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Checklist for PDA-test

Checklist for PDA-test. Mattias Grävare. Proper mounting of the gages. Gages have to be attached at least 2 diameters from top Place each pair of transducers diametrically opposite each other Always use a minimum of two strain transducer Can be ok with only one accelerometer.

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Checklist for PDA-test

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  1. Checklist for PDA-test Mattias Grävare

  2. Proper mounting of the gages • Gages have to be attached at least 2 diameters from top • Place each pair of transducersdiametricallyoppositeeachother • Always use a minimum of twostraintransducer • Can be ok with onlyoneaccelerometer

  3. Proper mounting of the gages Straintransducers: • Drill 3” (76mm) betweenholes (important!). • Use drill template on concrete piles • The twoholesshall be placedalong the axis of the pile (specially on micro piles) • Flat and smoothsurface • Drill perpendicular to the shaft • Usewashers • The small footingsshall be placedtowards the pile Range 1000me => 76mm x 0,001 = 0,076mm!!

  4. Proper mounting of the gages Accelerometers: • Place in line with the axis of the pile • The curvedside in • Usewashers • Cannot be placed up sidedown • Can useoneifneed be

  5. Proper mounting of the gages Check surface on concrete piles: No crack (if >2m from topoften cracks) Not nearliftinghook Steel piles: Not to close to weldseam (spiral welded piles) Sometimesneed to prepare/grind the steelsurface on micro piles

  6. PDA-win or PAX-L Prior to test: • Check offset (OF-command). Range +-10V • Check that the PDA is working ok by Calibration Test (CT) • Entercorrect Area, E-modulus, Specificweight • In case of steelpipe pile filled with concrete, usecombinedvalues • Frequensy of 10 000kHz is often OK (1024 samples) • 20 000 kHz => 51 ms • 10 000 kHz => 102 ms • 5 000 kHz => 204 ms

  7. PDA-win or PAX-L Start test: • Start of by hitting with a small drop • Works ok? Bending? • Hit with higherdropheight: • Electrical och mechanicalnoise – Tightenbolts? • Bending • Proportionality [F=vZ , eEA=vEA/(E/r)^½] • For regularreinforced piles wavespeed (WS) candiffer from calculatedwavespeed (WC) • Wave speed canvary from oneblow to another • Check individual sensors (DPFV)

  8. PDA-win or PAX-L • Good output quantities: • RMX, VMX, FMX, EMX, TSX, CSX,CSI,RX7,DFN (?) • Two letter commands to shiftbetweenscreens: • DPFV – individual sensors • DPWF – Force/Velocity, Wup/Wdn • DPE – Displacement/Energy • Use PD and PC to describe the pile and blow (hard to rememberafterwards) • Use LP (length of penetration) • Letsomeonemeasure the displacement per blow • Save pile in a longdescriptivefilename

  9. PDA-win or PAX-L • Is set small <2mm • Not mobilized all capacity • If set too high itshard to analyze (CAPWAP) >20mm • Set T1 /T2 rise to rise • Due to cracking WS and WC candiffer for regularreinforcedconcrete piles • Check if sensitive to Jc – Useconservativevalue and confirm with CAPWAP/iCAP

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