Performance characterization and design recommendations of socket connections for precast columns

Abstract

The socket connection has been proven to exhibit sufficient structural performance and offer constructability advantages for connecting precast columns. To further promote this type of connection, this paper presents the characterization of structural behavior and appropriate design recommendations of socket connections. By utilizing the numerical models that adequately replicate the responses obtained from an experimental test, it was found that the major nonlinear behavior of the socket connection was triggered by the radial cracks developed on the connection. After identifying the performance characteristics of socket connections, the numerical parametric study was conducted to investigate the effect of four primary connection parameters. The results indicated that the connection strength generally increased with the increasing column embedment length-to-column diameter ratio, connection diameter-to-column diameter ratio, and concrete strength of the connection. Increasing transverse reinforcement ratio was also found to improve the post-cracking performance of socket connections. As a result of the numerical investigation, the preferred column embedment length-to-column diameter ratio for various connection parameters and the detailing requirements were recommended. The paper also illustrates the proposed design recommendations using a field implementation.