Induction Field


 tech brief

The Induction Field (IF) testing method is used to measure the depth of foundations which are steel (such as H-Piles) or contain continuous reinforcing steel. The method involves inducing an electromagnetic field in a soil-foundation system in order to determine the lengths of the steel in the foundation. The testing is done by passing an AC current down the foundation and back through the soil to a reference electrode to create an electromagnetic field around the steel of the foundation. This field is then detected by a polarized magnetic field sensor which is lowered into an adjacent PVC cased borehole. The depth of the foundation is determined by measuring the magnetic field strength versus depth and looking for the inflection point in the graphed data.

NOTE: This method requires a cased boring. This method is often performed in conjunction with the Parallel Seismic (PS) or Downhole Seismic (DS) methods, which also require a borehole.

Applicable On: Deep Foundations made of or Containing Steel, Abutment Piers, Sheet Piles and Footings

Test For: Foundation Length, Determination of Reinforced Concrete and Steel Piles