Precast Ductile End-Diaphragm System for Accelerated Construction of Slab-On-Girder Prestressed Concrete Bridges in Seismic Regions
In recent years, public concern about road closures resulting from new construction, replacement, or retrofit of bridges has been on the rise. The consequences of these works could be economic losses, security concerns at the construction site, costs and delay time suffered by the users, and in general problems that worsen the public perception of transportation agencies. At the same time, due to current environmental awareness, there is a concern about unnecessary use of vehicles operating on fossil fuels, in this case due to detours or traffic congestion. To reduce the impacts on the driving public and the environment, accelerated bridge construction (ABC) techniques have been gaining popularity. In ABC projects, bridge elements or entire systems are prefabricated and erected to expedite construction (Culmo, 2011). Examples of such prefabricated elements include deck panels (Garber and Shahrokhinasab, 2019) and columns (Shafieifar et al., 2020). Prefabrication of beams and girders has been an integral part of bridge construction in the U.S. for many years (Culmo, 2011). Precast prestressed concrete (PC) girder bridges comprise a large percentage of the National Bridge Inventory (NBI). In PC bridges, end diaphragms are used to transmit loads—mainly transverse in the case of earthquakes—from the bridge superstructure to the substructure. Typically, these end diaphragms are cast-in-place concrete. Culmo (2009) notes, “The time for forming and curing of [these] connections can be significant,” motivating the need for prefabricated diaphragms for use in ABC projects. According to the investigators’ knowledge and extensive literature review, both experimental work and seismic design provisions for end diaphragms on PC girder bridges are limited despite their abundance in practice. The 2010 Chile earthquake came to demonstrate the importance of end diaphragms and the need for developing and understanding a viable and clear seismic load path in bridges (Yen et al., 2010; Marsh et al., 2015). Furthermore, for regions located in high-risk seismic zones, great care must be taken in the way the connections between precast elements are made (Marsh et al., 2011; Culmo, 2009). In the case of steel bridges, some important distress suffered by the superstructure and mainly by the substructure during the most significant earthquakes during the last three decades that occurred worldwide has been identified (Zahrai and Bruneau, 1999a). As a proposal to solve these problems through retrofit, Zahrai and Bruneau (1999a) developed a system of ductile end- diaphragms for slab-on-girders steel bridges. They tested three types of diaphragms based on three successful bracing frames systems for steel buildings (Zahrai and Bruneau, 1999b). Furthermore, they proposed a simplified design procedure based on analytical evidence from 2-D and 3-D computational models. The solution has evolved until it became the Type 2 Global Seismic Design Strategy (GSDS) of the AASHTO Guide Specifications for LRFD Seismic Bridge Design (2011) that applies only to steel superstructures, and likewise it forms part of other important seismic design and retrofit codes in the U.S. Therefore, following the concept proposed by Zahrai and Bruneau (1999a; 1999b) for steel bridges, it would be important to develop guidelines on the behavior and detailing of precast concrete ductile end-diaphragm elements for seismic resistance. With this regard, the use of concrete ductile diaphragms as fuses (Type 2 GSDS) should be explored for the seismic lateral resistance of slab-on-girder concrete bridges. This diaphragm system should be developed to be part of ABC solutions for design of new bridges, has potential as an ABC solution for retrofitting of old infrastructure, and even could be used for a combination of both, in the case of simply supported PC girder bridges located in high-risk seismic regions.
Language
- English
Project
- Status: Active
- Funding: $50000
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Contract Numbers:
69A3551747121
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Sponsor Organizations:
Accelerated Bridge Construction University Transportation Center (ABC-UTC)
Florida International University
10555 W. Flagler Street
Miami, FL United States 33174Office of the Assistant Secretary for Research and Technology
University Transportation Centers Program
Department of Transportation
Washington, DC United States 20590 -
Performing Organizations:
University of Oklahoma, Norman
107 Carson Engineering Center
Norman, OK United States 73019-1021 -
Principal Investigators:
Harvey, P
- Start Date: 20230515
- Expected Completion Date: 0
- Actual Completion Date: 0
- USDOT Program: University Transportation Centers
Subject/Index Terms
- TRT Terms: Accelerated bridge construction; Diaphragms (Engineering); Earthquake resistant design; Prefabricated bridges; Prestressed concrete bridges
- Subject Areas: Bridges and other structures; Construction; Design; Highways;
Filing Info
- Accession Number: 01889314
- Record Type: Research project
- Source Agency: Accelerated Bridge Construction University Transportation Center (ABC-UTC)
- Contract Numbers: 69A3551747121
- Files: UTC, RIP
- Created Date: Jul 31 2023 12:17AM