PDA measurement & CAPWAP

PDA measurements are a dynamic test for documenting a coat's tensile load and bearing capacity.

The pole is mounted with 2-4 strain and acceleration sensors, which are read and recorded during impact. Based on this data, the integrity of the pile is ensured by monitoring the stresses to which the pile is exposed. Stress and integrity monitoring is typically used in connection with the framing, but can also be used in connection with post-framing of piles to document the pile's integrity. This allows engineers and contractors to get immediate information about the condition of the pile.

The recorded data can then be analyzed with the I-CAP program to provide a rough estimate of pile capacity or analyzed separately by the CAPWAP program* to provide more accurate estimates of pile bearing capacity. PDA measurements can be carried out for the framing of conventionally driven piles, post-framing of conventionally driven and vibrated piles, but also for High Strain Dynamic Drop Hammer testing for a variety of other piles such as bored piles, CISS piles and Fundex piles.

The Case Pile Wave Analysis Program (CAPWAP) is a software program that uses strain and acceleration data obtained from the PDA measurement to estimate the surface and tip bearing capacity of the tested pile, including estimating the distribution of the bearing capacity between individual pile sections.

*CAPWAP analysis is optimally performed on frame data obtained by post-framing piles after the soil around the pile has had time to regenerate to maximum capacity. However, due to time pressure on the projects, CAPWAP is often carried out just a few days after framing. If it is desired to demonstrate the greatest possible load-bearing capacity, it is our recommendation that the piles are allowed to stand in the ground for as long as possible.