All posts by trac

Seismic Collapse Prevention for WSDOT Bridges

Earthquakes threaten the functionality and safety of the highway transportation system in Washington state. Given the state’s funding constraints, WSDOT needs to focus scarce resources on the bridge failure mode that is most likely to lead to bridge collapse, namely the shear failure of reinforced concrete columns, and the bridges that are most likely to suffer from column shear failures. This project is developing a new methodology, or modifying an existing one, to evaluate the seismic-shear vulnerability of WSDOT bridges with reinforced-concrete columns.  This will allow WSDOT to account for the amount of shear-strength reduction that will result from repeated cycling during long-duration and shorter-duration earthquakes. The researchers will also provide WSDOT with the practical tools and training needed to implement the developed methodology. The results should enable more reliable characterization of post-earthquake transportation functionality, which will support improved emergency planning. 

Principal Investigators:
Marc Eberhard, Civil and Environmental Engineering, UW
Jeffrey Berman, Civil and Environmental Engineering, UW

Sponsor: WSDOT
WSDOT Technical Monitor: Amy Leland
WSDOT Project Manager: Mustafa Mohamedali
Scheduled completion: October 2027

Sound Mitigation Study of the SR 520 Bridge Modular Expansion Joints, Phase 3

While expansion joints are a necessary component of bridges, they also contribute to noise pollution. Previous studies have investigated the design and feasibility of strategies to mitigate noise caused by modular expansion joints on bridges in Washington state. This study is Phase 3 of an effort to develop a highly durable sound attenuation system in which researchers will perform laboratory-based testing of noise mitigation prototypes. The prototypes will be injected with mixtures of fiber-reinforced, natural, and synthetic rubber with protective additives. The researchers will use a selection of low-density foam to fill gaps for increased durability and protection against roadway debris. Finally, they will use laboratory equipment to evaluate the prototype systems for hydraulic compression, cyclic fatigue, weathering of the system, adhesive durability, abrasion between the prototype and the seal, and susceptibility to debris.

Principal Investigator: Per Reinhall, Mechanical Engineering, UW
Sponsor: WSDOT
WSDOT Technical Monitor: Omar Jepperson
WSDOT Project Manager: Mustafa Mohamedali
Scheduled completion: November 2026

Development of a Specification for Quality Acceptance of Chip Seals Using a Laser Texture Scanner

Chip seals are widely used in Washington state as a cost-effective pavement surfacing method. However, they can be subject to variations in performance and premature failures. This project developed a quality acceptance specification for chip seal construction that incorporates the use of a laser texture scanner to provide valuable, data-driven insights for quality control and performance assessment to enhance the quality and effectiveness of chip seals.

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Washington State Rest Area Site Evaluation Study

Washington state has 42 safety rest areas. These rest areas differ in their capacity, facilities, and accessibility in each traffic direction. Some are located at the most traffic-dense corridors such as I-5 and I-90, whereas others are on less traffic-dense state routes. This project provided information on Washington rest area use and user experiences and evaluated the impacts of rest areas on traffic safety.

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Ensuring Stream Stability with the Use of Organic Material in a Flume—Design Recommendation

Fish populations in the Pacific Northwest have declined as spawning grounds have disappeared because of river and stream barriers, often under-road culverts. This research investigated ways to incorporate different kinds of organic material inside a culvert that would both maintain the stream channel shape while also improving the ability of fish to successfully navigate those culverts during low water flow.

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Equity Analysis of WSDOT’s Toll Program

The Washington State Department of Transportation (WSDOT) uses tolling as a key mechanism for managing demand on I-405, SR 167, SR 99, SR 16, and SR 520 and for funding megaprojects on those facilities. Tolls impose an expense on roadway users, and imposition of these fees can raise concerns about equity. This project provided insight into the use of WSDOT’s toll facilities that is intended to serve as the basis for evaluating the equity implications of those toll facilities.

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Maintenance of the Active Transportation Elements of Complete Streets

The need for maintenance of active transportation facilities is relatively new, and the development of consistent levels of service and treatment intervals for all aspects of these facilities is just emerging. This project explored the challenges and opportunities associated with maintaining these facilities, with particular emphasis on lanes that serve bicyclists.

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Applications for Foamed Glass Lightweight Aggregate

Recycled and lightweight fill materials are increasingly used in construction because they can address challenging site conditions, accelerate project timelines, and reduce reliance on natural resources while contributing to an agency’s sustainability goals. This project investigated the use of one such material, foamed glass aggregate, for the Illinois State Toll Highway Authority.

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