Experimental Study of Precast Bridge Columns with Built-In Elastomer

Experimental Study of Precast Bridge Columns with Built-In Elastomer Sarira Motaref, M. Saiid Saiidi, and David H. Sanders Two one-third-scale precast concrete segmental column models with A series of innovative segmental precast concrete columns were energy-dissipating plastic hinges were designed and tested on a shake designed and studied at the University of Nevada, Reno, through a table at the University of Nevada, Reno. Conventional reinforced con- research project funded by the California Department of Trans- crete was used in the plastic hinge of one column (SC-2). In the other portation (Caltrans). The purpose of the study was to develop new model, a built-in elastomeric pad integrated with the footing and a con- systems for precast columns that are able to dissipate energy under crete segment constituted the plastic hinge (SBR-1). The purpose of using seismic loads while reducing damage. The project included design- ing and testing large-scale segmental concrete columns with differ- the pad was to minimize damage while dissipating energy through yield- ent low-damage plastic hinges. The columns were tested on a shake ing of the longitudinal bars and deformation of the pad. Both columns table subjected to the Sylmar station record for the 1994 Northridge, were subjected to the same ground motion as was recorded at the Sylmar California, earthquake with increasing amplitudes until failure. station during the 1994 Northridge, California, earthquake with increas- The first phase of this project involved analytical and experimental ing amplitudes until failure. Compared with conventional precast concrete study of a segmental concrete column incorporating an elastomeric segmental columns, both SC-2 and SBR-1 showed superior performance, bearing pad in the plastic hinge referred to as SBR-1 (segmental such as minimal residual displacement and larger energy dissipation. with built-in rubber pad). A reference segmental column with iden- SBR-1 with the...