Structural performance of perforated steel plate-CFST arch feet in concrete girder-steel arch composite bridges

Abstract

This paper investigates the mechanical behavior of perforated steel plate-concrete-filled steel tubular (P-CFST) arch feet in concrete girder-steel arch composite bridges. A total of thirteen arch feet specimens, varying testing parameters of the length, thickness and arrangement of perforated steel plates, and the wall thickness of steel tubular, were prepared and tested. Failure modes, load-slip curves, strain history, and ductility of the P-CFST arch feet were presented and discussed. Experimental results indicate that introducing perforated steel plates to traditional CFST arch feet prevented the early-age cracking of the concrete abutment, and the P-CFST with triple-line-shaped perforated plates gave the largest resistance among all specimens. Compared to the P-CFST using a 4 mm-thick perforated steel plate, the cracking resistance of the P-CFST with a perforated plate thickness of 5 mm and 6 mm were increased by 26.9% and 69.4%, respectively, while the improvements for the ultimate resistance of the structure was not obvious. It also magnifies that the cracking resistance of the P-CFST using a 5 mm- and 6 mm-thick steel tubular was increased by 24.3% and 32.9%, respectively, compared to those with a 4 mm-thick steel tubular. Moreover, an analytical model considering the end-bearing effect of the combined tubular-to-plate steel member, the supporting effect of the SRC core column, and the shear effect between the SRC core column and surrounding concrete to predict the capacity of the P-CFST arch feet was proposed. The capability of the developed model was verified by experimental results.