ST. VINCENT COLLEGE
SIS AND HERMAN DUPRÉ SCIENCE PAVILION
SECTION 31 63 30 – MICRO PILES
PART 1 – GENERAL
1.01 RELATED DOCUMENTS
A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 1 Specification Sections, apply to this Section.
1.02 SUMMARY
A. Section includes grout filled steel pipe piles
B. Related Sections include the following:
1. Division 3 Sections “Cast-in-Place Concrete”
1.03 SCOPE
A. This specification governs the technical requirements pertaining to the placement of grout filled pipe piles into augerable soil and bedrock. Design calculations for pipe piles should be derived from the Geotechnical Investigation Addendum #3 completed by CEC, Inc. dated October 2, 2008. The following parameters should be utilized for design of all pipe piles. Piles driven into bedrock can have end bearing value of twelve (12) tons per square foot and side friction bearing utilizing forty (40) pounds per square inch for the surface area of the rock socket.
1.04 UNIT PRICES
A. General: See Division 1 Section “Unit Prices” for piles affected by unit prices.
B. The Contract Sum: Base the Contract Sum on number and dimensions of piles indicated from tip to cutoff, plus not leas than 12 inches (305 mm) of overlength.
C. Work of this Section is affected as follows:
1. Additional payment for pile lengths in excess of that indicated, and credit for pile lengths less than that indicated, will be calculated at unit prices stated in the Contract, based on net addition or deduction to total pile length as estimated by the pile designer measured to nearest 12 inches (305 mm).
a. Additional payment for splices required to extend pile lengths in excess of that indicated will be calculated at unit prices stated in the contract.
2. Additional payment for number of piles in excess of that indicated, and credit for number of piles less than that indicated, will be calculated at unit prices stated in the Contract.
3. Unit prices include labor, materials, tools, equipment, and incidentals of furnishing, driving, cutting off, capping, and disposing of cutoffs.
4. Test piles that become part of permanent foundation system will be considered as an integral part of the Work.
5. No payment will be made for rejected piles, including piles driven out of tolerance, defective piles, or piles damaged during handling and driving.
1.05 SUBMITTALS
A. Product Data: For each type of product indicated.
B. Shop Drawings: Show fabrication and installation details for piles, including splices and tip details.
1. Indicate locations, sizes, type, and arrangement of reinforcement.
2. Indicate welds by standard AWS symbols, distinguishing between shop of field welds, and show size, length, and type of each weld.
3. Include arrangement of static pile reaction frame, test and anchor piles, equipment, and instrumentation. Submit structural analysis data signed and sealed by the qualified professional engineer responsible for their preparation. If an alternate pile testing method is proposed, submit an acceptable letter for this type of testing from project’s geotechnical engineer.
C. Design Mixes: For each grout mix. Include revised mix proportions when characteristics of materials, project conditions, weather, test results, or other circumstances warrant adjustments.
1. Laboratory Test Reports: For evaluation of grout materials and mix design tests.
D. Welding Certificates
E. Qualification Data: For firms and persons specified in “Quality Assurance” Article to demonstrate their capabilities and experience. Include lists of completed project and project names and addresses, names and addresses of architects and owners, and other information specified.
F. Pile Installation Equipment: Include type and details.
G. Pile Test Reports: Submit
H. Strength Tests of Grout: Test cubes shall be made and tested in accordance with ASTM C109.
I. Field quality-control reports.
J. Records: Submit within two days of installation.
1.06 QUALITY ASSURANCE
A. Installer Qualifications: An experienced installer who has specialized in installing piling similar to material, design and extent to that indicated for this Project.
B. Survey Work: Provide pile installation records, including surveys, layouts and measurements, prepared by a surveyor or professional engineer who is legally qualified in jurisdiction where Project is location to perform these kinds of services.
C. Professional Soils Engineer Qualifications: A professional engineer who is legally qualified to practice in jurisdiction where Project is located and who is experienced in providing engineering services for piles that are similar to those indicated for this Project in material, design and extent.
D. Testing Agency Qualifications: An independent testing agency, acceptable to authorize having jurisdiction, qualified to conduct the testing indicated.
E. Welding Qualifications: Qualify procedures and personnel according to the following:
1. AWS D1.1/D1.1M, “Structural Welding Code – Steel”
2. AWS D1.3, “Structural Welding Code – Sheet Steel”
F. Comply with requirements of the following publications:
1. ACI 301, “Specifications for Structural Concrete”
2. ACI 318, “Building Code Requirements for Structural Concrete”
3. American Society for Testing and Materials, “ASTM Specifications”
4. All applicable local, county, state and federal codes and OSHA.
G. Pre-installation Conference: Conduct conference at Project site to comply with requirements in Division 1 Section “Project Meetings.
PART 2 – PRODUCTS
2.01 STEEL PIPE (CASING)
A. Steel Pipe: ASTM A 252, Grade 3; seamless or welded minimum. Pipe grade to be determined by pile installer.
2.02 REINFORCING MATERIALS
A. Reinforcing Bars: ASTM A 615/A 615M, The grade, thickness and number of bars shall be indicated by the designer and shall conform to any minimum or maximum properties shown on the plans. Continuous thread bars shall be used. Bar tendon couplers, if required should develop the ultimate tensile strength of the bars without evidence of any failure.
2.03 GROUT MATERIALS
A. Grout: Neat cement or fine aggregate/cement mixture. The designer is responsible for indicating 28 day compressive strengths. The grout shall conform to specification ASTM C109 and to any minimum and/or maximum properties shown on the plans.
B. Portland Cement: ASTM C150, Type I or Type II
C. Aggregates: Sand shall meet the requirements of current ASTM C-33. The sand shall consist of hard, dense, durable, uncoated rock particles and shall be free from injurious amounts of salt, loam, lumps, soft or flaky particles, shale, alkali, organic matter, mica, and other deleterious substance. If washed, the washing method shall be such as will not remove desirable fines, and the sand shall subsequently be permitted to drain until the residual-free moisture is reasonably uniform and stable. The sand shall be well graded from fine to course, with fineness modulus between 1.40 and 3.40.
D. Water: Fresh, clean, potable, and free from injurious amounts of sewage, oil acid, alkali, salts or organic matter complying with ASTM C94 requirements.
E. Admixtures: Provide admixtures certified by manufacturer to be compatible with other admixtures and to contain not more than 0.1 percent chloride ions by mass of cementitious material.
1. Water-Reducing Admixture: ASTM C 494, Type A
2. High-Range, Water-Reducing Admixture: ASTM C 494, Type F
3. Water Reducing and Accelerating Admixture: ASTM C 494, Type E
4. Water Reducing and Retarding Admixture: ASTM C 494, Type D
2.04 GROUT MIXES
A. Prepare design mixes, according to ACI 301, for concrete by either laboratory trial batch or field experience method. For trial batch method, use a qualified independent testing and inspecting agency for preparing and reporting proposed mix designs.
1. Do not use Owner’s independent testing and inspecting agency.
B. Proportion mixes according to ACI 211.1 and ACI 301 to provide grout piles that meet the designers criteria.
PART 3 – EXECUTION
3.01 EXAMINATION
A. Site Conditions: Do not start pile installation operations until earthwork fills have been completed or excavations have reached the elevation indicated on the Drawings.
3.02 STATIC PILE TESTS
A. General: A pile load-testing program shall be required. The load-testing program shall be conducted prior to the installation of production piles. Individual test piles shall be loaded to not less than 200% of the design capacity. A qualified professional soils engineer experienced in pile foundations shall monitor the test pile installation of the load test.
1. Furnish test piles similar in length to production piles.
2. The Piling Contractor shall submit the testing procedure to the Owner’s representative for approval before testing.
B. Pile Tests: Arrange and perform the following pile tests:
1. Axial Compressive Static Load Test: ASTM D 1143
2. Axial Tensile Static Load Test: ASTM D 3689
C. Install test piles at locations indicated to the elevation noted on the Drawings.
1. Install reinforcement and grout according to Project requirements.
2. Before load-testing pile, allow grout to reach it’s specified 28-day design compressive strength as established by test cubes.
D. Provide pile reaction frame, anchor piles, equipment, and instrumentation with sufficient reaction capacity to perform tests. Notify Engineer at least 48 hours in advance of performing tests. On completion of testing, remove testing structure, anchor piles, equipment, and instrumentation.
1. Number of Test Piles: One test pile
E. Test Piles: Use test piles identical to those required for Project and install with the same equipment to be used for permanent piles.
1. Uplift Design Load for Piles: as indicated on the Drawings
2. The uplift capacity of piles shall be verified by monitoring the uplift of the reaction piles that are part of the load test.
F. Approval Criteria: Allowable design capacity of test piles shall be based on the results of the pile test per the direction of a qualified professional soils engineer experienced in pile foundations. Professional soils engineer shall submit a letter stating required pile capacity has been verified per IBC 2006.
G. Test Records: Prepare testing records for each test pile, compiled and attested to be a qualified professional soils engineer. Include same data as required for records of permanent piles.
3.03 INSTALLING PILES
A. General: Prior to beginning installation, the Pile Contractor shall submit a letter to the Owner’s Representative for approval, including a proposed design mix for the concrete grout, the minimum 7-day strength for the proposed grout (subject to approval by Approved Testing Lab) and a statement certifying that the proposed concrete grout will meet or exceed the 28 day strength for pile design.
1. Concrete grout mix shall not be changed from approved mix without the Owner’s approval.
2. If the Piling Contractor is using grout provided by an outside Vendor, said Vendor shall provide Contractor with a copy of every delivery ticket, clearly indicating ingredients of mix.
3. Load testing of piles and installation of production piles should be observed by a professional soils engineer or his representative.
B. Procedure: Piles shall be placed per pile installer’s specifications.
1. The maximum permissible off-center variation of the pile top shall be two inches, and vertical shafts shall not deviate more than 2 percent out of plumb for the entire depth.
2. If obstructions are encountered which prevent placing the pile to the desired depth, or cause the pile to drift from the required locations or if a pile is not terminated on the required bearing stratum, the Contractor shall immediately contact the Engineer. The decision to terminate a hole or continue placement of a pile will be made by the Engineer. Plies shall not be terminated on an obstruction or soft rock as determined by a professional soils engineer or his representative.
3. Piles shall not be placed closer than 3 pile diameters until the grout in the completed piles has achieved its initial set after being placed in the pile pus a time period of 12 hours. This procedure shall be revised if there are any indications of instability or inter-pile connection.
4. Do not terminate piles on soft bedrock or an obstruction. Refusal shall be obtained when the rate of penetration is less than one foot per minute for a rated torque of 9,000 ft. lbs.
5. If non-drillable materials, such as boulders or debris, are encountered above the desired tip elevation additional adjacent piles shall be placed at the direction of the Engineer.
C. Pile Tops: Where the pile cutoff level is below the existing ground surface, metal casing of proper diameter shall be placed around the pile tops and extend above the existing ground surface. The casing shall prohibit loose material from falling onto the pile top. This may require inserting a large size casing to the cutoff elevation and inserting the smaller casing after the pile is completed. Where the pile cutoff is above bottom of excavation, metal sleeves of the proper diameter and at least eighteen inches in length shall be placed around the pile tops.
D. Installation Record: Maintain accurate records for each pile. Include the following data:
1. Project name and number.
2. Name of Contractor.
3. Type of pile and date.
4. Pile location in pile group and designation of pile group.
5. Pile dimensions.
6. Ground elevation.
7. Elevation of tip.
8. Cutoff elevation of pile after grouting.
9. Pile installation start and finish time.
10. Record of unusual occurrences during pile installation.
11. Pile design load
12. Reinforcement size.
13. Bond length.
3.04 MIXING AND PUMPING OF THE GROUT MIX
A. Use only approved continuous mixing, pumping, and agitating equipment in the preparation and handling of the mortar mix. Use a screen no larger than ¼ inch mesh between the mix and pump or between the mixer and agitator. Remove oil and other rust inhibitors from the mixing drums, stirring mechanism, and portions of the equipment in contact with the mortar before the mixers are used. If ready-mix mortar is used, an agitating storage tank of sufficient size shall be used between the ready-mix truck and the mortar pump to ensure a homogeneous mix and continuity in the pumping operations.
B. All materials shall be accurately measured by volume or weight as they are fed into the mixer. The order of placing the materials into the mixer shall be as follows:
1. Water.
2. Admixture; approved with submission of prior test results.
3. Other solids in order of increasing particle size.
C. The quantity of water used shall be such as to produce a mortar having a consistency in accordance with ASTM Specification C-91. Time of mixing shall not be less than one minute. If agitated continuously, the mortar may be held in the mixer or agitator for a period not exceeding two (2) hours at temperatures below 70oF and for a period not exceeding one and one-half (1 ½) hours at higher temperatures. The time period shall be measured from the time that all cement is placed in the mixer.