再生混凝土柱强剪弱弯设计可靠度分析

Analysis on Design Reliability of Strong Shear Weak Bending of Recycled Concrete Column

为评价再生混凝土能否满足结构抗震性能要求,提出了一种在地震作用下再生混凝土柱强剪弱弯设计可靠度指标的计算方法。将柱强剪弱弯设计的失效概率视为在不发生弯曲破坏的条件下发生剪切破坏的概率。用该方法计算了在不同的柱截面尺寸、配筋率与配箍率、剪切增强系数下的柱强剪弱弯设计可靠度指标。结果表明:在相同的设计参数下,再生混凝土柱强剪弱弯设计可靠度指标低于普通混凝土柱;截面尺寸对其影响较小;该指标随配筋率提高而增大,随配箍率和轴压比提高而降低;为达到与普通混凝土柱相同的目标可靠度指标,须提高剪切增强系数约0.05。

To evaluate whether recycled concretes meet the structural anti-seismic requirements,a method is proposed to calculate the reliability index of strong shear weak bending of recycled concrete columns under earthquake.The failure probability of strong shear weak bending of columns is considered as the probability of shear failure prior to bending failure.Using the method here,the design reliability indices are analyzed in terms of different sectional sizes,longitudinal reinforcing steel bar ratios,hoop steel ratios and enhanced shear coefficients.The results show that the design reliability index of the strong shear weak bending of recycled columns are lower than that of ordinary concrete columns when applying the same design parameters;it increases with the increase of the longitudinal reinforcing steel bar ratio,declines with the increase of the axial force ratio and hoop steel ratio,and maintains invariable when changing sectional sizes;to obtain the same target reliability index of common concretes,the enhanced shear coefficients should be improved by 0.05.