Performance of new CFST square column-to-foundation connections for cyclic loads

Abstract Although the structural behavior of circular Concrete Filled Steel Tube (CFST) columns-to-foundation connections has been studied substantially, there are limited studies on connections for square CFST columns, which are more in demand in high-rise buildings. The acceptable behavior of these columns for their use in high-rise buildings require sufficient stiffness for controlling the drift, safe and efficient transfer of imposed loads, and adequate ductility for withstanding earthquake loads. In the present study, authors aim to develop two such column-to-foundation connections for the square CFST columns. The performance of the two square CFST column-to-foundation connections was assessed experimentally as well as numerically under cyclic lateral loading. The comparison of the connections was made with one of the prevalent square CFST column-to-foundation connections and a conventional RC connection to study the inelastic deformation capacity of connections under cyclic loads. The test results illustrate the efficient and improved behavior of the suggested connections. Numerical models were also developed, and the experimentally obtained results were predicted and compared. The developed numerical models were capable of predicting the experimental response of connections to large drift levels with acceptable accuracy. The numerical results were reasonably close to the experimental response.