Bearing and Shear Failure of Pipe-Pin Hinges Subjected to Earthquakes

Abstract

Pipe-pin rotational two-way column hinges were developed by bridge designers at the California Department of Transportation. An extensive experimental and analytical study was undertaken to understand the behavior of pipe-pin hinges and develop design guidelines. As part of the study, six 1:3.5 scale push-off tests were carried out to assess the bearing capacity of the concrete against the pipe. The tests showed that the bearing strength of concrete is as high as twice the concrete compressive strength because of the confining effect of the concrete and reinforcement. In addition, to determine the shear capacity of the concrete-filled steel pipe, six concrete-filled pipe specimens were tested in pure shear, and an empirical design equation was developed to assess their shear strength. In the analytical studies, ABAQUS finite-element (FE) package was used to perform a series of detailed nonlinear analyses. The results showed that the FE models accurately simulated the behavior of the push-off specimens and the observed modes of failure.