NEHRP Clearinghouse
- Title
- Mechanical Characteristics of Base Isolation Bearings for a Bridge Deck Model Test.
- File
- PB90262668.pdf
- Author(s)
- Kelly, J. M.; Buckle, I. G.; Koh, C. G.
- Source
- National Science Foundation, Washington, DC., November 1987, 66 p.
- Identifying Number(s)
- UCB/EERC-86/11
- Abstract
- The report describes the mechanical characteristics of rubber bearings designed for a base isolated bridge deck model which represents a typical highway bridge superstructure. Two different forms of isolation system were used in the test program. The first set of isolators were elastomeric bearings made from natural rubber layers and reinforced with steel plates. The second set of isolators were also elastomeric bearings of the same construction as the first set but with a lead plug on a vertical axis to enhance damping. Static compression and shear tests, cyclic shear tests at different compression loads, and a series of shaking table tests were undertaken at the Earthquake Engineering Research Center of the University of California at Berkeley to establish fundamental stiffnesses, buckling loads and dynamic performance of the bearings. Of particular interest is the confirmation of theoretical predictions of the static stiffnesses, the buckling loads using a Southwell plot procedure, the reduction in lateral stiffness due to vertical load, and the limiting shear displacement defining the onset of overturning instability.
- Keywords
- Earthquake resistant structures; Structural vibration; Seismic waves; Compressing; Bridge decks; Highway bridges; Displacement; Cyclic loads; Vibration isolators; Bearings; Mechanical properties; Rubber