基于简化修正压力场理论的钢筋混凝土柱荷载变形分析

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摘要：基于简化修正压力场理论对钢筋混凝土柱抗剪机理进行了分析，并考虑核心混凝土膨胀对箍筋抗剪承载力贡献的影响，计算了骨料咬合作用及受压区的抗剪承载力贡献，获得受拉区和受压区的抗剪强度，从而建立箍筋屈服后柱构件抗剪强度计算方法；结合传统截面纤维分析法，同时引入弯曲变形、剪切变形及滑移变形3种变形分量，在箍筋屈服前对柱构件进行抗弯分析，最终得出压弯剪作用下钢筋混凝土柱荷载变形曲线，并与所收集的15个钢筋混凝土柱低周反复试验结果进行了对比。研究结果表明：采用该方法计算的荷载变形曲线与试验骨架曲线吻合较好，对发生弯曲破坏、弯剪破坏及剪切破坏3种不同破坏类型的钢筋混凝土柱均有较好的分析效果，可用于压弯剪作用下钢筋混凝土柱的荷载变形分析。

关键词：钢筋混凝土柱；荷载变形；修正压力场理论；骨架曲线

中图分类号：TU375.3文献标志码：A

Abstract： The shear mechanism of reinforced concrete columns was analyzed based on simplified modified compression field theory. Considering the effect of expansion of core concrete on the shear capacity contribution of stirrups， the shear capacity contribution of aggregate interlock behavior and compressive zone were calculated. The shear strengths of tensile area and compressive area were obtained， and the calculation method of shear strength of column after stirrups yielded was established. Combined with the conventional section fiber analysis method， while three deformation components of bending deformation， shear deformation and slip deformation were introduced， the bending analysis of columns before stirrups yielded was carried out， the loaddeformation curves of reinforced concrete columns under compression bending shear action were obtained， and compared with the low cycle test results of 15 reinforced concrete columns collected. The results show that the loaddeformation curves calculated by the proposed method agree well with the test loaddeformation skeleton curves， and have better analysis effect on the reinforced concrete columns with flexural failure， bending shear failure and shear failure. The proposed method can be used for loaddeformation analysis of reinforced concrete columns under compression bending shear action.

Key words： reinforced concrete column； loaddeformation； modified compression field theory； skeleton curve

0引言

钢筋混凝土柱作为钢筋混凝土框架结构和桥梁结构中的主要承重及抗侧力构件，其抗震性能的优劣对整体结构有着重要影响。根据钢筋混凝土柱在地震作用下的破坏特征，其破坏模式可分为弯曲破坏、弯剪破坏以及剪切破坏3种，其中发生弯曲破坏的钢筋混凝土柱延性发展充分，具备良好的耗能机制，在地震中的危害相对较小，可以满足结构抗震延性设计要求。以剪切起控制作用的剪切破坏及弯剪破坏具有明显的脆性特征，设计中应予以避免。……