THE CONCRETE BRIDGE MAGAZINE

WINTER 2018

ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.

Issue link: http://www.aspiremagazinebyengineers.com/i/922349

Contents of this Issue

Navigation

Page 11 of 59

P E R S P E C T I V E 10 | ASPIRE Winter 2018 Designing Precast, Prestressed Concrete Bridge Girders for Lateral Stability: An Owner's Perspective The Washington State Department of Transportation (WSDOT) investigates initial lifting, hauling, and erection conditions during the design of precast, prestressed concrete bridge girders. The design engineer's objective, stated simply, is to be reasonably satisfied that safe handling of girders can occur at all stages of construction. T h e f o l l o w i n g e x c e r p t s f ro m t h e American Association of State Highway and Transportation Officials' AASHTO LRFD Bridge Design Specifications 1 show that constructability, safety, and stability must be considered by the design engineer. Article 1.3.1 Bridges shall be d e s i g n e d f o r s p e c i f i e d l i m i t states to achieve the objectives of constructability, safety, and serviceability, with due regard to issues of inspectability, economy, and aesthetics, as specified in Article 2.5. A r t i c l e 2 . 5 . 1 T h e p r i m a r y responsibility of the Engineer shall be providing for the safety of the public. Article 2.5.3 Constructability issues should include, but not be limited to, consideration of deflection, strength of steel and concrete, and stability during critical stages of construction. Bridges should be designed in such a manner that fabrication and erection can be performed without undue difficulty... Article 5.5.4.3 Buckling of precast m e m b e r s d u r i n g h a n d l i n g , transportation, and erection shall be investigated. T h e l a t e r a l s t a b i l i t y o f p r e c a s t , prestressed concrete bridge girders is an important constructability and safety concern. Lateral bending failures are sudden, catastrophic, costly, and they pose a serious threat to surroundings and people, including the traveling public during transportation of girders from fabrication facilities to bridge sites. Investigation of potential instability conditions is well within the purview of the design engineer. Lateral-Stability Design W S D O T h a s d e s i g n e d p r e c a s t , prestressed concrete girders for lifting and hauling for more than 25 years. When spans were generally less than 120 ft long, 120 ft long, bulb-tee and wide flange girder sections were not particularly deep, and stability was not a significant concern. Handling design consisted of evaluating stresses during lifting from the form and hauling to the bridge site. by Richard Brice, Washington State Department of Transportation R e p o r t R e c o m m e n d e d P r a c t i c e f o r L a t e r a l S t a b i l i t y o f P r e c a s t , P r e s t r e s s e d Co n c r e t e B r i d g e G i r d e r s C B - 0 2 - 1 6 F i r s t E d i t i o n Recommended Practice for Lateral Stability of Precast, Prestressed Concrete Bridge Girders contains state-of-the-art analysis techniques and best practices for lateral stability of precast, prestressed concrete bridge girders.

Articles in this issue

Archives of this issue

view archives of THE CONCRETE BRIDGE MAGAZINE - WINTER 2018