control Measures

(1) This item shall consist of providing a sanitary toilet facility for the job site; collecting and disposing of chemical pollutants; installing sediment barriers where indicated on the drawings or as directed by the engineer; and performing all construction activities in a manner that will minimize water pollution, air pollution, and soil erosion.

(2) No separate payment will be made for Pollution Control. Compensation for this item will be included in the payment for Earthfill, Auxiliary Spillway Repair, SITE 36-A, and Earthfill, Auxiliary Spillway Repair, SITE 37.

NRCS – January 2009 252-1

Construction Specification 252—Clearing and Grubbing

The work consists of clearing, grubbing, and disposing of trees, snags, logs, brush, stumps, shrubs, and rubbish from the designated areas.

2. Protection of existing vegetation Trees and other vegetation designated to remain undisturbed shall be protected from damage throughout the duration of the construction period. Any damages resulting from the contractor's operations or neglect shall be repaired or replaced by the contractor.

3. Marking The limits of the area(s) to be cleared and grubbed will be marked by stakes, flags, tree markings, or other suitable methods. Trees to be left standing and uninjured will be designated by special markings that are conducive to preventing injury to the tree and shall be placed on the trunk about 6 feet above the ground surface.

4. Clearing and grubbing All trees not marked for preservation and all snags, logs, brush, stumps, shrubs, rubbish, and similar materials shall be cleared from within the limits of the designated areas. Unless otherwise specified, all stumps, roots, and root clusters that have a diameter of 1 inch or larger shall be grubbed out to a depth of at least 2 feet below subgrade for concrete structures and 1 foot below the ground surface at embankment sites and other designated areas.

5. Disposal All materials cleared and grubbed from the designated areas shall be disposed of at locations shown on the drawings or in a manner specified in section 7. The contractor is responsible for complying with all local rules and regulations and the payment of any and all fees that may result from disposal at locations away from the project site.

6. Measurement and payment Compensation for any item of work described in the contract (but not listed in the bid schedule) will be included in the payment for the item of work to which it is made subsidiary. Such items and the items to which they are made subsidiary are identified in section 7.

7. Items of work and construction details

Subsidiary Item - Clearing and Grubbing

(1) This item shall consist of clearing, grubbing, and disposing of materials from the construction site as designated on the drawings or as staked in the field.

(2) All woody debris and brush is to be stacked in piles as shown on the drawings or as staked in the field. The brush piles will be between 5 feet and 10 feet tall and between 15 feet and 25 feet in diameter. The piles will be spaced at least 150 feet apart.

(3) No separate payment will be made for Clearing and Grubbing. Compensation for this item will be included in the payment for Earthfill, Auxiliary Spillway Repair, SITE 36- A, and Earthfill, Auxiliary Spillway Repair, SITE 37.

NRCS – March 2009 254-1

Construction Specification 254—Earthfill

The work shall consist of the construction of all earthfill structures and earth backfills required by the drawings and specifications.

Earthfill is composed of natural earth materials that can be placed and compacted by construction equipment operated in a conventional manner.

Earth backfill is composed of natural earth material placed and compacted in confined spaces or adjacent to structures (including pipes) by hand tamping, manually directed power tampers or vibrating plates or their equivalent.

2. Material Fill material shall be obtained from required excavations and/or designated borrow areas. The selection, blending, routing, and disposition of material in the various fills shall be subject to approval by the engineer.

Fill material shall be free of sod, brush, roots, trash, or other objectionable material. Rock particles larger than 6 inches shall be removed prior to compaction of the fill.

3. Foundation preparation The earth foundation surface shall (after stripping and before placing the first layer of earthfill) be graded to remove surface irregularities, be scarified and moisture-conditioned to a minimum depth of 2 inches to facilitate compaction and a good bond with the earthfill. The moisture content of the foundation materials at the time of compaction shall be the same as the earthfill to be placed on the foundation.

No embankment material shall be placed upon the earth surfaces of excavations, foundation preparation, or previous embankment when such surfaces have dried sufficiently to form shrinkage cracks. Such earth surfaces being readied for embankment shall have all loose, hard, dry, and cracked material removed and then scarified and moisture conditioned to a minimum depth of 2 inches.

4. Placement Earthfill shall not be placed upon a frozen surface nor shall snow, ice, or frozen material be incorporated into the earthfill matrix.

Earthfill shall be placed in approximately horizontal layers starting at the lowest point in the foundation. The earthfill materials shall be placed in nearly horizontal layers not exceeding 9 inches before compaction or as shown on the drawings. Materials placed by dumping in piles or windrows shall be spread uniformly to not more than the specified thickness before being compacted.

Machine compaction shall be accomplished by the controlled movement of hauling and spreading equipment over the fill area. Every point on the surface of each lift shall be traversed by not less than one tread track of the equipment.

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Hand compaction shall be required in areas inaccessible to heavy equipment. The hand-compacted fill shall be compacted by hand tamping or manually directed power tampers or plate vibrators. The backfill shall consist of clay material (CL or SC) free of stones larger than 2 inches. The fill shall be placed in layers not more than 4 inches thick before compaction. Such protective measures as necessary shall be taken to ensure that the fill does not dry sufficiently to form cracks after placement.

5. Control of moisture content During placement and compaction of earthfill and earth backfill, the moisture content of the material being placed shall be sufficiently moist to prevent dusty conditions. The material will also be sufficiently dry to be workable (without excessive rutting of the compacted surface by the earthmoving equipment). Tracks from the earthmoving equipment should not exceed one-half of the compacted fill layer depth. The top surface of the preceding layer of fill shall have adequate moisture to permit suitable bonding with the next layer of fill prior to the placement of additional fill.

6. Measurement and payment For items of work for which specific lump sum prices are established in the contract, the quantity of work will not be measured for payment. Payment for this item will be made at the contract lump sum price and will constitute full compensation for completion of the work.

For items of work for which specific unit prices are established in the contract, the volume of earthfill is determined from the design dimensions as staked in the field and computed to the nearest cubic yard by the method of average cross sectional end areas. The design dimensions shall be the measured surface of the foundation prior to the stripping of vegetation and the specified neat lines of the constructed surface unless otherwise specified in section 7. No deduction in volume will be made for embedded items such as (but not limited to) conduits and water control structures.

Compensation for any item of work described in the contract (but not listed in the bid schedule) is included in the payment for the item of work to which it is made subsidiary. Such items and the items to which they are made subsidiary are identified in section 7 of this specification.

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7. Items of work and construction details

a) Bid Item 2 - Earthfill, Auxiliary Spillway Repair, SITE 36-A

(1) This item shall consist of the construction of the machine-compacted fill required to replace and/or restore the material eroded from the auxiliary spillway. The completed work shall conform to the lines and grades of the auxiliary spillway as shown on the drawings.

(2) Fill material will be obtained on-site from the locations as shown on the plans.

Material deposited from the eroded areas may be recovered and used as fill within one foot of the finished surface. As allowable, recovered material shall be used first before proceeding to the designated borrow area. Rock larger than 6 inches will be allowed if compaction can be accomplished and does not hinder construction operations.

(3) Compaction shall be accomplished by two passes entirely over each 9-inch lift of fill material below the topsoil and over each 12-inch lift of topsoil by the machine hauling or pushing the fill material. Foundation surfaces shall be scarified a minimum of 4 inches deep prior to placement of fill material. Vertical foundation surfaces shall be worked down adequately prior to placement of fill to ensure proper bonding with the fill material.

(4) For items of work for which specific lump sum prices are established in the contract, the quantity of earthfill will not be measured for payment. Payment for earthfill will be made at the contract lump sum price and will constitute full compensation for all labor, equipment, tools, and all other items necessary and incidental to the completion of the work.

(5) Payment will constitute compensation for the following related subsidiary items:

(a) Pollution Control Measures - Construction Specification 251

(b) Clearing and Grubbing - Construction Specification 252

(c) Excavation, Outlet Channel - Construction Specification 255

(d) Excavation, Borrow - Construction Specification 255

b) Bid Item 3 - Earthfill, Auxiliary Spillway Repair, SITE 37

(1) This item shall consist of the construction of the machine-compacted fill required to replace and/or restore the material eroded from the auxiliary spillways. The completed work shall conform to the lines and grades of the auxiliary spillways as shown on the drawings.

(2) Fill material will be obtained on-site from the locations as shown on the plans.

Material deposited from the eroded areas may be recovered and used as fill within one foot of the finished surface. As allowable, recovered material shall be used first

NRCS – March 2009 254-4 before proceeding to the designated borrow area. Rock larger than 6 inches will be allowed if compaction can be accomplished and does not hinder construction operations. Rock larger than 6 inches will be used to armor the channel of the side drain near the right groin of the right auxiliary spillway. The finish grade of the side drain shall be the same elevation as the auxiliary spillway at that location.

(3) Compaction shall be accomplished by two passes entirely over each 9-inch lift of fill material below the topsoil and over each 12-inch lift of topsoil by the machine hauling or pushing the fill material. Foundation surfaces shall be scarified a minimum of 4 inches deep prior to placement of fill material. Vertical foundation surfaces shall be worked down adequately prior to placement of fill to ensure proper bonding with the fill material.

(4) For items of work for which specific lump sum prices are established in the contract, the quantity of earthfill will not be measured for payment. Payment for earthfill will be made at the contract lump sum price and will constitute full compensation for all labor, equipment, tools, and all other items necessary and incidental to the completion of the work.

(5) Payment will constitute compensation for the following related subsidiary items:

(a) Pollution Control Measures - Construction Specification 251

(b) Clearing and Grubbing - Construction Specification 252

(c) Excavation, Borrow - Construction Specification 255

NRCS – March 2009 255-1

Construction Specification 255 — Excavation

The work shall consist of the excavation required by the drawings and specifications and disposal of the excavated materials.

2. Use of excavated material To the extent they are needed, all suitable material from the specified excavations shall be used in the construction of required permanent earthfill or rockfill. The suitability of material for specific purposes is determined by the engineer. The contractor shall not waste or otherwise dispose of suitable excavated material.

3. Disposal of waste materials All surplus or unsuitable excavated materials are designated as waste and shall be disposed of at the locations shown on the drawings.

4. Borrow excavation When the quantities of suitable material obtained from specified excavations are insufficient to construct the specified earthfill structures and earth backfill, additional material shall be obtained from contractor supplied borrow areas.

5. Overexcavation Excavation in earth beyond the specified lines and grades shall be corrected by filling the resulting voids with approved, compacted earthfill. The exception to this is that if the earth is to become the subgrade for riprap, rockfill, sand or gravel bedding, or drainfill, the voids may be filled with material conforming to the specifications for the riprap, rockfill, bedding, or drainfill.

Before correcting an overexcavation condition, the contractor shall review the planned corrective action with the engineer and obtain approval of the corrective measures.

6. Measurement Compensation for any item of work described in the contract, but not listed in the bid schedule is included in the payment for the item of work to which it is made subsidiary. Compensation for such items is identified in section 8 of this specification.

NRCS – March 2009 255-2

7. Items of work and construction details All excavations shall be constructed to the lines and grades shown on the drawings or as directed by the engineer or his representative.

therefor are:

a. Subsidiary Item - Excavation, Outlet Channel

(1) This item shall consist of the excavation required for the removal of debris from the outlet channel on Site 36-A. The channel shall be shaped to the approximate cross sections and grades shown on the drawings or as staked in the field.

(2) Excavated materials unsuitable for direct placement as earthfill shall be placed in the waste areas as directed by the engineer.

(3) The surfaces of waste areas shall be left in a neat and sightly condition and sloped to provide drainage. Compaction of waste materials shall not be required.

(4) The volume of Excavation, Outlet Channel will not be measured and no separate payment will be made for this item. Compensation for Excavation, Outlet Channel, will be included in the payment for Earthfill, Auxiliary Spillway Repair, SITE 36-A.

b. Subsidiary Item - Excavation, Borrow

(1) This item shall consist of the excavation in the designated borrow and debris areas for obtaining fill materials needed for construction of the permanent fill. Additional borrow areas, if needed, will require approval of the engineer prior to using the material as earthfill.

(2) All surface materials suitable for topsoil shall be stripped from the borrow areas and placed in designated locations.

(3) The surfaces of the finished borrow areas between the spillway repair areas and the existing channel, or outlet channel, shall be uniformly graded to drain to the existing channel, or outlet channel. The borrow areas shall be at least as wide as the spillway exit channel and the finished cross section shall be nearly level for that width.

(4) On Site 37, the excavation in the debris area located in the existing downstream channel shall be sufficient to provide a positive grade in the channel bottom to maintain low flows. The excavation shall provide a flow area nearly equivalent to the undisturbed portion of the channel with a minimum channel bottom width of 14 feet.

(5) The volume of Excavation, Borrow will not be measured and no separate payment will be made for this item. Compensation for Excavation, Borrow, will be included in the payment for Earthfill, Auxiliary Spillway Repair, SITE 36-A, and Earthfill, Auxiliary Spillway Repair, SITE 37.