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SUITABILITY OF BRIDGE MADE WITH PRECAST COMPONENTS IN AREAS OF HIGH OR MODERATE SEISMISITY
Presented By:
Bijan Khaleghi1
Abstract
The need for rapid construction arises from the inevitable increases in traffic congestion that have occurred in the past few decades, and the corresponding costs and safety manifested in many forms, including exposure of workers to traffic hazards, and most importantly, the waste of time due to delays. Prefabricated bridge components are in increasing demand for accelerated bridge construction. Precasting eliminates the need for forming, casting, and curing of concrete in the work zones, making bridge construction safer while improving quality and durability. This paper provides an overview of WSDOT precast bridges, relevant research and bridge projects using precast members.
Introduction
Precast concrete bridge systems provide effective and economical design solutions for new bridge construction as well as for the rehabilitation of existing bridges. Proper seismic design begins with a global analysis of the structure and a detailed evaluation of the connections between precast components as well as the connections between superstructure and the supporting substructure system. The system must be made to protect the superstructure from force effects due to ground motions through fusing or plastic hinging. In seismic regions, provisions must be made to ensure ductile behavior in both longitudinal and transverse directions. Studies have already been carried out to investigate seismic resistance and rapid construction. Requiring both characteristics together poses some special problems. While precast concrete is used to speed site assembly of components, the locations of the structural connections are critical. Transportation constraints point towards the use of line members, such as beams and columns, yet these lead to the need for making connections where bending moments are largest and inelastic behavior is virtually inevitable.
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http://pwri.go.jp/eng/ujnr/tc/g/pdf/24/2...aleghi.pdf
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[attachment=5071]
SUITABILITY OF BRIDGE MADE WITH PRECAST COMPONENTS IN AREAS OF HIGH OR MODERATE SEISM
Abstract
The need for rapid construction arises from the inevitable increases in traffic congestion that have occurred in the past few decades, and the corresponding costs and safety manifested in many forms, including exposure of workers to traffic hazards, and most importantly, the waste of time due to delays. Prefabricated bridge components are in increasing demand for accelerated bridge construction. Precasting eliminates the need for forming, casting, and curing of concrete in the work zones, making bridge construction safer while improving quality and durability. This paper provides an overview of WSDOT precast bridges, relevant research and bridge projects using precast members.
Introduction
Precast concrete bridge systems provide effective and economical design solutions for new bridge construction as well as for the rehabilitation of existing bridges. Proper seismic design begins with a global analysis of the structure and a detailed evaluation of the connections between precast components as well as the connections between superstructure and the supporting substructure system. The system must be made to protect the superstructure from force effects due to ground motions through fusing or plastic hinging. In seismic regions, provisions must be made to ensure ductile behavior in both longitudinal and transverse directions. Studies have already been carried out to investigate seismic resistance and rapid construction. Requiring both characteristics together poses some special problems. While precast concrete is used to speed site assembly of components, the locations of the structural connections are critical. Transportation constraints point towards the use of line members, such as beams and columns, yet these lead to the need for making connections where bending moments are largest and inelastic behavior is virtually inevitable.
Reference:
http://studentbank.in/report-suitability...z11TmisN00
