【作者】 李辉；

【导师】 邓宗才；

【作者基本信息】 北京工业大学 ， 土木工程， 2012， 硕士

【摘要】 短柱的刚度大，变形能力和耗能性能差，在地震中往往发生脆性的剪切破坏，国内外多次震害调查都表明短柱破坏是造成钢筋混凝土（RC）框架结构破坏甚至倒塌的一个重要因素，但是在混凝土框架结构设计中短柱难以避免。预应力钢绞线加固是一种新型的抗震加固方法，可显著改善RC短柱的抗震性能，在既有建筑加固领域有着广泛的应用前景。本文以实际框架短柱为模型，主要开展了以下两个方面的研究：1）预应力钢绞线加固RC短柱抗震性能试验研究；2）探讨预应力钢绞线加固的受剪机理，采用简单叠加方法提出预应力钢绞线加固RC圆形截面短柱的抗剪承载力计算公式。完成了13根预应力钢绞线加固RC短柱在低周反复荷载下的抗震性能试验，分析了各柱的破坏形态、延性、刚度、累积耗能以及损伤的发展规律，探讨了钢绞线配置特征值、预应力水平、轴压比等因素对短柱抗震特性的影响。结果表明：预应力钢绞线可有效改善RC短柱的抗震性能，延性和耗能能力显著提高，与未加固试件相比，预应力钢绞线加固短柱的位移延性系数、累积耗能最大值分别提高1.87倍和6.78倍；钢绞线配置量及预应力水平对加固柱滞回曲线有明显的影响，其他条件相同时，钢绞线配置量大或者预应力水平较高的试件滞回曲线较饱满；对于低轴压比(n≤0.30)试件，钢绞线配置特征值达到0.119、预应力水不小于0.40时即可获得较好的抗震性能；对于设计轴压比大于0.80的短柱，建议钢绞线配置特征值不宜小于0.237。文中还研究了试验过程中预应力钢绞线应变增量和箍筋应变的发展规律，发现随着水平位移的增大，箍筋对混凝土的约束及抗剪作用逐渐被钢绞线分担，预应力水平和配置特征值越大，钢绞线参与受力越早，分担的部分越大；分析了预应力钢绞线加固短柱抗剪的受力机理，提出了预应力钢绞线加固混凝土圆形截面短柱抗剪承载力计算公式。所建议公式具有形式简单，计算方便等特点，且具有一定的安全保证，与试验结果符合较好，可作为工程应用参考。更多还原

【Abstract】 As new strengthening technology, prestressed steel wires (PSW)strengthening can effectively enhance the seismic performance of RC shortcolumns, and it exhibits wide prospect in the field of structural rehabilitation. Inorder to study the engreening application of PSW technology, following studieswere carried out:1)Experimental Study on the Seismic Behavior of ConcreteShort Columns Strengthened with PSW;2)The mechanism of the concrete columnStrengthened with PSW has been studied in this paper,and formulas to calculatethe ultimate shear bearing capacity of RC columns retrofitted by PSW wereproposed.The seismic experiments of Thirteen RC short columns strengthened withPSW under low frequency cyclic loading are carried out, failure mode,hysteresiscurves, skeleton curves, ductility, stiffness degradation,energy dissipation anddamage evolution are analyzed, the effects of configuration index ofPSW,prestressing level of PSW and axial compression ratio on the seismicbehavior are studied.The results show that the seismic performance of the shortcolumns retrofitted in the method of PSW could be effectively enhanced. Theductility index and the energy dissipation capacity of the retrofitted specimensincrease with the configuration index and/or the prestressing level of steel wire.The biggest displacement ductility factor and accumulated energy dissipation ofthe columns strengthened with PSW are1.87times and6.78times higherrespectively than that of the un strengthened column. The seismic performance ofthe retrofitted columns can be improved significantly by increasing the theconfiguration index and/or the prestressing level of PSW.If the configurationindex of PSW is bigger than0.119,the prestressing level reaches0.40,the seismicperformance of the retrofitted specimens can be improved effectively when theaxial load ratio is lower than0.3.For retrofitted specimens that axial load ratio isbigger than0.8, the configuration index of PSW is recommended no less than0.237.The strain development of PSW and stirrup are analyzed,The mechanism ofthe concrete column has been studied in this paper. Based the test results, tworeasonable shear capability design formula is presented. the calculated results are safety and show good agreement with the tested one sand can be referenced inengineering practice.更多还原