AN EXPERIMENTAL STUDY ON LOAD-CARRYING MECHANISM OF A JOINT STRUCTURE WITHOUT JOINING BETWEEN CFT PILLAR AND RC SLAB REBAR

Abstract

 For the advanced use of the underground, a new joint between pillar and floor slab is proposed for an underground box which is loaded by structures, such as existing buildings and railway stations. In our proposed structure, a concrete filled tube (CFT), which is affected by high axial force, is adopted for the pillar. CFT is not connected to an RC slab in one horizontal direction with slab rebar, but is connected to an RC beam in another horizontal direction normally, to improve workability when constructing. In this study, from a cyclic loading test with joint specimens, the load carrying mechanism of the proposed joint structure is confirmed, and especially, the load sharing rate between bearing strength on side of CFT and other type of strength is shown quantitatively by using the proposed model.