DRIVEN PILES SECTION 605 188 SECTION 605 — DRIVEN PILES
605.1Description.
This work consists of providing, installing and dynamically testing foundation piles.
605.2Materials.
605.3Construction.
605.3.1 Submittals.
position during concrete placement.
pile driving system to the engineer for approval. Use Figure 605.3C -1 DelDOT Pile and Driving Equipment Data Form.
per minute for the hammer in use.
conduct load tests, record all data, and provide test result reports to the engineer.
interpreting dynamic pile testing.
collecting the data has documented experience on at least 10 previous projects with similar pile DRIVEN PILES SECTION 605 189 requirements and possesses a valid certificate of proficiency issued by the Pile Driving Contractors Association (PDCA).
collected data during pile driving.
the wave equation analysis submittal. The engineer will review the firm's qualifications and applicable previous experience on other projects.
registered Delaware professional engineer will sign and seal each analysis. Submit the wave equation analysis to the engineer 30 calendar days before driving t est piles.
predicts a need for alternate test pile lengths, clearly indicate the lengths of test piles in the submittal.
cushions, and any other applicable information for use in driving initial test piles to the required bearing resistance and tip elevation.
analysis for the pile driving throughout the various subsurface conditions of the site. Show resistance versus blow count, as well as maximum tension and comp ression stresses versus resistance on the plots.
depths of penetration using the proposed driving system. At a minimum, evaluate the driving conditions for 5 percent penetration, 70 percent penetration, 90 percent penetration, 100 percent penetration, and 110 percent penetration of the pile during initial driving and after set - up condition. Perform additional analysis at depths where the possibility exists of difficult driving or significant changes in driv ability. A value of 100 percent penetration refers to penetration to the plan estimated tip elevation to achieve the designated ultimate resistance. Use the wave equation analysis estimate of tip elevation for the ultimate resistance, if it differs from th e plan estimate by more than 10 percent at 100 percent penetration. Show the driving conditions for plan estimated depth in the analysis, if the chosen wave equation analysis estimate is used for 100 percent penetration.
soil layer specific quake and damping values and friction parameters for each level of penetration in the drivability analysis. At a minimum, include ulti mate resistances, blow counts, compressive and tensile stresses, and transferred energy plotted as a function of depth of penetration in the analysis output.
additional analysis that plots blow count versus stroke and energy for a fixed resistance equal to the ultimate resistance.
minimum tip elevation with a driving resistance not exceeding 120 -blows per 12 -inches. Driving resistance cannot exceed 20 -blows per 1 -inch in the last 6 -inches of penetration. DRIVEN PILES SECTION 605 190 9. Select a hammer that drives the pile without exceeding the following permissible stress limits:
the minimum yield strength of the pile material.
contract.
root of the concrete compressive strength, f c ′, plus the effective prestress value, fpe, or 3√fc ′ + fpe, with all units expressed in PSI. ii. For severe exposure, the maximum permissible tensile stress is fpe. iii. For all exposure conditions, the maximum permissible compressive stress is 85 percent of the compressive strength minus the effective prestress value, or 0.85 fc ′ - fpe.
permissible static design strength listed in the contract.
calendar days of receiving the contractor's Pile and Driving Equipment Data Form and wave equation analysis. Modify or replace the proposed methods or equipmen t for nonconforming analysis. The engineer will complete the conformance review of the revised driving system within 7 calendar days of receipt of a revised Pile and Driving Equipment Data Form and wave equation analysis.
additional test piles, and perform dynamic pile testing, as directed by the engineer, before driving any production piles.
days of the completion of each dynamic test. Include the following:
ii. blows per minute, and iii. ram stroke;
ii. indicate instances of pile damage or broken piles;
hammer blows: DRIVEN PILES SECTION 605 191 i. bearing resistance from the case method and 1 additional recognized method, ii. pile penetration depth and corresponding blow sequence, and iii. maximum compressive and tensile driving stresses;
piles as follows:
605.3.2 Pile Installation Equipment.
Equip the plant and equipment with easily accessible pressure gauges. Ensure that the weight of the striking parts of air and steam hammers are at least 1/3 the weight of the helmet and pile being driven, but in no case less than 2,750 -pounds.
Equip open -end, single -acting diesel hammers with a device to allow the engineer to visually determine hammer stroke at all times during pile driving.
Equip the power plant and equipment with easily accessible pressure gauges.
with the hammer manufacturer's guidelines. Do not use wood, wire rope, or asbestos hammer cushions. Place a striker plate, as recommended by the hammer manufacturer, on the hammer cushion to ensure uniform compression of the cushion material. Remove the hammer cushion from the helmet and inspect in the presence of the engineer when beginning pile driving at each structure, or after each 100 -hours of pile driving, whichever is less. Replace hammer cushions compressed to less than 75 percent of the original thickness before resuming pile driving.
hammer blow to the pile head. Use leads to guide the helmet and prevent it from swinging freely. Use the correct helmet or drive head size to appropriately fit the pile head, to hold the axis of the pile in line with the axis of the hammer, and to prevent eccentric impacts on the pile head.
DRIVEN PILES SECTION 605 192 1. Protect the heads of precast concrete piles with a pile cushion made of plywood, hardwood, or composite plywood and hardwood materials. Ensure the pile cushion dimensions prevent movement within the helmet during driving. Provide pile cushion of the thickn ess specified in the wave equation submittal or as determined from the results of dynamic testing. The engineer will evaluate the use of manufactured pile cushion materials instead of a wood pile cushion on a case -by-case basis.
allow the hammer to move freely while maintaining alignment with the pile to ensure concentric impact for each blow. The contractor may use either fixed or swinging -type leads. When using swinging -type leads, fit a pile gate at the bottom of the leads and, in the case of battered piles, fit a horizontal brace between the crane and the leads, as necessary. Provide leads of su fficient length to raise the hammer into a clear position while placing the pile in the leads and with the leads embedded.
the contract. In cases of follower allowance, drive the first pile in each bent, and every tenth pile driven thereafter, full -length without a follower, to determin e adequate pile penetration attainment in order to develop the ultimate pile resistance.
follower of the material and dimensions that allows driving the piles to the penetration depth as determined necessary from the driving of the full -length piles. Ve rify the final position and alignment of the first 2 piles installed with followers in each substructure unit, according to the location tolerances specified in Section 605.3.6.A before installing additional piles. 605.3.3 Preparation and Driving of Test Piles.
ASTM D4945 - Standard Test Method for High -Strain Dynamic Testing of Piles.
not drive test piles prior to approval of the wave equation analysis.
during dynamic testing, unless otherwise approved by the engineer.
the production piles. Install test piles at the locations indicated in the contract.
cables, lift the pile and align in the leads, and set the hammer and helmet. Once the pile set and the pile driving system is in place, attach dynamic monitoring instrumentation. DRIVEN PILES SECTION 605 193 3. Perform dynamic testing during the entire initial drive and re -strike of all test piles so designated in the contract, or as otherwise directed by the engineer. Continuously monitor the tensile and compressive stresses during driving to prevent exceedin g permissible stress limits during driving. Immediately reduce the hammer stroke or stop the driving operation if stresses in the pile approach, or exceed, the permissible limits. If non -axial driving appears by dynamic test measurements, stop pile driving immediately and realign the driving system, or take other corrective action, before resuming driving.
stop pile driving and cut off the damaged area in accordance with Section 605.3.4.B. Prepare the remaining pile section for gauge installation. After the eng ineer inspects and approves, continue driving.
minimum initial driving resistance. Do not exceed the permissible stress limits.
surface, water surface, or pile template. If driving and dynamic testing are complete, remove the gauges.
and splice the pile before proceeding. Before splicing, properly prepare the pile splice segment for gauge installation, in accordance with ASTM D4945, and mak e it accessible to the engineer for inspection. After splicing the pile and resetting the hammer and leads, reattach the gauges to the new pile segment and continue the drive.
do not drive the remainder of the pile without the approval of the engineer.
sequence of driving, the engineer will review the driving records and make 1 or more of the following requirements:
for the driving of production piles based on satisfactory test pile results. The engineer reserves the right to establish or modify the minimum tip elevation for all the piles, depending on the actual conditions encountered.
piles governed by the test pile, or group of test piles, within 5 working days after completing test pile driving.
completing the initial driving.
re-strike. Make the driving splice in accordance with the driving splice details shown in the contract. Upon completion of driving the spliced pile, the engin eer will review the new driving records and make 1 of the above recommendations.
production pile. DRIVEN PILES SECTION 605 194 f. Approve the driven test pile for load testing when requiring static load testing. The engineer may select 1 of the above requirements before authorizing performance of a load test, or if a load test is unsatisfactory.
inconclusive, or unsatisfactory in any way, the engineer will order another test pile driven for additional information within 2 working days after receipt of the p ost-driving report.
tests in accordance with the procedures specified in ASTM D1143. Upon completion, the engineer will review the load test records and make 1 or more of the requirements in Section 605.3.3.C.1. 605.3.4 Preparation and Driving of Production Piles.
piles. Prior to installation, repair or replace piles with damage incurred during shipping, handling, or storage. Piles with any of these defects will caus e rejection by the engineer:
test or production piles at any location until the engineer approves the schedule for that location. Do not depart from these schedules without the prior approval of the engineer.
proceeding outwards in both directions, or starting at the outside row and proceeding progressively across the group.
changes to the pile driving system, see Section 605.3.1.F.
allows the engineer to obtain essential measurements and data. The engineer will observe the progress of all pile driving work. The engineer will record a co mplete driving log for each pile driven. The driving log will list all data essential for the determination of correct bearing resistance.
maintain alignment of the pile during driving. Do not apply side pressure to move piles into the correct position for driving.