Cyclic loading tests on exposed column-base plate weak-axis connections of small-size steel structures

Research on evaluating the seismic performance of exposed column-base plate weak-axis connections of small size steel structures is substantially limited. Therefore, in this study, six exposed column-base plate weak-axis connection specimens with L-shaped anchor bolts under cyclic loading were tested. The primary test variables were the thickness of base plates, the presence of rib plates, and the number and embedment length of anchor bolts. Furthermore, round and threaded rods with L-shape were used as anchor bolts to assess the effect of bond performance. It was found that the structural performance of the connections was influenced by the thickness of base plate and the bond performance of anchor bolts. It should be noted that although base plate meets the minimum thickness requirements by the current design code, if the base plate yields before the moment capacity of steel column reaches the plastic moment, the structural performance of the connection will decrease. The connection details in this study can be considered semi-rigid connections. Threaded anchor bolts with L-shape are more preferred over the smooth round anchors for increased bond strength. Furthermore, equations for required tensile capacity and cross-sectional area for anchor bolts were derived in this study.