Comparative study of design procedures for CFST-to-steel girder panel zone shear strength

• Tests and design procedures of CFST-to-steel girder panel zone were summarized.
• Accuracy and reliability of the design procedures were validated by tests.
• Applicability of the procedures was proposed by detailed parametric analysis.
• Amendments of the procedures were proposed to account for special details.

In this work, experiments on composite connections consisting of steel girders framing into concrete-filled steel tube (CFST) beam-columns conducted in recent years were investigated and the test results were compared with the calculation results of the AIJ specification, the calculation method proposed by Fukumoto and Morita, and the calculation method verified by Nishiyama et al. Through data analysis, the study confirmed the applicability of each of the three methods. The ultimate shear strength calculation results of Fukumoto and Nishiyama were found to be more accurate and reliable than AIJ specification procedure, and the shear yield strength calculation results of the two methods were also shown to be appropriate. Through a parametric analysis, this study confirmed that the three methods have a broad applicability for joints of various axial compression ratios, connection formations and column cross sections. The analysis results suggested that the applicable steel tensile strength and concrete compression strength for the AIJ specification should not exceed 450 MPa and 70 MPa, respectively, and the applicable ratio of steel tensile yield strength to concrete compression strength should not exceed 8 for the AIJ procedure to yield accurate results. This paper also provides proposed amendments to these procedures for joints having special connection details.