B08_Solit_Attach_1B_YOSE-229677_Techincal_Specs_Div_31-33.pdf

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6/2/21 SITE CLEARING

SECTION 31 10 00 – SITE CLEARING

PART 1 - GENERAL

1.1 RELATED DOCUMENTS

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

1.2 SUMMARY

A. Section Includes:

1. Protecting existing vegetation to remain.

2. Removing trees.

3. Clearing and grubbing.

4. Surface material, weedy scrape, and organic material.

5. Disposal of material from clearing, grubbing, thinning and demolition in approved off-site disposal areas.

6. Filling of voids and excavations resulting from the work.

B. Related Sections:

1. Section 01 57 13 – Temporary Storm Water Pollution Prevention

2. Section 02 41 13 – Selective Demolition

3. Section 31 20 00 – Earth Moving

1.3 MATERIAL OWNERSHIP

A. Except for materials indicated to be stockpiled or to remain on the Owner’s property, cleared materials shall become Contractor’s property and shall be removed and disposed of legally. When possible, the Contractor should re-use or sell materials generated by Site Clearing such as timber, firewood, or wood chips.

1.4 SITE CONDTIONS

A. Site conditions existing during the bidding period will be maintained by the government insofar as practical.

B. Actual site condition variations that differ from those of the bidding period and which affect site clearing operations shall be brought to the attention of the Contracting Officer (CO) prior to the commencement of any site work.

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1.5 SUBMITTALS

A. The Contractor shall submit the following information to the CO for review before commencing work:

1. Permits for transport and disposal of debris.

2. Demolition procedures and operational sequence.

PART 2 - PRODUCTS

2.1 TREE PROTECTION FENCING

A. Tree protection fencing shall be an orange plastic web fence, 4 feet high minimum. Wood stakes shall be six (6) foot long by 1 inch by 1 inch square driven a minimum of two (2) feet into the ground. Posts shall be spaced eight (8) feet on center, maximum.

PART 3 - EXECUTION

3.1 PROTECTION

A. The Contractor shall flag the limits of clearing shown on the drawings by accurate field survey with marked stakes or other means acceptable to the CO. Trees to remain shall be clearly identified during this staking process. The CO shall be notified a minimum of five (5) working days prior to scheduled commencement of clearing operations to review the flagged limits. Adjust the clearing limits as directed by the CO.

B. Install erosion-control measures prior to start of any other construction to prevent soil erosion and discharge of soil-bearing water runoff or airborne dust to adjacent properties and roadways in accordance with Section 01 57 21 – Temporary Storm Water Pollution Prevention.

C. Before clearing begins, protect designated trees to remain with tree protection fencing to the approximate diameter of foliage (dripline of the tree) to prevent damage to the trunk, foliage and root system by construction equipment and procedures.

D. Place tree protection fencing as required to protect other plants, adjacent property areas to remain uncleared, monuments, and existing improvements from damage.

E. The Contractor shall repair or replace immediately any damage to existing trees or root systems that are to remain. The Contractor shall employ an arborist licensed in the State of Washington to determine the repair and replacement needs and methods for approval by the CO.

F. Replace damaged shrubs and other vegetation designated to remain with the same size and species.

G. The tree protection fencing shall be maintained for the duration of construction operations. The work shall include immediate replacement of any damaged fence. Fencing shall be removed from the site at the completion of construction operations. The fencing disposal shall be in accordance with local, state, and federal laws and regulations for the disposal of the material.

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3.2 UTILITIES

A. Notify all corporations, companies, individuals, or local authorities owning or having jurisdiction over utilities running to, through, or across areas to be affected by site clearing operations.

B. Locate and identify existing utilities that are to remain and protect them from damage.

C. For utilities to be disconnected, have utility services disconnected in accordance with the requirements of the utility owner.

3.3 CLEARING AND GRUBBING

A. Clearing shall include cutting, removal, and off-site disposal of trees, bushes, shrubs, stumps, fallen timber, brush, refuse, trash, fencing and other incidental materials not required for reuse on the site.

B. The Contractor shall grub the area within the clearing limits to completely remove stumps and root systems, except for those to remain.

C. Depressions, excavations and voids resulting from the removal of stumps or roots shall be filled with suitable material and compacted as specified under Section 31 20 00 – Earth Moving.

3.4 DISPOSAL

A. Remove all material resulting from site clearing and demolition operations from site.

B. No burning of any material will be allowed.

END OF SECTION 31 10 00

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6/2/21 EARTH MOVING

SECTION 31 20 00 – EARTH MOVING

PART 1 - GENERAL

1.1 SUMMARY

A. This Section includes the following:

1. Preparing subgrades for roadways, parking areas, walkways, and buildings.

2. Subbase and base course for walks.

3. Subbase and base course for cement concrete paving.

4. Subbase and base course for asphalt paving.

5. Excavating and backfilling for utility trenches.

B. Related Sections include the following:

1. Section 01 57 13 – Temporary Storm Water Pollution Prevention

2. Section 31 10 00 – Site Clearing

3. Section 31 25 00 – Erosion and Sediment Control

4. Section 32 13 20 – Site Concrete

5. Section 32 12 16 – Asphalt Paving

1.2 DEFINITIONS

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

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

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

B. Base Course: The layer or layers of specified material placed on a subbase or subgrade to support a surface course.

C. Bedding Material: Granular material placed over the excavated subgrade in a trench above and below a pipe.

D. Borrow Soil: Satisfactory soil imported from off-site for use as fill or backfill.

E. Earth Grade: The elevation of the completely graded roadway before placing the pavement structure.

F. Engineered Fill: Clean, crushed, granular material that will support structures. Structural fill material will be material that is considered an all-weather fill material.

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

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

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

I. Pavement Structure: All combinations of subbase, base course, and surface course, including shoulders, placed on a subgrade.

J. Rock: Rock material in beds, ledges, unstratified masses, conglomerate deposits, and boulders of rock material 3/4 cu. yd. (0.57 cu. m) or more in volume that exceed a standard penetration resistance of 100 blows/2 inches (97 blows/50 mm) when tested by an independent geotechnical testing agency, according to ASTM D 1586.

K. Structures: Buildings, footings, foundations, retaining walls, curbs, or other man-made stationary features constructed above or below the ground surface.

L. Subbase Course: The layer of specified material placed on the subgrade as a part of the pavement structure.

M. Subgrade: The portion of the earth grade upon which the pavement structure is placed.

N. Utilities: On-site underground pipes, conduits, ducts, and cables.

O. Earthwork Terminology: Terms used in this Section and not defined herein shall be interpreted in accordance with the definitions given in ASTM D653.

P. Embankment: Soil or soil-rock material placed to raise the subgrade or natural grade of the site for embankment construction.

Q. Native Soil: Sand or silt naturally occurring on site that was never imported to the site, is weed free, and supports local native habitats.

R. Unsuitable Material: Excavated material or material below the natural ground surface in embankment areas or below subgrade elevation in excavated areas, which is unsuitable for its planned use as determined by the Contracting Officer. Unsuitable material is further defined as material determined to be:

1. Of such unstable nature as to be incapable of being compacted to specified density using ordinary methods at optimum moisture content.

2. Too wet to be properly compacted and circumstances prevent suitable in-place drying prior to incorporation into the Work.

3. Not meeting requirements specified in Part 2 of this Section.

4. Otherwise unsuitable for the planned use.

The presence of excessive moisture in a material is not, by itself, sufficient cause for determining that the material is unsuitable.

Q. Relative Compaction: The ratio, expressed as a percentage, of the in-place dry density of fill materials as compacted in the field to the maximum dry density of the same material.

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R. Optimum Moisture Content: The water content at which a soil can be compacted to a maximum dry unit weight by a given compactive effort.

1.3 LAWS AND REGULATIONS

A. Work shall be accomplished in accordance with regulations of local, township, county, state and federal agencies or utility company standards as they apply.

1.4 SUBMITTALS

A. Delivery Tickets: Submit a delivery ticket with each load of imported material delivered to the site, stating the type of fill material, source, and the quantity.

B. Product Data: For the following:

1. All aggregates proposed for use.

2. Import fill.

C. Material Test Reports: The Contractor shall conduct testing at their own expense for material testing of material that does not come from a pre-approved quarry. The test information shall be provided to the CO for approval prior to material import. Material test reports shall be from a qualified testing agency indicating and interpreting test results for compliance of the following with requirements indicated:

1. Classification according to ASTM D 2487 of each on-site and import soil material proposed for fill and backfill.

2. Laboratory compaction curve according to ASTM D 1557 for each on-site and import soil material proposed for fill and backfill.

D. Compaction test results.

E. Pre-excavation Photographs or Videotape: Show existing conditions of adjoining construction and site improvements, including finish surfaces, that might be misconstrued as damage caused by earthwork operations. Submit before earthwork begins.

1.5 QUALITY ASSURANCE

A. Pre-excavation Conference: Conduct conference at Project site to comply with requirements in Division 01 Section “Project Management and Coordination.”

B. Tolerances:

1. Construct finished subgrades to plus 0 or minus 1/2-inch of the elevations indicated.

2. Construct finished grade of slopes not steeper than 2:1 plus or minus 1/2 inch and on slopes steeper than 3:1 plus or minus two inches (2").

3. Maintain the moisture content of fill material as it is being placed within plus or minus 2% of the optimum moisture content of the material as determined by the laboratory tests herein specified.

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1.6 PROJECT CONDITIONS

A. A geotechnical engineering “desktop study” has been prepared by Golder Associates, Inc., dated February 23, 2021. This report is specifically not part of the Contract Documents but is available to bidders for informational purposes.

B. Existing Utilities: Do not interrupt utilities serving facilities occupied by Owner or others unless permitted in writing by Owner and then only after arranging to provide temporary utility services according to requirements indicated.

1. Notify Owner not less than two days in advance of proposed utility interruptions.

2. Do not proceed with utility interruptions without Owner’s written permission.

3. Contact utility-locator service for area where Project is located before excavating.

C. Demolish and completely remove from site existing underground utilities indicated to be removed. Coordinate with utility companies to shut off services if lines are active.

D. Unfavorable Weather Conditions:

1. Excavating, filling, backfilling, and grading work shall not be performed during weather conditions that might damage or be detrimental to the condition of existing ground, in-progress work, or completed work. When the Work is interrupted by rain, freezing weather, or other conditions deemed unsuitable by the Project Representative, excavating, filling, backfilling, and grading work shall not resume until the site and soil condition (moisture content) are suitable for compaction.

2. Subgrade shall be free from mud, snow, ice, and deleterious material when work is resumed.

3. Soil material that is too wet for compaction shall be left to drain, to be aerated and dried by disking and harrowing or other approved method until the moisture content of the area is uniform and within the specified limits.

E. Erosion Prevention: Protect stockpiles, ditches, embankments, filled, backfilled, and graded areas to prevent erosion until such time as permanent drainage and erosion control measures have been installed per the requirements of Section 01 57 23 – Temporary Storm Water Pollution Prevention.

F. Control of Dust: Employ construction methods and means that keep flying dust to the minimum throughout the entire Contract period. It may include watering and sprinkling, or other approved methods at the construction site of such frequency that will satisfactorily control the dust caused by construction operations.

G. Control of Dirt: Promptly remove from existing roadways all dirt and other materials that have been spilled, washed, tracked, or otherwise deposited thereon by construction operations whenever the accumulation is sufficient to cause the formation of mud, interfere with drainage, damage pavements, or create a traffic hazard.

H. Indicated locations of existing facilities and systems are approximate. Investigate and determine exact location and nature of utilities, facilities, and systems, and be solely responsible for damages caused by construction activities.

I. Excavation in areas that have or may have underground facilities:

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1. Delineate with white paint, flags, or other methods the area to be excavated and contact Underground Location Service to request that facility owners mark the location of underground utilities.

2. Identify temporary survey markings using PINK colored markings in accordance with Underground Service alert requirements.

3. Facility owners will field mark approximate location and number of subsurface installations affected by excavation using the following colors:

a. Safety RED – Electric power, distribution, and transmission installations, or municipal electric installations.

b. High Visibility Safety YELLOW – Gas distribution and transmission installations, oil distribution and transmission installations containing or transporting dangerous materials, products, or steam.

c. Safety Alert ORANGE – Telephone and telegraph installations, police and fire communication installations, and cable television installations.

d. Safety Precaution BLUE – Water installations and slurry pipelines.

e. Safety GREEN – Sewer installations.

f. Do not use above listed colors for Contractor’s temporary markings suck as survey points; use U.S.A. designated PINK color.

PART 2 - PRODUCTS

2.1 STRUCTURAL FILL MATERIALS

A. Imported engineered fill shall have the following characteristics:

1. No particles greater than 3-inches in maximum dimension.

2. 35 to 100 percent passing the No. 4 sieve.

3. 20 to 100 percent passing the No. 30 sieve.

4. No more than 10 percent passing the No. 200 sieve.

5. The percent passing the No. 40 sieve should have a plasticity index less than 10.

6. Non-corrosive to buried concrete and metallic structures.

B. Structure backfill:

1. Structure backfill must be free of organic or other unsatisfactory material.

2. Structure backfill compacted to a relative compaction of at least 95 percent and material placed behind retaining walls must have a sand equivalent value of at least 20 and comply with the following gradation requirements:

Sieve Size Percentage Passing 3″ 100

No. 4 35-100 No. 30 20-100

3. Excavated material not suitable for use as structure backfill may be used to replace imported borrow or other excavated material.

C. Pervious backfill material:

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1. Pervious backfill must consist of one or any combination of the following materials:

a. Gravel

b. Crushed gravel

c. Crushed rock

d. Natural sand

e. Manufactured sand

2. Pervious backfill shall comply with the following gradation requirements:

Sieve Size Percentage Passing 2″ 100

No. 50 0-100 No. 100 0-8 No. 200 0-4

2.2 SOIL MATERIALS

A. Aggregate for Base Course: Class 2 Aggregate Base as defined in Section 32 15 00 – Aggregate Surfacing.

B. Outfall Protection Material: Material as described in Section 33 42 00 – Culverts.

C. Embankment: All embankment material shall consist of clean well-graded soil with little or no potential for expansion.

D. Geotextile:

1. When tested under ASTM D4491, geotextile permittivity must be at least 0.05 sec-1.

2. Subgrade enhancement geotextile shall either be polyester or polypropylene.

3. Geotextile shall comply with the requirements in the following table:

Quality Characteristic Test Method Requirement Class A1 Class A2 Class B2 Class B3

Elongation at break (percent) ASTM D4632 <50 >50 <50 >50 Grab breaking load, 1-inch grip in each direction (min, lb) ASTM D4632 250 160 320 200

Wide width tensile strength at 5 percent strength (min, lb/ft) ASTM D4595 -- -- -- --

Wide width tensile strength at ultimate strength (min, lb/ft) ASTM D4595 -- -- -- --

Tear strength (min, lb) ASTM D4533 90 60 120 80 Puncture strength (min, lb) ASTM D6241 500 310 620 430 Permittivity (min, sec-1) ASTM D4491 .05 .05 .20 .20 Apparent opening size (max, inches) ASTM D4751 .012 .012 .012 .012 UV resistance, retained grab breaking load, 500 hours (min, percent)

ASTM D4355 70 70 70 70

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E. Pipe Bedding Material: Type A bedding material shall consist of natural sand obtained from acceptable pits. The sand shall be free of clay or organic material and shall comply with the following gradation requirements:

Sieve Size Percentage Passing No. 4 90-100

No. 200 0-5

F. Sand: ASTM C 33; fine aggregate, natural, or manufactured.

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 earthwork operations.

B. Preparation for earthwork operations including removal of vegetation, topsoil, debris, and obstructions, from ground surface is specified in Section 31 10 00 – Site Clearing.

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

3.2 STAKING AND GRADES

A. Layout the work, establish all necessary markers, benchmarks, grading stakes, and other stakes as required, in accordance with the lines and grades of the Plans.

3.3 UTILITIES

A. Verify on site the location and depth (elevation) of all existing utilities and services before performing any excavation work. Use the 811 call utility service and other means required to verify locations.

B. Active utility lines encountered, which are not indicated in the Contract Documents, shall be reported immediately to the Contracting Officer and utility owners involved. The Contracting Officer and utility authorities shall be permitted free access to determine the measures deemed necessary to repair, relocate, or remove the utility.

C. For utility trenches, compact each layer of initial and final backfill soil material at 90 percent.

3.4 EARTHWORK GENERAL REQUIREMENTS

A. Erosion Protection: Prevent erosion of the site and turbidity in adjacent waterbodies of the site at all times. Conform to all the requirements as per Section 01 57 13 – Temporary Storm Water Pollution Prevention and Section 31 25 00 – Erosion and Sediment Controls.

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B. Construction Traffic: Protect exposed soil layers with high moisture content from excessive wheel loads.

C. On-Site Excavation:

1. Do not excavate or remove any material from the project site which is not within the designated excavation.

2. The Contractor is responsible for retaining enough excavated material for reuse for any actions and for disposing excess material off-site.

D. Disposal of Surplus Material:

1. Excess earth materials, unsuitable materials, and debris shall be removed from the site and disposed of in a legal manner. The Contractor is to provide the CO with copies of the documentation for the legal disposal of materials.

E. Maintenance of Excavations, Slopes, and Embankments:

1. Reroute surface water runoff away from excavated areas. Do not allow water to accumulate in excavations. Do not use excavated trenches as temporary drainage ditches.

2. Maintain slopes and embankments until final completion and acceptance of the Work.

Promptly repair slides, slipouts, washouts, settlements, and subsidence that occur for any reason, and refinish the slope or embankment to the indicated lines and grades.

F. Safeguarding of Walls: Heavy equipment and rollers shall not be operated within four feet (4') of walls.

G. Dust and Dirt Control: Provide satisfactory control or remove dust and/or dirt at the project site and adjacent roadways whenever traffic or buildings that are occupied or in use, are affected.

3.5 ROUGH GRADING AND FILLING

A. Fill or backfill holes, swales, and low points that will not otherwise be removed in the course of the Work, to the indicated grades.

3.6 DEWATERING

A. Prevent surface water and ground water from entering excavations, from ponding on prepared subgrades, and from flooding Project site and surrounding area. Discharge locations shall be identified in a preconstruction submittal and approved by the CO. All discharge shall avoid turbidity or erosion into adjacent water bodies.

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

1. Reroute surface water runoff away from excavated areas. Do not allow water to accumulate in excavations. Do not use excavated trenches as temporary drainage ditches.

2. Install a dewatering system to keep subgrades dry and convey ground water away from excavations. Maintain until dewatering is no longer required.

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3.7 EXPLOSIVES

A. Explosives: Do not use explosives.

3.8 EXCAVATION

A. The bottoms of excavations shall be level, firm, undisturbed earth, clean and free from loose material, debris, and foreign matter.

B. Protect existing structures during excavation.

C. Excavate to the lines and grades indicated on the Contract Drawings.

D. Support and maintain excavation so that sides are stable and will not move. Excavations may be maintained by sloping cut faces where space permits, or by providing structural support of earth walls.

E. Limits of excavations shall allow for adequate working space for installing forms, and as required for safety of personnel.

F. Excavation and its restoration, when conducted for convenience of the Contractor, shall be at no additional expense to the Owner.

G. Place excavated material at sufficient distance from edge of excavation so as not to cause cave-ins or bank slides, but in no case closer than three feet (3') from the edge of excavations.

H. Condition excavated earth material that is suitable for backfill or embankment for re-use. Test, screen, and mix as necessary to meet specified requirements.

I. Footing excavations shall be free of any loose, soft, or disturbed material, and water prior to placement of reinforcing bars and concrete.

3.9 EMBANKMENT CONSTRUCTION

A. Fill shall be placed in level lifts not exceeding 8 inches in loose thickness. Each lift shall be brought to within 3 percent of optimum moisture content and compacted to at least 90 percent compaction.

B. Finished fill slopes shall be constructed at an inclination no steeper than 2:1. Fill slopes shall be overbuilt and trimmed back as necessary to expose a well-compacted surface.

C. Structural fill supporting footings shall extend laterally outside of the footing base at a 1H:1V or flatter inclination projected down and away from the bottom edges of the footing.

D. Routine maintenance of slope sloughing and erosion should be anticipated. Fill slopes and areas disturbed during construction shall be planted with vegetation to reduce erosion.

E. Remove material that cannot be compacted to the required density within specified tolerances and replace with suitable material at no additional expense to the Owner.

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3.10 STRUCTURAL FILL SUBGRADE PREPARTION

A. The subgrade surface shall be free of any water, debris, organic, loose, soft, disturbed, or other deleterious material prior to placement of fill, reinforcing bars, and concrete.

B. If grading or excavation to the subgrade during construction reveal highly variable conditions within the foundation footprint, subgrade shall be over excavated and replaced with compacted engineered fill to achieve a uniform subgrade surface.

C. Native subgrade that is wet, unsuitable, or that has become loosened by the contractor’s operation shall be properly moisture conditioned and compacted or over-excavated and replaced with a suitable engineered fill. Caution should be exercised if compacting by means of proof rolling so as not to damage the subgrade.

D. Engineered fill shall be placed in level lifts not exceeding 8 inches in loose thickness and compacted to at least 95 percent of maximum ASTM D 1557 dry density below all footings and within 3 feet of final grade in pavement areas.

E. Engineered fill placed around footings should be compacted to at least 95 percent of maximum ASTM D 1557 dry density.

F. Engineered fill behind walls shall be compacted to 90 percent of maximum ASTM D 1557 dry density, provided the backfill is not supporting buildings and is not within 3 feet of final grade in pavement areas.

G. After the densification process, a firm, unyielding, stable surface shall be produced.

H. Proof-rolling shall be performed prior to constructing any structures founded on engineered fill with a fully loaded 10-yard dump truck. Remove yielding areas to expose suitable subgrade.

I. Notify CO when excavations have reached required subgrade and before placing any fill material.

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

J. For pavement, slab, structural fill, or foundation subgrade, any suitable material loosened during excavation or other activities prior to placement of structural fill, pavement or slab materials, or foundations shall be compacted.

K. If wet fine-grained soils are encountered at the subgrade, geotextile meeting the requirements of Section 2.2D shall be installed prior to backfilling.

L. Where fill will be placed adjacent to an existing slope, steps shall be excavated into the existing slope to help “key” the new fill into the slope.

M. Structural fill shall be placed on firm, un-yielding subgrade prepared in accordance with these specifications.

N. Perform all cutting, blading, and shaping as required to cut and shape the subgrade to the grades and elevations indicated.

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O. Subgrade preparation includes fine grading, reworking as necessary, and preparation of cut, fill, or embankment upon which structure and equipment foundations, pipe, base, and pavement will be placed.

P. The upper 6 inches of subgrade under pavements shall be moisture conditioned and compacted to at least 95 percent relative compaction and should be smooth and unyielding.

Q. After the material has been thoroughly mixed and moisture-conditioned, accurately construct and fine grade the subgrade to indicated line, grade, and contour with high and low spots eliminated.

Compact for full width to the specified density. Remove soft spots developed during working, fill with approved material, and re-compact.

R. If soil moisture conditions allow, after exposing the subgrade for pavement, slab, or structural fill, proof-rolling the subgrade with a loaded dump truck or other heavy wheeled vehicle to identify soft pockets and areas of excess yielding. Do not proof-roll wet or saturated subgrades.

1. Completely proof-roll subgrade in one direction, repeating proof-rolling in direction perpendicular to first direction. Limit vehicle speed to 3 mph (5km/h).

2. Proof-roll with loaded 10-wheel, tandem-axle dump truck weighing not less than 15 tons (13.6 tonnes).

3. Excavate soft spots, unsatisfactory soils, and areas of excessive pumping or rutting, as determined by CO and replace with compacted backfill or fill as directed.

S. Authorized additional excavation and replacement material will be paid for according to Contract provisions for unit prices.

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

3.11 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. Temporary stockpiles shall be no higher than 5 feet.

3.12 BACKFILL

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

B. Place backfill in horizontal layers not to exceed 8 inches of loose material and compact each layer to at least 90 percent of maximum ASTM D1557 dry density before the next layer is placed.

C. Place backfill material in such a manner that unbalanced horizontal loads will not be applied to a newly placed structure or portion of a structure, utilities, or pipelines.

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D. Do not backfill on or against structural concrete until the specified 28-day concrete strength has been attained.

E. Do not use compaction equipment and methods that produce excessive horizontal or vertical earth pressures.

3.13 UTILITY TRENCH BACKFILL

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

B. Trenches shall be graded uniformly sloped between pipe elevations as shown on the drawings.

C. Place and compact bedding course on trench bottoms and where indicated. Shape bedding course to provide continuous support for bells, joints, and barrels of pipes and for joints, fittings, and bodies of conduits.

D. Place and compact initial backfill of pipe bedding material to a height of 6 inches over the utility pipe or conduit.

1. Carefully compact initial backfill under pipe haunches and compact evenly up on both sides and along the full length of utility piping or conduit to avoid damage or displacement of piping or conduit. Coordinate backfilling with utilities testing.

E. Backfill voids with satisfactory soil while installing and removing shoring and bracing.

F. Backfill and compact over excavations to ninety (90) percent relative compaction with bedding material. There shall be no additional payment to the Contractor for over excavations not directed by the CO. Remove unsatisfactory material encountered below the grades shown as directed by the CO and replace with bedding material. Payment for removal and replacements of such unsatisfactory material directed by the CO shall be made in accordance with the provisions of the General Conditions.

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

3.14 SOIL MOISTURE CONTROL

A. Uniformly moisten or aerate subgrade and each subsequent fill or backfill soil layer for the parking lot/picnic area or trail before compaction to within 3 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 3 percent and is too wet to compact to specified dry unit weight.

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3.15 COMPACTION OF SOIL BACKFILLS AND FILLS

A. Place backfill and fill soil 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.

B. Place backfill and fill soil materials evenly on all sides of structures to required elevations, and uniformly along the full length of each structure.

C. Fill compaction shall be verified by means of in-place density tests performed per ASTM D6938 (or appropriate alternative when ASTM D6938 is not suitable for the fill material) during fill placement so that compaction may be evaluated as earthwork progresses.

D. Compact soil materials to not less than the following percentages of maximum dry unit weight according to ASTM D 1557:

Fill Application Minimum

Compaction % Building Pad 95 Footing subgrade or bearing pad 95 Slab-on-grade floor subgrade and subbase 95 Retaining wall footing subgrade 95 Concrete slab subgrades 95 Asphalt pavement base and subbase 95 Asphalt pavement subgrade, within 3 feet of finished grade 95 Asphalt pavement subgrade, more than 3 feet below finished grade 90 Retaining wall backfill 90 Footing and stem wall backfill 90

3.16 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 Grading: Slope grades to direct water away from buildings and to prevent ponding. Finish subgrades to required elevations within the following tolerances:

1. Unpaved Areas: Plus or minus 1 inch.

2. Walks: Plus or minus 1 inch.

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

3.17 SUBBASE AND BASE COURSES

A. Place subbase and base course on subgrades free of mud, frost, snow, or ice.

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B. On prepared subgrade, place subbase and base course under pavements and walks as follows:

1. Place base course material over subbase course under hot-mix asphalt pavement.

2. Shape subbase and base course to required crown elevations and cross-slope grades.

3. Place subbase and base course 6 inches or less in compacted thickness in a single layer.

4. Place subbase and base course that exceeds 6 inches in compacted thickness in layers of equal thickness, with no compacted layer more than 6 inches thick or less than 3 inches thick.

5. Compact subbase and base course at optimum moisture content to required grades, lines, cross sections, and thickness to not less than 95 percent of maximum dry unit weight according to ASTM D 1557.

3.18 SHORING AND SHEETING

A. Construct and maintain all shoring, sheeting, and slope lay-back necessary to protect the excavation, as need for safety of the employees and as required by applicable State and Federal laws.

B. For trenches over five (5) feet deep, provide suitable barricades for worker protection. When work area is left open and unattended by Contractor, provide suitable barricades for public safety, regardless of trench depth.

C. For trenches over four (4) feet deep, provide suitable exit means in accordance with applicable provisions in OSHA.

D. Do not remove timber or sheeting if it is in a compacted zone. Trim timber or sheeting off at a safe level above that zone.

E. As directed, remove all other sheeting and shoring when no longer needed.

3.19 FIELD QUALITY CONTROL

A. Testing Agency: Contractor shall engage a qualified independent geotechnical engineering testing agency to perform field quality-control testing.

B. Allow testing agency to inspect and test subgrades and each fill or backfill layer. Proceed with subsequent earthwork only after test results for previously completed work comply with requirements.

C. Testing agency will test compaction of soils in place according to ASTM D 1556, ASTM D 2167, ASTM D 2922, and ASTM D 2937, as applicable. Tests will be performed at the following locations and frequencies:

1. Paved Areas: At subgrade and at each compacted fill and backfill layer, at least 1 test for every 2000 sq. ft. or less of paved area or building slab, but in no case fewer than 3 tests.

2. Trench Backfill: At each compacted initial and final backfill layer, at least 1 test for each 150 feet or less of trench length, but no fewer than 2 tests.

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D. When testing agency reports that subgrades, fills, or backfills have not achieved degree of compaction specified, scarify and moisten or aerate, or remove and replace soil to depth required;

recompact and retest until specified compaction is obtained.

3.20 PROTECTION

A. The subgrade must be protected from other construction activities, traffic, and weather conditions.

The subgrade will degrade and become unsuitable if the soil gets too wet or too dry. Construction activity and equipment of all types have the potential to disturb and negatively impact the prepared subgrade. The contractor shall implement suitable procedures to protect the subgrade, such as excavating without tracking on the native soils, use of a crushed rock or gravel-working mat, dewatering, soil admixing, geotextiles, or other suitable procedures during construction.

B. Pavement and foundation subgrade shall be maintained in a well-compacted state and protected from degradation prior to paving or placing concrete. Protection measures may include restricted traffic, perimeter drain ditches, or placement of a protective gravel layer on the subgrade.

Disturbed or wet areas in the subgrade shall be removed and replaced with suitably compacted structural fill.

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

D. 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 recompact.

E. 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.

3.21 DISPOSAL OF SURPLUS AND WASTE MATERIALS

A. Disposal: Remove surplus satisfactory soil and waste material, including unsatisfactory soil, trash, and debris, and legally dispose of it.

B. Disposal: Remove and legally dispose of all miscellaneous debris, trash, construction materials off Park property.

END OF SECTION 31 20 00

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TOPSOIL

SECTION 31 23 16 – TOPSOIL

PART 1 - GENERAL

1.1 SUMMARY

A. This section includes the following: furnishing, stripping, stockpiling and placing topsoil on a previously prepared subgrade.

B. Related Sections:

1. Section 31 20 00 – “Earth Moving”

2. Section 32 15 43 – “Stabilized Decomposed Granite”

1.2 SUBMITTALS

A. Sources: Submit name and address of sources for imported soil materials. Sources must be on YOSE approved list of Quarries, Borrow Pits and Other Material Sources Outside of YOSE Boundaries.

B. Delivery Tickets: Submit delivery tickets to CO on a daily basis upon delivery of these materials:

1. Imported Topsoil

1.3 QUALITY ASSURANCE

A. Submit soil analysis report for imported topsoil from the State University Agricultural Extension Service or other approved soil testing laboratory. Report shall cover soil textural classification (percentages of sand, silt, and clay), pH, % organic matter, and soluble salts (electric conductivity in millimoles/centimeter), and shall include additive recommendations. Testing will be at the expense of the Contractor.

1.4 DELIVERY, STORAGE AND HANDLING

A. Do not deliver or place topsoil in frozen, wet, or muddy condition.

PART 2 - PRODUCTS

2.1 ON-SITE TOPSOIL

A. On-Site Topsoil – Topsoil limits shall be the top six (6) inches of soil within the limits of the area to be disturbed by the Contractor. If sufficient Topsoil does not occur on site, on-site topsoil can include on-site surface soil. Remove and stockpile sufficient topsoil to allow replacement on all planted surfaces according to the soil preparation type after natural settlement. A minimum depth

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of eighteen (18) inches after natural settlement is required in areas of road or pavement removal.

The Contractor shall protect placed topsoil from undue compaction for the duration of construction.

PART 3 – EXECUTION

3.1 EXAMINATION:

A. General: Verify that existing site conditions are as specified and indicated before beginning work under this Section.

1. Grades: Inspect to verify rough grading is within +/- 0.1 foot of grades indicated and specified.

2. Damaged Earth: Inspect to verify that earth rendered unfit to receive planting do to concrete, water, mortar, limewater or any other contaminant dumped on it has been removed and replaced with clean earth from a source approved by the CO.

B. Surface Grade: Remove weeds, debris, clods and rocks larger than 8". Dispose of accumulated debris at direction of the CO.

C. Runoff: Take measures and furnish equipment and labor necessary to control the flow, drainage, and accumulation of water. Insure that all water will run off grades.

3.2 PREPARATION

A. Remove vegetation prior to stripping of topsoil.

B. Strip topsoil and surface soil from 6" depth to prevent intermingling with underlying subsoil or other waste material.

C. Limits of topsoil stripping shall be verified with the Contracting Officer prior to removal, and stockpile locations shall be identified so as not to interfere with the other work.

D. Decompact soil preparation areas where existing surface is compacted from pedestrian and vehicular use. Mechanically decompact to depths noted on the plans.

3.3 INSTALLATION

A. Minor Soil Decompaction and Fine Grading in areas to be landscaped by Park

1. Scarify soil in planting areas and any area to be restored by the Park Revegetation Program to a minimum depth of 12-inches by plowing, harrowing, or disking until soil is well pulverized and thoroughly mixed.

2. Till 1-inch of topsoil into the previously scarified 12-inches of soil. Topsoil shall be free from weeds, sod, clods and stones larger than 8", toxic substances, litter or other deleterious material

3. For ground surface areas surrounding buildings and hardscape, maintain required positive drainage away from buildings and hardscape

3. Establish finish grades to 0.1 foot of grades indicated.

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4. Noxious weeds or parts thereof shall not be present in the surface grade

5. Prior to acceptance of grades, hand rake to smooth, even surface, free of debris, clods, rocks and vegetable matter greater than 8".

6. Utilize salvaged topsoil as the top layer to the extent available.

B. Major Soil Decompaction and Fine Grading in areas to be landscaped by Park

1. Scarify soil in planting areas and any area to be restored by the Park Revegetation Program to a depth of minimum 18-inches by plowing, harrowing, or disking until soil is well pulverized and thoroughly mixed.

2. Till 2-inch of topsoil into the previously scarified 18-inches of soil. Topsoil shall be free from weeds, sod, clods and stones larger than 8", toxic substances, litter or other deleterious material.

3. For ground surface areas surrounding buildings and hardscape, maintain required positive drainage away from buildings and hardscape.

4. Establish finish grades to 0.1 foot of grades indicated.

5. Noxious weeds or parts thereof shall not be present in the surface grade.

6. Prior to acceptance of grades, hand rake to smooth, even surface, free of debris, clods, rocks and vegetable matter greater than 8".

7. Utilize salvaged topsoil as the top layer to the extent available.

C. Soil Amendments and Fine Grading in areas to be landscaped by Park

1. Till 1-inch of topsoil to a minimum depth of 3-inches after settlement. Topsoil shall be free from weeds, sod, clods and stones larger than 8", toxic substances, litter or other deleterious material. Spread evenly and grade to elevations and slopes shown. Hand rake areas inaccessible to machine grading.

2. For ground surface areas surrounding buildings and hardscape, maintain required positive drainage away from buildings and hardscape.

3. Establish finish grades to 0.1 foot of grades indicated.

4. Noxious weeds or parts thereof shall not be present in the surface grade.

5. Prior to acceptance of grades, hand rake to smooth, even surface, free of debris, clods, rocks and vegetable matter greater than 8".

6. Utilize salvaged topsoil as the top layer to the extent available.

3.4 STORING

A. The topsoil, after being stripped, shall be immediately stockpiled for reuse.

B. Stockpile slopes shall not be steeper than 3 horizontal to 1 vertical and stockpiles shall be protected from wind and water erosion, unnecessary compaction, and contaminants. Topsoil stockpiles shall be separate from each other and from other excess and unsuitable material piles.

C. Stockpiles shall be watered down periodically by the Contractor as necessary to mitigate the formation of windblown dust.

D. Stockpile topsoil and surface soil away from edge of excavations without intermixing it with subsoil.

Grade and shape stockpiles to drain surface water. Cover to prevent windblown dust.

1. Limit height of topsoil stockpiles to 36" unless authorized by Contracting Officer.

2. Stockpile surplus topsoil to allow for respreading a thicker layer of topsoil

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3.5 WEED CONTROL

A. All stockpiles shall remain weed free.

END OF SECTION 31 23 16

YOSE - 229677 31 25 00 - 1

6/2/21 EROSION AND

SEDIMENT CONTROL

SECTION 31 25 00 – EROSION AND SEDIMENT CONTROL

PART 1 - GENERAL

1.1 RELATED DOCUMENTS

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

B. Standard Specifications published by Department of Transportation (Caltrans), latest Edition.

1.2 SUMMARY

A. This Section includes:

1. Perimeter erosion control.

2. Site erosion control.

3. Brush layering.

4. Shoreline stabilization.

B. Related Sections:

1. Section 01 57 23 – Temporary Storm Water Pollution Prevention

2. Section 31 10 00 – Site Clearing

3. Section 31 20 00 – Earth Moving

1.3 SUBMITTALS

A. Product data for the following:

1. Wattles.

2. Triangular silt dike.

3. Dormant willow cutting and conifer branch bundles.

4. Jute netting.

PART 2 - PRODUCTS

2.1 GENERAL

A. To the extent feasible, use wildlife safe materials for erosion control products.

2.2 WATTLES

A. Wattles shall be a premanufactured roll filled with rice or coconut fiber and filled with biodegradable jute, sisal, or coir fiber netting secure tightly at each end.

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SEDIMENT CONTROL

B. Wattles shall meet one of the following:

1. 8 to 10 inches in diameter and at least 1.1 lb/ft

2. 10 to 12 inches in diameter and at least 3 lb/ft.

C. Wattles shall have a minimum functional longevity of 1 year.

D. Wattles shall be seed free or made of a different biodegradable material less likely to introduce seed into the park.

2.2 TRIANGULAR SILT DIKES

A. Triangular silt dikes shall consist of urethane foam and geotextile fabric.

B. Triangular silt dikes shall be a minimum of 8 inches high.

C. Geotextile fabric shall meet the following requirements:

Quality Characteristic Test Method Requirement Permittivity, (min, sec-1) ASTM D4491 0.5 Apparent opening size, average roll value, (max, US standard sieve size) ASTM D4751 40

Grab breaking load, 1-inch grip, in each direction, (min, lb) ASTM D4632 157

Apparent elongation, in each direction, (min, percent) ASTM D4632 50

Puncture strength, (min, lb) ASTM D6241 310 Trapezoid tearing strength, (min, lb) ASTM D4533 56 UV resistance, retained grab breaking load, 500 hours, (min, percent) ASTM D4355 70

2.3 DORMANT WILLOWS CUTTINGS AND CONIFER BRANCH BUNDLES

A. To be provided by park as a government furnished item.

2.4 JUTE NETTING

A. Jute netting shall be 100% biodegradable woven jute fiber with no plastic or metal staples.

B. Jute netting shall have a minimum functional longevity of 1 year.

C. Jute netting shall be seed free or made of a different biodegradable material less likely to introduce seed into the park.

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SEDIMENT CONTROL

D. Jute netting shall meet the following requirements:

Property Test Method Requirement Mass per Unit Area, (min, oz/yd2) ASTM D6475 7.6 Light penetration,(max, %) ASTM D6567 45 Tensile strength MD x CD, (min, lb/in) ASTM D6818 10 x 6 Elongation MD x CD, (max, %) ASTM D6818 38 x 33 C-Factor (max) ASTM D6459 0.15

MD: Machine Design, CD: Cross Direction

PART 3 - EXECUTION

3.1 WATTLES

A. Before installing wattles remove obstructions from the ground, including rocks, clods, and debris greater than one inch in diameter.

B. Wattles shall be installed and maintained per the manufacturer’s recommendations and Caltrans Specifications Section 21-2.03P.

C. Wattles shall be installed as soon as construction will allow or when designated by the CO. Wattle installation and trenching shall begin from the base of the slope prior to any topsoil or compost placement.