SECTION 02370 AUGER CAST PILES PART 1 - GENERAL 1.1 SECTION INCLUDES: The work covered by these specifications consists of furnishing all labor, equipment and materials for the installation of auger cast piles with working load capacity as detailed in the project geotechnical report. 1.2 RELATED SECTIONS A. Section 01290 Application for Payment B. Section 01330 Submittals C. Section 01450 - Testing 1.3 REFERENCES A. ASTM D 1143 Piles Under Static Axial Compressive Load (Standard Loading Procedure) B. ASTM C 150 Portland Cement C. ASTM D 109 Grout Test Cubes D. ASTM C-33 Mineral Aggregates 1.4 SUBMITTALS A. Submit mix design of proposed grout at least 5 days prior to delivery or use at the site. The submittal shall indicate the manufacturer and/or source of all materials and admixtures and the 7-day and 28 day compressive strengths. B. Submit details of the sequence and method of installation at least 5 days prior to the installation of auger cast piles. Approval by the Owner will not relieve the Contractor of his responsibility to install auger cast piles in accordance with these specifications. C. Provide a minimum of 48 hours written notice before the installation begins to the supplier and the Owner. Do not place auger cast piles until all involved parties have been notified. D. Submit details of auger equipment, grout pumping, and continuous mixing equipment at least 5 days prior to installation of auger cast piles. Approval to the Owner will not relieve the Contractor of his responsibility to install auger cast piles in accordance with these specifications. 1.5 PILE TESTING AUGER CAST PILES 02370-1
A. Perform two pile load tests in accordance with ASTM D-1143 using the standard loading procedure as described in section 5.1 of the ASTM specifications. Furnish test pile(s), reaction beam(s), reaction pile(s), calibrated jack(s), personnel, and rigging necessary to perform the tests. B. Owner shall provide an engineer to observe the tests. C. Provide a written report of the pile test results to the Owner and geotechnical engineer within 72 hours of completing the tests. 1.6 QUALITY CONTROL A. Owner shall provide an experienced technician to continuously inspect installation of auger cast piles. 1. Owner s technician shall verify compliance with Specification and communicate anomalous subsurface conditions that may require modification of design to geotechnical engineer and Owner. 2. Contractor shall cooperate fully with technician, geotechnical engineer, and Owner and provide appropriate assistance and access to Work. B. Contractor shall provide a suitable, adequately protected location for temporary storage of test specimens. C. Owner s Testing Lab shall provide containers or storage boxes suitable for protecting test specimens from extremes in temperature or other threats. 1.7 PILE TOLERANCES A. Locate piles as shown on Drawings or as otherwise directed by the Owner. B. Locate center of pile to within three inches of design location. C. Install piles plumb within a tolerance of one inch in ten feet. 1.8 MEASUREMENT AND PAYMENT A. Measurement will be based on Work actually placed and recorded on daily work records signed by Contractor and Owner s Representative. 1. Auger cast piles shall be measured on the total number of planned piles, estimated volume of grout, and the total estimated footage for all piles as shown on the Drawings. 2. Auger cast piles installed in addition to the planned piles shall be measured per actual linear foot installed. 3. Planned auger cast piles not completely installed, thus reducing the linear footage of planned piles, shall be measured per linear foot of planned pile. 4. Load test shall be measured per each test actually completed. AUGER CAST PILES 02370-2
B. Payment shall be at the unit prices stated on the Bid Form for Auger Cast Piles. Payment shall constitute full compensation for all labor, materials, grout, tools, and equipment required or specified to complete the work in this Section. 1. Payment of a percentage of the lump sum price on the Bid Form for the planned auger cast piles shall be based on the actual percent of planned piles installed during each billing period. 2. Payment for additional auger cast piles shall be based on the unit price for ADDITIONAL AUGER CAST PILES on the Bid Form. 3. Credit to the Owner for auger cast piles not installed shall be based on the unit price for AUGER CAST PILES NOT INSTALLED on the Bid Form. 4. Payment for Load tests shall be based on the unit price for LOAD TESTS on the Bid Form. 5. No payment shall be made for misplaced, faulty, rejected or otherwise unacceptable piles as defined by the Owner s representative. PART 2 - PRODUCTS 2.1 GROUT MATERIALS A. Portland Cement: Portland Cement shall conform to ASTM C-150. B. Mineral Filler: Mineral Filler shall be finely powdered siliceous material, which possesses the property of combing with lime liberated during the process of Portland Cement hydration. C. Plasticizer: Plasticizer shall be a compound characteristics, which will increase flowability of grout, assist in dispersal of cement grains, and neutralize setting shrinkage of high-strength cement grout. D. Water: Water shall be fresh, clean and free from injurious amounts of sewage, oil, acid, alkali, salts or organic matter. E. Fine Aggregate: Sand shall meet requirements of current ASTM C-33 and the following: Sand shall consist of hard, dense, durable, uncoated rock particles and shall be free from injurious amounts of silt, loam, lumps, soft or flaky particles, shale, alkali, organic matter, mica or other deleterious substances. If washed, washing method shall be such that it will not remove desirable fines, and sand shall subsequently be permitted to drain until the residual freemoisture is reasonably uniform and stable. The sand shall be well graded from fine to coarse, with a fineness modulus between 1.40 and 3.40. F. Materials shall be stored under cover, on a clean, dry, elevated platform that protects the materials from: precipitation, sunlight, chemicals, flames and sparks, temperatures in excess of 160 F, and physical damage. G. Follow the manufacturer s recommendations regarding handling and storage of the materials. 2.2 HIGH-STRENGTH GROUT AUGER CAST PILES 02370-3
A. Grout used to construct auger cast piles shall consist of a mixture of Portland Cement, mineral filler, plasticizer, sand and water so proportioned and mixed as to provide a grout capable of maintaining the solids in suspension without appreciable water gain, yet which may be pumped without difficulty and which will penetrate laterally and fill voids in the foundation material. B. Grout shall be proportioned to provide a hardened grout having a minimum compressive strength of 4,000 pounds per square inch (PSI) at 28-days. 2.3 GROUTING EQUIPMENT A. Grout pump shall be a positive displacement piston type pump capable of developing pressures at the pump up to 350 PSI. The pump shall be equipped with a suitable gauge to permit verification of pumping pressures. B. Maintain the grouting equipment in a condition so that breakdowns and down time are minimized. Provide for prompt (24 hours or less) replacement of broken down equipment so that Work is not delayed. 2.4 AUGER EQUIPMENT A. Provide a minimum three-inch diameter hole at the bottom of the auger head below the cutting teeth through which high-strength grout shall be pumped during installation of the pile. B. Provide auger flights, from auger head to top of augers, with no gaps or other breaks. C. Provide a middle guide for Auger strings over fifty feet in length. D. Prevent auger cast piling leads from twisting. E. Provide an auger power plant with a minimum torque of 30,000 ft/lbs. F. Maintain the augering equipment in a condition so that breakdowns and down time are minimized. Provide for prompt (24 hours or less) replacement of broken down equipment sot that Work is not delayed. PART 3 - EXECUTION 3.1 INSPECTION A. Examine substrates and installation conditions. Inform the Owner, in writing, of any unsatisfactory conditions. Do not start auger cast pile installation work until unsatisfactory conditions are corrected. 3.2 INSTALLATION AUGER CAST PILES 02370-4
A. Install auger cast piles by rotating a continuous-flight, hollow shaft auger of the proper diameter to obtain the minimum specified shaft diameter into the ground to the specified pile bearing depth. B. Pump a sufficient volume of high-strength grout to fill the resulting hole as the auger is withdrawn. C. Place grout in a manner to prevent hold collapse and to cause grout to penetrate laterally into soft or porous zones of the surrounding soil. D. Place reinforcement steel, if required, while grout is fluid. E. Maintain a positive head of grout of not less than seven feet within the augers during auger withdrawal. F. Piles shall be rejected and replaced if the grout level in any completed pile drops. G. Piles shall be rejected if the augers are withdrawn from a hole for any reason without placing grout. H. Maintain a minimum of six pile diameters center to center between adjacent piles until the grout in the piles has reached 50% of its design compressive strength. I. Position pile installation equipment sufficiently far away from pile locations to prevent squeezing, damage, or distortion of the pile. 3.3 MIXING, PUMPING, AND TESTING HIGH-STRENGTH GROUT A. Use only approved pumping and continuous mixing equipment to prepare and handle grout. Remove any oil or other rust inhibitors from mixing drums and pressure grout pumps. B. Place a volume of grout at least 1.25 times the theoretical volume of the augered hole or the volume placed in the test pile, whichever is greater, in each pile. C. Re-circulate grout through the pump if there is a lapse in installation operations. D. Owner s testing agency shall test grout mix by as follows: 1. Make one set of 2 inches by 2 inches cubes, or one set of 2-inch diameter by 4-inch high cylinders for each day that auger cast piles are installed. 2. A set of cubes/cylinders shall consist of a total of six cubes/cylinders. 3. Test three cubes/cylinders at 7-days and three cubes/cylinders at 28-days. 4. Report results of grout compressive strength tests to Owner and Contractor within 24 hours. 3.4 OBSTRUCTIONS A. Terminate installation of any pile if any obstruction (including, but not limited to buried concrete, boulders, or timbers) is encountered which would prevent properly installing the pile to the depth required, or cause the pile to drift from the required location. AUGER CAST PILES 02370-5
B. Immediately notify Owner. C. Backfilled hole with grout and install a replacement pile only if directed by Owner. 3.5 PILE TOPS A. Place metal sleeves of the proper diameter around top of pile where pile cutoff is near the ground surface or above the bottom of the excavation. B. No piles shall be dipped greater than twelve inches. END OF SECTION 02370 AUGER CAST PILES 02370-6