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根据现有关于钢筋混凝土无腹筋细长梁剪切破坏机理问题的研究成果,介绍了基于修正压力场理论的抗剪模型、临界剪切裂缝理论、塑性理论、压力路径理论、劈裂破坏理论和基于截面应变分析的抗剪模型的基本假设、核心观点及受剪承载力计算方法,并给出总结、归纳及评析;另一方面,利用相关试验数据和ACI-DAfStb无腹筋细长梁剪切破坏数据库,分别对不同理论模型的受剪承载力计算公式进行了设计参数的影响评估和统计评估;并展望了无腹筋细长梁剪切破坏机理研究的发展方向。研究结果表明:不同理论模型的部分假设缺少直接的试验依据支持,梁腹混凝土的受拉(劈裂)或受剪(骨料咬合)以及受压区混凝土对抵抗剪力的贡献成为抗剪机制的主要分歧;不同受剪承载力计算公式对不同影响因素的考虑方式的合理性和计算结果的准确度均有待进一步提高。后续深入研究应综合考虑剪切破坏问题的随机性和物理属性,利用先进测试技术、应力演化分析方法,进一步揭示剪切破坏机理。
According to the existing research results on shear failure mechanism of reinforced long bar without web reinforcement, the shear model, critical shear fracture theory, plastic theory, pressure path theory, splitting failure theory and The basic assumption, core view and calculation method of shear strength of shear model based on cross-sectional strain analysis are summarized, summarized and evaluated. On the other hand, using the relevant experimental data and ACI-DAfStb shear without web reinforcement The damage evaluation database and the calculation formulas of the shear capacity of different theoretical models were respectively used to evaluate the influence of design parameters and evaluate the statistical results. The development direction of shear failure mechanism of long web without web ribs was also prospected. The results show that the partial assumptions of different theoretical models lack of direct experimental support, and the tensile (splitting) or shearing (aggregate bite) of beam-girder concrete and the contribution of concrete to shear resistance in compression zone become the shear mechanism The rationality of different factors considering the calculation formulas of different shear bearing capacity and the accuracy of calculation results need to be further improved. Subsequent in-depth study should take into account the randomness and physical properties of the shear failure problem, using advanced testing techniques, stress evolution analysis method to further reveal the shear failure mechanism.