16_31_20_00_Earth_Moving_-_Amendment_0003_0003.pdf

NATIONAL PARK SERVICE

REHABILITATION OF THE EIELSON VISITOR CENTER

DENALI NATIONAL PARK AND PRESERVE, ALASKA

SECTION 31 20 00

EARTH MOVING

Design Alaska, Inc. 31 20 00- 1

PART 1 GENERAL

1.1 SCOPE: SECTION 31 20 00 – EARTH MOVING

A. This section includes:

1. Soil Materials

2. Site preparation

3. Excavation, Filling, and Compaction

B. See specification 32 96 13 for Groundcover Transplanting and soil stockpiling.

1.2 DEFINITIONS

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

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

C. Fill: Soil materials used to raise existing grades.

D. Structures: Buildings, footings, foundations, retaining walls, slabs, tanks, curbs, mechanical and electrical appurtenances, or other man-made stationary features constructed above or below the ground surface.

E. Utilities: On-site underground pipes, conduits, ducts, and cables as well as underground services.

1.3 ACTION SUBMITTAL

A. Submit traffic control plan for the facility including proposed signage, barriers, routing of vehicles and pedestrians to CO for plan review and approval before interrupting or altering existing vehicle and pedestrian traffic patterns.

1.4 INFORMATIONAL SUBMITTALS

A. Submit ASTM C-117/C-136 Gradation Analyses for structural fill, gravel aggregate drain rock, and common fill, or other backfill material specified to be used for this work. Submit test results prior to beginning any backfill work. At the discretion of the Engineer retest and resubmittal may be required when source of material changes or when the appearance of the product delivered to the jobsite varies significantly.

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 2

B. Submit ASTM D-1557 Modified Proctor test results for structural fill, common fill, and in-situ soils below structures requiring compaction of subgrade. Submit test results prior to beginning any backfill work. Retest and resubmittal required when source of fill changes or varies significantly. Determination to be made by the Engineer.

C. Submit copies of all ASTM D-2922 compaction test results within 24 hours of the performance of the test.

1.5 QUALITY ASSURANCE

A. Testing Agency Qualifications: Employ a qualified independent geotechnical engineering testing agency to classify proposed on-site and borrow soils to verify that soils comply with specified requirements and to perform required field and laboratory testing. Agency shall be under the direct supervision of an engineer registered to practice in Alaska.

1.6 FIELD CONDITIONS

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

1. Do not close or obstruct road, parking lot, walks, pathways or other adjacent occupied or used facilities without permission from NPS.

B. Utility Locator: Notify Owner for utility locates before beginning earth-moving operations.

PART 2 PRODUCTS

2.1 SOIL MATERIALS

A. General: Provide borrow soil materials when sufficient satisfactory soil materials are not available from excavations.

B. Satisfactory Soils: Soil Classification Groups GW, GP, GM, SW, SP, and SM according to ASTM D 2487, or a combination of these groups; free of rock or gravel larger than 3 inches in any dimension, debris, waste, frozen materials, vegetation, and other deleterious matter and is compactable under the provisions of SSHC 203-3.04 and 203-3.05.

C. Unsatisfactory Soils: Soil Classification Groups GC, SC, CL, ML, OL, CH, MH, OH, and PT according to ASTM D 2487, or a combination of these groups.

1. Unsatisfactory soils also include satisfactory soils not maintained within 2 percent of optimum moisture content at time of compaction.

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 3

D. Structural Fill: Well graded, course grained soil meeting the following gradation:

Size % Passing

4" 100

No. 4 Mesh 30-60

No. 200 Mesh 0-5

E. Common Fill for Area Grading or Landscape Areas: Any sandy gravel, sand, sandy-silt, or other common soil material containing no debris. Organic materials up to 10 percent by weight may be mixed in the soil mass provided the material is reasonably mixed and the organic content does not consist of large roots, stumps or tree limbs.

1. Excavated material meeting these requirements may be re-used as backfill if contractor maintains separate, tested stockpiles.

F. Crushed Aggregate: Base Course: Material meeting the requirements of SSHC 703-2.03 AGGREGATE FOR BASE AND SURFACE COURSE, Gradation D-1. Mechanically crushed and artificially graded mixture of crushed gravel, crushed stones and natural or crushed sand free of organic material, debris or other deleterious material and meeting the following gradation:

Size % Passing

1 100

¾” 70-100

3/8” 50-80

No. 4 35-65

No. 8 20-50

No. 40 8-30

No. 200 0-6

1. At least 70% by weight of the particles retained on a No. 4 sieve shall have at least one fractured face as tested by Alaska Test Methods Manual (ATM 305).

G. Sand: ASTM C 33/C 33M; fine aggregate.

H. Surface Course Aggregate:

1. Per SSHC, Section 703 - 2.03 Grade E-1.

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 4

2.2 BORROW SOURCE

A. Use materials from excavation where qualified.

B. Additional topsoil shall be certified weed free.

C. Other additional materials to come from source of Contractor's choosing. All borrow materials shall be approved by the CO.

PART 3 EXECUTION

3.1 PREPARATION

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

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

C. Protect subgrades and foundation soils from freezing temperatures and frost. Remove temporary protection before placing subsequent materials.

3.2 DEWATERING

A. Prevent surface water and subsurface or ground water from flowing into excavations and from flooding Project site and surrounding area.

B. Do not allow water to accumulate in excavations. Remove water to prevent softening of foundation support, undercutting footings, and soil changes detrimental to stability of subgrades and foundations.

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

3.3 EXCAVATION, GENERAL

A. General:

1. Depth and extent of excavation shall be in conformance with Contract Drawings and Specifications and shall be sufficient for placement of structural fill, or other specified backfill at elevations shown on Drawings.

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 5

2. No excavation is authorized below indicated depths unless so required in writing by CO to obtain suitable bearing materials or to remove objectionable debris.

3. Protect adjacent building foundations, utilities, road surfacing, and survey controls by careful excavation and shoring as required.

4. Contractor is responsible for excavating all types of material encountered in excavations including frozen soils down to the specified excavation limits without extra cost to the Owner, except for solid rock (where rock is not indicated on Drawings). Solid rock shall consist of igneous, metamorphic and sedimentary rock, which cannot be excavated without the use of blasting or rippers.

3.4 SUBGRADE INSPECTION

A. Notify CO when excavations have reached required subgrade.

B. Notify CO minimum 24 hours prior to any on-site inspections.

C. If CO determines that unsatisfactory soil is present, continue excavation and replace with compacted backfill or fill material as directed.

D. Subgrade preparation under building foundation, paved parking areas and pathways.

1. Once all unsuitable soils and existing foundation material have been removed, and prior to placement of the structural fill, the base of the excavation shall be compacted.

E. Soft or yielding spots shall be replaced and recompacted. Adjust moisture content as necessary to achieve proper compaction.

F. Compact subgrade to specified compaction requirements as described in section 3.10 Compaction of Soil Backfills and Fills.

G. Subgrade compaction shall be tested with the same number and manner of tests as required for fill as described in section 3.12 Field Quality Control.

H. Subgrade shall have no irregularities varying more than 0.1 foot above or below grade after compaction.

I. Authorized additional excavation and replacement material will be paid for according to Contract provisions for changes in the Work.

J. Reconstruct subgrades damaged by freezing temperatures, frost, rain, accumulated water, or construction activities, as directed by the CO, without additional cost to the Owner.

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 6

3.5 STORAGE OF SOIL MATERIALS

A. Stockpile borrow soil materials and excavated satisfactory soil materials without intermixing. Place, grade, and shape stockpiles to drain surface water. Cover to prevent windblown dust.

1. Stockpile soil materials away from edge of excavations. Do not store within drip line of remaining trees.

2. Stockpile location to be determined by Owner prior to start of work.

3.6 BACKFILL

A. General:

1. Place and compact backfill in excavations promptly.

2. Obtain CO’s approval of excavations prior to placement of fills.

3. No extra payment for fill in excess of limits shown on Drawings or as specified herein without written approval of CO.

4. Edges of fills shall be compacted and brought up at a maximum slope of 2:1.

5. Clean up and grade all areas disturbed by excavation and placement of backfill.

B. Structural Fill:

1. Maximum loose depth of each lift shall be 8 inches in areas to be compacted by machine.

2. Fill in horizontal layers shall not exceed 6 inches loose depth where hand tampers or hand operated vibratory compactors are used.

3.7 COMPACTION OF SOIL BACKFILLS AND FILLS

A. General.

1. Compaction shall be thorough.

2. Compact by hand tamping or walk behind plate compactor.

3. Do not cover any lift by another until the adequate compaction has been completed.

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 7

B. Sand Bedding:

1. Sand fills shall be placed in lifts as required to fill the designated areas.

2. Adjust lift thickness, moisture content and placement methods as necessary to achieve specified density.

C. Common Fill:

1. Use common fill for backfill as shown on the plans and for areas outside of building and paved parking areas, except where other materials are indicated on Drawings.

2. Maximum loose lift thickness 8 inches under footings or gravel drive or walks.

3. Maximum loose thickness 12 inches under area grading or landscape areas.

3.8 BACK FILL FOR STRUCTURES

A. Backfill shall be placed at same vertical rate and at same time on both sides of all foundations.

B. Avoid damage to foundation walls.

C. Tamp by hand tampers only unless walls are equally backfilled both sides as a simultaneous operation, or unless structural floor system which serves to brace wall is in place and properly anchored.

D. Backfill with care to prevent damage.

3.9 SOIL MOISTURE CONTROL

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

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

2. 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.

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 8

3.10 COMPACTION OF SOIL BACKFILLS AND FILLS

A. General:

1. See SSHC 203-3.03.

2. Add water to adjust moisture content as required to accomplish proper compaction and to provide dust control when required by the Engineer.

3. Compaction shall be thorough and to minimum density specified herein at all points throughout depth of fill.

4. For compaction under structures, compact to specified percentage of maximum dry unit weight at optimum moisture content obtainable by ASTM D-1557, Procedure A or B as appropriate.

5. For paved areas, compact to specified percentage of maximum dry unit weight at optimum moisture content obtainable by AASHTO T-180 and corrected by AASHTO T-224, as required.

6. When multiple lifts are required to achieve the specified grade, each lift shall be compacted to the specified density prior to placing the next lift.

B. Compaction Requirements:

Soil Material % of Maximum Dry Unit Weight

Top 6 inches of subgrade under structural fill or bedding 95%

Structural Fill 95%

Sand 98%

Pea Gravel 98%

Top 6 inches of subgrade under common fill 90%

Common Fill against foundations and footings within 5 feet of foundation wall 95%

Top 18 inches of Common Fill in areas to receive topsoil or tundra 90%

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 9

3.11 GRADING

A. General: Uniformly grade areas to a smooth surface, free of irregular surface changes.

Comply with compaction requirements and grade to cross sections, lines, and elevations indicated.

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

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

B. Site Rough Grading: Slope grades to direct water away from buildings and to prevent ponding. Finish subgrades to elevations required to achieve indicated finish elevations, within the following subgrade tolerances:

1. Turf or Unpaved Areas: Plus or minus 1-inch.

2. Walks: Plus or minus 1-inch.

3. Pavements: Plus or minus 1/2-inch.

C. Grading inside Building Lines: Finish subgrade to a tolerance of 1/2-inch when tested with a 10-foot straightedge.

3.12 FIELD QUALITY CONTROL

A. Soil Testing:

1. Soil testing shall be performed by the Contractor’s approved independent geotechnical engineering testing agency (see Section 1, TESTING AND INSPECTION SERVICE) according to the approved Quality Control (QC) plan.

2. OR Maximum dry unit weight determination shall conform with ASTM D-1557, Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort.

B. Compaction Testing:

1. Test methods:

a. Field density testing shall conform with ASTM D-2922 (nuclear gauge method), ASTM D-1556, (Sand-Cone Method) or by ASTM D-2167 (Rainhart Volumeter). The ASTM D-1556 and D-2167 is applicable only to cohesive soils and silty sands and shall only be used to test densities in sand bedding, or common fill which do not contain appreciable amounts of coarse materials in excess of 1.5 inches.

DENALI NATIONAL PARK AND PRESERVE, ALASKA

Design Alaska, Inc. 31 20 00- 10

b. The number and location of the tests shall be according to the QC plan.

The number of tests shall be (minimum) as follows. Additional testing shall be required if, in the opinion of the Engineer, the soil compaction test results indicate that the specified compaction is not being obtained:

1) For fill under paved parking areas: Minimum 3 tests per lift.

2) For common fill under landscape or area grading areas: Minimum 2 tests per lift.

3.13 PROTECTION

A. Protecting Graded Areas: Protect newly graded areas from traffic, freezing, and erosion.

Keep free of trash and debris.

B. 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.

1. Scarify or remove and replace soil material to depth as directed by CO; reshape and re-compact.

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

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

3.14 DISPOSAL OF SURPLUS AND WASTE MATERIALS

A. Transport surplus satisfactory soil to designated storage areas on Owner's property.

Stockpile or spread soil as directed by CO.

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

END OF SECTION