A Design Live Load Model for Long-Span Bridges Based on Traffic Data and Simulations
Publication: ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering
Volume 8, Issue 4
Abstract
Current design codes for long-span bridges rely on the conservative live load models developed based on the assumed severe traffic congestion scenarios. To properly consider the site-specific traffic environment in designs of long-span bridges, this study proposes a new live load model. First, traffic environments of long-span bridges are investigated to propose classifications according to the percentage of heavy vehicles and the occurrence frequency of traffic congestion. For multilane bridges, characteristic lanes (car, middle, and truck) are defined depending on their locations, and congested traffic flows are generated through microsimulation models to consider changes in vehicle speed and driving lanes. The traffic simulation produces live load samples, which provide a basis for a design lane load model and multiple presence factors for long-span bridges. As numerical examples, the live load effects of an actual bridge were estimated by the proposed live load model and compared with those in the current bridge design code of South Korea. The results show that the live load model of the existing code is overly conservative, whereas the proposed live load model reflects the actual traffic environments of long-span bridges effectively.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request. This includes live load data and MATLAB code for the calculation of multiple presence factors and lane loads.
Acknowledgments
This work is supported by the Korea Agency for Infrastructure Technology Advancement (KAIA) grant funded by the Ministry of Land, Infrastructure and Transport (Grant No. 21SCIP-B119960-06). The second author is supported by the Institute of Construction and Environmental Engineering at Seoul National University. These supports are gratefully acknowledged.
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Information & Authors
Information
Published In
ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering
Volume 8 • Issue 4 • December 2022
Copyright
© 2022 American Society of Civil Engineers.
History
Received: Oct 29, 2021
Accepted: May 10, 2022
Published online: Jul 28, 2022
Published in print: Dec 1, 2022
Discussion open until: Dec 28, 2022
ASCE Technical Topics:
- Bridge design
- Bridge engineering
- Bridges
- Bridges (by type)
- Design (by type)
- Engineering fundamentals
- Engineering mechanics
- Highway and road design
- Infrastructure
- Live loads
- Load and resistance factor design
- Load factors
- Models (by type)
- Span bridges
- Static loads
- Statics (mechanics)
- Structural design
- Structural engineering
- Traffic congestion
- Traffic engineering
- Traffic management
- Traffic models
- Transportation engineering
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