Segura Christopher L, Sattar Siamak, Hariri-Ardebili Mohammad Amin
National Institute of Standards and Technology (NIST).
NIST.
ACI Struct J. 2022 May 1;119(3). doi: 10.14359/51734486.
In seismic performance evaluations, the force-deformation response of a structure is typically assessed using a deterministic analytical model, and inherent uncertainty is often neglected. For reinforced concrete structures, a source of uncertainty is variability in the mechanical properties of reinforcing steel and concrete (that is, material uncertainty). This paper presents an analytical investigation to quantify the impact of the statistical variability in mechanical properties of ASTM A706 Grade 60, 80, and 100 reinforcing steel and normalweight concrete on the seismic response of reinforced concrete bridge columns. The effects on the drift response, expressed by the coefficient of variation (COV), range between COV values of 0.1 for low-to-moderate ductility demands (that is, drift ratio < 5%), and 0.3 for larger ductility demands. The COV of the force demand is lower, ranging between 0.05 and 0.1. Overall, the study shows that material uncertainty can be incorporated in seismic performance assessments through a few additional analyses.
在地震性能评估中，通常使用确定性分析模型来评估结构的力-变形响应，而固有不确定性常常被忽略。对于钢筋混凝土结构，不确定性的一个来源是钢筋和混凝土力学性能的变异性（即材料不确定性）。本文进行了一项分析研究，以量化ASTM A706等级60、80和100钢筋以及普通重量混凝土力学性能的统计变异性对钢筋混凝土桥柱地震响应的影响。对位移响应的影响，用变异系数（COV）表示，对于低到中等延性需求（即位移比<5%），COV值在0.1之间，对于更大的延性需求，COV值在0.3之间。力需求的COV较低，在0.05到0.1之间。总体而言，该研究表明，通过一些额外的分析，可以将材料不确定性纳入地震性能评估中。
