Finding the depth of socketing of foundations into bedrock involves finding two depths-the foundation and the bedrock. Finding the depth of the foundations was discussed in Surface NDT Methods and Borehole Nondestructive Testing Methods. Bedrock depths can be found using either surface geophysical methods or borehole methods for those piles with a borehole close by.

Alternatively, cross-borehole tomographic imaging can be used to determine the depth of foundation socketing, as was discussed in Cross-borehole Seismic Tomography. Several methods can be used to find bedrock depth. The particular method to use depends on the expected depth and the local conditions. The methods include Ground Penetrating Radar (GPR), Seismic Refraction, Seismic Reflection, Resistivity, and Time Domain Electromagnetic Soundings methods. These methods are discussed in Subsurface Characterization.