EFFECT OF DIAPHRAGM ON SEISMIC BEHAVIOUR OF PARTIALLY CONCRETE-FILLED STEEL TUBE

Abstract

The present paper is aimed to study the behaviour of a partially concrete-filled steel tube (PCFST) under the seismic load. The PCFSTs are used as bridge piers due to the superior strength and ductility. In Japan, the diaphragm of the PCFST must be installed just above the concrete to fix the concrete and transmit the load to the concrete. However, the effect of the diaphragm on the tube behaviour is not clear. Therefore, we conducted the analysis of the PCFST subjected to the seismic load to discuss the effect of the diaphragm on the tube behaviour. Obtained results indicated the failure pattern of the PCFST was influenced by the presence or absence of the diaphragm. On the other hands, the opening size of the diaphragm give very small effect on the tube behaviour.