Unknown Foundation Evaluation

Screenshot 2025-12-10 at 10.23.28 AM

BDI’s unknown foundation investigation program helps bridge and asset owners overcome the challenges of missing structural records by delivering reliable foundation assessments and scour evaluations. Through the evaluation of nearly 800 bridges and thousands of unknown foundations over the last decade, BDI has developed a comprehensive program equipped to address the most challenging circumstances presented by timber, steel, or concrete foundation elements. Using advanced acoustic testing methods and scalable workflows, we’ve reclassified thousands of structures including bridges, towers, parking garages, and more, into regulatory (NBIS included) compliance and Scour Stable status. On one project alone, BDI successfully reclassified up to 92% of bridges with an Unknown Foundation designation to Scour Stable, evaluating 580 bridges in a single year.

What Can We Do?

BDI’s unknown foundation services utilize advanced nondestructive evaluation (NDE) techniques to extract the information required for owners to reclassify structures or make decisions on asset management or modifications. Our team provides expert guidance to define the appropriate NDE scope, always selecting the best tool for the job.

Throughout all investigations, we seek to gather information required for you to make informed decisions. Depending on request results could include:

 

  • Foundation Configuration: BDI can determine dimensional data for foundations including foundation depth and overall geometry, using wave propagation methods. Even if the top of the foundation is inaccessible BDI can determine these parameters using methods such as SE/IR, Ultraseismic Vertical Profiling, and Parallel Seismic testing. 

 

  • Foundation Condition: BDI can determine the foundation condition and detect internal defects such as voids, poorly consolidated concrete, or geological anomalies in soil using SE/IR or crosshole sonic logging. BDI also provides services for determining the overall integrity of pile as discussed in our “Plain / Reinforced Concrete Structure Evaluation” and “Steel Structure Evaluation” pages.

 

  • Scour Risk: Coupled with other key parameters (e.g. waterway and soil properties), BDI can also utilize the test results to perform a scour evaluation. 

 

What We Deliver

The primary deliverable of Unknown Foundation testing is the effective depth and condition assessment of the tested piles. Coupled with other parameters (e.g. waterway and soil properties), BDI can utilize the test results to perform a scour evaluation for the bridge(s). Depending on the client’s needs, BDI can simply provide test result reports to scour evaluation reports and inspection report updates.

How We Measure

The following unknown foundation testing methods/technologies have a proven track record in providing critical foundation data:

  • Sonic Echo / Impulse Response (SE/IR)
  • Ultraseismic Vertical Profiling
  • Parallel Seismic Survey
  • Crosshole Sonic Logging

 

Ultraseismic Vertical Profiling in the Field
Ultraseismic Vertical Profiling in the Field
Ultraseismic Vertical Profiling in the Field
Ultraseismic Vertical Profiling in the Field
Parallel Seismic Survey Field
Parallel Seismic Survey Field