Response of shear-deficient reinforced circular RC columns under lateral impact loading

摘要

This paper reports the results of an extensive experimental investigation on the behavior of shear-deficient reinforced circular RC columns under lateral impact loading. First, it provides a brief literature review on studies of the dynamic response induced by vehicle collisions on RC columns highlighting the lack of experimental tests on vertical elements. In this context, a novel facility for testing of vertical elements under lateral impact loading was realized. Two different types of RC columns characterized by different hoop spacing were tested, representing a one-third scaled model of a reinforced circular bridge pier, designed with obsolete design practice with particular reference to non-seismic areas. A total of 10 specimens (5 for each type) were tested under a lateral rigid-hammer impact at different impact velocities (2.25, 3 and 4.5 m/s) and boundary conditions (cantilever and fixed-simply-supported). The impact load was applied at the typical vehicular impact location, i.e. near the base. A description of the impact and reaction forces, of the lateral displacements and accelerations, of the damage development and of the post-impact damage is given. The dynamic response and the observed damage are found to be significantly affected by the column type, the impact velocity and the boundary condition. A brittle shear-type damage was observed, characterized by one main diagonal crack originating from the base of the column to the impact point, revealing the high vulnerability of these structural elements. (C) 2017 Elsevier Ltd. All rights reserved.