基于改进拉压杆模型的PC框架节点抗剪强度预测*
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王国林1，孟少平2（1 上海应用技术学院城市建设与安全工程学院， 上海 201418; 2 东南大学混凝土及预应力混凝土结构教育部重点实验室， 南京 210096）［摘要］针对预应力混凝土（PC）框架节点抗剪强度合理计算模型的缺乏，建立了一个显式考虑预应力效应的改进拉压杆模型。依据Kupfer-Gerstle双向拉压强度准则，考虑了节点核心区混凝土软化效应，并基于此准则推导了一个简便实用的受剪承载力预测公式。通过对文献中21组内、外节点进行分析，得到试验值与模型预测结果的平均比值为1.14，离散系数为0.139，表明本文公式预测结果较精确、连续且偏于安全，而且还优于《混凝土结构设计规范》（GB 50010—2010）中的设计方法，可用于有、无粘结PC框架节点的抗震设计。［关键词］预应力混凝土; 梁柱节点; 抗剪强度; 预应力效应; 拉压杆模型; 混凝土双向拉压强度准则中图分类号：TU378.4 文献标识码：A 文章编号：1002-848X(2013)19-0038-04Shear strength prediction of prestressed concrete beam-column joints based on modified strut-and-tie modelWang Guolin1, Meng Shaoping2(1 School of Urban Construction and Safety Engineering, Shanghai Institute of Technology, Shanghai 201418, China;2 Key Laboratory of C & PC Structures, Ministry of Education, Southeast University, Nanjing 210096, China)Abstract: Due to the scarcity of rational models for predicting the shear strength of prestressed concrete (PC) beam-column joints, a modified strut-and-tie model was established. In the proposed model, the effect of prestress was explicitly taken into account. Kupfer-Gerstle biaxial tension-compression failure criterion of concrete was utilized to take account of the concrete softening effect, based on which a simple and convenient formula was derived. A comparison of 21 exterior and interior beam-column joints shows that the model predictions were accurate, consistent and conservative with an overall average test result to prediction of 1.14 and a coefficient of variation of 0.139, and also illustrate its superior accuracy over the design method of Code for design of concrete structures(GB 50010—2010). It indicates that the proposed model can be employed for design of PC beam-column joints with bonded and unbonded tendons.Keywords: prestressed concrete; beam-column joint; shear strength; effect of prestress; strut and tie model; biaxial tension-compression failure criterion of concrete*国家自然科学基金项目（51308339），上海市教育委员会科研创新项目（13YZ123）。作者简介：王国林，博士，讲师，Email: felixwseu@163.com。参考文献［1］PAULAY T. Equilibrium criteria for reinforced concrete beam-column joints［J］. ACI Structural Journal, 1989, 86(6): 635-643.［2］WANG G L, DAI J G, TENG J G. Shear strength model for RC beam-column joints under seismic loading［J］. Engineering Structures, 2012, 40: 350-360.［3］PARK R, THOMPSPON K J. Cyclic load test on prestressed and partially prestressed beamcolumn joints［J］. PCI Journal, 1977, 22(5): 84-110.［4］唐九如. 部分预应力框架梁柱节点在反复荷载下的受力性能［J］. 建筑结构学报，1987, 8(5): 1-15.［5］孟少平，韩重庆. 预应力框架节点抗震设计中两个问题的探讨［J］. 工程抗震，1998(4): 3-7.［6］KASHIWAZAKI T, NOGUCHI H. Structural performances of prestressed concrete interior beam-column Joints［C］//In Proceedings of the 12th World Conference on Earthquake Engineering (12WCEE). Auckland, New Zealand, 2000.［7］UCHIDA R, HAMAHARA M, SATOH N, et al. Effects of prestress on ultimate strength of concrete beam-interior column frame assemblies［J］. Journal of Structural and Construction Engineering,AIJ,2004,69(583):107-113.［8］NISHIYAMA M, WEI Y. Effect of post-tensioning steel anchorage location on seismic performance of exterior beam-to-column joints［J］. PCI Journal, 2007, 52(2): 1-13.［9］薛伟辰，姜东升，陈以一，等. 预应力混凝土空间节点抗震性能试验研究［J］. 建筑结构学报，2007, 28(1): 43-51, 58.［10］李旭红，房贞政，陈浩德. 预应力混凝土空间框架节点二维拟静力试验研究［J］. 地震工程与工程振动，2009, 29(1): 70-77.［11］NZS 3101—2006 Concrete structures standard, Part 1-The design of concrete structures［S］. Wellington: Standards New Zealand, 2006.［12］GB 50010—2010 混凝土结构设计规范［S］. 北京：中国建筑工业出版社，2011.［13］JGJ 140—2004 预应力混凝土结构抗震设计规程［S］. 北京：中国建筑工业出版社，2004.［14］刘鸣，刘伯权，邢国华. 基于简化拉压杆模型的钢筋混凝土框架异型节点抗剪性能研究［J］. 地震工程与工程振动，2011, 31(2): 63-67.［15］秦全，王立成，宋玉普.混凝土框架内节点受剪承载力计算模型和方法研究［J］.建筑结构，2013，43(8)：63-68.［16］SHIOHARA H. New model for shear failure of RC interior beam-column connections［J］. Journal of Structural Engineering,ASCE,2001,127(2):152-160.［17］KUPFER H, GERSTLE K H. Behavior of concrete under biaxial stress［J］. ASCE Journal of Engineering Mechanics Division, 1973,99(EM4)：853-866.［18］ACI 318R—08 Building code requirements for structural concrete and commentary［S］. Farmington(MI)：American Concrete Institute, 2008.［19］HWANG S J, LEE H J. Strength prediction for discontinuity regions by softened strut-and-tie model［J］. ASCE Journal of Structural Engineering，2002，128(12): 1519-1526.［20］PAULAY T, PRIESTLEY M J N. Seismic design of reinforced concrete and masonry buildings［M］. John Wiley & Sons, 1992: 744.［21］岳庆霞，张鑫，贾留东，等. 基于拉压杆模型的框架结构平移托换梁受剪承载力研究［J］. 建筑结构学报，2012, 30（10）: 110-115.［22］Eurocode 8 Design of structures for earthquake resistance, Part 1: general rules, seismic actions and rules for buildings［S］. London: 2004.［23］ZHANG N, TAN K H. Direct strut-and-tie model for single span and continuous deep beams［J］. Engineering Structures, 2007, 29(11):2987-3001.［24］ACI 352R—02 Recommendations for design of beam-column connections in monolithic reinforced concrete structures［S］. Farmington Hills (MI): American Concrete Institute, 2002.
