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Long Term Bridge Performance

Federal Highway Administration Long-Term Bridge Performance Program Power Point Presentation

PowerPoint Version (2,390 kb)

FHWA Long-Term Bridge Performance Program

  • Designated in the "SAFETEA-LU" surface transportation authorization legislation as a 20-year research effort to improve our knowledge of bridge performance

  • Funding is currently only authorized through FY-2009


Challenges!


FHWA's Perspective

1) Aging bridge population - performance poorly understood

2) Currently available data will not support desired performance assessments

3) LTBP Program is essential to understanding, improving bridge performance

LTBP program should,

a.) Focus on most common bridges
b.) Serve FHWA and stakeholder needs
c.) Not burden bridge owners with new requirements
d.) Encourage international cooperation

State DOTs' Perspective

1) Available road and bridge funds have leveled off or decreasing

2) Key material prices escalating beyond inflation rate

3) Traffic Volume and load demands growing rapidly

4) Demand and expectations from users of the system will continue to grow

5) Eliminating deficient bridges

LTBP program should,

a.) Help States meet challenges
b.) Set data protocols
c.) Focus on practical, useful data
d.) Take advantage of sensing technology

Research Community's Perspective

Availability and quality of data will affect the degree of uncertainty in assessing bridge performance, developing deterioration models and performing LCC analysis

Uncertainty in data is

Aleatory- that is the inherent randomness or variability in the data
Epistemic- that is the lack of sufficient knowledge or the inability to predict or estimate the desired data correctly

Bridge Performance

  • Define
  • Measure
  • National Consensus
    • Number of bridges needing work
    • Structural deficiencies, posting or sufficiency rating (uncertainties)
    • Deficiencies and load carrying capacity
    • Customer satisfaction

Challenges in Measuring Bridge Performance

  • It is not well defined and understood or documented
  • Relies too heavily on expert opinion and not on objective data
  • Based on significant assumption or generalization based on a very simplistic understanding of bridge behavior
  • Uncertainties
    • Subjectivity of current condition ratings
    • Lack of proper documentation (i.e., records of actions and costs)
    • Incomplete data (i.e., cost, maintenance)
    • Many hidden deterioration and damage escape visual inspection
chart detailing bridge condition over time. Follow link for more details

Measuring Performance

Moving Target!

Diagram. Goals and performance categories. Structural Condition and Integrity, Safety of User, and Cost to User and Agency. The diagram depicts three main performance categories. Three separate orange boxes arranged top-down with white text in each box stating Structural Condition and Integrity in the top box, Safety of User in the middle box, and Cost to User and Agency in the lower box. Three bigger light green boxes to the right of the three orange boxes with outlined black text explaining the text in the left orange boxes
Column Chart. Bridge Construction History. The chart depicts the annual number of bridges constructed until year 2006. The title of the chart is Bridge Construction History. The horizontal axis is denoted Year of Construction with an interval of five-year periods between 1901 and 2000. The first period is for all bridges constructed in 1990 and before. The last period is between 2000 and 2006. The vertical axis is denoted Number of Bridges with 1000 interval. A small white box in the top left corner of the chart includes the number ~600,000 (approximate total number of bridges), and Mean Age: 40 yrs. A thick blue arrow at the top right of the chart starting from above the column representing 1966-1970 bridges pointing to the right with a label on top stating NBI. Another thick blue arrow under the first arrow starting from above the column representing 1981-1985 bridges pointing to the right with a label on top stating PONTIS. The chart shows that the highest numbers of constructed bridges were in the periods 1961-1965 and 1966-1970.

Stewardship and Management

  • Quantitative Database
  • Better information
  • Sensor Technology (i.e., NDE, SHM)
  • Training and education
  • Deployment
  • Improved Bridge management

Diagram. LTBP Program Objective. The diagram depicts an arrow starting thin at the left bottom part of the diagram and widening towards the top-right. There are three circles near the tail, middle, and head of the arrow proportion to the arrow width. The text below the first (smallest) circle near the tail states the first LTBP program objective as Collect, document and maintain high quality, quantitative performance data. The text below the middle circle near the middle of the arrow states the second LTBP program objective as Improved knowledge of bridge performance. The text below the last (largest) circle near the arrow head states the third LTBP program objective as Improved asset management.

Anticipated Impacts of the LTBP Program

  • Improved knowledge of bridge performance
  • Advances in deterioration and predictive models
  • Effective use of Life-Cycle Cost Analysis
  • Improved inspection/condition information thru NDE and SHM
  • Help foster the next generation of bridge and asset management systems

Vision

  • Detailed inspection, periodic objective evaluation and monitoring (Representative sample of bridges, excluding long-span bridges)
  • Instrument and continuously monitor
  • Forensic autopsies of decommissioned bridges

LTBP Team

Project Lead and Administrator

  • Center for Advanced Infrastructure and Transportation (CAIT)
  • Rutgers, The State University of New Jersey
  • Ali Maher, Ph.D., Principal Investigator

Principal Industry Partner

  • Parsons Brinckerhoff (PB)
  • Thomas A. Fisher, P.E., Program Manager
  • Andrew J. Foden, P.E., Ph.D., Deputy Program Manager

Academic Partners

  • Utah Transportation Center, Utah State University
  • Virginia Transportation Research Council
  • University of Virginia, Virginia Tech
  • Institute of Transportation Studies
  • University of California, Berkeley

Industry Partners

  • Siemens Corporate Research
  • Bridge Diagnostics, Inc. (BDI)
  • Advitam

Special Consultant

  • John Hooks
  • Emin Aktan
Organization Chart. LTBP Team. The chart depicts the organization of the LTBP program team. The organization of LTBP program starts by a box in the top with the FHWA program manager in TFHRC. The second box of the management team comes below the FHWA box and includes two boxes inside representing Rutgers University and PB. A small box to the right is connected with a line to Rutgers University box and includes TFHRC labs. The second level of the team includes four boxes below the management team. These boxes from left to right represent Utah State University, Virginia Transportation Research Center, Siemens America, and Institute of Transportation Studies UC Berkeley. The third level comes below the second level and includes two boxes which are from left to right: Bridge Diagnostic Inc., and Advitam.
Diagram. LTBP Overview Map for Data Collection, Inspection and Management. The diagram depicts how data collection, inspection and monitoring is positioned in the LTBP overview map. A curved line with different spots on the line showing the logical flow of the LTBP program. Three spots at the beginning of the line represent the advisory board, the program administration and management, and the stakeholder communication and public education. The following spot is to identify specific data to be collected, followed by sampling methodology and implementation plan. The following is a group of three spots for the database, the data interface, and the data infrastructure and management. The data collection, inspection and management comes after the set of data spots and before the data mining and analysis that also gives feedback to the data infrastructure and management. The data mining and analysis is followed by two spots for the lifecycle cost and deterioration models, and maintenance and repair verification and optimization. The last spot on the curved line representing the map is for better bridge management.
Matrix Diagram. Development and Pilot Tasks and Responsibilities. The diagram depicts a matrix with the two sub matrices; one representing the development phase and the other representing the pilot program. Both sub matrices have common columns representing the responsibilities of team member. The team members represented by the matrix columns are from left to right: CAIT, PB, UTC, VTRC, Siemens, Advitam, BDI, and Program Consultant. The development phase matrix include rows representing the LTBP tasks/activities that are from top to bottom road map, specific data to be collected, development of data infrastructure, protocols for data sampling, collection and QA, bridge sampling methodology, synthesis of bridge monitoring and autopsy methods, protocols for bridge monitoring and autopsy, communication/marketing plan and products. The pilot program matrix includes rows representing the project coordination (for fieldwork), draft pilot study plan, and pilot study execution. The cells (blocks) in the matrix are colored by orange or yellowish green or left blank. The yellowish green cells represent a significant participation of the team member. The orange cells represent a primary responsibility by the team member.
Map. LTBP Pilot Program. GIS map of the US States that will have pilot bridges colored red and the other US States colored blue. The map depicts that the pilot bridges are located in the states of California, Utah, Florida, Virginia, New York, and New Jersey.

Concluding Remarks

  • Current bridge performance assessments are based on subjective data and generalization
  • There is a broad consensus in the bridge community that the state-of-the-knowledge about bridge performance can and should be greatly improved
  • There is need for a quantitative bridge database

Concluding Remarks Continued....

  • Quantitative data and knowledge learned from the LTBP program could lead to
    • Better understanding of bridge performance
    • Improved knowledge of bridge deficiencies
    • Design and construction of bridge of the future
    • Improvements in the effectiveness of the NBI and PONTIS
    • Efficient management of highway systems

LTBP Program Web site
www.tfhrc.gov/structur/ltbp.htm

Hamid Ghasemi, Ph.D., Program Manager
LTBP Program
Hamid.ghasemi@fhwa.dot.gov
202-493-3042

Ali Maher, Ph.D., Principal Investigator
Mmaher@rci.rutgers.edu

Thank You!

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Related Links

National Bridge Inventory

National Bridge Inspection Standards