1Nondestructive Testing and Nondestructive Testing and Evaluation of Steel BridgesEvaluation of Steel BridgesBy. James BaderBy. James BaderENCE 710ENCE 710Spring 2008Spring 2008OutlineOutlineIntroduction to Nondestructive Evaluation (NDE)Introduction to Nondestructive Evaluation (NDE)Deficient Bridges in the USDeficient Bridges in the USCommon problems with steel bridgesCommon problems with steel bridgesNDE methods and their applicationsNDE methods and their applicationsConclusionsConclusionsIntroduction to NDEIntroduction to NDEWhat is NDE?What is NDE?Nondestructive Evaluation is a means of Nondestructive Evaluation is a means of analyzing and evaluating the condition of analyzing and evaluating the condition of various structural components without various structural components without damaging them.damaging them.Advantageous for use on existing, inAdvantageous for use on existing, in--service bridge structures since they can service bridge structures since they can remain intact and open to traffic during remain intact and open to traffic during testing. testing. 18%15%3%% DEFICIENT8847161684,891TRI-AREA TOTAL17%5484361123,306VIRGINIA18%268221471,470MARYLAND59%68599115D.C.% Deficient# Total# Functionally Obsolete# Structurally Deficient# NHS BridgesAs of December 2007NHS Bridges 29%19%10%% DEFICIENT4,0782,6261,45213,898TRI-AREA TOTAL29%2,8941,7981,09610,111VIRGINIA30%1,1007593413,657MARYLAND65%846915130D.C.% Deficient# Total# Functionally Obsolete# Structurally Deficient# NNHS BridgesAs of December 2007(Railroad, Pedestrian, and < 20' clear span bridges)Non NHS Bridges*FHWA Deficient Bridges By State and Highway System* Non NHS bridges are not required to be reported to FHWA, thus these values only represent a partial sample of Non NHS bridges in the US.FHWA Deficient Bridges By State and Highway System* Non NHS bridges are not required to be reported to FHWA, thus these values only represent a partial sample of Non NHS bridges in the US.25%13%12%% DEFICIENT25%152,31679,79272,524599,766US TOTAL27%129,00762,64366,364483,621Non NHS TOTAL*20%23,30917,1496,160116,145NHS TOTAL% Deficient# Total# Functionally Obsolete# Structurally Deficient# U.S. BridgesAs of December 2007Deficient Bridges for all 50 states including D.C. and Puerto RicoFHWA Office of Bridge Technology, FHWA Office of Bridge Technology, ““Deficient Bridges by State and Highway SystemDeficient Bridges by State and Highway System””Steel Bridge Defects Steel Bridge Defects Steel bridges make up about 34% of the near 600,000 Steel bridges make up about 34% of the near 600,000 reported bridges in the US (FOCUS, FHWAreported bridges in the US (FOCUS, FHWA--HRTHRT--0707--017, September 2007)017, September 2007)Several common defects found in steel bridge structures Several common defects found in steel bridge structures include:include:Corrosion and pack rusting between platesCorrosion and pack rusting between platesCracks in welds, high stress zones, and areas prone to cyclic Cracks in welds, high stress zones, and areas prone to cyclic loading and fatigue.loading and fatigue.NDE is particularly useful in locating and sizing cracks in NDE is particularly useful in locating and sizing cracks in steel and welds, since they are often difficult to spot steel and welds, since they are often difficult to spot during routine visual inspections. during routine visual inspections.2Steel Bridge DefectsSteel Bridge DefectsPhoto courtesy of Greenhorne & O’Mara, Inc.Steel Bridge DefectsSteel Bridge DefectsPhoto courtesy of Greenhorne & O’Mara, Inc.Steel Bridge DefectsSteel Bridge DefectsPhoto courtesy of Greenhorne & O’Mara, Inc.NDE Validation CenterNDE Validation CenterEstablished by FHWA in 1998.Established by FHWA in 1998.Provides State highway agencies with Provides State highway agencies with independent evaluation and validation of independent evaluation and validation of NDE technologies.NDE technologies.Develops new NDE technologies.Develops new NDE technologies.Provides technical assistance to States Provides technical assistance to States exploring the use of these advanced exploring the use of these advanced technologies.technologies.http://www.tfhrc.gov/hnr20/nde/home.htmNDE Validation CenterNDE Validation CenterLocated at TurnerLocated at Turner--FairbankFairbankHighway Highway Research Center in McLean, VA.Research Center in McLean, VA.Supplements laboratory results with test Supplements laboratory results with test bridges in Northern VA and Southern PA bridges in Northern VA and Southern PA for field studies. for field studies. Collects component specimens (welded Collects component specimens (welded members, pin/hanger assemblies, builtmembers, pin/hanger assemblies, built--up up members) for test validationmembers) for test validationhttp://www.tfhrc.gov/hnr20/nde/home.htmNDE MethodsNDE MethodsVisual InspectionVisual InspectionEddy Current MethodEddy Current MethodRadiographic TestingRadiographic TestingUltrasonic TestingUltrasonic TestingManual and AutomatedManual and Automated3Visual InspectionVisual InspectionMost common NDE inspection methodMost common NDE inspection methodRoutine, InRoutine, In--Depth, and Special / Damage Depth, and Special / Damage inspectionsinspectionsEconomical, requires no special Economical, requires no special equipment outside of access equipmentequipment outside of access equipmentResults are subjective and often vary Results are subjective and often vary based on the inspector, location, structural based on the inspector, location, structural complexity, and access.complexity, and access.Publication No. FHWA-RD-01-020, FHWA-RD-01-105Visual InspectionVisual Inspection2001 2001 --Investigation into reliability of visual Investigation into reliability of visual inspections for highway bridges.inspections for highway bridges.ObjectivesObjectivesMeasure accuracy and reliability of Routine Measure accuracy and reliability of Routine and Inand In--Depth inspections.Depth inspections.Study key human and environmental factors Study key human and environmental factors that influence the reliability of inspections.that influence the reliability of inspections.Study differences between State Inspection Study differences between State Inspection procedures and reports.procedures and reports.Publication No. FHWA-RD-01-020, FHWA-RD-01-105Visual InspectionVisual InspectionStudy observed 49 State bridge inspectors Study observed 49 State bridge