BRIDGE MANAGEMENT, EVALUATION AND
REHABILITATION
Idaho Transportation DepartmentMatt Farrar
Introduction• Matt Farrar
– State Bridge Engineer for the Idaho Transportation Department
– Responsibilities include• Bridge Design and Construction Support• Bridge Management, Planning and
Programming
– AASHTO SCOBS T‐18 Bridge Management, Evaluation, and Rehabilitation‐
Chairman
Bridge Inspection & Load Rating Experience
1978 BRIDGE INSPECTOR TOOLS
2011 NORTHWEST BRIDGE INSPECTION CONFERENCE
• AASHTO T‐18–MANUAL FOR BRIDGE EVALUATION–GUIDE MANUAL FOR BRIDGE
ELEMENT INSPECTION
T – 18 Update• What is T‐18?• AASHTO SCOBS• Subcommittee on Bridges and Structures• 20 Technical Committees• T‐18 is the Technical Committee for Bridge
Management, Evaluation, and Rehabilitation• T‐9 is the Technical Committee for Bridge
Preservation• T‐14 is the Technical Committee for Steel
Bridges
T – 18 Update (Continued)
• T‐18 Responsibilities–Maintain and Update the Manual
for Bridge Evaluation (MBE)
–Maintain and Update the NEW Guide Manual for Bridge Element
Inspection
T – 18 Update (Continued)
T – 18 Update (Continued)Manual for Bridge Evaluation
T – 18 Update (Continued)
• MBE SECTION 4 ‐
INSPECTION
– Types of Inspection
– Frequency
– Procedures
• Trusses
• Pin and Hangers
• Special Structures
T – 18 Update (Continued)
• MBE SECTION 6 – LOAD RATING
– LRFR
– ALLOWABLE STRESS
& LOAD FACTOR RATING
T – 18 Update (Continued)
• 2011 Manual for Bridge Evaluation Ballot Items
1.
Article 2.4.3, New Article to introduce the AASHTO Guide Manual for Bridge Element Inspection into the Manual for Bridge Inspection
2.
New Section 3, Complete revision to Bridge Management Systems Section in the Manual for
Bridge Evaluation
T – 18 Update (Continued)
• 2011 Manual for Bridge Evaluation Ballot Items (…continued)
3.
Article C4.4.3, adds new commentary acknowledging that training and experience are
essential for non‐engineer and engineer team leaders
4.
Article 6A.6.12.5 & 6B.6.3.1 revises the way in which rivet shear capacity is determined
T – 18 Update (Continued)What’s in the future for the Manual for Bridge
Evaluation?
– Provisions for Load Rating of Culverts and other buried structures with examples
– Updates to Sec. 5 Material Testing
– Updates to Sec. 7 Fatigue Evaluation
– Updates to Sec. 8 Nondestructive Load Testing
T – 18 Update (Continued)
AASHTO GUIDE MANUAL FOR BRIDGE ELEMENT INSPECTION
T – 18 Update (Continued)AASHTO GUIDE FOR COMMONLY RECOGNIZED (CoRe)
STRUCTURAL ELEMENTS
T – 18 Update (Continued)AASHTO Guide Manual for Bridge Element Inspection
Significant Changes• Four condition states for all elements.
– Follows – Good, Fair, Poor, Serious convention.• Wearing surfaces separated from deck
element.– Deck element units changed to square feet with
multiple deterioration paths.• Steel protective coatings separated from
steel.• All smart flags have been incorporated into
condition state language.• New elements for timber trestle and
framed/built up tower supports.
Element Types• National Bridge Elements (NBE’s)
– Represent the primary structural components of bridges necessary to determine overall condition and safety.
– Includes all primary structural elements.• Decks, Slabs, Girders, Columns, Abutments etc.
– Condition state language is not editable.– Designed to remain consistent from agency to
agency– Minimal implementation level for non‐element
inspection agencies.
National Bridge Elements
Element Types• Bridge Management Elements (BME’s)
– Elements define secondary bridge components.• Joints, wearing surfaces, protective coatings,etc.
– Provide and added level of condition assessment for agencies utilizing bridge management
systems.
– Can be extended to capture other components as desired by the agency.
– Can influence deterioration modeling.
Bridge Management Elements
Element Types• Agency Developed Elements
– Supports agency developed elements.– Require fours conditions states following
general definitions.– May be sub‐sets of NBE’s or BME’s.
• Sub‐sets of NBE’s require same condition state
language.• Can be sub‐sets of BME’s.
– May be unrelated to any defined element.– May be subject to deterioration modeling or
not.– Allows the incorporation of non‐bridge assets.
Agency Developed Elements
Sign Structures
Beam Ends
CoRe Deck Element
CoRe Deck Element Example
Numerous areas of delaminations and open
spalls in the deck surface. Spans 2, 3, and 5 have
heavy delaminations with asphalt and concrete
patches. Approximately 60% or more of the deck is
patched, spalled or delaminated.
Guide Deck Element Example
8000 sq ft6000 sq ft
Guide Deck Element ExampleElement Commentary
CoRe Steel Painted Element
CoRe Steel Painted Element Example
Paint is off down to the bare metal. Areas where the
paint has peeled at the joints has started to rust.
There are small areas that have pitted.
624 ft 105
ft
312 ft
Guide Steel Open Girder/Beam Element Example
National Bridge Element
640 ft 417 ft
Guide Steel Open Girder/Beam Element Example (…continued)
Bridge Management Element
400 sq ft
16,000 sq ft
2000 sq ft 13000 sq ft 600 sq ft
Questions and AnswersWhy change the elements?• Goal of capturing all condition defects on the
bridges.• Provide the means for consistent detailed bridge
condition information.• Improve the deck and slab language to capture
structural capacity and defects of these high maintenance items.
• Separate wearing surfaces and protective coatings out for management of these protection systems.
Questions and AnswersWill retraining of our inspectors be required?
• The new elements build on a concept that they are familiar with, however some training will be required.
• Many of the changes in the new elements will appeal to the field inspectors and will be welcome improvements.
• The consistent four state model will provide for more standardized inspection from one element to the next.
Questions and AnswersWill the new element manual impact the
sufficiency rating?• The new elements are not currently associated with
the sufficiency rating and will have no impact on project eligibility or apportionment.
What is the status of implementation of the new Guide Manual for Bridge Element Inspection?
Conclusion1.
Improvements to the Manual for Bridge
Evaluation will continue so as to be a more useful tool to bridge inspections and load raters .
Conclusion (…continued)
2.
Implementation and future revisions of the Guide Manual for Bridge
Element Inspection will provide the States with an improved Bridge
Management System .