This standard is issued under the fixed designation D ; the number 1 This test method is under the jurisdiction of ASTM Committee D18 on Soil and. D Standard Test Method for High-Strain Dynamic Testing of Deep Foundations axial Standard + Redline PDF Bundle, 20, $, ADD TO CART . Dynamic Pile Testing. ASTM D Pile Driving Analyzer ®. Garland Likins, Pile Dynamics, Inc. PDCA Professor's Institute. Garland Likins, Pile Dynamics.
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DYNAMIC LOAD TEST Dynamic pile load test procedure is standardized by ASTM D Standard Test Method for high strain dynamic testing of piles. This standard is issued under the fixed designation D ; the 1 This test method is under the jurisdiction of ASTM Committee D18 on Soil. Both are covered by ASTM D • Pile Driving Monitoring consists of using a PDA to perform real time evaluation of Case Method capacity.
A series of hammer blows are made with the hammer drop height progressively increased and decreased . Q The main difference between this system and other dynamic load test systems is the using of an electronic scanning theodolite that records penetration for each blow and records real time elastic displacement . The measured force at the pile top is separated into components upward and downward.
The dynamic or total reaction, Rdy is calculated for each hammer blow and plotted versus cumulative penetration for the whole set of blows. The dynamic load is converted to static load and the predicted static load-settlement curve can be plotted.
The static plot is verified by modeling. Svinkin analyzed a distinctive case history presented by Briaud et al. All tests were carried out on bored concrete piles. Three projects are residential tower buildings representing a part of the residential tower buildings complex of Red Sea state.
This is Portsudan city, which is located in western coast of the Red Sea in eastern Sudan .
The formation at this area is predominantly coralline deposits consisting of completely to slightly weathered coral reef limestone that contains marine shells and fossils. This formation is characterized with great variability in horizontal and vertical directions. Q Tower 7 Load kN D. L Load KN 0 0 0. Q D. In our opinion, it is wise that to determine the actual pile ultimate capacity for a project by testing at least one pile to failure.
This will enable an economical pile design and offer a considerable saving of cost for the project.
The comparisons of load-settlement behaviors for dynamic and static load tests, shown in Figure 5 , Figure 6 and Figure 7 , indicate that the predicted settlement from dynamic and the measured settlement from static are generally consistent to a reasonable extent as reflected by the results of towers 7 and 8. But generally the settlements predicted by dynamic load test are slightly higher than the settlement measured by the static load test.
This is very clear especially in the results of the pile of tower 1 project. This paper has been focused on this type of pile loading test.
Four case studies of dynamic and static pile loading tests conducted in the eastern of Sudan have been presented. The load-settlement behaviors for dynamic and static load tests were compared for the three case studies of the residential tower buildings complex project.
This shows a reasonable agreement between the two test results. But generally the dynamic load test slightly overestimates the Vol. Q settlement. It can be concluded that the dynamic load pile test can be used for predicting pile capacity and pile integrity under proper care and it should be calibrated by at least one static test.
Therefore, it is strongly recommended to optimize the pile design for projects by determining the actual ultimate pile capacity, which may need to conduct pile test to failure or near to failure. The force output shall be balanced to a reference level for example, zero prior to the impact event.
If displacement transducers are used, the apparatus shall differentiate the displacement over time to obtain velocity. If required, the apparatus shall zero the velocity between impact events and shall adjust the velocity record to account for transducer zero drift during the impact event. Alternatively, field maximum stresses, maximum displacement, energy transferred personnel may transmit the data concurrently as acquired to a to the pile, etc.
The apparatus for recording, processing, and qualified engineer supervising the testing from a remote displaying data shall include compensation for temperature location. No error shall exceed 6. Record applicable shall be recorded on site, electronically in digital form, with a project information Section 7. Attach the transducers Section minimum of 12 bit ADC resolution and including at most only 5 to the deep foundation, perform any calibration checks the minimal processing required to obtain the force and recommended by the equipment manufacturer, and take the velocity.
Transducer data recorded after minimal processing dynamic measurements for the impacts during the interval to shall also record the information required to recover the raw be monitored together with routine observations of number of data signals for later reprocessing as needed, for example, blows per unit penetration blow count or set per blow.
When Determine the pile response to the high-strain dynamic test determining velocity by analog integration of acceleration, or from a minimum of ten impact records during initial driving analog differentiation of displacement, use a minimum sample and, when used for soil resistance computations, normally from frequency for each data channel of Hz for concrete piles one or two representative blows at the beginning of a restrike.
When determining NOTE 4Warning: Never approach a deep foundation being tested velocity by digital integration of acceleration, or digital differ- while the hammer or large drop weight is operating as materials or entiation of displacement, use a minimum sample frequency appurtenances may break free and jeopardize the safety of persons in the for each data channel of 10 Hz for concrete piles and 40 vicinity.
Preferably the contractor crew will attach the transducers to the Hz for timber or steel piles. Both analog and digital pile. Divide two times the intervals to prepare for recording blow counts. Attach the length of pile below transducers by the observed time between transducers as described in Section 5.
Determine the pile wave start of the impact for example, initial sharp rise of the signal speed see 6. For concrete piles or and the start of the tensile reflection for example, later relative concrete filled pipe piles, place a pile cushion made of plywood velocity increase to obtain the wave speed.
For piles with or other material with similar stiffness on top of the pile. For instrumentation at both the head and near the toe, the wave concrete filled pipe piles, the concrete must completely fill the speed can be calculated from dividing the distance between pile top so that the impact is transferred through the pile these locations by the time between impact arrivals at these cushion to the concrete.
Position the impact device on the pile locations. Alternatively, place the pile on supports or level head to apply the impact force concentric with the long axis of ground free and clear from neighboring piles and obstructions. Prepare the apparatus for recording, processing, and Then attach an accelerometer to the pile and strike the end of displaying data to receive the dynamic measurements and the pile with a sledge hammer of suitable weight.
Take care not balance the strain or force and acceleration signals to their to damage or dent the pile. Record see 5. Measure the total time between 6. Divide the product of the number of cycles and twice height of the ram or the ram travel length.
For double acting the total pile length by this total time to determine the wave diesel hammers, measure the bounce pressure, and for double speed. Assumed wave speed values, and those deter- air pressure in the pressure line to the hammer. For hydraulic mined during a low strain event, should be verified directly or hammers or any of the previously listed hammer types, record indirectly if possible.
The overall wave speed observed during the kinetic energy from the hammer readout when available. Compare the length. Obtain the net permanent displacement per The density of each wood pile shall be determined from the impact from the pile driving blow count record, or from marks total weight of the pile, or a sample of the pile, the correspond- placed on the pile prior to and after the test using the same ing volume, and the gravitational constant.
The density of reference, directly from the displacement transducers if used , concrete or grout can be measured in a similar manner. The multiplied by velocity. The mass density of composite deep foundations, such initial installation of a driven pile typically monitor the as concrete filled steel pipes, can be computed from a weighted performance of the impact device, the driving stresses in the average of the areas of the materials at each differing cross- pile, the pile integrity, and relative changes in capacity.
If the section. Assumed and computed values of mass density should test results are used for static capacity computations, then be verified directly if possible, or indirectly through their effect dynamic measurements should also be performed during on impedance and proportionality see 6.
See Note 1. The dynamic cally checking that the average of the measured force signals modulus of elasticity may be assumed as 3 kPa for and the product of the impedance and the average of the structural steel.
Assumed and computed values of the dynamic measured velocity signals agree proportionally at the moment modulus of elasticity should be verified directly if possible, or of impact. Do not expect proportionality when reflections indirectly through their effect on impedance and proportional- occur from pile impedance changes nearby and below the ity see 6. Reject non proportional data. Two velocity signals 7 D 08 should generally agree well at a particular measurement parallel to the pile axis.