A06_-__140L1722Q0031-Section_312000_1.docx

Bureau of Land Management - Colorado State OfficeBLM CO State Office SECTION 31 20 00.00312000 - Earth MovingEARTH MOVING

GENERAL

RELATED DOCUMENTS

Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section.

SUMMARY

Section Includes:

Excavating and filling for rough grading the Site.

Related Requirements:

Section 311000 "Site Clearing" for site stripping, grubbing, stripping and stockpiling topsoil, and removal of above- and below-grade improvements and utilities.

Referenced Standards:

Colorado Department of Transportation (CDOT) “Standard Specifications for Road and Bridge Construction” 2017 edition.

MEASUREMENT AND PAYMENT

General: Measurement and payment for earthwork will be either by the lump-sum method or by the unit-price method as determined by the listing of the bid items for earthwork indicated in the Bid Schedule or the Bid Form Items Not Measured for Payment:

Compacting original ground or scarified sub grade will not be measured separately for payment, and all costs in connection therewith will be considered incidental to the material or structure to be placed or constructed on the compacted original ground or sub grade.

Sub grade and bearing-foundation preparation will not be measured separately for payment, and all costs in connection therewith will be considered incidental to the material or structure to be placed or constructed on the sub grade or bearing foundation Re-handling of stockpiled material will not be measured separately for payment, but will be considered incidental to the earthwork to which it pertains.

Spoiling excavated material and management of spoils stockpile will not be measured separately for payment.

Payment: Payment for earthwork will be made at the Contract unit prices for the computed quantities as determined by the measurement methods specified herein. Payment will be made only for items listed in the Bid Schedule of the Bid Form. All other work will be considered incidental to and included with the Bid Items.

DEFINITIONS

Backfill: Soil material or controlled low-strength material used to fill an excavation.

Initial Backfill: Backfill placed beside and over pipe in a trench, including haunches to support sides of pipe.

Final Backfill: Backfill placed over initial backfill to fill a trench.

Excavation: Removal of material encountered above subgrade elevations and to lines and dimensions indicated.

Authorized Additional Excavation: Excavation below subgrade elevations or beyond indicated lines and dimensions as directed by Government. Authorized additional excavation and replacement material will be paid for according to Contract provisions for changes in the Work.

Bulk Excavation: Excavation more than 10 feet (3 m) in width and more than 30 feet (9 m) in length.

Unauthorized Excavation: Excavation below subgrade elevations or beyond indicated lines and dimensions without direction by Government. Unauthorized excavation, as well as remedial work directed by Government, shall be without additional compensation.

Rock Excavation: Removal of material is rock excavation when it consists of igneous, metamorphic, and sedimentary rock which cannot be excavated without using a hydraulic hammer attachment mounted onto an excavator or skid steer. Minimum impact energy of 300 ft-lbf.

Common Excavation: Removal of materials which can be excavated without the use of the hydraulic hammer attached to a skid steer or hydraulic excavator.

Fill: Soil materials used to raise existing grades.

Shall be mineral soil free from peat, frozen material, brush, trees, roots over 2 inches in diameter and rocks over 6 inches in greatest diameter obtained from site during grading and excavation.

Subgrade: Uppermost surface of an excavation or the top surface of a fill or backfill immediately below subbase, drainage fill, drainage course, or topsoil materials.

PREINSTALLATION MEETINGS

Preinstallation Conference: Conduct pre-excavation conference at Project site.

Review methods and procedures related to earthmoving, including, but not limited to, the following:

Personnel and equipment needed to make progress and avoid delays.

Coordination of Work with utility locator service.

Coordination of Work and equipment movement with the locations of tree- and plant-protection zones.

Field quality control.

FIELD CONDITIONS

Traffic: Minimize interference with adjoining roads, streets, walks, and other adjacent occupied or used facilities during earth-moving operations.

Do not close or obstruct roads without permission from Owner and authorities having jurisdiction.

Provide alternate routes around closed or obstructed traffic ways if required by Owner or authorities having jurisdiction.

Utility Locator Service: Notify Call Before You Dig (Colorado 811) for area where Project is located before beginning earth-moving operations.

PRODUCTS

SOIL MATERIALS

General: Cut existing soils to achieve grades on plan documents.

Borrow necessary to meet planned grades is minimal.

Obtain borrow material as needed from excavation within project improvement areas.

Do not borrow from undisturbed areas.

Use clean subgrade soil with minimal organic content to meet grades as needed.

Stockpile cut soil as shown on plans or directed by Contract Officer..

EXECUTION

PREPARATION

Protect utilities from damage caused by settlement, lateral movement, undermining, washout, and other hazards created by earth-moving operations.

Protect and maintain erosion and sedimentation controls during earth-moving operations.

DEWATERING

Provide dewatering system of sufficient scope, size, and capacity to control hydrostatic pressures and to lower, control, remove, and dispose of ground water and permit excavation and construction to proceed on dry, stable subgrades.

Dewatering system may consist of drained excavations to prevent build-up of storm water.

Protect subgrades from softening, undermining, washout, and damage by rain or water accumulation.

Dispose of water removed by dewatering in a manner that avoids endangering public health, property, and portions of work under construction or completed. Dispose of water and sediment in a manner that avoids inconvenience to others.

EXPLOSIVES

Do not use explosives.

EXCAVATION, GENERAL

Unclassified Excavation: Excavate to subgrade elevations regardless of the character of surface and subsurface conditions encountered. Unclassified excavated materials may include rock, soil materials, and obstructions. No changes in the Contract Sum or the Contract Time will be authorized for rock excavation or removal of obstructions.

If excavated materials intended for fill and backfill include unsatisfactory soil materials and rock, replace with satisfactory soil materials.

SUBGRADE INSPECTION

Notify Government when excavations have reached required limits.

Reconstruct subgrades damaged by freezing temperatures, frost, rain, accumulated water, or construction activities, as directed by Government, without additional compensation.

STORAGE OF SOIL MATERIALS

Stockpile borrow soil materials and excavated satisfactory soil materials without intermixing. Place, grade, and shape stockpiles to drain surface water.

Stockpile soil materials away from edge of excavations at locations marked on construction documents.

Stockpile slopes shall be no steeper than 1 vertical to 3 horizontal.

BACKFILL

Place backfill on subgrades free of mud, frost, snow, or ice.

SOIL FILL

Plow, scarify, bench, or break up sloped surfaces steeper than 1 vertical to 4 horizontal so fill material will bond with existing material.

Place and compact fill material in layers to required elevations as follows:

Under grass and planted areas, use satisfactory soil material.

Place soil fill on subgrades free of mud, frost, snow, or ice.

SOIL MOISTURE CONTROL

Uniformly moisten or aerate subgrade and each subsequent fill or backfill soil layer before compaction to within 2 percent of optimum moisture content..

Do not place backfill or fill soil material on surfaces that are muddy, frozen, or contain frost or ice.

Remove and replace, or scarify and air dry, otherwise satisfactory soil material that exceeds optimum moisture content by 2 percent and is too wet to compact to specified dry unit weight.

COMPACTION OF SOIL BACKFILLS AND FILLS

Place backfill and fill soil materials in layers not more than 6 inches (200 mm) in loose depth for material compacted by heavy compaction equipment and not more than 4 inches (100 mm) in loose depth for material compacted by hand-operated tampers.

Compact aggregate base course according CDOT Standard Specifications for Road and Bridge Construction Section 304

GRADING

Site Improvement Areas: Uniformly grade areas to a smooth surface, free of irregular surface changes. Grade to cross sections, lines, and elevations indicated.

Provide a smooth transition between adjacent existing grades and new grades.

Cut out soft spots, fill low spots, and trim high spots to comply with required surface tolerances.

Site Rough Grading: Slope grades to direct water into exiting drainage pathways. Finish subgrades to elevations required to achieve indicated finish elevations, within the following subgrade tolerances:

Turf or Unpaved Areas: Plus or minus 2 tenths of one foot.

Spoils area: Grade spoils area to an irregular surface to simulate the natural landscape in the area.

FIELD QUALITY CONTROL

Special Inspections: Government will inspect performance of the following:

Determine prior to placement of fill that site has been prepared in compliance with requirements.

Determine that maximum lift thickness comply with requirements.

Determine, during placement and compaction, that in-place density of compacted fill complies with requirements.

Allow Government to inspect and test subgrades and each fill or backfill layer as required. Proceed with subsequent earth moving only after test results for previously completed work comply with requirements.

When Government reports that subgrades, fills, or backfills have not achieved degree of compaction specified, scarify and moisten or aerate, or remove and replace soil materials to depth required; recompact and retest until specified compaction is obtained.

PROTECTION

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

Repair and reestablish grades to specified tolerances where completed or partially completed surfaces become eroded, rutted, settled, or where they lose compaction due to subsequent construction operations or weather conditions.

Scarify or remove and replace soil material to depth as directed by Government; reshape and recompact.

Where settling occurs before Project correction period elapses, remove finished surfacing, backfill with additional soil material, compact, and reconstruct surfacing.

Restore appearance, quality, and condition of finished surfacing to match adjacent work, and eliminate evidence of restoration to greatest extent possible.

DISPOSAL OF SURPLUS AND WASTE MATERIALS

Remove waste materials, including trash and debris, and legally dispose of them off Owner's property.

Transport surplus soil to designated storage areas on Government property. Stockpile or spread soil as directed by Government.

Slope of stockpiled material shall not exceed 3 horizontal to 1 vertical.

Remove waste materials, including trash and debris, and legally dispose of them off Owner's property.

MEASUREMENT AND PAYMENT

METHOD OF MEASUREMENT

Units: The work described in this section will not be measured for payment.

BASIS OF PAYMENT

Payment: No direct payment for the work described under this section will be made. Consideration for this item shall be included in the bid price for other items of the Contract.

END OF SECTION 312000