【作者】 李进；

【导师】 史庆轩；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2008， 硕士

【摘要】 高强钢筋强度高、性能稳定,能有效减轻建筑物自重并提高资源利用率,在国外已得到广泛的应用。随着《混凝土结构设计规范》(GB50010-2002)的颁布和实施,HRB400(新Ⅲ级钢)级钢筋已经作为主导钢筋推广并应用于工程结构。然而我国对于高强度钢筋作为抗剪箍筋的研究才刚刚起步,缺乏试验资料,对于依靠试验资料经统计分析法确定的抗剪承载力公式,可能会出现计算承载力不满足高强箍筋混凝土梁抗剪承载力的情况,因此有必要对高强箍筋混凝土梁的试验资料进行收集、整理和分析,从而对抗剪承载力计算公式有所改进和完善。本文统计了335根无腹筋梁和104根高强箍筋有腹筋梁的试验数据,并对影响梁抗剪极限承载力的因素,如剪跨比(跨高比)、混凝土强度等级、纵筋配筋率、箍筋强度、截面高度等进行了分析,并总结了其中的规律。根据国内外相关文献,提出了修正的变角桁架-拱模型,该模型考虑了混凝土的软化现象、拱体效应等因素。利用统计的试验数据,结合桁架-拱模型,提出了基于模型改进的集中荷载作用下,高强箍筋混凝土梁极限抗剪承载力的计算公式。经验算,该计算公式能较好地符合试验结果,可以作为梁抗剪承载力计算的预测公式。利用统计的试验数据,提出了集中荷载作用下高强箍筋混凝土简支梁的建议计算公式。为了证明该公式的普遍性,用此公式的计算值,与试验结果、我国《混凝土结构设计规范》(GB50010-2002)及美国规范(ACI318M-05)的计算值进行了对比分析,结果表明,我国规范计算的承载力值较高,偏于不安全,美国规范的计算值则偏小,偏于保守,建议公式的计算值则介于二者之间,可以定量的计算高强箍筋混凝土梁的抗剪承载力。对试验中的高强箍筋筋混凝土梁用ANSYS进行了非线性有限元分析,对数值分析结果和试验结果进行了比较,结果表明,分析结果与试验结果吻合较好。更多还原

【Abstract】 The intensity of the High strength reinforced bar is high, and the property of it is stable. It can reduce the building’s deadweight effectively, raise the availability of resources, and become popular in overseas. After the application of the Code for Design of Concrete Structures (GB50010-2002), high strength reinforced bars (HRB400) have been widely used in concrete structures as the shear stirrup. But our country is short of the relative research about the high strength reinforced bar as the shear stirrup. The formula depending on the statistical analysis of the test datum may not satisfy the actual requirement. Therefore the test datum about the high-strength concrete beam stirrups should be collected to improve the formula on calculating the ultimate shear capacity.In this paper, 335 non-web reinforcement beams and 104 high-strength stirrups web reinforcement beams were collected to test datum. The factors that affect shear strength of concrete including shear span ratio, concrete strength, ratio of longitude bar, ratio of stirrup, overall thickness of member and so on were analyzed and Summarized.The revised angle truss-arch model was proposed based on the relative literature and experimental data collected. The soft phenomenon of concrete, arch-effects and others were considered in the model. A revised formula on calculating the ultimate shear capacity of RC beam under the concentrated load was proposed based on the test data collected and the truss-arch model. The results from the proposed formula conformed fine to the experiment data. So it could be used to predict the ultimate shear capacity.On the basis of statistical data, an empirical equation to estimate the ultimate shear capacity was proposed. In order to prove the universality of the formula, the calculation of the formula was compared with the test results, Code for design of Concrete structures (GB50010-2002) and ACI 318M-05 Building Code. The results indicated that the calculation of Chinese code was high and insecurity, the calculation of American code was low and conservative while the calculation of regression formula lay between the two. It can be used to calculate the shear capacity of the high-strength concrete beam stirrups.The high-strength concrete beam stirrups listed in literature were analyzed by ANSYS. The results of nonlinear element analysis were compared with the test results. It indicated that the analysis was in good agreement with the test results.更多还原