31 00 00 EARTHWORK
31 01 00 GENERAL REQUIREMENTS AND OWNER INTENT
.01 Earth Disturbance Management Guidelines
- On March 13, 2003, the Pennsylvania State University commitment to erosion and sedimentation control was elevated to a new level when the University submitted its municipal separate storm sewer system (MS4) permit application. The MS4 permit requires the University to manage storm water using the six best management (BMP) practices of:
- Public education
- Public participation
- Illicit discharge detection and elimination
- Construction storm water management
- Post construction storm water management
- Pollution prevention
- The following guidelines address the University’s commitment to addressing construction storm water management. This will be addressed in a five level system that outlines the practices that need to be used in all earth disturbance situations. All disturbances less than 5000 ft2 shall be handled with OPP staff, while those above 5000 ft2 shall be submitted to the local conservation district for approval.
- These guidelines utilize Engineering Services as the contact and manager of the permits and E&S plans. This centralization of the permits will allow the management of all permits’ requirements. All renewal and revision tracking will be the responsibility of Engineering Services. All fees and professional services associated with renewing or revising these permits will be the responsibility of the project for which coverage exists.
- Erosion and Sediment Control Plan Levels
- Level 1 - Minor Earth Disturbances Less Than 1000 ft2
Level 2 - Earth Disturbances Less Than 1000 ft2
- Level 1 disturbances are less than 1000 ft2 and with slopes less than 5% such as tree planting, garden management, flower bed restoration, minor turf restorations, and flower planting. Aeration and over seeding activities of turf areas of unlimited size are included in this level.
- In most cases these activities are of short duration, 1 to 2 days, and provide little or no opportunity for sediment pollution. The control measures associated with this work would consist mostly of installation of mulch at the conclusion of work and clean up of adjacent landscape.
Level 3 - Earth Disturbances Greater Than 1000 ft2 and Less Than 5000 ft2
- Level 2 disturbances are less than 1000 ft2 and will cover earth disturbances that involve the use of heavy construction equipment, durations greater than 2 days, slopes greater than 5%, and in close proximity to storm water features. Examples of these disturbances would be utility work, landscape installation, turf restoration on slopes and or in close proximity to storm inlets and flower beds on slopes greater than 5%.
- Erosion and Sediment Control (E&S) for such activities will be at the discretion of the project leader. In most cases, this would include, but not be limited to, mats for access, silt fence, silt socks, inlet bagging, and a filter bag for pumping. Project leaders will require training on E&S controls. Projects managed by leaders not trained will be required to follow Level 3 criteria. In the event of complication, the Manager of Engineering Services or his designee will provide direction as required.
Level 4 - Earth Disturbances Greater Than 5000 ft2
- All earth disturbances greater than 1000 ft2 and less than 5000 ft2 will require an E&S plan. This plan, while not requiring approval by the conservation district, must be protective of the waters of the commonwealth and as such should follow the 25 PA Code 102.
- These plans will consist of a map of the area that delineates the disturbance and the best management practices or E&S controls to be utilized during the disturbance. A narrative should describe the area in ft2, the sequence of operations, erosion control installation, maintenance, and removal determinations. Details for E&S control measures are available in the Pennsylvania Department of Environmental Protection Erosion Control Manual. All E&S plans for projects greater than 1000 ft2 and less than 5000 ft2 will be approved by the campus designee and a copy kept on file. All projects in this category at University Park will be entered into a spreadsheet and reported to the local conservation district for monthly review.
Level 5 - NPDES Permits
- Earth disturbances greater than 5000 ft2 must be covered by an E&S plan. When such a disturbance is within an existing NPDES permit boundary, the E&S plan will serve as a revision to the permit. (See flowchart “PSU Earth Disturbance Process” ) The E&S plan must be developed and submitted to the local conservation district for approval. The plan shall be developed using 25 PA Code 102 as a reference. All plans for the University shall be submitted to the local conservation district through the Manager of Engineering Services or his designee. Submissions should be comprised of 4 plan sets, an application, and a check made payable to the local conservation district. Upon approval by the conservation district, the plan information will be logged, and approvals will be copied and approvals attached to the file copy for forwarding to the appropriate project manager for distribution to the contractor. All originals will be maintained at Engineering Services. Note: An approved copy must be at the job site at all times.
Erosion and Sediment Control plan notes.
- When earth disturbances are greater than one acre with a point source discharge to the waters of the commonwealth or greater than five acres, a NPDES permit is required. If sufficient development will take place on the campus over the next ten years, the total campus area or a manageable section of the total area should be included in the NPDES permit boundary.
- The application process for the General and Individual permit is shown in the referenced flow chart. The professional will submit four sets of E&S plans, NPDES application form (Individual or General), application fee, and the General Information Form to the Manager of Engineering Services for logging, review, and submission.
- Once the permit is reviewed and issued by the Conservation District or DEP, it will be logged, approvals copied and attached to the file copy for forwarding to the appropriate project manager for distribution to the contractor. All originals will be maintained at Engineering Services. Notes: Prior to starting the earth disturbance, a copy of the original permit will be required to be on site. All jobs excavated by outside contractors will require permit coverage through a co-permittee agreement.
- Visual site inspections are to be performed on at least a weekly basis and after each measurable precipitation event to ascertain that the E&S BMP’s are operational and effective. Record all inspections on Penn State’s “Sedimentation Control Inspection Log Sheet”. All preventative and remedial maintenance work, including clean out, repair, replacement, regrading, reseeding, remulching, or renetting, must be performed immediately. The contractor and permittee must attempt, whenever possible, to recycle all waste generated on-site during this project. All waste material not recycled must be disposed of at an approved waste site. For all sites covered by an NPDES Permit, the outside contractor, when applicable, shall develp and implement a Preparedness, Prevention, and Contingency (PPC) Plan.
.02 Test Borings
- Data on indicated subsurface conditions are not intended as representations or warrants of continuity of such conditions between soil borings. The complete foundation investigation including boring logs and recommendation is available for review from the Professional upon request. It is expressly understood that the University will not be responsible for interpretations or conclusions drawn therefrom by the Contractor. Additional test borings and other exploratory operations may be made by the Contractor at no cost to the University, with the understanding that he is fully responsible for any damage resulting therefrom and he restores the site to its original condition upon completion.
.03 Inspection and Testing
- Continuous inspection and testing by a testing laboratory with a Soils Engineer as approved by the Professional shall be provided during filling and compaction. All footing excavations shall be inspected by a qualified inspector to ascertain that all excavations have penetrated topsoil, soil with organic matter, or fill to undisturbed soil; that the bottom of the excavation is on suitable bearing material; and that all loose material, water and water-softened material has been removed just prior to placing concrete. The Contractor shall contract and pay for the services of the testing laboratory and the Soils Engineer. Copies of the reports from the testing laboratory shall be forwarded to the Contractor, the University, and the Professional.
- Compaction Tests (if required)
- The Contractor shall employ a recognized testing laboratory, approved by the Professional, to perform verification testing of compaction.
- The Professional and the University reserve the right to direct where tests shall be taken.
- Certification of compliance from testing laboratory shall be provided to the Professional, which shall state that the earth compaction conforms to the requirements of these specifications. Certificates shall be received and approved by the Professional prior to concreting operations.
.04 Soil Protection Zones
- The Pennsylvania State University is committed to protecting its native soils.
- The Soil Protection Zones shall be protected during the entire construction process.
- Areas within the Soil Protection Zone shall not be turned, excavated, compacted, or altered in any way.
- Protection of Existing Utilities:
- Prior to any work being performed the Contractor shall insure that all existing utilities within and surrounding the project site have been clearly marked in accordance with the Pennsylvania Underground Utility Line Protection Act, Act 287 as amended by Act 199.
- The Contractor shall meet with the University Representative prior to beginning any excavation, grading or other construction activities to review and verify all work procedures, trailer locations, stockpile and staging areas, access and haul roads, equipment operation methods, and soil protection measures.
- The Contractor shall provide a scaled grading plan indicating all existing and proposed grading. Limits of disturbance will be marked/labeled on the plan to outline all soil protection measures. This plan will become part of the construction documents.
- The Contractor shall submit a written guarantee that he/she shall not enter the soil protection zones at any time during construction without first getting approval from the University Representative.
- The Contractor shall verify in writing that all soil protection measures have been met.
- Soil Protection Zones
- Prior to the start of any site work the Contractor will erect fencing around existing soil volumes which are to be preserved within the construction site.
- Soil protection areas outlined on the plan to not be disturbed shall be protected from unnecessary excavation, compacting, and/or spoiling during the entire construction process. Protection of these zones shall be by the placement of temporary fencing as outlined in Part B.1.b - Materials.
- NO REMOVAL OF OR ENCROACHMENT INTO SOIL PROTECTION ENCLOSURES SHALL BE PERMITTED UNLESS COORDINATED WITH THE UNIVERSITY REPRESENTATIVE.
- The Contractor shall be responsible for the installation and maintenance of all soil protection fencing. Protective fencing shall remain undisturbed until all construction activities have been completed. The Contractor shall remove fencing upon completion of construction and approval by the University Representative.
- If protective fencing is damaged, the Contractor shall immediately execute the necessary repairs to re-establish it back to its original configurations outlined on the Soil Protection Zone Plan.
- At the conclusion of the project, as soil protection fencing is being removed, the Contractor shall continue to identify and enforce soil protection zones through temporary measures until final acceptance. The use of these temporary protection methods is only acceptable for a period not to exceed 5 business days. A list of appropriate materials and methods for temporary protection are listed in PART B.1 – MATERIALS.
- The Contractor shall be held liable for any damage to the existing soil within the soil protection zone caused by unauthorized intrusions into the protected areas during the construction period.
- Erosion control devices shall be installed as per the contract drawings with particular emphasis on preventing silting and/or erosion within the soil protection zone.
- Equipment and Materials:
- As selected by the Contractor, except as otherwise indicated, to complete work in a safe manner and to protect all personnel and bystanders involved.
- Protective fencing shall be 6 feet high chain link fence supported by 2 inch diameter galvanized iron posts set to a minimum depth of 2 feet. Posts shall be spaced a minimum of 10 feet on center. Movable fence panels may only be used upon approval from the University Representative.
- An 8 ½” x 11” sign indicating the area as a soil protection zone shall be prominently displayed on each fence panel. Signs may be obtained by contacting the University Representative.
- Temporary protection measures may be used at the conclusion of the project, up until final acceptance. These methods may include, but are not limited to the use of signs, post and wire, or other methods approved by the University Representative.
- Scope of work within the Soil Protection Zone:
- For those construction projects requiring temporary access or haul roads through the protection zone, a roadbed shall be installed using road plates, Alturnamat, or a PADOT Class IV Geotextile base covered with 6 inches (minimum) of mulch, wood chips or gravel to protect soil and minimize soil compaction. Approval shall be given by the University Representative. The roadbed material shall be maintained as necessary to keep its original condition.
- No material shall be stored or piled within the soil protection zone unless otherwise approved by the University Representative. No gasoline, fuel oil, harmful chemicals or other deleterious materials shall be stored, spilled or deposited on the ground within the soil root protection zone.
- There shall be no vehicular traffic or parking permitted within the soil protection zone.
- Foot traffic shall be kept to a minimum within the soil protection zone. If temporary foot traffic must be directed over the soil protection zone a pathway shall be installed using Alturnamat or a PADOT Class IV Geotextile base covered with 3 inches (minimum) of mulch, wood chips or gravel to protect soil and minimize soil compaction. Approval shall be given by the University Representative. The pathway material shall be maintained as necessary to maintain its original state.
- No access to the soil protection zone is allowed during periods when the soil is excessively wet due to rain or snow unless approved construction access way is in place.
- The Contractor shall be held liable for any damage to protected soil volumes. A dollar value shall be determined by an independent soils testing laboratory based on the square footage of compacted soil.
- The Contractor shall be held liable for any remedial measures required to treat compacted, excavated, or tilled soil within the soil protection zone. All remedial treatments shall be conducted by the University and/or their designee.
31 10 00 SITE CLEARING
.01 Site Clearance
- Protection: The Contractor shall provide and maintain adequate guards, fences, lights, warning signs and similar items as may be required.
- Grubbing: The Contractor shall remove and dispose of all shrubs, stumps and roots larger than 1 1/2" in diameter, to a depth of 20 inches.
- Plantings to be removed by the University will be removed prior to commencement of any work at the site.
- Plantings to be removed by the Contractor shall be classified as debris and shall be removed by the Contractor off University property.
- Disposal of Material: All refuse and other debris shall be disposed of by hauling from the site and off University property.
- Material to be removed shall be removed daily and shall not be allowed to accumulate on the site.
31 20 00 EARTH MOVING
- Proper placement of all erosion-control facilities shall occur prior to any earthwork activity.
- Puddling will not be permitted.
- All backfill must be mechanically tamped, in layers not to exceed 6 inches in depth, and thoroughly compacted to prevent settlement.
- If blasting is required, refer to standard blasting requirement, Section F.
- Unclassified Excavation:
General: All excavation shall be to the lines and grades as shown:
- All excavation for projects funded by the University will be unclassified and will include (without limitation thereto) the excavation and removal of all soil, shale, rock or rock formations, boulders, existing foundations, fill, and any type of subsurface condition encountered in the contract area.
- No claims for extra compensation or extension of contract time because of the nature of subsurface conditions encountered will be considered by the University.
Excavation shall provide sufficient clearance for bracing, shoring, formwork, inspection and installations, as required.The bottoms of all excavations shall be trimmed, by hand if necessary, to grades indicated or required.The Contractor, at his option, shall make any exploration of the subgrade and areas requiring excavation as he may see fit, at his own cost and expense.
- Six inches below finished grades in seeded areas.
- To grades indicated at paved areas minus thickness of base course and surface materials.
- Where new work meets existing, grades shall be adjusted to allow new work to meet and match existing finished grades at paved areas.
All existing topsoil shall be removed to a depth of six inches and stockpiled on the site. All topsoil is the property of the University. Excess topsoil removed and not required for finish grading shall be removed by the Contractor and stockpiled as directed by the University at a location on University property.Excavated materials to be used for filling may be stored at the site.Excavated materials not required or not suitable for filling or other purposes shall be hauled from the site as excavated and disposed of off University property.
- Prior to starting any excavation, the Contractor shall thoroughly familiarize himself with the location of all existing underground utilities that may be affected by his work.
- All excavation within three feet of any existing underground utility line shall be accomplished by hand labor. Extreme caution shall be used in this area to prevent any damage to existing facilities.
- All underground utilities and/or facilities uncovered or exposed shall be adequately protected by the Contractor, as necessary. Utilities serving existing facilities must not be interrupted until the Contractor has made the necessary arrangements with and received approval from the University.
.02 Stockpiling, Furnishing, and Placing Topsoil
- The work in this section includes the labor, materials, and installation methods for the separation and salvaging of topsoil, furnishing of topsoil from an outside source and the placing of topsoil.
- Protection of Existing Utilities
- Prior to any work being performed the Contractor shall insure that all existing utilities within and surrounding the project site have been clearly marked in accordance with the Pennsylvania Underground Utility Line Protection Act, Act 287 as amended by Act 199.
- Quality Assurance:
- Topsoil shall consist of friable surface soils reasonably free of grass, roots, weeds, sticks, rocks or other unsuitable materials as determined under Part A.4. – Submittals.
- Salvaged and Stockpiled Topsoil:
- Prior to the start of any seeding activity, the Contractor shall have the existing soil tested by an approved soils testing laboratory. Copies of the soil test results shall be furnished to the University Representative prior to any grading, excavating, or other construction activity.
- Furnished Topsoil:
- The Contractor shall have the soil tested by an approved soils testing laboratory and shall make copies of the soil test available to the University Representative prior the hauling or delivery of any soil to the project site.
- The Contractor shall submit a one-gallon sample, source, and letter of certification from the supplier to the University Representative for approval prior to installation.
- Delivery, Storage, and Handling:
- Select a stockpile location to avoid slopes and natural drainageways, and to avoid traffic routes. Perimeter pollution controls shall be implemented as outlined in 31 01 00.01 – Earth Disturbance Management Guidelines and as outlined on the Erosion and Sedimentation Control Plan. Stockpiles shall not exceed 35’ above grade.
- Job Conditions:
- Areas where topsoil will be placed will be free of waste or debris developed by other trades. Any discrepancy from such conditions shall be reported to the University Representative before beginning any installation.
- Salvaged and Stockpiled Topsoil: Acceptable friable loam that is reasonably free of subsoil, clay, brush, roots, weeds, other objectionable vegetation, stones, other foreign material larger than 2 inches in any dimension, litter, and/or other material unsuitable or harmful to the growing of vegetation.
- Furnished Topsoil: Same criteria as outlined for Salvaged and Stockpiled Topsoil and containing not less than 2.0% or more than 10% organic matter. The soils shall be obtained from a site where the soil quality has proven ability to grow crops.
- The Contractor is responsible for the reconditioning of the area from which the topsoil is obtained, and in accordance with all Local, State, and Federal regulations.
- The contractor shall supply necessary documentation verifying that topsoil is free of contamination.
- Protection of Existing Vegetation: All existing vegetation to remain shall be protected at all times in accordance with 32 90 00.01 – Tree Canopy / Tree Root Protection Zones.
- Preparation of the Subgrade:
- Using acceptable methods, the Contractor shall loosen the subgrade to a depth of 6 inches or otherwise required to provide adequate drainage before placing the topsoil. Remove stones and other foreign materials 2 inches or larger in any dimension. Remove and satisfactorily dispose of unsuitable and surplus material.
- Spreading of Topsoil:
- Spreading shall not be conducted when the ground or topsoil is frozen, excessively wet or otherwise in a condition detrimental to uniform spreading operations.
- Topsoil shall be spread to the following depths:
- Turf Areas (Seed or Sod): Minimum depth of 6 inches as outlined in 32 90 00.
- Planting Beds: Minimum depth of 12 inches as outlined in 32 90 00.
- Finishing of Topsoil:
- The topsoil surface shall be left reasonably smooth and without ruts or surface irregularities that could contribute to concentrated water flow down slope or surface ponding conditions, Rake and grade planting beds.
- Compact the topsoil enough to ensure good contact with the underlying soil, but avoid excessive compaction, as it increases runoff and inhibits seed germination and seedling growth.
- All topsoil areas are to be finished in accordance with specified planting type for that area. Reference:
- 32 90 00.02 – Lawns and Grasses
- 32 90 00.03 – Trees, Shrubs, and Groundcovers
- Once all topsoil areas have been finished and ready for planting and/or seeding, no vehicles will be allowed to drive on the placed topsoil at any time.
- Pre-grading Inspection: Prior to the commencement of site work, contact the University Representative to provide an inspection to verify the delineation and protection of native soils and vegetation to remain in place, as outlined in 32 90 00.01 – Tree Canopy / Tree Root Protection Zones and 31 01 00.04 – Soil Protection Zones.
- Interim Grading Inspection: Prior to the placement of topsoil, contact the University Representative to provide an inspection of the subgrade. Make corrections and adjustments as directed by the University Representative.
- Post Grading Inspection: Prior to planting and/or seeding, contact the University Representative to provide an inspection to verify that the placement of soil and soil preparation is consistent with guidelines listed in this specification and on the grading plan. Make corrections and adjustments as directed by the University Representative.
- Final Inspection: After all planting, seeding, sodding, paving, and/or other construction related activities are complete the Contractor shall contact the University Representative to provide an inspection to verify that all conditions are as stipulated in this specification. Make corrections and adjustments as directed by the University Representative.
- Secondary Verification for Failing Sites: If the University Representative determines that the installation does not meet the conditions outlined in this specification or on the approved grading plan, additional testing by an independent soils testing laboratory will be ordered by the University Representative and paid for by the Contractor. Make corrections and adjustments as directed by the University Representative.
- Establishment Period:
- All Establishment Periods pertaining to 32 90 00.02 – Lawns and Grasses and .03 – Trees, Shrubs, and Groundcovers will pertain to the establishment of topsoil on the project site. If at any time during the 120 day Establishment Period it is determined that the topsoil does not meet the conditions outlined in this specification or on the approved grading plan, the University Representative reserves the right for additional testing, paid for by the Contractor, to determine the correct course of action.
- Final acceptance for soil preparation will be contingent on the approval of all inspections and that the soil preparation is consistent with these specifications and with the approved grading plan.
31 30 00 STRUCTURAL BACKFILL AND COMPACTION
- Section Includes: Backfill and compaction requirements for building, structures, roads, sidewalks, etc.
- American Society for Testing and Materials (ASTM):
- ASTM C 295: Guide to Petrographic Examination of Aggregates for Concrete.
- ASTM C 1580: Standard Test Method for Water-Soluble Sulfate in Soil
- ASTM D 698: Standard Test Methods for Laboratory Compaction of Soil Using Standard Effort.
- ASTMD 2922: Density of Soil and SOil-Aggregate in Place by Nulcear Methods (Shallow Depth).
- Pennsylvania Department of Transportation (PENNDOT), Standard Specifications Publication 408, as supplemented.
- PENNDOT Section 703, Coarse Aggregate.
- American Association of State Highway and Transportation Officials (AASHTO):
- AASHTO R 18-97, Establishing and Implementing a Quality System for Construction Materials Testing Laboratories.
- Pennsylvania Department of Transportation Directive:
- "Acid Bearing Rock Policy" by Tucker Ferguson P.E.; Director, Bureau of Construction and Materials; September 30, 2009.
- Aggregate: Submit samples and lab tests to Professional for approval as specified below in Quality Control.
- Field Test Reports: Submit copies of all field tests performed to confirm that backfill materials have been compacted to the specified density.
- Testing Laboratory: Submit for approval the AASHTO Materials Reference Laboratory (AMRL) certification of the proposed testing laboratory.
- Quality Control
- Provide advance examination and testing according to methods referenced, or as required by the Professional, for aggregate materials.
- Conduct aggregate quality tests in accordance with requirements of PENNDOT Section 703.
- Conduct petrographic examination of aggregate samples representative of proposed materials according to procedure defined in ASTM C 295.
- Examination shall be performed by an experienced petrographer.
- The selected aggregate material shall meet these additional restrictions:
Conduct chemical analysis of aggregate samples representative of proposed materials according to procedures defined in ASTM C 1580.Professional reserves the right to accept aggregate materials based on certification from supplier that aggregate originates from a source approved by PENNDOT and that aggregate complies with specified PENNDOT requirements and the additional requirement included in this specification.
Independent Testing Agency shall perform testing of aggregate samples prior to the start of the work and every three months thereafter. Testing results must be resubmitted for review each time the source material is changed. Testing shall include soundness, abrasion, petrographic examination and chemical analysis.
- Less than 0.5% pyrite (i.e. 0.3% S).
- Contain less than 2% deletrious materials.
- Limit the sulfur content to 0.1% if it is in the form of framboidal pyrite in a carbonaceous shale (Antes Member of the Reedsville Formation and parts of the Coburn Formation) or as whisker pyrite in veins.
- Less than 15% thin, elongate, or platy pieces for Type A, 20% for Type B.
Quality Assurance Testing
- The Quality Assurance Agency will perform tests related to backfill compaction density, moisture content, and inspection of the subgrade.
- Testing shall be performed and approved for each subgrade and each fill layer before proceeding to the next layer. Any area which does not meet density, percent moisture, or other requirements at any time shall be suitably reworked by the Contractor and retested at the expense of the Contractor.
- Environmental Requirements:
- Pumping: Keep excavations free from water. Build dams and other devices necessary for this purpose, including lowering water table below excavation bottom by deep wells, well points, and pumping. Provide and operate pumps of sufficient capactiy for dewatering excavations. Dispose of water removed from excavations in a manner not to cause injury to public health, public or private property, work of other trades or contractors, portions of work completed or in progress, or produce an impediment to highway, road, lane, or street usage by public. No additional payment will be made for pumping or other difficulties encountered due to water.
- Maintain water table elevation sufficiently below excavation levels so that slopes remain stable and bottoms of excavations do not become loosened by water flow.
- Explosives and Blasting: Not permitted in performance of structural excavating.
- Responsibility for Condtion of Excavation: Assume responsibility for condition and results of excavations. Remove slides and cave-ins without extra compensation at whatever time and under whatever circumstances they occur.
- At no additional expense, sustain in places, and protect from direct or indirect injury, pipes, walls, buildings, and other structures or property in vicinity of work, whether above or below ground, or that may appear in or adjacent to excavation.
- Adequately support pipes and underground conduits exposed as a result of operations. Provide adequate support along entire exposed length by timber or planking, install in a manner that anchorage of supporting members is not disturbed or weakened during backfilling operation. Carefully ram and tamp specified backfill materials under and around supports and leave in place as a guard against breakage of supported structure due to backfill settlement. No additional payment will be made for material left in place or for labor of installing and maintaining supports.
- Assume risks attending presence or proximity of pipes, conduits, and other items of every kind and description, in or over excavation, or in vicinity of work, whether above or below ground surface. Assume responsibility for damages and expenses for direct or indirect injury, caused by work, to persons or property by reason of them or by reason of injury to them whether structures are or are not indicated on Drawings.
- Removal of Obstructions:
- Should a pipe, conduit, or other structure, above or below ground be in a position in opinion of Professional, to require its removal, realignment, or change due to work to be done under Contract, work of removal, realignment, or change will be done as extra work, or will be done by the owner of obstructions, without cost to Contractor. The Contractor is required to uncover and sustain structures, at no additional expense, before removal and before and after realignment or change as constituting part of Contract; and no claim for damage or extra compensation on account of presence of structure, or on account of delay in removal or rearrangement of structure.
- Dewatering: Contractor is responsible for keeping groundwater levels at least 2 feet below working subgrades. Contractor shall provide adequate pumps and piping to maintain groundwater levels at this level without an increase in the contract price. Subgrades damaged by groundwater infiltration will be overexcavated and replaced as required by the Professional at no increase in the contract price.
- Aggregate Backfill: Coarse aggregate consisting of hard, tough, durable, and uncoated inert particles free from clay, silt, vegetation, and other deleterious material such as reactive chert, gypsum, iron sulfide, amorphous silica, and hydrated iron oxide.
- Stuctural Aggregate Backfill: PENNDOT 2A Coarse Aggregate.
- Aggregate Fill: AASHTO 57 conforming to gradation requirements defined in PENNDOT 703.
- Furnish aggregate backfill crushed and prepared from one of the following for listed materials:
- Nealmont Formation (Rodman and Centre Hall members)
- Linden Hall Formation (Valentine, Valley View, and Stover members)
- Snyder Formation
- Hatter Formation
- Bellefonte Formation (Tea Creek and Coffee Run members)
- Nittany Formation
- Mixed limestone and dolostone:
- Lower Loysburg Formation
- Axemann Formation
- Keep excavation free from water during the performance of the work. Provide and operate dewatering equipment of sufficient capacity for dewatering the excavations.
- Dewatering efforts are to be maintained until excavations are closed or when determined by the Owner or Professional no longer necessary.
- Subgrade Preparation and Inspection
- After removal of existing subbase material under floor slab to limits defined by Owner, scarify the exposed disturbed surface to a depth of 4 inches and compact to 97 percent of maximum dry density determined in accordance with ASTM D 698.
- Compact all subgrades in the presence of the Professional. Provide at least 48 hours advance notice of anticipated proofrolling.
- Compact subgrade using walk-behind rollers and hand tampers.
- The Professional will evaluate subgrade acceptability and will determine the lateral and vertical limits of any unsuitable materials. Excavate loose, soft, or otherwise unsuitable soils as directed by the Professional.
- Backfill the excavated areas with Aggregate Backfill Materials as directed by the Professional after approval of subgrade is received.
- Approved subgrades shall be protected from degradation caused by construction activities or other causes. Subgrade that is degraded or weakened shall be reevaluated and repaired as directed by the Professional.
- Aggregate Backfill Placement
- Place aggregate backfill as indicated on Drawings.
- Perform backfilling using walk-behind rollers and hand tampers.
- Prior to backfilling, clean excavation free of trash and debris.
- Do not proceed with additional layer until density obtained.
- Place backfill material in such a manner that unbalanced horizontal loads will not be applied to structure, utilities, or pipelines.
- Do not use compaction equipment or methods that produce excessive horizontal or vertical earth pressures.
- Aggregate Placement:
- Aggregate Fill: Place in 4-inch lifts and compact each lift with the vibratory equipment to the satisfaction of the Construction Manager based on non-movement of material under compaction equipment.
- Structural Aggregate Backfill: Place in 4-inch lifts and compact to 97 percent of maximum dry density determined in accordance with ASTM D 698.
- Remove and dispose of excess material that cannot be used on Project off site in a legal manner at no additional expense to the Owner. Leave area in a clean and neat condition.
- Field Quality Control
- Compacted backfill shall be tested to verigy compliance with specified requirements in accordance with ASTM D 2922.
- Perform one test per 50 cubic yards.