Title: Bearings and Joints in the Pasco-Kennewick Intercity Bridge

Author(s): Conrad P.Bridges

Publication: Symposium Paper

Volume: 94

Issue:

Appears on pages(s): 71-84

Keywords: bridge bearings; bridges (structures); control joints; cable-supported structures; concrete construction; creep properties; installing; performance; shrinkage; structural design; temperature; Construction

DOI: 10.14359/3471

Date: 9/1/1986

Abstract:
The concrete girder for the Pasco-Kennewick Intercity Bridge is continuous (i.e., without intermediate expansion joints) for its entire 2500-ft (762-m) length. Nearly 1800 ft (549 m) of this girder is suspended entirely from towers by stay cables. The remaining portions are supported on sliding disk bearings. The girder is fixed at only one end; all expansion and contraction occurs at the opposite end, requiring an expansion joint with a 26-in. (660-mm) movement capability--the largest of any as of the time it was installed (1978). To control permanent deformations and thereby minimize the size of bearings and joints, the designer called for: (1) the girder to be precast in segments; (2) a minimum 28-day compressive strength of 6000 psi (41 MPa); (3) special requirements for curing the segments; and (4) the segments to be stored for at least 90 days prior to erecting them. The sequence of construction complicated the installation of the bearings. The bridge was built in stages with each stage having a different temporary fixed bearing. Thus, the setting (offset) of each bearing had to provide for the permanent deformations that the partial-length girder would undergo before being incorporated into the final structure, as well as for the predicted temperature at that later date. Following seven years of service, the deformations in the girder and movements in the bearings and joints have been within the limits assumed in their design. All components are performing fully as intended.