Reliability analysis and formula adjustment for shear capacity of concrete shear walls

Abstract

The Unified Standard for Reliability Design of Building Structures of China (GB50068-2001) requires that the average value of a component’s reliability index should not be lower than the target reliability index. However, the newly revised code GB50068-2018 increases the partial load factor and requires that the minimum value of the component reliability index should not be lower than the target reliability index. The reliability of the shear capacity of shear walls has not been calibrated in the Chinese codes. To determine whether the reliability of the shear capacity of reinforced concrete shear walls meets the requirements of GB50068-2018, 74 shear wall test data were collected and screened. The test and calculated values of the shear capacity of the specimens were analysed to obtain statistical parameters of the uncertainty of the computational model; subsequently, the statistical parameters of the resistance could be calculated. The Rackwitz-Fiessler method was used to calculate the reliability index of the shear capacity of shear walls. This study also compared the reliability of the shear capacity of shear walls according to GB50068-2018 and GB50068-2001. The reliability index obtained in GB50068-2018 is 5.88 %–8.02 % higher than that obtained in GB50068-2001. However, the reliability index of the shear capacity of shear walls does not meet the target reliability index requirements of GB50068-2018. In this work, the formula for the shear capacity of shear walls is updated with a reliability index adjustment coefficient of 0.9 so that the reliability index calculated using the adjusted formula meets the current code’s requirements.

Keywords

• Reliability index
• Shear capacity
• Concrete shear wall
• Statistical parameter