U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000


Skip to content
FacebookYouTubeTwitterFlickrLinkedIn

Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

 
REPORT
This report is an archived publication and may contain dated technical, contact, and link information
Back to Publication List        
Publication Number:  FHWA-HRT-16-007    Date:  January 2016
Publication Number: FHWA-HRT-16-007
Date: January 2016

 

Long-Term Bridge Performance (LTBP) Program Protocols, Version 1

Long-Term Bridge Performance Program Logo

Steel Superstructure—Cracking, Deflection, Uplift, Distortion, Buckling, Rotation, and Impact Damage
LTBP Protocol #: FLD-DC-VIS-004


1.

Data Collected

 
1.1 Description and location of each instance of cracking, deflection, distortion, rotation, and buckling, as well as any damage from strikes by vehicles, ships, or floating debris.  

2.

Onsite Equipment and Personnel Requirements

 
2.1 Equipment:  
2.1.1 PRE-PL-LO-004, Personal Health and Safety Plan.  
2.1.2 Ladder, access platform, snooper, bucket truck, man lift, and/or high-reach equipment.  
2.1.3 Tape measure.  
2.1.4 6-ft folding rule.  
2.1.5 Slide caliper.  
2.1.6 Crack comparison cards.  
2.1.7 Sounding hammer.  
2.1.8 Wire brush or hand broom.  
2.1.9 Hand scraper (for paint and rust remover).  
2.1.10 Plumb bob.  
2.1.11 Hand compass or other angle measuring device.  
2.1.12 Level.  
2.1.13 Laser measuring device (optional).  
2.1.14 Temporary marker.  
2.1.15 Digital camera.  
2.1.16 Pencil, sketch pad, and clipboard.  
2.2 Personnel: PRE-PL-LO-005, Personnel Qualifications.  

3.

Methodology

 
3.1 Use the segmentation and numbering system for the superstructure (FLD-OP-SC-002, Structure Segmentation and Element Identification System) to locate and document defects according to the unique element identifier.  
3.2 Use FLD-OP-SC-003, Determination of Local Origins for Elements, to establish a local origin on each individual element. Establish the two relevant coordinate axes for each face of each element being evaluated.  
3.3 Cleaning:  
3.3.1 Use the hammer, scraper, and/or wire brush to clean loose, deteriorated protective coating and loose surface corrosion, if any are present.  
3.4 After cleaning, if areas of section loss in the steel are evident, follow FLD-DC-VIC-003, Steel Superstructure—Section Loss, for the elements where section loss is noted.  
3.5 For each element of the steel superstructure, identify and document each instance of the following defects:  
3.5.1 Cracks:  
3.5.1.1 Mark the ends of each crack on the superstructure element with a temporary marker, and photograph the crack.  
3.5.1.2 Record the type and unique element identifier of the superstructure element where the crack is located.  
3.5.1.3 Record the location of the beginning and the end of each crack by measuring the coordinates from the local grid origin.  
3.5.1.4 Measure the length of the crack in a straight line from one end of the crack to the other using the tape measure, folding rule, measuring wheel, or laser measuring device.  
3.5.1.5 Measure the orientation of the crack (degrees) using a plumb bob, compass, or other angle- measuring device.  
3.5.1.6 Measure the crack width (opening) with the crack comparator (crack gage) at the maximum width.  
3.5.1.7 Measure or estimate the depth of the crack at the deepest point.  
3.5.1.8 Document any rust present in the crack using FLD-DC-VIC-002, Steel Superstructure—Corrosion.  
3.5.2 Deflections, uplifts, distortions, or buckling:  
3.5.2.1 Record the type and unique element identifier of the superstructure element where the deflection, uplift, distortion, or buckling is located. If possible, photograph the defect.  
3.5.2.2 Document the location of the deflection, uplift, distortion, or buckling by determining the coordinates of the beginning and the end of the affected portion of the element.  
3.5.2.3 Measure the amount of deflection, uplift, distortion, or buckling using a tape measure, folding rule, or laser measuring device.  
3.5.3 Rotation:  
3.5.3.1 Record the type and unique element identifier of the superstructure element where the rotation is located. If possible, photograph the rotation.  
3.5.3.2 Document the location of the rotation by determining the coordinates of the beginning and the end of the affected portion of the element.  
3.5.3.3 Measure the amount of rotation (degrees) using a plumb bob, compass, angle-measuring device, or laser measuring device.  
3.5.4 Impact damage:  
3.5.4.1 Record the type and unique element identifier of the superstructure element where the impact damage is located and photograph the damage.  
3.5.4.2 Mark the extent (length, width, depth) of the impact damage with a temporary marker, and photograph the damage.  
3.5.4.3 Measure the extent (length, width, and/or depth) of the impact damage.  
3.5.4.4 Document the location of the impact damage by determining and recording the coordinates of the beginning and the end of the affected portion of the element.  
3.6 Documenting defects:  
3.6.1 Take photographs to document the defects using FLD-DC-PH-002, Photographing for Documentation Purposes, and create a photo log.  
3.6.2 Use sketches to document defects and supplement the photographs.  
3.7 Storing data, documents, and images:  
3.7.1 FLD-DS-LS-001, Data, Document, and Image Storage—Local, for local storage.  
3.7.2 FLD-DS-RS-001, Data, Document, and Image Storage—Remote, for remote storage.  
3.8 Reporting: Transfer all metadata, data, documents, and images to Federal Highway Administration (FHWA), and/or upload all metadata, data, documents, and images into the Long-Term Bridge Performance (LTBP) Bridge Portal.  

4.

Data Collection Table

 
4.1 Table:  
# Field Name Data Type Accuracy Unit Field Description Row Color
1 State
Text
 
 
State Code, e.g., Virginia = VA
Green
2 NBI structure number
Text
 
 
Item 8, structure number, from NBI Coding Guide
Green
3 Structure name
Text
 
 
Descriptive name for the bridge, e.g., Route 15 SB over I–66
Green
4 Protocol name
Text
 
 
Title of the protocol
Green
5 Protocol version
Text
Month and year
 
Month and year the protocol version was published; e.g., May 2015
Green
6 Personnel performing data collection activities
Text
 
 
First name(s) last name(s)
Green
7 Date data were collected
Text
Exact date
 
mm/dd/yyyy
Green
For Individual Cracks on a Steel Element
Pink
8 Location of crack: element type and number
Text
 
 
Example: Girder, 1A; evaluate and record data for cracks in each individual element
Blue
9 Location of crack on the element
Text
 
 
Examples: in the top flange; in the weld at the third longitudinal stiffener from the bottom
Yellow
10 Location of the start of the crack
Number
1
in.

(x,y,z) coordinates of the ends of the crack

Yellow
11 Location of the end of the crack
Number
1
in.
Yellow
12 Crack length
Number
0.125
in.
Measured in a straight line from the beginning to the end of the crack
Yellow
13 Axes used to determine crack orientation
Text
 
 
Example: x and y
Yellow
14 Crack orientation
Number
1
Degrees
Based on the angle between the line of the crack and the axis of the local coordinate system for the element
Yellow
15 Maximum crack width
Number
0.125
in.
 
Yellow
16 Maximum crack depth
Number
0.125
in.
 
Yellow
17 Presence of rust at crack
List
 
 
Yes or No
Yellow
18 Comments
Text
 
 
 
Orange
For Deflection, Uplift, Distortion, or Buckling on a Steel Element
Pink
19 Location of defect: element type and number
Text
 
 
Evaluate and record data for deflection, uplift, distortion, or buckling in each individual element
Blue
20 Type of defect
Text
 
 
Deflection
Uplift
Distortion
Buckling
Yellow
21 Amount of deflection, uplift, distortion, or buckling
Number
0.125
in.
 
Yellow
22 Comments
Text
 
 
 
Orange
For Rotation on a Steel Element
Pink
23 Location of the rotation: element type and number
Text
 
 
Example: Girder, 1A; evaluate and record data for cracks in each individual element
Blue
24 Location on element of rotation
Text
 
 
 
Yellow
25 Amount of rotation
Number
1
Degrees
 
Yellow
26 Comments
Text
 
 
 
Orange
For Impact Damage on a Steel Element
Pink
27 Location of impact damage: element type and number
Text
 
 
Example: Girder, 1A; evaluate and record data for cracks in each individual element
Blue
28 Location of the beginning of the impact damage: x‑coordinate
Number
1
in.
Measured from the element local origin to the beginning of the impact damage
Yellow
29 Location of the end of the impact damage: x‑coordinate
Number
1
in.
Measured from the element local origin to the end of the impact damage
Yellow
30 Length of impact damage
Number
1
in.
 
Yellow
31 Width of impact damage
Number
1
in.
 
Yellow
32 Depth of impact damage
Number
1
in.
 
Yellow
33 Defect photos and sketches
BLOB
 
 
Document all defects with photos and/or sketches
Yellow
34 Comments
Text
 
 
 
Orange
4.2 Table Key:  
Column Descriptions
#
Sequential number of data item
Field Name
Data field name
Data Type
Type of data, such as text, number, predefined list, binary large object (BLOB), or PDF file
Accuracy
Accuracy to which the data are recorded
Unit
Unit in which a measurement is taken and recorded
Field Description
Commentary on the data or list of items in a predefined list
Row Color Key
Green
Data items only entered once for each protocol for each day the protocol is applied
Pink
Logical breakdown of data by elements or defect types (not always used)
Blue
Data identifying the element being evaluated or the type of defect being identified
Yellow
LTBP data reported individually for each element or defect identified
Orange
Comments on the data collection or data entered

5.

Criteria for Data Validation

 
5.1 Compare measurements with measurements from previous inspections of the same structure to make sure that values make sense.  
5.2 Compare measurements with photo documentation to make sure results shown in photos are consistent with items measured.  
5.3 If an element’s condition is improved when compared to the condition documented in a previous inspection, check with the State department of transportation to determine if any maintenance, repair, and/or bridge preservation actions have occurred. If so, document these maintenance, repair, and/or bridge preservation actions using appropriate protocols.  

6.

Commentary/Background

 
6.1 This protocol provides guidance for identifying different types of defects on steel elements and documenting the location and extent of the defect.  
6.2 A steel superstructure can consist of girders (rolled beams, rolled beams with a cover plate, or plate girders), floor beams and stringers (concrete encased, rolled beams, or rolled beams with welded or bolted plates), cross-frames, diaphragms, and vertical and/or horizontal stiffeners.  
6.3 Truss structures may have built-up sections for top and bottom chords, vertical and diagonal elements/members, lateral and sway frame bracings, and gusset plates.  
6.4 Impact damage can result from strikes by vehicles, ships, trains, or debris.  

7.

References

 
7.1 LTBP Protocols:  
7.1.1 PRE-PL-LO-004, Personal Health and Safety Plan.  
7.1.2 PRE-PL-LO-005, Personnel Qualifications.  
7.1.3 FLD-OP-SC-002, Structure Segmentation and Element Identification System.  
7.1.4 FLD-OP-SC-003, Determination of Local Origins for Elements.  
7.1.5 FLD-DC-VIS002, Steel Superstructure—Corrosion.  
7.1.6 FLD-DC-PH-002, Photographing for Documentation Purposes.  
7.1.7 FLD-DS-LS-001, Data, Document, and Image Storage—Local.  
7.1.8 FLD-DS-RS-001, Data, Document, and Image Storage—Remote.  
7.2 External:  
7.2.1 FHWA-NHI-12-053, Bridge Inspector’s Reference Manual, Federal Highway Administration, Washington, DC, 2012.  

 

 

 

Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000
Turner-Fairbank Highway Research Center | 6300 Georgetown Pike | McLean, VA | 22101