Abstract
Steel reinforced concrete (SRC) columns are widely used in high-rise and super-high-rise buildings, and the design of their shear strength is directly related to the safety and reliability of structures. At present, the design provisions for the shear capacity of SRC columns in various codes vary significantly in prediction accuracy and safety margin, and there still exist research gaps in the relevant systematic reliability analysis and load factor calibration. In addition, the load factor provisions in the updated Chinese structural design code have not been fully verified. To address the above problems, this paper conducts a probabilistic code calibration of shear strength design for I- and H-shaped steel reinforced concrete (SRC) columns based on the provisions of Code for Design of Composite Structures (JGJ 138–2016) , Specification for Structural Steel Buildings (ANSI/AISC 360–22) , Standard for Structural Calculation of Reinforced Concrete Structures (AIJ-SRC14) , and Design of Composite Steel and Concrete Structures—Part 1–1: General Rules and Rules for Buildings (BS EN 1994–1–1:2004). An experimental database with 108 samples (i.e., datasets based on low-frequency cyclic loading tests) concerning the shear-dominated failure is compiled and served as the basis for calibrating shear design provisions from the assessed codes. As demonstrated, the American code achieves the best prediction, while having the least conservative estimate of SRC column shear capacity among all assessed models. In contrast, the Chinese code considers both accuracy and safety margin. To further evaluate the safety levels specified in the Chinese and American codes, a reliability-based code calibration procedure is used to determine the optimal load factor combination for SRC column design. The study results indicate that when designing SRC columns based on the American codes of Minimum Design Loads and Associated Criteria for Buildings and Other Structures (ASCE 7–22) and ANSI/AISC 360–22, the reliability indices of SRC columns designed considering only the shear contribution of steel section or only the shear contribution of reinforced concrete meet the target reliability. However, the SRC columns designed considering both contributions simultaneously fail to meet the target requirements. In contrast, SRC columns designed based on the Chinese codes of Unified Standard for Reliability Design of Building Structures (GB 50068–2018) and JGJ 138–2016 show better performance in achieving the target reliability. However, this enhanced performance comes with greater redundancy, indicating that the load factor combination suggested in the GB 50068–2018 cannot achieve an optimal level. Theoretical analysis shows that a dead load factor of 1.2 is more in line with the target reliability index; however, considering the theoretical accuracy, the uniformity of code implementation and the whole-life safety of structures, it is recommended that the current code-specified value of γG=1.3 still be adopted in engineering practice to balance the design safety level and engineering application requirements. The findings of this study provide valuable insights for the shear design of SRC columns.