基于桁-拱叠加模型的体外预应力混凝土梁抗剪承载力计算方法  

A method based on truss-arch model for calculating the shear strength of externally prestressed concrete beams

作　　者：贺志启[1] 刘钊[1] 张宇峰[2] 

机构地区：[1]东南大学,江苏南京210096 [2]江苏省交通科学研究院,南京210017

出　　处：《土木工程学报》2010年第1期56-63,共8页China Civil Engineering Journal

基　　金：国家自然科学基金资助项目(50778038);江苏省交通科学研究计划项目(06Y41);东南大学优秀博士论文基金(2009)

摘　　要：通过剪力传递途径分析和结构拓扑优化,揭示了桁架-拱模型可以反映体外预应力混凝土梁主要受剪承载机理。通过桁架模型和拱模型的叠加,建立了体外预应力混凝土梁的抗剪承载力简化计算方法。公式形式简单,能够反映结构的受力机理,包含了梁的几何尺寸、剪跨比、配箍率、轴向预应力、混凝土强度、荷载形式等影响因素。公式可以统一考虑无腹筋梁和有腹筋梁,不同的剪跨比,以及体内体外混合配束的情况。应用本文方法与国内外已有试验进行对比,表明计算值与试验结果吻合良好且偏于安全。最后,通过参数分析得出了主要因素对抗剪承载力的影响规律。Based on shear transfer pathway analysis and structural topology optimization, a trnss-arch mode[ that rellects the principal mechanisms of shear resistance of externally prestressed concrete beams is proposed. Combining truss model and arch model, a calculation method for the shear strength of externally prestressed beams is derived, suitable for beams with and without web reinforcement, beams with different shear span-to-depth ratios, and beams prestressed with external and internal mixed tendons. The proposed simplified formulae have clear physical significance, including several substantial factors, such as beam geometry, shear span-to-depth ratio, transverse reil^foreement ratio, axial compression, concrete strength and load type. The. accuracy of the proposed method is verified through comparisons with experimental results in the literature. Parametric analysis is conducted tot identify the influences of several key factors to the shear strength.

关 键 词：体外预应力混凝土梁 抗剪承载力 桁一拱叠加模型 拓扑优化 

分 类 号：U448.35[建筑科学—桥梁与隧道工程] TU378.1[交通运输工程—道路与铁道工程]