锈蚀钢筋混凝土柱基于变形的性能指标研究

采用ABAQUS有限元软件，对按GB 50011-2010《建筑抗震设计规范》和GB 50010-2010《混凝土结构设计规范》设计的342个锈蚀钢筋混凝土柱进行有限元分析，研究钢筋的锈蚀率、轴压比、剪跨比、配箍率和纵向钢筋配筋率等参数对钢筋混凝土柱变形性能的影响。结果表明：当钢筋的锈蚀率较小时，构件的变形性能受锈蚀率影响不大；当钢筋的锈蚀率达到10%以后，构件的破坏形态发生改变，变形能力急剧退化;随着轴压比的增大，构件的变形能力降低;轴压比较小的构件变形性能受剪跨比影响比轴压比较大的构件明显；随着配箍率和纵向钢筋配筋率的增大，构件的变形能力有所提高；提出了锈蚀钢筋混凝土柱抗震性能等级和性能界限状态的划分方法，以塑性转角作为变形性能指标，对数值计算结果进行统计分析，得到了锈蚀钢筋混凝土柱各性能界限点的塑性转角统计特征值。研究成果可为钢筋混凝土结构全寿命的性能化抗震设计和抗震性能评估提供参考。

Study on deformation-based performance index of corroded reinforced concrete column

The finite element analysis of 342 numerical samples of corroded reinforced concrete (RC) columns designed according to GB 50011-2010 ‘Code for seismic design of buildings’ and GB 50010-2010 ‘Code for design of concrete structures’ was performed with the aid of ABAQUS software to evaluate the effect of corrosion ratio of reinforcing bars, axial compressive load ratio, shear-span ratio, volumetric stirrup ratio and longitudinal reinforcement ratio on the deformation performance of corroded RC columns. It is found that the corrosion ratio of reinforced bars has little effect on the deformation capacity of corroded RC columns when the corrosion ratio is low. For RC columns with corrosion ratio exceeding 10%, the columns fail due to the deterioration of bond between the concrete and the longitudinal reinforcing bars, which induces significant degradation of deformation capacity of the columns. With the increasing of axial compressive load ratio, the deformation capacity of corroded RC columns decreases. The shear-span ratio has more pronounced effect on the deformation capacity of RC columns with low axial compressive load ratio than those with high axial compressive load ratio. The deformation capacity of corroded RC columns increases with the increase of stirrup ratio and longitudinal reinforcement ratio. The classification criteria of seismic performance levels and limit states of corroded RC columns are proposed in this paper. Plastic rotation angle is selected as the performance index. The statistical characteristic values of plastic rotation angle corresponding to the performance limit states of corroded RC columns are obtained based on the numerical results. The research results can be utilized for life-cycle oriented seismic design and seismic performance evaluation of RC structures.