COMPARATIVE STUDY OF EXPERIMENTAL PERFORMANCE ON BOX-SHAPED COLUMN CONNECTION ACHIEVED BY PLUG WELDING-CORE SLEEVE AND SELF-LOCK ONE-SIDE BOLT-CORE SLEEVE

The pseudo-static tests were conducted for a box-shaped column connection achieved by plug welding-core sleeve (SHJD), for a box-shaped column connection achieved by self-lock one-side bolt-core sleeve (DLJD), and for a traditional fully-penetrated welded connection (HJJD), to comparatively analyze the difference of mechanical behaviors on test phenomenon, on a restoring force model, on ductility coefficients, on the strain of typical position and on the pretension of high strength friction type bolt of each connection. Based on the test results, the mechanism of a box-shaped column connection achieved by core sleeve has been analyzed. The test results indicate that the SHJD-1, SHJD-2, and DLJD all have excellent bearing capacity and connection stiffness. Equipped with the same number of plug welds and self-lock one-side bolts, the trends of the hysteretic curves, of bearing capacity, of ductility coefficient and of stiffness degradation induced from the SHJD-1 and from the DLJD are basically consistent. The increasing number of plug welds could increase the connection stiffness as well as the ductility coefficient of the connection and could reduce the pretension loss of the bolts. The increasing number could not contribute to the improvement of bearing capacity obviously. Similar mechanical performance is shown between the SHJD-2 and HJJD due to the increasing number of plug welds. The costs of SHJD is relatively low, which is suitable for the construction site where a small amount of welding is allowed. The proposed connection DLJD could realize a box-shaped all-bolted column connection and no welding operation on the construction site. The two kinds of connection could be flexibly selected according to the requirements in an actual engineering design.