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Furnish and install piling, including performing wave equation analysis. Perform Dynamic Pile Monitoring using Pile Driving Analyzer (PDA) and Case Pile Wave Analysis Program (CAPWAP) as specified. When drilled shafts (caissons) are specified, refer to Section 412. When a Load Test item is included in the Contract Documents, conduct and record load tests.
Sand       901.01
Concrete for Steel Pipe       902.10, Mix No. 3 Slump 4-6 in.
Tremie Concrete for Steel Pipe Piles       902.10, Mix No. 4
Timber Piles       907.01
Timber Sheet Piles       907.01
Resin and Fiberglass Caps       907.01.01
Steel Pipe Piles       907.02
Steel H Piles       907.03
Steel Sheet Piles       907.04
Reinforcing for Steel Pipe Piles       908.01
Hardware       909.10
Water       921.01
Timber Preservatives       921.06
410.03.01 WEAP Analysis and Hammer Approval. At least one month prior to the start of pile driving operations submit the Pile and Driving Equipment Data sheet and a Wave Equation Analysis of Pile (WEAP) for the tested piles. Submit, for approval, to the Director, Office of Structures, the hammer name, model, and manufacturer’s data for each pile hammer and procedure proposed to be used for pile driving, including any special operational and site or pile preparation requirements, Manufacturer’s Catalog Information and a completed Pile and Driving Equipment Data Form provided in the Contract Documents.
Drive all test and production piles with impact hammers. Vibratory hammers are prohibited, except for the driving of sheet piling.
Furnish for each test pile, a Wave Equation Analysis of Pile (WEAP), sealed and signed by a professional engineer, registered in the State of Maryland, experienced in such work. The analysis shall demonstrate that the pile hammer and driving procedure proposed by the Contractor has sufficient power to drive the piles to the Minimum Driving Load and Estimated Tip Elevation shown on the plans without exceeding the maximum permitted driving stress values stated in AASHTO LRFD Bridge Design Specifications, Section 10.7.8.
The analysis shall, at a minimum, include the following:
(a) Analysis methodology
(1) The ultimate soil resistance used in the analysis shall be not less than the Minimum Driving Load shown on the Plans. The proportioning of the tip resistance and the distribution of the side resistance shall be based on the soil boring data using either static analysis or other strength correlations.
(2) For hammers with an adjustable energy range, analysis shall demonstrate that minimum energy used within the range can mobilize the ultimate soil resistance, and that the maximum energy used within the range will not exceed the maximum permitted driving stresses during driving operations.
(3) The analysis shall demonstrate that with the hammer used, the required ultimate soil resistance shall be attained using hammer blows in the range of 2 to 15 blows per in.
(b) Interpretation of Soil Boring Data necessary to determine the resistance the pile will develop during driving to the estimated pile tip elevation.
(c) Computer input and output sheets and graphs showing soil resistance versus blow counts, and maximum tensile and compressive stresses in the pile versus blow counts.
(d) Provide for each hammer, at each test pile, charts of Driving Load versus Energy (blow/minute) and Pile Set (blow/in. and blow/ft) based on the WEAP analysis.
(e) Provide maximum driving stresses allowed in the piles during installation.
(f) Provide recommended hammer speeds or speed range to achieve required pile hammer energy.
410.03.02 Test Piles and Dynamic Pile Monitoring. Test pile driving operations shall not commence until approval of the WEAP and pile hammer has been received in writing for each applicable test pile or structure/substructure location.
Drive test piles to determine the actual depth of penetration and the length of piling to be ordered for each structure and substructure location. Based off of test pile results, ensure that the piling ordered and delivered to the site is of correct type and length.
Acceptance of the pile hammer and driving equipment will not relieve the Contractor's responsibility for properly driving piles, in satisfactory condition, to the driving resistance and tip elevations indicated in the plans in accordance with the approved WEAP analysis.
Drive test piles in permanent vertical position. Test piles found to be satisfactory shall be utilized as permanent piles.
(a) Dynamic Pile Monitoring Independent Testing Firm. Secure and provide the services of an independent testing firm to furnish and operate all equipment necessary to perform dynamic Pile Driving Analyzer (PDA) and CAPWAP tests. These tests shall be performed on all piles indicated in the plans as a test pile or on production piles designated by the Engineer. The independent testing firm shall be experienced in the use of the test equipment described herein and shall be subject to approval. All incidental labor and material necessary to make the work area accessible and to operate the equipment shall be supplied by the Contractor.
The independent testing firm shall direct the progress of the testing work, obtain and record the test data, perform monitoring of the stresses on the tested piles during initial driving and restrike (if required), and evaluate the driven pile capacity. The independent testing firm shall be responsible for conducting the actual tests of the test piles.
Prior to being driven with the pile-driving hammer, each pile to be tested shall be instrumented with force and acceleration transducers by the independent testing firm with the aid of the Contractor’s personnel.
Dynamic measurements resulting from the pile hammer blows shall be automatically recorded electronically. The independent testing firm shall operate all the equipment that analyzes the data from the sensors installed on the piles to capture pile stresses, pile-soil capacity, and the hammer efficiency.
The independent testing firm shall prepare a hand written daily field report summarizing the dynamic testing results. In addition to the PDA printout information to be provided below, the daily reports shall include the calculated driving stresses, transferred energy, and estimated pile capacity at the time of testing. Variations from previous trends in the dynamic test data shall also be noted. Daily field reports shall be hand-delivered or faxed to the Engineer.
Upon determination by the independent testing firm that valid data have been secured, the independent testing firm with the assistance of the Contractor’s crew shall remove the instrumentation from the piles.
(b) PDA Equipment. Perform the dynamic monitoring using a GC, GCPC, or PAK Model PDA. The independent testing firm shall furnish all equipment necessary for the dynamic monitoring such as gauges, cables, etc. The equipment shall conform to the requirements of D4945.
Provide the power supply to the tested pile locations for the dynamic testing duration. The power supply shall consist of a regular power source providing 110 volt AC power with a frequency of 60 Hz. Direct current welders or non-constant power sources are unacceptable.
Dynamic testing involves attaching two strain transducers and two accelerometers near the pile head. The dynamically tested piles shall be of sufficient length so that gauges are not driven below the water surface, pile template, or into the ground. Cables connecting the gauges near the pile head with the PDA located at the ground or water level shall be of sufficient length to reach 50 ft to 100 ft from the pile.
Maintain a stock of at least four working accelerometers and strain transducers at the job site whenever dynamic testing is being performed.
All repair or replacement costs shall be performed at no additional cost to the Administration.
(c) PDA Driving and Testing Procedures. Drive the pile based on the recommendations provided in the WEAP Approval Letter. Conduct dynamic testing according to D4945 “Standard Test Method for High Strain Dynamic Testing of Piles.”
Prior to lifting the pile to be dynamically tested, provide a 3 ft minimum clear envelope around the pile so the dynamic testing consultant can access and prepare the pile for testing. Holes shall then be drilled and prepared for gauge attachment.
Test piles shall be driven to achieve the Minimum Driving Load and the Minimum Penetration Elevation as shown on the plans. For cohesionless soils, once pile driving begins, the driving shall be continuous until refusal has been achieved. For cohesive soils, if the estimated tip elevation is surpassed and the Minimum Driving Load is not achieved, the pile driving should stop and pile restrike shall be required. Pile restrike shall occur no sooner than three days (72 hours) after the tested pile, or any pile within a 25 ft radius, has been driven and approved.
(d) Test Piles Failing to Meet Design Requirements. If tested piles fail to achieve the required capacity on restrike, pile driving shall be stopped and the Office of Structures consulted for further direction.
Propose a new pile driving system, modifications to the existing system, or new pile installation procedures if the pile installation stresses calculated by the PDA exceed the maximum values stipulated in the approved WEAP analysis. Submit revised WEAP analysis, driving procedure, hammer and hammer configuration for approval.
(e) PDA Daily Printout Reports. The results of the dynamic testing shall be printed by the PDA daily and shall include, for each blow count selected by the Engineer, the following information:
(1) Bearing capacity for the Case Goble method.
(2) Input and reflected values of force and velocity.
(3) Maximum transferred energy.
(4) Maximum compression force.
(5) Velocity and displacement.
(6) Blows per minute.
(7) Value of upward and downward traveling force wave.
(8) Ram stroke and corresponding blow sequence.
All of the above information shall be supplied to the Engineer within one day (24 hours) of the testing. All recorded signals from the pile sensors captured electronically shall be stored and shall be made available upon request by the Engineer at a later date for additional analysis.
(f) Case Pile Wave Analysis Program (CAPWAP) Pile Analyses. All PDA dynamically tested piles shall be evaluated using the Case Pile Wave Analysis Program (CAPWAP).
Within three days (72 hours) of completion of driving a test pile and the conducting of the final CAPWAP restrike, furnish the Engineer with a written report containing all computer print-outs and graphs from the CAPWAP. A copy of the written report shall be furnished to the Office of Structures and the results be approved in writing prior to driving any remaining test pile(s) or production piles at any location within the project site.
Each CAPWAP analysis report shall include the following information:
(1) Graph showing the bearing capacity versus blow count and pile stress versus blow count.
(2) Simulated static load test curves for the tip and the top of the pile.
(3) Evaluation of the soil parameters based on the matching of the measured and computed values of forces, velocities and displacements.
(4) Static resistance distribution along the length of the pile.
410.03.03 Storage and Handling. Store and handle piling to avoid damage. Repair or replace damaged piling as directed.
410.03.04 Preparation for Driving. Do not drive piling until completing embankment, soil improvements and excavation in the area of the pile driving operation.
Provide templates or other approved means to ensure that the piles are properly aligned and positioned.
Provide a cap or cushion so that hammer energy is transmitted to the pile evenly without damaging the top or butt. Ensure that the top of the pile, irrespective of type, is normal to the axis of the moving parts of the hammer.
410.03.05 Pile Tips
(a) Provide pointed timber piles where driving conditions require. The point shall be symmetrical and at least 4 in. diameter. Shod timber pile tips or bottoms with a metal shoe or point when specified.
(b) Drift sharpen or bevel the bottom of timber sheet piling to wedge continuous piles in tight contact.
(c) Drive steel H piles without any special tip reinforcement unless otherwise specified.
(d) Drive steel pipe piles open ended, unless otherwise specified.
410.03.06 Splicing. Do not splice timber piles. If an isolated timber pile penetrates below planned elevation, thereby resulting in the top being below planned elevation, the Engineer will determine when replacement is required, whether to supplement it with an additional pile, or when the structure can be changed without detriment.
When splicing of steel H piles and steel pipe piles is necessary, splice them as specified using electric arc welding conforming to AWS Structural Welding Code for the full periphery. The number of splices permitted shall be compatible with driving conditions at the site and the standard lengths of piling produced by manufacturers; however, only one section of each pile shall be less than 20 ft.
When welding is required above a specified maximum elevation, weld as specified in 430.03 excluding the submerged arc welding requirement. Welders shall be qualified to 430.03.19(a) or 430.03.19(b) for steel pipe piles 24 in. in diameter or greater, and to meet 430.03.19(b) for pipe piles less than 24 in. in diameter.
All welding above these limits shall receive 100 percent Magnetic Particle Inspection (MT) on the root pass and completed weld, and 100 percent Radiographic Inspection (RT), in accordance with AWS D1.5. Inspectors shall be approved by the Office of Materials and Technology (OMT) as specified for certification testing in accordance with AWS D1.5.
Inspectors certified by an accredited/certified American Society for Non-Destructive Testing (ASNT), Level III in the inspection discipline, may submit certifications to OMT for review.
Where a manufactured pile type is designed to be spliced by screwing two pieces together or by the use of coupling or collars, and the details for the splice are not specified, submit the device for approval.
Drive piles in a continuous operation, and make splices prior to approaching the estimated tip elevation.
410.03.07 Pile Driving. Drive the permanent piles with the same hammer used to drive the test piles. If the hammer is changed, even if the energy ratings of the hammers are identical, drive additional test piles at no additional cost.
Operate hammers at speeds specified in approved WEAP analysis. The manufacturer’s manual for the hammer employed shall be available to the Engineer at the project site.
Use pile-driving equipment of an acceptable type, mass (weight), and capacity as determined by WEAP analysis and approved by the Administration. Use air compressors of sufficient capacity to provide 25 percent more air than shown in the manufacturer's specifications for air-driven hammers. Do not use capblocks or cushions containing asbestos.
Use either drop-steam, air, diesel, or hydraulic actuated pile-driving hammers. Hammers shall be capable of developing at least the energy shown on the plans.
Equip hammers with a suitable drive head that accurately and securely holds the top of the pile in correct position, with reference to the hammer, and that distributes the blows from the ram over the entire top area of the pile or mandrel.
Use a hammer of a type and size that enables piles to be driven to the required driving resistance without pile damage due to driving stresses, as indicated by the WEAP. Acceptance of a hammer relative to driving stress damage will not relieve the Contractor's responsibility for piles damaged because of misalignment of the leads, failure of capblock or cushion material, failure of splices, malfunctioning of the hammer, or other improper construction methods.
Construct pile driver leads to allow free movement of the hammer. Hold the leads in true vertical or inclined positions, as required, by guys or stiff braces to ensure support of the pile during driving. Provide leads of sufficient length so a follower will not be necessary under normal conditions.
Construct leads or spuds to afford freedom of movement of the hammer during the driving phases. Drive the piles within the tolerance as specified without damaging the piles. Remove any leads that do not produce satisfactory results from the project.
Do not drive with the hammer out of leads.
On all special, marine or water projects and pile bents, use leads of sufficient length that a follower will not be necessary. Provide guides and additional support to prevent excessive bending or buckling under the hammer blow when driving long piles and batter piles. Hold piles in place and alignment by templates or other approved means.
Do not perform external jetting of any pile. If it is necessary to remove material from within a pile shell to advance the pile tip or merely to obtain room for concreting, leave at least 10 ft soil plug undisturbed at the tip of the pile. Install turbidity curtain around piles being cleaned when appropriate.
Auger or drill holes through strata that resist driving. Use an approved auger or drill that is no larger than the nominal diameter of a circle in which an H pile will fit.
After the hole is completed, insert the pile and fill voids between the pile and the walls of the hole with dry sand. Complete the driving and then fill remaining voids with dry sand.
410.03.08 Steel Pipe Piles. After driving, remove soil plugs to the specified elevation. Prior to placing filling (when specified) or reinforcing, use a suitable light to inspect the interior for the entire unplugged length. Do not fill or place reinforcing until the pile is approved.
Provide all required equipment for inspection including oxygen, light, boatswain’s chair, and lift. Comply with Federal, State, and local safety regulations.
For requirements for micropiles or pin piles, see the Contract Documents.
410.03.09 Concreting Steel Pipe Piles. Perform concreting as specified in Section 420. Perform reinforcing work as specified in Section 421. Securely fasten the reinforcing together to form a cage, positioned and held at a uniform distance from the shell.
Except as specified herein, use tie wire to secure tie bars and bands of cage reinforcing. For foundation (footing) piles, tack welding may be used, provided it is performed by an Administration certified welder.
For bents and column piles, tie bars, bands, and spacer lugs shall not be welded to the main reinforcing bars, except that a bend may be placed at the top and bottom of the pile cage and all main bars welded to the band. Use tie wires to fasten the reminder of the intersections of ties and main bars.
Clean the areas in the top portion of the pile that are to be filled with reinforced concrete and tremie concrete. Place and cure tremie concrete prior to dewatering the top of the pile shell. Place the reinforcing unit in the top portion of the pile prior to filling with Mix No. 3 concrete.
Do not place concrete in any pile until completing driving within a radius of 15 ft or until all the piles for any unit of structure (pier, bent, or abutment) have been driven to their final penetration and accepted. If this procedure is not feasible, discontinue driving within the above limits until the concrete in the last pile placed has set at least 72 hours.
Immediately prior to concreting remove water and other foreign substances. Deposit the concrete in one continuous operation.
The restriction in Section 420 for dropping concrete more than 5 ft does not apply.
Set and fasten reinforcing steel cages in proper position in the pile before filling with concrete, except when the reinforcing steel cage extends 6 ft or less below the top of the pile, the concrete filling may be placed before installing the reinforcing. Thoroughly consolidate using mechanical vibrators from the bottom of the reinforcing steel cages to the pile top.
Do not disturb or apply loads to concreted piles until all concrete has been in place and cured at least 72 hours.
410.03.10 Pile Cutoff and Removal. Cut off the tops of piles and pile casing, except timber piles that support timber caps, at the elevations specified. Make cuts on a true plain perpendicular to the axis of the pile unless otherwise specified. Cut off timber piles that support timber caps to ensure that the plane of the bottom of the cap will bear fully on the pile head. Shims shall not be placed between the timber cap and pile head.
Cut off piles used for sheeting and shoring to at least 1 ft below existing grade, channel bottom, or mud line as applicable. When specified, these piles may be removed. Dispose of all removed material.
410.03.11 Treatment for Timber Pile Heads. Use an approved asphalt treatment to paint timber pile heads that are not to be embedded in concrete. After the asphalt has sufficiently cured, cover it with a glass resin composite shield. Apply the first coat of resin to the top and down the side at least 1 in. beyond the limits of the woven glass. Apply precut woven glass cloth using a 3 in. grooved aluminum roller to achieve “wet out.” Neatly wrap woven glass cloth over the top of the pile, drape it down the side at least 2 in., and secure using copper nails. When the first coat of resin has taken a tack free set, apply a second coat of resin to seal the entire application.
410.03.12 Pile Driving Tolerances
(a) General. Do not use foundation piles out of the specified position by more than 6 in. in any direction after driving, regardless of the length of piles. Variation from the vertical or from the batter shall not be more than 1/4 in./ft.
(b) H Piles. Limit rotation of the pile to 25 degrees from the as planned axis.
(c) Bents. Drive piles so that the cap may be placed as specified.
410.03.13 Unacceptable Piles. Take one or more of the following actions or propose other actions for approval:
(a) Withdraw and replace the pile with a new pile.
(b) Drive a second pile adjacent to the unacceptable pile.
(c) Splice or build up the pile (except timber piles).
(d) Extend a sufficient portion of the footing to properly embed the pile.
410.03.14 Unanticipated Driving Conditions. Should unanticipated driving conditions occur, such as when resistance on the pile results in hammer blows per inch in excess of 20 with the hammer operated at its maximum fuel or energy setting, or at a reduced fuel or energy setting recommended by the Engineer based on pile installation stress control, stop driving and contact the Office of Structures for further guidance.
The payment will be full compensation for all material, labor, equipment, tools, and incidentals necessary to complete the work.
410.04.01 Piling (permanent and test) will be measured and paid for at the Contract unit price per linear foot for the pertinent Piling item. The measured length of all piling will be from its tip up to final cutoff, unless otherwise specified. For test piles not utilized as permanent piles, the measurement for cutoff will be at the same elevation as the nearest proposed permanent pile or to actual top of test pile, whichever is lower. Where piling designated as test piles is accepted for use in the permanent structure, measurements will be made as test piles, and no additional allowance will be made in other piling items.
410.04.02 Furnishing and set up of pile driving equipment for pile driving operations, including test piles, will not be measured but the cost will be incidental to the Contract unit price for the pertinent Pile item.
No additional compensation will be paid for any setup required for redriving or any additional driving of any pile no matter what reason the particular pile may require redriving or additional driving.
When an item for Setup for Driving Pile is included in the Contract Documents, the furnishing and setup of pile driving equipment will be measured and paid for at the Contract unit price per each for the pertinent Setup for Driving Pile item. The unit price per each for the setup required for driving each pile for the proposed structure will be used regardless of the distance that the equipment is moved for each pile setup. A maximum of one setup will be paid per pile location.
410.04.03 Pile points for steel H piles will be measured and paid for at the Contract unit price per each for the pertinent Pile Point for Steel H Pile item.
410.04.04 Timber sheet piling will be measured and paid for at the Contract unit price per 1000 board foot (MBM) for the pertinent Timber Sheet Piling item. Computation of quantities will be based on nominal thickness of lumber, the length of the sheet piling, and the average depth of the sheet piling from cutoff at the top to the tip of the sheet piling in the completed structure. No allowance will be made for waste.
410.04.05 Steel sheet piling will be measured and paid for at the Contract unit price per square ft as measured along the plane of surface for the pertinent Steel Sheet Piling item.
410.04.06 The following will not be measured but the cost will be incidental to other pertinent items:
(a) When specified, tips for steel pipe piles.
(b) Test pieces of sheet piling (timber or steel).
(c) Dewatering, clean out, filler, reinforcement, and concrete used in steel pipe piles.
(d) Pile splices.
(e) Auguring, including sleeve and backfill when required.
(f) Cleaning, painting, or coating of piling.
(g) Piling or sheet piling for temporary structures, piles or sheet piling driven for the Contractor’s convenience, or for any piles or sheet piling not specified.
(h) Piling not approved by the Engineer, such as piles not properly driven, piles with questionable safe bearing values, piles damaged during driving, or piles driven below planned cutoff or the removal of any pile rejected by the Engineer as unsatisfactory.
(i) Glass resin composite shield used on timber piles.
410.04.07 WEAP analysis and report will not be measured, but the cost will be incidental to the Contract unit price for the pertinent Test Pile item.
410.04.08 Dynamic Pile Monitoring will be measured and paid for at the Contract unit price per each. The payment will be full compensation for furnishing, installing, operating, maintaining, and removing the PDA and for the preparation of reports.
410.04.09 CAPWAP analysis will be measured and paid for at the Contract unit price per each. The payment will be full compensation for performing the analysis and preparation of reports.