SECTION FILL AND BACKFILL

Transcription

1 PART 1 GENERAL 1.1 SECTION INCLUDES A. Filling, backfilling, and compacting for building volume below grade, footings, slabs-on-grade, paving, site structures, and utilities within the building. B. Backfilling and compacting for utilities outside the building to utility main connections. C. Filling holes, pits, and excavations generated as a result of removal (demolition) operations. 1.2 RELATED SECTIONS A. Section Cast-In-Place Concrete. 1.3 UNIT PRICES A. See Section Unit Prices, for general requirements applicable to unit prices for earthwork. B. Structural Fill: Applies to Unit Price CA Includes: Excavating existing soil, stockpiling, scarifying substrate surface, removing existing material from site, preparing subgrade, placing where required, and compacting. C. Graded Granular Fill: Applies to Unit Price CA Includes: Excavating existing material, stockpiling, scarifying substrate surface, removing existing material from site, preparing subgrade, placing where required, and compacting. D. Open Granular Fill: Applies to Unit Price CA Includes: Excavating existing material, stockpiling, scarifying substrate surface, removing existing material from site, preparing subgrade, placing where required, and compacting. E. Concrete Fill: Applies to Unit Price Lean Concrete 1. Measurement Method: by the cubic yard 2. Includes: Excavating existing material, scarifying substrate surface, removing existing material from site, preparing subgrade, forming and placing where required 1.4 REFERENCES A. Illinois Department of Transportation (IDOT): Standard Specifications for Road and Bridge Construction, Latest Edition. B. ASTM C Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates;. C. ASTM D Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft3 (600 kn-m/m3)); D. ASTM D Standard Test Method for Density and Unit Weight of Soil in Place by the Sand- Cone Method; E. ASTM D Standard Test Method for Density and Unit Weight of Soil in Place by the Rubber Balloon Method; F. ASTM D Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System); G. ASTM D Standard Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow Depth); H. ASTM D Standard Test Method for Water Content of Soil and Rock in Place by Nuclear Methods (Shallow Depth). 1.5 DEFINITIONS A. Finish Grade Elevations: Indicated on drawings. B. Subgrade Elevations: 6 inches below finish grade elevations indicated on drawings, unless otherwise indicated. C. SOIL MATERIALS: 1. General: Provide approved borrow soil materials from off-site when sufficient approved soil materials are not available from excavations. 2. Satisfactory Soil Materials: ASTM D2487 soil classification groups CL, GC GW, GP, GM,

2 SW, SP, SC and SM, free of rock or gravel larger than 2 inches (50 mm) in any dimension, debris, waste, frozen materials, vegetation and other deleterious matter and as per AASHTO T180 and IDOT references above. 3. Unsatisfactory Soil Materials: ASTM D2487 soil classification groups ML, MH, CH, OL, OH and PT and as per AASHTO T180 and IDOT references above. 4. Subsoil Structural Fill: Select site excavated subsoil or approved off-site imported inorganic materials meeting the following requirements: a. Graded b. Free of lumps or rocks greater than three inches in size. c. Free of roots and other organic materials. d. Conforming to ASTM D2487 group symbol CL. 1.6 SUBMITTALS A. See Section Administrative Requirements, for submittal procedures. B. Samples: 5 lb sample of each type of fill; submit in air-tight containers to testing laboratory. C. Fill Composition Test Reports: Results of laboratory tests on proposed and actual materials used. 1. Test Reports: In addition to test reports required under field quality control, submit the following: a. Laboratory analysis of each soil material proposed for fill and backfill from on-site and borrowed sources. b. One optimum moisture-maximum density curve for each soil material. c. Report of actual unconfined compressive strength and/or results of bearing tests. D. Compaction Density Test Reports. 1.7 PROJECT CONDITIONS A. Provide sufficient quantities of fill to meet project schedule and requirements. When necessary, store materials on site in advance of need. B. When fill materials need to be stored on site, locate stockpiles where designated. 1. Separate differing materials with dividers or stockpile separately to prevent intermixing. 2. Prevent contamination. 3. Protect stockpiles from erosion and deterioration of materials. C. Verify that survey bench marks and intended elevations for the Work are as indicated. PART 2 PRODUCTS 2.1 FILL MATERIALS A. General Fill: Satisfactory soil materials as noted in definitions above from Subsoil excavated onsite or from off-site source. 1. Graded. 2. Free of lumps larger than 3 inches, rocks larger than 2 inches except where permitted by sieve analysis, and debris. 3. Free from all organic materials, roots, black dirt, shale and chert. B. Structural Granular Fill - Fill Type IDOT Designation CA-6: Angular crushed stone, conforming to Illinois Department of Transportation (IDOT): Standard Specifications for Road and Bridge Construction, Latest Edition. Free from Chats, Slag of any designation, Chert, Pit or Bank Run materials and Novaculite Gravel. 1. Free of organic material. C. Concrete for Fill: Lean concrete. D. Graded Granular Fill - Fill Type IDOT Designation CA-6: Angular crushed stone, conforming to Illinois Department of Transportation (IDOT): Standard Specifications for Road and Bridge Construction, Latest Edition. Free from Chats, Slag of any designation, Chert, Pit or Bank Run materials and Novaculite Gravel. 1. CA-6 Composition passing sieve size and percentage under ASTM C 136: 1-1/2 inch, 100%

3 ; 1 inch, 95 ± 5 % ; 1/2 inch, 75 ± 15%; No. 4, 43 ± 13%; No. 16, 25 ± 15; No ± 4% E. Open Granular Fill - Fill Type IDOT Designation CA-7: Angular crushed stone; free of shale, clay, friable material and debris. Conforming to Illinois Department of Transportation (IDOT): Standard Specifications for Road and Bridge Construction, Latest Edition. Free from Chats, Slag of any designation, Chert, Pit or Bank Run materials and Novaculite Gravel. 1. CA-7 Composition passing sieve size and percentage under ASTM C 136: 1-1/2 inch, 100%; 1 inch, 95 ± 5 %; 1/2 inch, 45 ± 15%; No. 4, 5 ± 5%. F. Sand: Natural river or bank sand; free of silt, clay, loam, friable or soluble materials, and organic matter conforming to IDOT designation FA-1. G. Topsoil - Fill Type: Topsoil excavated on-site or from off-site borrow. 1. Graded and pulverized. 2. Free of roots, rocks larger than 1/4 inch, subsoil, debris, large weeds and foreign matter. 3. Conforming to ASTM D2487 Group Symbol OH. 2.2 ACCESSORIES A. Geotextile Fabric: Non-biodegradable, woven conforming to IDOT Standard Specification for Road and Bridge Construction for intended use. 2.3 SOURCE QUALITY CONTROL A. See Section Quality Requirements, for general requirements for testing and analysis of soil material. B. If tests indicate materials do not meet specified requirements, change material and retest. C. Provide materials of each type from same source throughout the Work. D. CA-7 shall NOT be substituted for CA-6 without exception. CA-7 is not considered to be a self compacting material and must be compacted to meet or exceed project requirements. E. Pea gravel shall not be substituted for FA-1 or any other aggregate material without express written permission of the Architect of Record--consultant approval is not sufficient. F. The use of bank run, spherical aggregates, or other unspecified aggregate materials is strictly prohibited. No substitution shall be permitted. PART 3 EXECUTION 3.1 EXAMINATION A. Identify required lines, levels, contours, and datum locations. B. See Section for additional requirements. C. Verify subdrainage, damp proofing, or waterproofing installation has been inspected. D. Verify structural ability of unsupported walls to support imposed loads by the fill. 3.2 PREPARATION A. Scarify subgrade surface to a depth of 6 inches to identify soft spots. B. Cut out soft areas of subgrade not capable of compaction in place. Backfill with general fill and recompact. C. Compact subgrade to density equal to or greater than requirements for subsequent fill material. D. If density or compaction requirements for subgrade can not be achieved, disc, aerate and recompact subgrade for a minimum depth of 10 inches. E. Until ready to fill, maintain excavations and prevent loose soil from falling into excavation. 3.3 FILLING A. Fill to contours and elevations indicated using unfrozen materials. B. Employ a placement method that does not disturb or damage other work. C. Systematically fill to allow maximum time for natural settlement. Do not fill over porous, wet, frozen or spongy subgrade surfaces. D. Maintain optimum moisture content of fill materials to attain required compaction density. E. Granular Fill: Place and compact materials in equal continuous layers not exceeding 8 inches

4 compacted depth. F. General Fill: Place and compact material in equal continuous layers not exceeding 12 inches compacted depth. G. Slope grade away from building minimum 2 inches in 10 ft, unless noted otherwise. Make gradual grade changes. Blend slope into level areas. H. Correct areas that are over-excavated. 1. Other areas: Use fill required at specific location, flush to required elevation, compacted to minimum 95 percent Modified Proctor. I. Compaction Density Unless Otherwise Specified or Indicated: As listed in Fill at Specific Locations. J. Reshape and re-compact fills subjected to vehicular traffic. 3.4 FILL AT SPECIFIC LOCATIONS A. Structural Fill at areas designated by Architect/Engineer: 2. Maximum depth per lift: 8 inches, compacted. 3. Compact to minimum 95 percent Modified Proctor. B. Under Interior Slabs-On-Grade: 1. Use graded Fill Type CA Depth: minimum 6 inches compacted. 3. Compact to 95 percent Modified Proctor. C. At Foundation Walls, Footings, and foundation related items: 2. Fill up to subgrade elevation. 3. Maximum depth per lift: 8 inches, compacted. 4. Compact each lift to 95 percent Modified Proctor. 5. Do not backfill against unsupported foundation walls. 6. Backfill simultaneously on each side of unsupported foundation walls until supports are in place. D. Over Subdrainage Piping at Foundation Perimeter and Under Slabs: 1. Bedding: Use open granular Fill Type CA-7. Fill to cover piping maximum of 18 inches above top edge of pipe or a. Cover drainage piping with CA-7 for maximum 18 inches. b. Fill up to subgrade elevation with graded granular CA-6 in lifts not to exceed 8 compacted inches. 2. Compact to 95 percent Modified Proctor. E. Over Buried Utility Piping, Conduits, and Duct Bank in Trenches except small diameter (2 inches or less) Polypropylene, Polyvinyl-flouridiene, polyethylene, polybutylene, and Chlorinated Polyvinyl Chloride (CPVC) piping where manufacturer does not permit angular stone: 1. Under all paved areas and within 3 feet of paving: a. Bedding: Use Fill Type CA-7. Fill to cover piping 8 inches above top edge of pipe or b. Cover with Fill Type CA-6. d. Compact in maximum 8 inch lifts to 95 percent Modified Proctor. 2. Under all landscaped areas: a. Bedding: Use Fill Type CA-7. Fill to cover piping 8 inches above top edge of pipe or b. Cover with general fill. d. Compact in maximum 12 inch lifts to 85 percent Modified Proctor. F. Over Buried Utility Piping, Conduits, and Duct Bank in Trenches where small diameter (2 inches or less) Polypropylene, Polyvinyl-flouridiene, polyethylene, polybutylene, and Chlorinated Polyvinyl Chloride (CPVC) piping is present and the manufacturer does not permit angular stone: 1. Under all paved areas and within 3 feet of paving:

5 a. Bedding: Use Fill Type FA-1. Fill to cover piping 8 inches above top edge of pipe or Consolidate sand prior to placing CA-6 without restricting piping below. b. Cover with Fill Type CA-6. d. Compact in maximum 12 inch lifts to 95 percent Modified Proctor at surface. 2. Under all landscaped areas: a. Bedding: Use Fill Type FA-1. Fill to cover piping 8 inches above top edge of pipe or b. Cover with general fill. d. Compact in maximum 12 inch lifts to 85 percent Modified Proctor. G. Base material under all paved areas: 2. Depth: minimum as indicated on Drawings. 3. Compact in maximum 6 inch lifts to 95 percent Modified Proctor. H. At Lawn Areas: 1. Use general fill. 2. Fill up to 6 inches below finish grade elevations. 3. Compact to 85 percent Modified Proctor. 4. See Section for topsoil placement. I. Around all Underground structures unless otherwise noted: 1. Bedding: CA-7 Fill to cover piping 8 inches above top edge of pipe or other items unless otherwise noted. 2. Cover with Fill Type CA Fill up to subgrade elevation. 4. Maximum compacted depth of each lift: 8 inches. 5. Compact to 95 percent Modified Proctor. 3.5 TOLERANCES A. Top Surface of General Filling: Plus or minus 1 inch from required elevations. B. Top Surface of Filling Under Paved Areas: Plus or minus 1 inch from required elevations. 3.6 FIELD QUALITY CONTROL A. See Section Quality Requirements, for general requirements for field inspection and testing. B. Perform compaction density testing on compacted fill in accordance with ASTM D1556, ASTM D2167, ASTM D2922, or ASTM D3017. C. Evaluate results in relation to compaction curve determined by testing uncompacted material in accordance with ASTM D 698 ("standard Proctor"), ASTM D 1557 ("modified Proctor"), or AASHTO T 180. D. If tests indicate work does not meet specified requirements, remove work, replace and retest. E. Frequency of Tests: 1 for each 2000 SF or fraction thereof per lift. F. Proof roll compacted fill at surfaces that will be under paving in the presence of the Testing Agency, Owner, Architect and local municipality. Proof roll with fully loaded 6-wheel dump truck. Areas with 1 inch deflection or greater shall be scarified, aerated, dried, recompacted and retested. Contractor has the option to replace material in leau of scarification, aeration, drying and recompaction at no cost to the owner. 3.7 CLEAN UP A. Remove unused stockpiled materials, leave area in a clean and neat condition. Grade stockpile area to prevent standing surface water. Restore any vegetation to original condition. END OF SECTION