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Determination of the Ultimate Capacity of Elastomeric Bearings under Axial Loading



G L. Bradley, P Chang, A W. Taylor


Elastomeric bearings are used as base isolation systems in order to reduce the response of buildings to earthquake ground motions. In order to facilitate the use of this technology, the National Institute of Standards and Technology (NIST) has published guidelines for testing base isolation systems. NIST seeks to improve the current guidelines for determining the capacity of bearings under axial loading. Very few full-scale bearings have been tested to failure because the capacity of a typical bearing is often beyond the loading capacity of existing testing facilities. This research has sought to determine if tests to failure under axial loading on scale models can be used to predict the axial failure load of a full-scale bearing. Tests to failure were conducted on full-scale, 1/2-scale, and 1/4-scale bearings. However, there were dissimilarities in steel shim thickness, cover layer, and the central alignment hole. The stress-strain responses were similar, but not identical. Nonlinear finite element analysis conclusively demonstrates that similarity in shim and rubber thickness is most important. The dissimilarities in the cover layer and central alignment
NIST Interagency/Internal Report (NISTIR) - 6121
Report Number


building technology, compression testing, earthquake engineering, elastomeric bearings, seismic base isolation


Bradley, G. , Chang, P. and Taylor, A. (1998), Determination of the Ultimate Capacity of Elastomeric Bearings under Axial Loading, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 18, 2024)


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Created January 31, 1998, Updated October 12, 2021