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Individual Highlight

Laboratory Evaluation of Salvaged Bridge Girders from U.S. Route 66

Photo of Typical timber bridge example.Typical timber bridge example.Snapshot : Timber bridges have been in-service for nearly nine decades along Southern California's Historic Route 66 National Trails Highway.  Several untreated sawn timber stringers were recently salvaged and transported to the FPL for a laboratory investigation.

Principal Investigators(s) :
Wacker, James P. 
Research Location : FPL's Centennial Research Laboratory
Research Station : Forest Products Laboratory (FPL)
Year : 2018
Highlight ID : 1508


Laboratory testing has been completed on the physical and mechanical properties of sawn timber girders salvaged from timber bridges along California's Historic Route 66 National Trails Highway.  Several girders were apparently damaged while in-service due to vehicle overloads.  Nondestructive testing revealed limited levels of internal decay, with most limited to their topside where a timber deck was toe-nailed in place during construction.  Mechanical testing revealed residual strength values that exceeded design values and with good load resiliency characteristics.  These results should be helpful to California engineers who must routinely inspect and assign a load capacity to over 100 similar timber bridges along the Historic Route 66 corridor.

Forest Service Partners

External Partners

  • none
  • County of San Bernardino in California? Biggs Cardosa & Associates