Transcript FHWA's Roadside Safety Policy

Two Test Level 4 Bridge Railing and Transition
Systems For Transverse Timber Deck Bridges
by
Ronald K. Faller, Ph.D., P.E.
Michael A. Ritter, P.E.
Barry T. Rosson, Ph.D., P.E.
Michael D. Fowler
Sheila R. Duwadi, P.E.
Introduction
• Bridge railing research
• Bridge deck systems
- concrete
- timber (longitudinal vs. transverse)
• Need for high performance crashworthy
•
railings
FPL, FHWA, & MwRSF
Research Objectives
• Two bridge railings for transverse timber deck
•
•
•
bridges
- steel
- wood
High performance railing systems (TL-4)
Two approach guardrail transitions
Force level determination
Bridge Railing History
• Bridge railing design
- 10-kip static load method
- LRFD method
- computer simulation modeling
• Full-scale crash testing
- NCHRP Report 230
- AASHTO Guide Specifications
- NCHRP Report 350
Test Requirements and Evaluation Criteria
• NCHRP Report 350
• Three required tests
- 820C - 100 kph & 20 deg
- 2000P - 100 kph & 25 deg
- 8000S - 80 kph & 15 deg
• Structural adequacy, occupant risk, & vehicle
trajectory after collision
Wood Bridge Rail
Steel Bridge Rail
Conclusions
• Two bridge railings for transverse timber deck
bridges
• Wood and steel rail options
• Two approach guardrail transitions
• Crash tests met the TL-4 evaluation criteria
• Modifications based on load data