钢筋混凝土无腹筋细长梁剪切破坏机理模型研究综述

摘要

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。%Based on the review of domestic and foreign researches on the shear failure mechanism of slender reinforced concrete beams without shear reinforcement,the basic assumptions,the key points and the calculation methods for shear strength of different models were introduced and commented,such as the modified compression field theory,the critical shear crack theory,the plasticity theory,the compressive force path theory,the splitting failure theory and the strain based shear strength model.Using the test data from the related experimental programs and the ACI-DAfStb shear database of slender beams,impact assessments of important design parameters and statistical evaluations were conducted on the calculation methods for shear strength of different models.Some points of view on expectation of shear failure were presented.The results showed that the absences of direct experimental proofs of some hypotheses were apparent and different opinions on the shear transfer contribution of diagonal tension (splitting ),shear (aggregate interlock )and the flexural compression zone were the main divergence of the shear transfer mechanism.Further improvements in the rationality of the considerations for different factors and the accuracy of the calculation methods for shear strength were essential.In subsequent research work,the random and physical characteristics of shear failure should be considered synthetically.Advanced testing technology and analysis of the evolution of the stress field can be utilized in revealing the mechanism of shear failure.