Seismic perormance of precast steel-embedded composite columns

Abstract

Fast Construction of infrastructures in congested areas is essential requirement from clients and needs more investigation on design and construction methods. Especially, the construction of bridge piers and foundations is always in the middle of critical path in construction schedule. Innovative ideas on the substructures need to be created to solve these problems. In the design of bridge piers in the congested area, it is necessary to reduce the dimensions of columns considering design criteria and to minimize the construction time by adopting prefabrication. Composite section can provide various alternatives for bridge piers. Ductility requirement for seismic design is the most important factor. In this paper, prefabricated composite columns with core steel elements embedded in concrete were proposed. Bolt connection details between footing and pier element were also suggested for the fast erection. In order to investigate the seismic performance of the composite columns, several tests on concrete encased composite columns, which are prefabricated, were performed. Quasi-static tests were executed and their performance was evaluated and compared each other. The cross-sections of these specimens are composed of concrete-encased circular tubes with partial in-filled concrete. Through the tests, it was evaluated the ductility of SRC composite specimens. It has become clear from the test results that encased steel elements filled with concrete makes the deformation capacity of the columns to be large. For relatively small size columns, precast SRC columns can be excellent alternatives for bridge substructures without any prestressing. Based on the test results, design considerations and examples on the details of the reinforcements were derived.