1. Section 02315 - Excavation and Fill: Excavating to working level.
2. Section 03300 - Cast-In-Place Concrete: Concrete requirements for placement of pile caps.
1.2 UNIT PRICES - MEASUREMENT AND PAYMENT
A. Designed Piles:
1. Design Pile Quantity: Determined by number of piles indicated in Contract Documents.
2. Design Pile Length: Determined by number of piles indicated in Contract Documents.
3. Test Piles: Minimum of 1 pile for each pile specified and each load type designed for.
B. Actual Piles:
1. Actual Pile Quantity: Determined by number of piles identified in Project Record Documents.
2. Actual Pile Length: Determined by length of piles identified in Project Record Documents.
1.3 REFERENCES
A. ASTM International:
1. ASTM A123 - Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products
2. ASTM A153 - Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware.
3. ASTM A325- Standard Specification for High-Strength Bolts for Structural Steel Joints.
4. ASTM A500 – Standard Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes.
5. ASTM A563 – Standard Specification for Carbon and Alloy Steel Nuts.
6. ASTM A576 – Standard Specification for Steel Bars, Carbon, Hot Wrought, Special Quality.
7. ASTM A958 – Standard Specification for Steel Castings, Carbon, and Alloy with Tensile Requirements, Chemical Requirements Similar to Standard Wrought Grades.
8. ASTM A1011 – Standard Specification for Steel, Sheet and Strip, Hot-Rolled, Carbon, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, and Ultra-High Strength.
9. ASTM A1018 - 10 Standard Specification for Steel, Sheet and Strip, Heavy-Thickness Coils, Hot-Rolled, Carbon, Commercial, Drawing, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, and Ultra-High Strength
10. ASTM D1143 - Standard Test Methods for Deep Foundations Under Static Axial Compressive Load
11. ASTM D3689 - Standard Test Methods for Deep Foundations Under Static Axial Tensile Load
B. American Welding Society:
1. AWS D1.1 - Structural Welding Code – Steel
C. Society of Automotive Engineers:
1. SAE J429 – Mechanical and Material Requirements for Externally Threaded Fasteners Specification
1.4 PERFORMANCE REQUIREMENTS
A. Install the helical steel piles until the average torque for the last 3 feet of penetration is greater than the installation torque on the construction documents. The average torque is the average of the last 3 torque readings recorded at one-foot intervals.
1.5 SUBMITTALS
A. Section 01330 - Submittal Procedures: Requirements for submittals.
B. Construction Documents shall include:
1. Number and location of piles on the site
2. Design load
3. Type and diameter of shaft
4. Diameter and configuration of the helical plates
5. Minimum installation torque
6. Minimum overall length
7. Angle of Installation
8. Pile top termination device
9. Elevation of the top of the pile
C. Shop Drawings: Indicate the helical pile configuration, type, diameter, length, and components, including the corrosion protection and pile top termination device.
D. Installation Procedures: Detailed construction procedures proposed for use along with a list of the major installation equipment to the Owner or their representative.
E. Calibration report for each torque motor and indicator shall include:
1. Name of project and contractor
2. Name of testing agency
3. Identification (serial number) of device calibrated
4. Description of calibrated testing equipment
5. Date of calibration
F. Field load test report shall include:
1. Name of project and contractor
2. Name of contractor’s supervisor during installation
3. Name of third party testing agency
4. Date, time, and duration of the test
5. Location of the test pile
6. Description of calibrated test equipment
7. Description of test setup
8. Actual helical pile type and configuration – including lead section (number and diameter of helical plates, number and type of extensions sections)
9. Duration and amount of load increment
10. Deflection at each load increment
11. Comments, observations, or adjustments to any testing procedures
12. Signed by third party testing agency or professional engineer if required by the owner and/or governing agency
G. Work shall not commence until all submittals have been received and approved by the Owner or their representative. The contractor shall provide the Owner or their representative a reasonable amount of time to review, comment, and return the submittal documents after a complete set has been received.
1.6 CLOSEOUT SUBMITTALS
A. Section 01700 - Execution Requirements: Requirements for submittals.
B. The contractor shall provide the Owner or their representative copies of all helical pile installation records within 24 hours after each installation is completed. These installation records shall include, but are not limited, to the following information:
1. Name of project and contractor
2. Name of contractor’s supervisor during the installation of the piles
3. Date and time of installation
4. Name and model of installation equipment
5. Type of torque indicator used
6. Location of helical pile by assigned identification number
7. Actual helical pile type and configuration – including lead section (number and diameter of helical plates, number and type of extensions sections)
8. Helical piles installation time and any observations
9. Total length of installed helical pile
10. Cut-off elevation
11. Installation angle of the helical pile
12. Installation torque at one-foot intervals for at least the final 10 feet of installation
13. Comments regarding any interruptions, obstructions, or other installation relevant information
14. Rated load capacities
1.7 QUALITY ASSURANCE
A. The contractor shall verify that all helical piles can be installed in accordance with all relevant codes and regulations regarding such items as underground obstructions, utilities, right-of-way limitations, etc.
B. All work as described herein shall be performed in accordance with all applicable safety codes in effect at the time of installation.
1.8 QUALIFICATIONS
A. All steel helical piles must be manufactured by MacLean-Dixie, Birmingham, AL.
B. Installation contractor’s qualifications: installation shall be by a MacLean-Dixie Helical Foundation Systems authorized installation contractor. Proof of current certification by MacLean-Dixie Anchoring Systems shall be submitted to the Owner or their representative prior to starting installation upon request of the Owner or their representative.
C. All helical piles shall be installed in the presence of a designated representative of the Owner unless the Owner or their representative informs the installation contractor otherwise.
1.9 PRE-INSTALLATION MEETINGS
A. Section 01300 - Administrative Requirements: Pre-installation meeting.
B. Convene minimum one week prior to commencing Work of this section.
1.10 DELIVERY, STORAGE, AND HANDLING
A. Section 01600 - Product Requirements: Requirements for transporting, handling, storing, and protecting products.
B. Protect galvanized piles from damage to coating.
1.11 SCHEDULING
A. Section [01300 - Administrative Requirements] [01323 - Network Analysis Schedules]: Requirements for scheduling.
B. Schedule Work to perform driving during [________] and [________] hours.
C. Schedule test piles.
D. Do not install piles until excavation or filling of area surrounding piles is completed to design grades indicated on Drawings.
PART 2 PRODUCTS
2.1 MATERIALS
A. The work of this section consists of furnishing and installing steel helical piles manufactured by MacLean-Dixie LLC, Birmingham, AL.
B. Helical pile system shall be ICC-ES listed. The installation contractor shall furnish evidence to the Owner or their representative by means of the ICC-ES Evaluation Report number PFC-5551 if required.
C. Solid Shaft Piles (lead and extensions):
1. The 1½, 1¾ and 2 inch round cornered square (RCS) solid steel shafts shall be formed from hot-wrought carbon steel and shall confirm to [ASTM A576] and the following descriptions:
a. Grade 10V45M or equal, having a minimum yield strength of 70 KSI
b. Grade 1530M or equal, having a minimum yield strength of 90 KSI
2. The round cornered square (RCS) solid steel shafts shall conform to the following torque rating (torsional strength):
a. 5,500 ft-lbs for 1½ inch RCS shafts
b. 7,000 ft-lbs for 1½ inch RCS high strength shafts
c. 10,000 ft-lbs for 1¾ inch RCS shafts
d. 15,000 ft-lbs for 2 inch RCS shafts
3. Bolt holes cannot exceed +1/16 inch the nominal bolt diameter
D. Pipe Piles (lead and extensions):
1. The 2-7/8”, 3-1/2” and 4-1/2” O.D. pipe piles shall conform to ASTM A500 Grade C, 50 ksi
2. The coupling material shall confirm to AISI 8620 or SC1045 per ASTM A958.
3. The pipe helical pile shall conform to the following torque rating:
a. 7,500 ft-lbs for P28 series 2⅞ inch O.D. Schedule 40 Pipe Pile
b. 9,000 ft-lbs for P28 series 2⅞ inch O.D. Schedule 80 Pipe Pile
c. 11,400 ft-lbs for P35 series 3½ inch O.D. Schedule 40 Pipe Pile
d. 15,000 ft-lbs for P35 series 3½ inch O.D. Schedule 80 Pipe Pile
e. 20,000 ft-lbs for P45 series 4½ inch O.D. Schedule 40 Pipe Pile
f. 26,000 ft-lbs for P45 series 4½ inch O.D. Schedule 80 Pipe Pile
E. Helical Plates:
1. Helical plates shall be either ⅜ or ½ inch thick and shall conform to ASTM A1011 and ASTM A1018 HSLA 55 or equal.
2. The leading edge of all helices welded to the shaft intersection must be in the same plane.
F. Bolts and Nuts:
1. The sizes and types of bolts and nuts used to connect the helix pile extensions to lead sections or another extension shall conform to the following ASTM specifications:
a. Coupling bolts with ¾, ⅞ or 1 inch diameter shall comply with ASTM A325 Grade 5, and shall have a Class C, hot- dipped, zinc coating that complies with ASTM A153.
b. Coupling bolts with 1 1/8 inch diameter on the 2 inch RCS shall comply with SAE J429 Grade 8 and shall have yellow dichromate zinc coating.
c. Coupling nuts shall conform to ASTM A563 and shall have a Class C, hot-dipped, zinc coating that complies with ASTM A153.
G. Connection (coupling leads and extensions):
1. Couplings (engagement) for round corner steel (RCS) extensions will be formed as an integral part of the shaft extension material through a forging process except the 2” RCS. For the 2” RCS, the engagement will be a cast coupling.
2. Pipe pile couplings must be square engagement with connecting bolts not subjected to shear or bending during installation.
3. Couplings for pipe piles shall be cast steel AISI 8620 or SC1045 grade 40/80.
2.2 FINISH
A. All other materials, if galvanizing is specified, shall have a Class B1, hot-dipped, galvanized coating, complying with ASTM A123.
B. Material may also be furnished black (non-galvanized), if requested.
2.3 SOURCE QUALITY CONTROL
A. Section 01400 - Quality Requirements: Testing, inspection and analysis requirements.
B. Test sample piles in accordance with [ASTM D1143] [ASTM D3689].
PART 3 EXECUTION
3.1 EXAMINATION
A. Section 01300 - Administrative Requirements: Verification of existing conditions before starting work.
3.2 PREPARATION
A. The contractor shall review the work of all other trades and verify that all said work is completed to the point where helical pile installations may commence without restriction.
B. The contractor shall protect structures including overhead and buried utilities near the Work, from damage.
C. The contactor shall notify the Owner or their representative of any noted discrepancy. The contractor shall not proceed with the installation of helical piles in the area(s) of said discrepancies until the discrepancies have been resolved. All costs associated with unresolved discrepancies shall be the responsibility of the Owner.
3.3 INSTALLATION EQUIPMENT AND TOOLING
A. Torque Motor:
1. Shall be a rotary type, hydraulic power driven torque motor with equal forward and reverse torque capabilities.
2. Shall be capable of continual adjustment of the torque drive unit’s revolutions per minute (RPM’s) during installation
3. Shall be capable of continuous position adjustment to maintain the proper helical pile alignment
4. Shall be capable of simultaneously applying adequate down pressure (also referred to as crowd) and torque.
5. Shall have a torque capacity at least 15% greater than the torsional strength of steel shaft to be installed.
B. Percussion drilling equipment will not be allowed.
C. Tooling:
1. Shall consist of a Kelly Bar Adapter (KBA) and drive tools for the helical pile types to be used on the project.
2. Shall be used in accordance with the manufacturer’s written installation instructions.
D. Torque Indicator:
1. Shall be used during the installation of all helical piles.
2. Shall be monitored throughout the installation by the contractor.
3. Shall either be a part of the installing unit or an independent device in-line with the installing unit.
4. Shall be capable of providing continuous measurement of the applied torque throughout the installation.
5. Shall be capable of torque measurements in increments of at least 500 ft-lbs.
6. Shall be calibrated a minimum of forty five (45) days and shall be provided to the owner prior to pre-production testing and to the start of work:
a. Torque indicators, which are an integral part of the installation equipment, shall be calibrated on site.
b. Torque indicators, which are mounted in line with the installation tooling, shall be calibrated either on site or at an appropriately equipped test facility.
c. Torque indicators that measure torque as a function of hydraulic pressure shall be calibrated at normal operating temperatures.
d. Shall be recalibrated, if in the opinion of the Owner, their representative, and/or the contractor, reasonable doubt exists as to the accuracy of the torque measurements.
3.4 INSTALLATION
A. All helical piles shall be installed in the presence of a designated representative of the Owner unless the Owner or their representative informs the installation contractor otherwise.
B. The helical pile lead section shall be positioned at the location as shown on the working drawings. Battered helical piles can be positioned perpendicular to the ground to assist in initial advancement into the soil before the required batter angle is established. Engage and advance the helical pile lead and extension sections in a smooth, continuous manner with the rate of pile rotation in the range of 5 to 20 RPM’s. Extension sections shall be used to obtain the required minimum overall length and installation torque as shown on the working drawings. The coupling bolt(s) and nut(s) used to connect sections shall be torqued to minimum requirement per the hardware grade specifications.
C. Apply sufficient down pressure to uniformly advance the helical sections at a rate per revolution approximately equal to the pitch of the helices. The pitch of the helices is approximately 3 inches for standard RCS and pipe helical piles. The rate of rotation and magnitude of down pressure must be adjusted for different soil conditions and depths in order to maintain the penetration rate.
D. The torque as measured during the installation shall not exceed the torque rating (torsional strength) of the steel helical lead and extension shaft sections.
E. The minimum installation torque and minimum overall length criteria as shown on the working drawings shall be satisfied prior to terminating the installation of the helical pile.
F. The top most helix shall be located not less than 5 times its diameter below the bottom of the foundation for deep foundation behavior considerations. However, other site specific conditions, such as frost, fill, soft compressible soils, expansive soils, etc. may warrant a greater minimum depth.
G. Piles shall be spaced center-to-center as shown on the construction documents. Typically center-to-center spacing shall be approximately five times the diameter of the largest helix with a minimum spacing of three times the diameter.
H. If the torsional strength rating of the helical pile and/or installing equipment has been reached prior to satisfying the minimum length shown on the construction documents the installation contractor has the following options:
1. Terminate the installation at the length obtained with the approval by and acceptance of the Owner or their representative and the professional engineer responsible for the project.
2. Remove the existing helical pile and install a new pile with fewer and/or smaller diameter helical plates. This new pile configuration shall be reviewed by and accepted by the Owner or their representative and the professional engineer responsible for the project. If the new pile is installed at the same location as the original pile, then the top most helix of the new helical pile shall be installed at least three times the diameter of top most helix of the new pile beyond the termination depth of the original pile.
I. If the minimum installation torque shown on the construction documents is not achieved at the minimum overall length and there is no maximum overall length constraint, the installation contractor has the following options:
1. Install the helical pile deeper using additional extension sections
2. Remove the existing helical pile and install a new pile with additional and/or larger diameter helical plates. This new pile configuration shall be subject to review by and acceptance of the Owner or their representative and the professional engineer responsible for the project. If the new pile is installed at the same location as the original pile, then the top most helix of the new helical pile shall be installed at least three times the diameter of top most helix of the new pile beyond the termination depth of the original pile.
3. Contact the professional engineer for additional solutions.
J. If the helical pile is deflected by a subsurface obstruction, the installation shall be terminated and the helical pile removed. If feasible, the obstruction shall be removed and the helical pile shall be reinstalled. If the obstruction cannot be removed, the helical pile shall be installed at an adjacent location subject to review by and acceptance of the Owner or their representative and the professional engineer responsible for the project.
K. If the torsional strength rating of the helical pile shaft and/or installation equipment has been reached prior to the proper positioning of the elevation of the top of the helical pile, the contractor may remove the last extension and replace it with a shorter length extension. If it is not feasible to remove the last extension, the contractor may cut said extension to the proper elevation. The contractor shall not reverse (back-out) the helical pile to facilitate extension removal.
L. The average torque for the last 3 feet of penetration shall be used as a basis of comparison with the minimum recommended installation torque on the construction documents. The average torque is the average of the last 3 torque readings recorded at one-foot intervals. This average torque is intended solely as an indication of the helical pile’s ultimate bearing capacity.
3.5 WELDING
A. Perform welding in accordance with AWS D1.1.
B. All welders shall be AWS certified.
3.6 ERECTION TOLERANCES
A. Section 01400 - Quality Requirements: Tolerances.
B. Maximum Variation in Centerline: 2 inches.
C. Maximum Variation from Required Angle: 2 degrees.
D. Maximum Variation from Top Elevation: +1 inch to -1 inch.
3.7 FIELD QUALITY CONTROL
A. Section [01400 - Quality Requirements] [01700 - Execution Requirements]: Field inspecting, testing, adjusting, and balancing.
B. Perform load tests in accordance with [ASTM D1143] [ASTM D3689] by an independent testing agency.
C. Test Piles: Same diameter, type, and configuration as specified for other piling and placed in same manner.
D. Acceptance Criteria: Tested anchors shall be loaded to the ultimate load and shall not deflect more than the requirements listed in the construction documents.
E. Test piles may not be used as construction piles and shall be recovered and properly disposed of after testing is completed.
F. The contractor shall maintain a written installation record for each helical pile. END OF SECTION
