SECTION STEEL PIPE PILING

Transcription

1 SECTION STEEL PIPE PILING PART 1 GENERAL 1.1 SCOPE A. The work covered by this Section includes the furnishing of all materials, equipment, labor, and incidentals necessary for furnishing and installing steel pipe piles at the locations shown on the Contract Drawings and as herein specified or directed by the Engineer. B. This work shall include but is not limited to: 1. Furnishing, handling, driving, and restriking steel pipe piles. 2. Splicing piles 3. Pulling piles 4. Clearing obstructions 5. Jacking piles 6. Connection to existing wharf 1.2 RELATED SECTIONS A. Section High Strain Dynamic Pile Testing B. Section Metal Fabrications C. Section Coating of Steel Waterfront Structures D. Section Corrosion Control and Cathodic Protection 1.3 REFERENCES A. The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only. B. Unless otherwise indicated the most recent edition of the publication, including any revisions, shall be used. C. American Society for Testing and Materials (ASTM) ASTM A 252 (2010) Welded and Seamless Steel Pipe Piles D. American Welding Society, Inc. (AWS) AWS D1.1 (2010) Welding Code Structural Steel

2 1.4 SUBMITTALS A. General: Submit the following to the Engineer for approval. Note that approval of submittals by the Engineer shall not be construed as relieving the Contractor from responsibility for compliance with the Specifications nor from responsibility of errors of any sort in the submittals. B. Contractor Qualifications C. Certifications, test procedures, and other submittals shall show the appropriate ASTM test(s) for each material. D. Submit manufacturer s certified test reports, for each heat, indicating that materials have been tested and certified to meet the specified chemical, mechanical, and section properties prior to delivery at the site. Certifications shall be submitted for all materials, including but not limited to: 1. Steel Pipe Piles 2. Structural steel plate and shapes 3. Bolting materials E. Welding procedures, qualifications, and testing shall be submitted in conformance with the requirements of Section 05500, Metal Fabrications. F. Work Plans 1. The Contractor shall submit to the Engineer details of equipment, materials, methods, and procedures for the following items: a. Pipe Pile Installation: Plan shall include methods for handling piling, driving, and cut-off methods, details and dimensions of templates and other temporary guide structures for installing the piling. b. Pile reinforcing tips or steel points c. Splicing piles d. Pulling piles e. Clearing obstructions f. Jacking piles, including plan for reaction piles g. Collar installation 2. Approval by the Engineer will not relieve the Contractor of his responsibility to perform work in accordance with the contract documents and Specifications. G. Driving Equipment 1. Pile hammer a. Make and model b. Hammer Classification (i.e., diesel, air/steam, etc) c. Hammer type (single acting, double acting, etc)

3 d. Energy range e. Weight of striking part (impact hammers only) f. Total weight g. Total length h. Maximum stroke, if applicable i. Chart of blowcount rate versus energy through hammer (impact hammers only) j. Eccentric moment, inch-pound (vibratory hammers only) k. Dynamic force, tons (vibratory hammers only) l. Steady state frequency or frequency range, cycles per minute (vibratory hammers only) m. Vibrating weight, pounds (vibratory hammers only) n. Amplitude, inches (vibratory hammers only) o. Maximum pull capacity, tons (vibratory hammers only) p. Non-vibrating weight, pounds (vibratory hammers only) q. Power pack description 2. Driving helmets a. Cap blocks b. Pile Cushions c. Pile centering guide/template d. Leads e. Special driving shoes or points H. Pile Driving Records: Submit pile driving records in accordance with Paragraph 3.4. I. As-Built Drawings: Submit marked up drawings showing all deviations from planned arrangement or details that occurred during construction. 1.5 QUALITY ASSURANCE A. The Contractor shall be fully experienced in all aspects of steel pipe pile installation and jacking. The firm shall be thoroughly experienced in similar installations under like subsurface conditions. B. Before beginning work, the Contractor shall submit details of the piling to be furnished, the pile driving equipment and a description of the proposed method of installation including pile splicing; all shall be subject to the approval of the Engineer. 1.6 DELIVERY, STORAGE, AND HANDLING A. Materials delivered to the site shall be new and undamaged and shall be accompanied by certified test reports. The manufacturer s logo and mill identification mark shall be provided on the piles as required by the referenced specifications

4 B. Store and handle piles in the manner recommended by the manufacturer to prevent permanent deflection, distortion, or damage. Support on level blocks or racks spaced not more than 10 feet apart and not more than 2 feet from the ends. Supports between multiple lifts shall be in a vertical plane. Storage of piles should also facilitate required inspection activities. C. Protect piles to prevent damage to coatings and to prevent corrosion prior to installation. D. Piles over 80 feet in length shall be handled using a minimum of two pickup points. 1.7 SUBSURFACE INFORMATION A. A Boring Plan and Subsurface Profiles are presented in Appendix IV. A copy of the boring logs, laboratory test results, and geotechnical reports can be obtained from the MPA Engineering Office located at The World Trade Center, 401 East Pratt Street, Suite 1653, Baltimore, MD. The Contractor should anticipate difficult driving conditions when installing piles into very dense sand and clay layers at the site. The information shown in the report and boring logs was made available to the Engineer from the Administration for design and estimating purposes. The Contractor, at his own expense, may make additional investigations he considers justified. PART 2 PRODUCTS 2.1 PILES A. Steel pipe in accordance with ASTM A 252, Grade 3: 1. All welds shall conform to AWS D1.1 and the requirements of Section 05500, Metal Fabrications. Note that the alignment tolerance shall be 1/16th of an inch. 2. Spiral and/or straight seam and splice welds shall be double fused beveled submerged arc welds in accordance with AWS. Other pre-qualified welds under ASTM procedures shall be acceptable. B. Steel pipe piles shall be coated in accordance with Section 09970, Coating of Steel Waterfront Structures. C. Provide pile tip reinforcements or cast steel points. D. Furnish pipe pile connections in accordance with the requirements of Section 05500, Metal Fabrications. Pipe pile connections shall be coated in accordance with Section 09970, Coating of Steel Waterfront Structures

5 2.2 EQUIPMENT A. Select the proposed pile driving equipment, including hammers and other required items, and submit complete descriptions of the proposed equipment as specified. Final approval of the proposed equipment is subject to the satisfactory completion and approval of pile tests. Changes in the selected pile driving equipment will not be allowed after the equipment has been approved except as directed. No additional contract time will be allowed for Contractor proposed changes in the equipment. B. Pile Driving Hammer 1. Furnish a hammer capable of developing the indicated ultimate pile capacity, when applicable, and the tip elevation shown on the Contract Drawings considering the hammer impact velocity; ram weight; stiffness of hammer and pile cushions; cross section, length, and total weight of pile; and character of subsurface material to be encountered. The striking part of the hammer shall in all cases be of sufficient and proper size to drive the pile to the required depth without damage to the pile. Repair damage to piling caused by use of a pile hammer with excess delivered force or energy. 2. Piles may be driven with air, steam, diesel, hydraulic impact, or vibratory hammers. a. The plant and equipment furnished for air/steam hammers shall have sufficient capacity to maintain at the hammer, under working conditions, the volume and pressure specified by the manufacturer. The plant and equipment shall be equipped with accurate pressure gauges, which are easily accessible to the Engineer. The weight of the striking parts of air and steam hammers shall not be less than 1/3 the weight of helmet and pile being driven, and in no case shall the striking part weigh less than 2750 pounds. b. Open-end (single acting) diesel hammers shall be equipped with a device such as rings on the ram to permit the Engineer to visually determine hammer stroke at all times during pile driving operations. Also, the Contractor shall provide the Engineer a chart from the hammer manufacturer equating stroke and blows per minute for the open-end diesel hammer being used. Hammer shall be equipped with a skirt to prevent fuel spray. c. Closed-end (double acting) diesel hammers shall be equipped with a bounce chamber pressure gauge, in good working order, mounted near ground level so as to be easily read by the Engineer. Also, the Contractor shall provide the Engineer a chart, calibrated to actual hammer performance within 90 days of use, equating bounce chamber pressure to either equivalent energy or stroke for the closed-end diesel hammer to be used. Hammer shall be equipped with a skirt to prevent fuel spray. d. The power plant for hydraulic hammers shall have sufficient capacity to maintain at the hammer, under working conditions, the volume and pressure specified by the manufacturer. The power plant and equipment shall be equipped with accurate pressure gauges, which are easily accessible to the Engineer

6 B. Vibratory Hammers: The use of vibratory hammers is dependent upon satisfactory driving of piles to the elevations indicated on the Contract Drawings. The size or capacity of hammers shall be as recommended by the manufacturer for the pile mass weight and soil formation to be penetrated. The hammer shall provide for maintaining a rigid connection between the hammer and the pile. If a vibratory hammer is used, the Contractor shall drive the piles for the last 5 feet to reach the final tip elevation as indicated on the Contract Drawings. C. Approval of Pile Driving Equipment 1. All pile driving equipment furnished by the Contractor shall be subject to the approval of the Engineer. It is the intent of this Specification that all pile driving equipment is sized in such a way that the production piles can be driven with reasonable effort to achieve the ultimate pile capacity and/or the tip elevation as shown on the Contract Drawings. The steel pipe piles shall be driven to the tip elevation shown on the Contract Drawings. D. Drive System Components and Accessories 1. Hammer Cushion: Impact pile driving equipment designed to be used with a hammer cushion shall be equipped with a suitable thickness of hammer cushion material to prevent damage to the hammer or pile and to ensure uniform driving behavior. Hammer cushions shall be made of durable manufactured materials, provided in accordance with the hammer manufacturer s guidelines. Wood, wire rope, and asbestos hammer cushions are specifically disallowed and shall not be used. A striker plate as recommended by the hammer manufacturer shall be placed on the hammer cushion to ensure uniform compression of the cushion in the presence of the Engineer after each 100 hours of pile driving. Any cushion exhibiting reduction of thickness exceeding 25% of the original thickness shall be replaced by the Contractor before driving is permitted to continue. 2. Helmet: Piles driven with impact hammer require an adequate helmet or drive head to distribute the hammer blow to the pile head. The helmet shall be axially aligned with the hammer and pile. The helmet shall be guided by the leads and not be free-swinging. The helmet shall fit around the pile head in such a manner as to prevent transfer of torsional forces during driving, while maintaining proper alignment of hammer and pile. 3. Leads: Piles shall be supported in line and position with leads while being driven. Pile driver leads shall be constructed in a manner that affords freedom of movement of the hammer while maintaining alignment of the hammer and the pile to insure concentric impact for each blow. For driving battered piles, support and guide impact hammers with three-axis, fixed-extended leads capable of 1 H and 2-1/2 V fore and aft batter and 1 H on 6 V side batter, with 30 degree rotation each side of an axis running along the center line of rotation of the crane through the center line of the leads. The pile section being driven shall not extend above

7 the leads. The leads shall be adequately embedded in the ground or the pile constrained in a structural frame such as a template to maintain alignment. The leads shall be of sufficient length to make the use of a follower unnecessary, and shall be so designed as to permit proper alignment of batter piles. Vibratory hammers may be operated free hanging without leads. 4. Followers: The use of followers is not permitted. 5. Skirt: If a diesel hammer is used, it must be equipped with a skirt or sleeve to prevent fuel spray. 2.4 CATHODIC PROTECTION A. Zinc anodes shall be in accordance with the requirements stipulated in Section 16640, Corrosion Control and Cathodic Protection. PART 3 EXECUTION 3.1 ORDER LENGTHS A. Base bids on the number, size, and length of piles from cut-off to the estimated tip elevations shown on the Contract Drawings. B. Submit pile type, material grade, and order lengths for review by Engineer prior to placing order. Actual lengths will be determined from the results of the test piles in accordance with Section 02468, High Strain Dynamic Pile Testing. 3.2 EXAMINATION AND PREPARATION A. Inspect piles when delivered and when in the leads immediately before driving. Repair damage or defects in pile coating as specified. B. Prior to driving, the pile shall be marked continuously at 1 foot intervals with paint or keel beginning at an appropriate length above water level to allow delineation of pile length during installation. C. The heads of all piles shall be plane and perpendicular to the longitudinal axis of the pile before the helmet is attached. 3.3 PRODUCTION PILE INSTALLATION A. On each day of pile driving, the Contractor shall stab only the number of piles that can be driven and jacked below the wharf face by the end of the day, and all piling stabbed shall be driven and jacked below the wharf face by the end of each working day

8 B. Obstructions may be encountered during pile driving. The Contractor shall notify the Engineer of the obstruction and shall probe the area adjacent to obstruction to determine the depth and extent of the obstruction where directed. Spudding with heavy wall pile may be required. Where obstructions are encountered that cannot be broken, the Engineer shall then determine whether the obstruction should be removed, the pile offset, or additional piles driven. C. Provide temporary templates, wales, and/or guide structures to ensure that the piling is placed and driven to the correct position and alignment. Use a system of structural framing sufficiently rigid to resist lateral and driving forces and to adequately support the piling until design pile capacity and/or minimum tip elevation is achieved. Use templates or guide structures of a spacing and configuration that is appropriate for the length and batter of piling being installed. Templates and other guide structures shall not move when supporting piling. Fit templates with UHMW-PE or wood blocking to bear against the pile and hold the pile at the required position and alignment. Provide outer template straps or other restraints as necessary to prevent the pile from wandering from the required position and alignment. D. Take care to avoid damaging piles during handling, placing in the leads, and driving. Square the heads and tips of piles to the driving axis. Laterally support piles during driving, but do not unduly restrain piles from rotation in the leads. Where pile orientation is essential, take measures to maintain the orientation during driving. Carefully support battered piles to prevent excessive bending stresses in the pile. E. Drive production piles in accordance with the hammer manufacturer s recommendations. If a pile fails to reach the tip elevation or if the required driving resistance is reached before the pile tip elevation, notify the Engineer; the Engineer will determine the procedure to be followed. F. If upon reaching the estimated tip elevation, the pile has not attained the specified penetration resistance, the Contractor shall stop driving. After a period of at least 48 hours, the Contractor shall restrike the pile with or without performing dynamic analysis, as directed by the Engineer. If the pile has still not attained the specified bearing capacity, then the Engineer shall direct the Contractor to what corrective measures are required, such as driving additional piles. G. Jetting of piles is not permitted except as specifically indicated by the Engineer. H. Pre-drilling of piles is not permitted. I. Cut-offs 1. The tops of all piles shall be cut off at the elevations specified on the Contract Drawings and on a true plane perpendicular to the axis of the pile unless otherwise specified. 2. Pile cut-offs shall become the property of the Contractor and shall be disposed of offsite

9 J. Piles that do not meet the acceptance criteria when driven to cutoff elevation, are driven below the required top elevation, or are damaged by driving and cut off to permit further driving shall be extended as required to reach the top elevation by splicing when directed by the Engineer. Repair coating on and around patches in accordance with Section 09970, Coating of Steel Waterfront Structures. 3.4 PILE JACKING AND CONNECTION INSTALLATION A. Piles shall be driven at a slight batter, as nearly plumb as possible, in line with the row of piles, and pulled or pushed back under the pile cap beam to a plumb position. B. Remove and reinstall fendering as necessary in order to permit nearly plumb driving. C. Reaction Piles 1. Contractor shall select a minimum of three reaction piles in good condition for each jacking operation. D. Contractor shall take extreme care to prevent damage to new and existing piles and wharf structure while jacking new piles into proper alignment. Any damage resulting from pile installation and jacking work shall be repaired or replaced by the Contractor to the satisfaction of the Engineer at no additional cost to the Administration. E. Jacking of piles shall be performed using a come-along or other means as approved by the Engineer. Contractor shall measure jacking force and notify the Engineer if Jacking force exceeds 5,700 lbs. All piling stabbed during a working day shall be driven and jacked below the wharf face by the end of that working day. F. Connect piles to the concrete deck and seawall as shown on the Contract Drawings. 3.5 CATHODIC PROTECTION A. Install anodes on each pile in accordance with the requirements of Section 16640, Corrosion Control and Cathodic Protection. One anode shall be installed on each pipe pile. 3.6 TOLERANCES A. At cut-off elevation, butts shall be within 3 inches laterally of the correct location. B. A maximum variation of 0.25 inch per foot of pile length from the vertical for plumb piles is permitted. C. Heaved piles that have been forced up by more than 0.25-inches by any cause shall be redriven. Inspect piles for heave after all piles within a 50-foot radius have been driven. D. Remove and replace with new piles those damaged, mislocated, driven below the design cutoff, or driven out of alignment, at no additional cost to the Administration

10 3.7 PILE DRIVING RECORDS A. A Contractor s representative shall keep all records as required below. All direction as required by the pile driving operation shall be the sole responsibility of the Contractor. B. The Contractor s representative shall keep a complete and accurate record of each pile driven. Indicate the date and time driven, pile number, pile location, deviation from design location, cross section shape and dimensions, original length, ground (or mudline) elevation, tip elevation, cut-off elevation, penetration in blows per foot for the entire length of penetration, penetration in inches per blow for the last ten (10) blows, hammer data including rate of operation, total driving time, make, size, dimensions of driving helmet and cap used, and all unusual pile behavior or circumstances experienced during driving such as redriving, heaving, weaving, obstructions, jetting, predrilling, reheading or cutting of piles, and unanticipated interruptions. Immediately notify the Engineer of any unusual behavior or circumstances. Make pile driving records available to the Engineer at the site within 24 hours of completion of pile driving. Submit complete records of installed piles to Engineer within 15 calendar days after completion of the pile driving. Preprinted forms for recording pile driving data will be furnished upon request. 3.8 ACCEPTANCE CRITERIA A. The controlling tip elevation, depth of penetration, driving resistance, refusal blow count (number of blows required to attain the final inch of penetration), and restrike criteria for production piles will be determined by the Engineer, based on the results of the test piles. PART 4 COMPENSATION 4.1 MEASUREMENT A. Furnish 16-Inch Diameter, 1/2-Inch Wall Pipe Piles shall be measured on a vertical linear foot basis. B. Handle and Drive 16-Inch Diameter Piles shall be measured on a per each basis. C. Re-Strike 16-Inch Diameter Piles shall be measured on a per each basis. D. Field Splice 16-Inch Diameter Piles shall be measured on a per each basis. E. 16-Inch Diameter Pile Cutoffs shall be measured on a per each basis. F. Pile Jacking and Connection shall be measured on a per each basis. G. Removal of test piles shall not be measured

11 4.2 PAYMENT A. Payment for Furnish 16-Inch diameter, 1/2-Inch Wall Pipe Piles, complete, shall be made at the Unit Price Bid per vertical linear foot under Item No on the Proposal Form. This price shall include furnishing coated pipe piles, transporting them to the project site, storing them at the site, location surveys, inspection, pile tip reinforcement or cast steel points, and all work incidental thereto. B. Payment for Handle and Drive 16-Inch Diameter Piles, complete in place, shall be made at the Unit Price Bid per each under Item No on the Proposal Form. This price shall include pile inspection and driving, as well as furnishing and installing the anodes and mounting brackets and performing all corrosion control testing. C. Payment for Re-Strike 16-Inch Diameter Piles, complete, shall be made at the Unit Price Bid per each under Item No on the Proposal Form. This price shall include moving the driving rig (as necessary), re-driving the pile, and recording the results of re-strike. No payment shall be made for re-striking piles up to one (1) hour after initial drive or re-striking heaved piles. D. Payment for Field Splice 16-Inch Diameter Piles, complete in place, shall be made at the Unit Price Bid per each under Item No on the Proposal Form. E. Payment for 16-Inch Diameter Pile Cutoffs, complete in place, shall be made at the Unit Price Bid per each under Item No on the Proposal Form. This price shall include cutting off the excess pile tops and disposing of them offsite. F. Payment for Pile Jacking and Connection, complete in place, shall be made at the Unit Price Bid per each under Item No on the Proposal Form. This price shall include installing collars, jacking piles to a plumb position, and anchoring to concrete. G. No payment will be made for test piles that are unable to be used as production piles; where directed by the Engineer, such piles shall be removed at no cost to the Administration. H. The above prices shall include all the work described in this Section and shown on the Contract Drawings including all labor, materials, services, and equipment. END OF SECTION