Sessions & Events


All sessions and events take place in Eastern Daylight Time (EDT).
W = Westin Boston Seaport District; C = Boston Convention and Exhibition Center

On-demand sessions will be available for viewing in the convention platform under "On-Demand Content" within 24-48 hours of the session premiere. Please note, on-demand sessions are not available for CEU credit. *Denotes on-demand content.

Concrete Bridge Resilience: Design, Construction, Evaluation and Retrofit

Monday, October 30, 2023  1:30 PM - 3:30 PM, W-Marina Ballroom IV

Concrete bridges may encounter various extreme events during the service lives. Such events are increasing in intensity and frequency. The sessions will include recent developments to improve bridge resiliency through design, construction, evaluation and retrofit. Both natural and man-made events, and those included/not included in AASHTO LRFD Specifications, will be considered. Bridge designers, construction companies, federal/state/local government entities, educators and students should attend the sessions.

Learning Objectives:
(1) Discuss current bridge resiliency issues;
(2) Apply design, construction, evaluation and retrofit options to enhance resiliency;
(3) Assess aspects of life-cycle benefit/costs for various options;
(4) Develop informed decision making for bridge replacement or rehabilitation to enhance resiliency.

This session has been approved by AIA and ICC for 2 PDHs (0.2 CEUs). Please note: You must attend the live session for the entire duration to receive credit. On-demand sessions do not qualify for PDH/CEU credit.

Improving Transportation Network Resiliency Using In-Situ Evaluation and Innovative Construction Methods

Presented By: Andrew Foden
Affiliation: HNTB
Description: In the coming years, transportation networks will experience unprecedented demands due to trends in freight as well as extreme weather driven by climate variability. These demands are set against a backdrop of infrastructure deterioration as many bridges reach the end of their intended service lives. The resiliency framework has allowed bridge owners to be proactive at every level from materials and detailing through retrofits, rapid replaceability and route redundancy. Two aspects of structural resiliency will be examined. Firstly, the use of technology to load test in-service culverts that are experiencing loads that they were not originally designed for. Information gained allows bridge owners to assess performance and potentially avoid major rehabilitation, diverting critical funds elsewhere. Separately, it may lead to removing postings which can improve freight network efficiency. Secondly, rapid replacement of single span bridges by filler beam structures will be discussed. These structures simplify logistics during erection, are less sensitive to supply chain issues due to allowable variation in beam size, are highly resistant to truck impact and are shallower than conventional spans. Rapid replaceability can prove consequential in returning to normal after an extreme weather event affects an entire region and strains the construction supply chain. Small bridges can also play an outsized role in network vulnerability.

Dynamic Evaluation and Retrofitting of Prestressed Concrete Girder Bridge with Vibration Problem

Presented By: Nur Yazdani
Affiliation: University of Texas at Arlington
Description: Though often ignored, the unusual vibration of highway bridges causes human discomfort and affects the serviceability and durability of the deck. A recently constructed prestressed concrete I-girder bridge in the Dallas-Fort Worth metroplex experienced excessive vibration, leading to extensive transverse deck cracks and potholes. Non-Destructive Evaluation (NDE) and diagnostic load test revealed severe delamination on the deck and partial composite action at the deck-girder interface. An ambient vibration test on the bridge showed a considerably low natural frequency due to partial-composite action-induced stiffness reduction of the bridge. A Finite Element Model was developed and calibrated using the NDE and diagnostic load test results. The model was subsequently used to evaluate vibration mitigation retrofitting techniques, such as concrete shear keys restrainer between girders, dense concrete deck overlay, undercut anchors at the deck-girder interface and re-casting the deck areas with extensive delamination. Shear keys resulted in the most significant improvement in the bridge's natural frequency. In addition, it is the cheapest option and does not require traffic closure since the bridge bents are located outside the traffic.

Long-Term Performance of Composite Plate Girder Bridges with Full-Depth Precast Concrete (FDPC) Deck Systems

Presented By: Adel Abdelnaby
Affiliation: University of Memphis
Description: Accelerated bridge construction methods for building and rehabilitation of bridges have many economic and social merits. In this context, use of composite steel plate girder bridges with precast concrete deck planks has gained popularity considering their ease of construction, rapid installment, relatively low cost, and lightweight. Meanwhile, reported failure cases of the system after limited-service life raised concerns about its long-term performance and durability. Recent studies showed that long-term performance can be negatively affected by factors overlooked by regular designers. In addition, deterioration of joints between precast deck planks can lead to gradual loss of composite action causing steel sections to be subjected to stress levels not considered in the original design. The current study explores design and construction processes that can enhance the long-term performance of this system. A finite element model of a composite steel girder bridge using precast deck panels is established. Considered parameters include panel-to-panel joint types, use of haunch, use of post-tensioning, and bracing type. Results provided recommendations for best design and construction practices considering long-term bridge performance.

Investigation of Live Load Moment in Concrete Bridge Deck Slab Overhang Due to AASHTO Truck Loading

Presented By: Khaled Sennah
Affiliation: Toronto Metropolitan University
Description: AASHTO LRFD Bridge Design Specification, Clause, specifies an equation for the width of equivalent interior strip to determine the applied live load moment in concrete deck overhang due to ASSHTO truck wheels. AASHTO LRFD also states that the provisions of Article may be used in lieu of the strip width method. AASHTO LRFD Clause specifies that for deck slab overhang not exceeding 1.8 m (6.0 ft), the outside row of wheel loads may be replaced with a uniformly distributed line load of 14.59 kN/m (1 k/f) intensity, located 0.3 m (1.0 ft) from the face of the barrier. This paper investigates the accuracy of the above-mentioned methodologies as affected by the presence of the concrete continuous barrier built integrally over the overhang edge. A parametric study was conducted, using the finite-element method, on the overhang to determine the applied moments due to AASHTO vehicular loading. The key parameters considered in this study included deck overhang of constant thickness and tapered shape with a span ranging from 1 to 2.5 m, overhang length in the direction of traffic ranging from 5 m to 20 m, and single-slope concrete barrier types TL-2, TL-4 and TL-5. Results showed significant effects of the presence of the concrete barrier and the length of the barrier/overhang in the direction of traffic on the applied moment on the deck overhang. A summary table for use in design was proposed for the live load moment in deck overhang with unstiffened and stiffened edges.

Analysis and Design of Steel-Reinforced Concrete Deck Overhang for Combined Moment and Tensile Force Due to Vehicle Collision to Concrete Barriers

Presented By: Khaled Sennah
Affiliation: Toronto Metropolitan University
Description: AASHTO LRFD Bridge Design Specification, Clause A13.4, specifies that the deck slab overhang may be designed for an applied moment equal to the flexural resistance of the barrier base at the overhang-barrier junction, acting coincident with a tensile force. It also specifies that the applied tensile force in the deck overhang from transverse vehicle impact is based on the barrier ultimate transverse resisting force which should be dispersed at 45° to the deck-barrier interface from the ends of the critical length of the AASHTO yield-line failure pattern. On the other hand, Many US DOTs specify moments and tensile forces on the deck overhang using 20% to 33% increase in the AASHTO traffic load to ensure the barrier will fail before the overhang in a crash accident. To examine the differences in the above-mentioned analysis approaches, a parametric study was conducted, using the finite-element method, on the deck overhang-barrier system to determine the applied moments and tensile forces due to AASHTO traffic loads. The key parameters considered in this study included single-slope TL-2 and TL-4 barrier types, deck overhang stiffness, overhang length ranging from 1 to 2.5 m, and a barrier and overhang length in the direction of traffic ranging from 5 m to 20 m. The data generated from this study was used to develop equations for moments and tensile forces to be used to design the deck overhang. A design procedure for a steel-reinforced concrete section subjected to combined bending and tensile force was introduced to complete the design process.

Upper Level Sponsors

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