Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592


You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: Ground-Penetrating Radar Investigation of Salvaged Timber Girders from Bridges Along Route 66 in California

Source: Wood and Fiber Science

Author(s)Wu, Xi ; Senalik, Christopher Adam; Wacker, James P.; Wang, Xiping ; Li, Guanghui

Publication Year: 2020  View PDF »

Category: Journal Articles
Associated Research Project(s):   FPL-4714-3B

Abstract: This study describes assessment of the internal conditions of timber bridge structural members along Route 66 in California. These timber bridges were exposed to desert climate conditions for several decades, which can lead to a variety of deterioration. Overtime, the deterioration may cause loss of structural integrity within the bridges and lead to potentially hazardous conditions for the motoring public. Members from dismantled bridges were brought to the Forest Products laboratory inMadison,WI. Strength-reducing features including decay, splits and cracks, insect attack, and corrosion of metal components were initially identified using visual inspection. Further assessment was then performed using several nondestructive testing technologies including ground-penetrating radar (GPR). GPR was used, among other nondestructive techniques, to identify and locate internal features and defects within the timbers. The tomographic output of the GPR, known as radargrams, revealed deterioration. Based on the information contained within the radargrams, it was possible to classify some internal features and defects with a high degree of certainty, whereas others remained less clear. In this study, the potential of using GPR for inspection of bridge timbers is discussed and supported through interpretation of the radargrams.

Keywords: Ground-penetrating radar; timber bridge; steel nail; hole; decay; split

Publication Review Process: Formally Refereed

File size: 2,048 kb(s)

Date posted: 03/12/2020

This publication is also viewable on Treesearch:  view
RITS Product ID: 97301
Current FPL Scientists associated with this product (listed alphabetically)
Senalik, Christopher
Research General Engineer
Wacker, James P.
Research General Engineer
Wang, Xiping
Research Forest Products Technologist

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »

Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »

Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »

Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »