Strike with a hammer (force bar) in the vertical direction on the top surface of the pile (or superstructure such as pile cap without pile top connection) to generate stress wave, which propagates downward along the pile body and transmits when it meets t
Strike with a hammer (force bar) in the vertical direction on the top surface of the pile (or superstructure such as pile cap without pile top connection) to generate stress wave, which propagates downward along the pile body and transmits when it meets the surrounding soil layer. A sensor is placed in the hole drilled in advance next to the pile to receive the transmitted wave signal, so as to read the arrival sound of different depths and draw the relation diagram between time and depth. When the sensor is lower than the pile bottom, the sound velocity will change, and an inflection point will be displayed on the time-depth graph. The length of the pile will be inferred from the position where the slope of the straight line changes in the graph. The slopes of the two straight lines can be used to infer the average wave velocity of the pile body and the wave velocity of the bearing layer at the pile bottom respectively.
The buried depth Hp of the tested pile bottom can be determined according to the following formula:
Formula: Hg—— The depth (m) corresponding to the inflection point of the first wave arrival time-depth curve;
Dx—— Horizontal distance (m) between the projection position of the pile top at the pile end plane and the test hole;
Vm—— Longitudinal wave velocity of pile concrete (m/s);
Vc—— The average longitudinal wave velocity of soil at pile tip (m/s), which should be determined according to the field soil wave velocity test results.
Output report – separate output mode of graphics
Output report – combined output mode of graphics
Summary sheet of testresults
Test Result Summary Table
Project:whrsm
No
PileNo
TestDate
Measured Depth(m)
PileDia. (mm)
Velocity (m/s)
PileIntegrity
PileType
1
3
2016-04-20
12.30
500
5043.14
The depth 3.48m to 4.50m has defects;The depth 5.38m to 6.50m has defects;
