Calibration and Reliability Analysis of Eccentric Compressive Concrete Column with High Strength Rebars

The utilization of high-strength steel bars (HSSB) within concrete structures demonstrates significant advantages in material conservation and mechanical performance enhancement. Nevertheless, existing design codes exhibit limitations in addressing the distinct statistical characteristics of HSSB, particularly regarding strength design parameters. For instance, GB50010-2010 fails to specify design strength values for reinforcement exceeding 600 MPa, creating technical barriers for advancing HSSB implementation. This study systematically investigates the reliability of eccentric compression concrete columns reinforced with 600 MPa-grade HSSB through high-order moment method analysis. Material partial factors were calibrated against target reliability indices prescribed by GB50068-2018, incorporating critical variables including live-to-dead load ratios, design methodologies, and service conditions. The findings show that the value of k significantly affects the calibration of material partial factors, impacting the reliability of bearing capacity. Considering various k values and target reliability indices, it is recommended that the material partial factor be set at 1.15, implying that the design strength for 600 MPa high-strength steel bars should be considered as 522 MPa. For safety levels I and II, load adjustment factors of 1.1 and 0.9, respectively, may be applied.