Additions and replacements to existing superstructures, upgrading of structural loads and settlement or scour investigation all require the evaluation of existing foundations. Original pile installation records are often no longer available. GRL tackles the challenges of unknown foundations on a routine basis.

GRL assesses the depth and evaluates the integrity of piles supporting existing structures by one of several methods. The pulse echo, sonic echo or low strain integrity testing method (PIT), works well in certain soil-foundation conditions. In other situations GRL may perform the investigation by the Parallel Seismic Method or by the Inductive Field Method using the LITE (Length Inductive Test Equipment).  The latter is particularly recommended to find the length of existing steel piles (H-piles, Pipe piles, Cased Drilled Shafts, Steel Sheet Piles).

When capacity determination is the issue GRL Engineers perform a Wave Equation Analysis to select an adequate hammer to utilize for a Dynamic Load Test on a representative number of existing piles. The Dynamic Load Test gives sufficient information on pile capacity and integrity to aid the designer in the decision whether to reuse the piles.