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HomeMy WebLinkAbout31 20 00 Earth MovingTHE KENT 31 20 00 - THE KENT Issue Date 05.09.18 EARTH MOVING THE KENT SECTION 31 20 00 - EARTH MOVING 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. This Section includes the following: 1. Excavating and backfilling for buildings and structures. 2. Drainage course for slabs-on-grade. 3. Subsurface drainage backfill for walls and trenches. 4. Excavating and backfilling trenches for buried mechanical and electrical utilities and pits for buried utility structures within 5’-0” out from the building line. B. Related Sections include the following: 1. Division 03 Section "Cast-in-Place Concrete" for vapor retarder over granular drainage course. 2. Division 26 Sections for excavating and backfilling buried electrical utilities and buried electrical utility structures. 3. Work performed under a separate contract known as “The Kent Site work Project”: a. Preparing subgrades for building pad slabs-on-grade, walks, pavements, lawns, and plantings. b. Division 31 Section "Site Clearing" for site stripping, grubbing, removing topsoil, and protecting trees to remain. c. Division 33 Section "Sub-drainage" for drainage of footings, slabs-on- grade, and walls. 1.3 DEFINITIONS A. Base Course: Layer placed between the sub-base course and asphalt paving. B. Backfill: Soil material or controlled low-strength material used to fill an excavation. a. Initial Backfill: Backfill placed beside and over pipe in a trench, including haunches to support sides of a pipe. b. Final Backfill: Backfill placed over initial backfill to fill a trench. C. Bedding Course: Layer placed over the excavated subgrade in a trench before laying pipe. D. Drainage Course: Layer supporting slab-on-grade used to minimize capillary flow of pore water. E. Excavation: Removal of material encountered above subgrade elevations. 1. Unauthorized Excavation: Excavation below subgrade elevations or beyond indicated dimensions without direction by Architect. Unauthorized excavation, as well as remedial work directed by Architect, shall be without additional compensation. THE KENT 31 20 00 - THE KENT Issue Date 05.09.18 EARTH MOVING THE KENT F. Sub-grade: Surface or elevation remaining after completing excavation, or top surface of a fill or backfill immediately below sub-base, drainage fill, or topsoil materials. 1.4 SUBMITTALS A. Test Reports-Excavating: Submit following reports directly to Architect/Engineer from the testing services, with copy to Contractor: 1. Test reports on borrow material. 2. Verification of each footing subgrade. 3. Field density test reports. 4. One optimum moisture-maximum density curve for each type of soil encountered. 5. Report of actual unconfined compressive strength and/or results of bearing tests of each stratum tested. 1.5 QUALITY ASSURANCE A. Codes and Standards: Perform excavation work in compliance with applicable requirements of governing authorities having jurisdiction. B. Testing and Inspection Service: 1. Testing Laboratory: Employ, at Contractor's expense, testing laboratory to perform soil testing and inspection service for quality control testing during earthwork operations. 2. Soils Engineer: Testing laboratory shall assign a registered Soils Engineer to supervise the entire period of earthwork and be responsible for all testing and inspections. a. Soils Investigation Report: Soils Engineer shall obtain a copy of the soils investigation report and be responsible to make sure that all earthwork operations conform, unless directed otherwise by the Architect/Engineer or so indicated on by the Contract Documents. b. Soil materials used on the project whether existing or new shall be verified and approved by Soils Engineer. If not approved, the Soils Engineer shall make recommendations to the proper materials to be used for approval by the Architect/Engineer. C. Compaction of soil materials used on the project whether existing or new based on their intend use, shall be verified and approved by Soils Engineer. If not approved, the Soils Engineer shall make recommendations to the proper compaction and percent of relative density of soil materials for approval by the Architect/Engineer. 1.6 PROJECT CONDITIONS A. Existing Utilities: Do not interrupt utilities serving facilities occupied by Owner or others unless permitted in writing by Architect and then only after arranging to provide temporary utility services according to requirements indicated: 1. Notify Owner’s Representative and Architect in writing not less than three days in advance of proposed utility interruptions. 2. Do not proceed with utility interruptions without Architect's written permission. 3. Contact utility-locator service for area where Project is located before excavating. B. 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. THE KENT 31 20 00 - THE KENT Issue Date 05.09.18 EARTH MOVING THE KENT 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: ASTM D 2487 soil classification groups GW, GP, GM, SW, SP, and SM, or a combination of these group symbols; free of rock or gravel larger than 3 inches in any dimension, debris, waste, frozen materials, vegetation, and other deleterious matter. C. Unsatisfactory Soils: ASTM D 2487 soil classification groups GC, SC, ML, MH, CL, CH, OL, OH, and PT, or a combination of these group symbols. 1. Unsatisfactory soils also include satisfactory soils not maintained within 2 percent of optimum moisture content at time of compaction. D. Backfill and Fill: Satisfactory soil materials. E. Sub-base: Naturally or artificially graded mixture of natural or crushed gravel, crushed stone, and natural or crushed sand; ASTM D 2940; with at least 90 percent passing a 1- 1/2- inch sieve and not more than 12 percent passing a No. 200 sieve. F. Engineered Fill: Naturally or artificially graded mixture of natural or crushed gravel, crushed stone, and natural or crushed sand; ASTM D 2940; with at least 90 percent passing a 1-1/2-inch sieve and not more than 12 percent passing a No. 200 sieve. G. Bedding: Naturally or artificially graded mixture of natural or crushed gravel, crushed stone, and natural or crushed sand; ASTM D 2940; except with 100 percent passing a 1- inch sieve and not more than 8 percent passing a No. 200 sieve. H. Drainage Fill: Washed, narrowly graded mixture of crushed stone, or crushed or uncrushed gravel; ASTM D 448; coarse-aggregate grading Size 57; with 100 percent passing a 1-1/2- inch sieve and 0 to 5 percent passing a No. 8 sieve. 2.2 ACCESSORIES A. Detectable Warning Tape: Acid- and alkali-resistant polyethylene film warning tape manufactured for marking and identifying underground utilities, minimum 6 inches wide and 4 mils thick, continuously inscribed with description of utility, with metallic core encased in a protective jacket, detectable by metal detector when tape is buried up to 30 inches deep; colored as follows: 1. Blue: Water systems. 2. Green: Sewer systems. PART 3 - EXECUTION 3.1 PREPARATION A. Protect structures, utilities, sidewalks, pavements, and other facilities from damage caused by settlement, lateral movement, undermining, washout, and other hazards created by earthwork operations. THE KENT 31 20 00 - THE KENT Issue Date 05.09.18 EARTH MOVING THE KENT B. Protect subgrades and foundation soils against freezing temperatures or frost. Provide protective insulating materials as necessary. C. Provide erosion-control measures to prevent erosion or displacement of soils and discharge of soil-bearing water runoff or airborne dust to adjacent properties and walkways. 3.2 DEWATERING A. Prevent surface water and ground water from entering excavations, from ponding on prepared subgrades, and from flooding Project site and surrounding area. 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. 3.3 EXPLOSIVES A. Explosives: Do not use explosives. 3.4 EXCAVATION, GENERAL A. Unclassified Excavation: Excavation to subgrade elevations regardless of the character of surface and subsurface conditions encountered, including rock, soil materials, and obstructions. 1. If excavated materials intended for fill and backfill include unsatisfactory soil materials and rock, replace with satisfactory soil materials. 3.5 EXCAVATION FOR STRUCTURES A. Excavate to indicated elevations and dimensions within a tolerance of plus or minus 1 inch. Extend excavations a sufficient distance from structures for placing and removing concrete formwork, for installing services and other construction, and for inspections. 1. Excavations for Footings and Foundations: Do not disturb bottom of excavation. Excavate by hand to final grade just before placing concrete reinforcement. Trim bottoms to required lines and grades to leave solid base to receive other work. 2. Excavation for Underground Tanks, Basins, and Mechanical or Electrical Utility Structures: Excavate to elevations and dimensions indicated within a tolerance of plus or minus 1 inch. Do not disturb bottom of excavations intended for bearing surface. 3.6 EXCAVATION FOR BUILDING PATIOS A. Excavate surfaces under building patios to indicated cross sections, elevations, and grades. 3.7 EXCAVATION FOR UTILITY TRENCHES A. Excavate trenches to indicated gradients, lines, depths, and elevations shown on drawings. THE KENT 31 20 00 - THE KENT Issue Date 05.09.18 EARTH MOVING THE KENT 3.8 APPROVAL OF SUBGRADE A. Notify Architect when excavations have reached required subgrade. B. If Architect determines that unsatisfactory soil is present, continue excavation and replace with compacted backfill or fill material as directed. 1. Additional excavation and replacement material will be paid for according to Contract provisions for changes in the Work. C. Proof roll subgrade with heavy pneumatic-tired equipment to identify soft pockets and areas of excess yielding. Do not proof roll wet or saturated subgrades. D. Reconstruct subgrades damaged by freezing temperatures, frost, rain, accumulated water, or construction activities, as directed by Architect. 3.9 UNAUTHORIZED EXCAVATION A. Fill unauthorized excavation under foundations or wall footings by extending bottom elevation of concrete foundation or footing to excavation bottom, without altering top elevation. Lean concrete fill may be used when approved by Architect. 1. Fill unauthorized excavations under other construction or utility pipe as directed by Architect 3.10 STORAGE OF SOIL MATERIALS A. Stockpile borrow materials and satisfactory excavated soil materials. Stockpile 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. 3.11 BACKFILL A. Place and compact backfill in excavations promptly, but not before completing the following: 1. Construction below finish grade including, where applicable, damp proofing, waterproofing, and perimeter insulation. 2. Surveying locations of underground utilities for record documents. 3. Inspecting and testing underground utilities. 4. Removing concrete formwork. 5. Removing trash and debris. 6. Removing temporary shoring and bracing, and sheeting. 7. Installing permanent or temporary horizontal bracing on horizontally supported walls. 3.12 UTILITY TRENCH BACKFILL A. Place and compact bedding course on trench bottoms as indicated on drawings. Shape bedding course to provide continuous support for bells, joints, and barrels of pipes and for joints, fittings, and bodies of conduits. B. Backfill trenches excavated under footings and within 18 inches of bottom of footings; fill with concrete to elevation of bottom of footings. THE KENT 31 20 00 - THE KENT Issue Date 05.09.18 EARTH MOVING THE KENT C. Provide 4-inch- thick, concrete-base slab support for piping or conduit less than 30 inches below surface of roadways. After installing and testing, completely encase piping or conduit in a minimum of 4 inches of concrete before backfilling or placing roadway sub- base. D. Place and compact initial backfill of sub-base material, free of particles larger than 1 inch, to a height of 12 inches over the utility pipe or conduit. 1. Carefully compact material under pipe haunches and bring backfill evenly up on both sides and along the full length of utility piping or conduit to avoid damage or displacement of utility system. E. Coordinate backfilling with utilities testing. F. Fill voids with approved backfill materials while shoring and bracing, and as sheeting is removed. G. Place and compact final backfill of satisfactory soil material to final subgrade. H. Install warning tape directly above utilities, 12 inches below finished grade, except 6 inches below subgrade under pavements and slabs. 3.13 FILL A. Preparation: Remove vegetation, topsoil, debris, unsatisfactory soil materials, obstructions, and deleterious materials from ground surface before placing fills. B. Plow, scarify, bench, or break up sloped surfaces steeper than 1 vertical to 4 horizontal so fill material will bond with existing material. C. Place and compact fill material in layers to required elevations as follows: 1. Under grass and planted areas, use satisfactory soil material. 2. Under walks and pavements, use satisfactory soil material. 3. Under building slabs, use engineered fill. 4. Under footings and foundations, use engineered fill. 3.14 MOISTURE CONTROL A. Uniformly moisten or aerate subgrade and each subsequent fill or backfill layer before compaction to within 2 percent of optimum moisture content. 1. Do not place backfill or fill 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. 3.15 COMPACTION OF BACKFILLS AND FILLS A. Place backfill and fill 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 materials evenly on all sides of structures to required elevations, and uniformly along the full length of each structure. THE KENT 31 20 00 - THE KENT Issue Date 05.09.18 EARTH MOVING THE KENT C. Compact soil to not less than the following percentages of maximum dry unit weight according to ASTM D 1557: 1. Footings: Compact top 12" of subgrade and each layer of backfill or fill material at 95% maximum density for cohesive soils and 100% relative density for cohesionless soils. 2. Structures, Building Slabs and Steps, Pavements: Compact top 12" of subgrade and each layer of backfill or fill material at 90% maximum density for cohesive material or 95% relative density for cohesionless material. 3. Lawn or Unpaved Areas: Compact top 6" of subgrade and each layer of backfill or fill material at 85% maximum density for cohesive soils and 90% relative density for cohesionless soils. 4. Walkways: Compact top 6" of subgrade and each layer of backfill or fill material at 90% maximum density for cohesive material or 95% relative density for cohesionless material. 3.16 GRADING A. General: Uniformly grade areas to a smooth surface, free from 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. Lawn 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. 3.17 BUILDING SLAB DRAINAGE COURSE A. General: Place drainage fill material, in layers of indicated thickness, over subgrade surface to support concrete building slabs. B. Placing: Place drainage fill material on prepared subgrade in layers of uniform thickness, conforming to indicated cross-section and thickness. Maintain optimum moisture content for compacting material during placement operations. 1. Thickness of Layers: When a compacted drainage course is shown to be 6" thick or less, place material in a single layer. When shown to be more than 6" thick, place material in equal layers, except no single layer more than 6" or less than 3" in thickness when compacted. 3.18 FIELD QUALITY CONTROL A. Testing Agency: 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. THE KENT 31 20 00 - THE KENT Issue Date 05.09.18 EARTH MOVING THE KENT C. Footing Subgrade: At footing subgrades, at least one test of each soil stratum will be performed to verify design bearing capacities. Subsequent verification and approval of other footing subgrades may be based on a visual comparison of subgrade with tested subgrade when approved by Architect. D. 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 and Building Slab Areas: At subgrade and at each compacted fill and backfill layer, at least one test for every 2000 sq. ft. or less of paved area or building slab, but in no case fewer than three tests. 2. Foundation Wall Backfill: At each compacted backfill layer, at least one test for each 100 feet or less of wall length, but no fewer than two tests. 3. Trench Backfill: At each compacted initial and final backfill layer, at least one test for each 150 feet or less of trench length, but no fewer than two tests. E. 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. 3.19 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 Architect; reshape and recompact. 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 the greatest extent possible. 3.20 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 off Owner's property. B. Remove waste material, including unsatisfactory soil, trash, and debris, and legally dispose of it off Owner's property. END OF SECTION 31 20 00