强受扭损伤箱梁加固后的压弯性能研究  

Study on Bending Performance after Reinforcement of Strong Torsional Damaged Box Girder

作　　者：刘国坤[1] 颜东煌[1] 涂光亚[1] 袁明[1] 

机构地区：[1]长沙理工大学土木与建筑学院,湖南长沙410114

出　　处：《公路交通科技》2017年第12期66-72,共7页Journal of Highway and Transportation Research and Development

基　　金：国家重点基础研究发展规划(九七三计划)项目(2015CB057706);国家自然科学基金项目(51678068;51678070)

摘　　要：为研究某特大跨双索面混凝土斜拉桥因火灾致强受扭损伤的混凝土箱梁能否修复使用,对强受扭损伤加固后主梁的压弯刚度、扭转刚度及抗弯极限承载力开展了模型试验研究,评估灌浆-锚钢加固对主梁的压弯刚度及扭转刚度的影响。依据常用规范公式对箱梁抗弯极限承载力及正常使用极限状态下的变形、裂缝特征进行验算,评估规范中相应计算公式的适用性,并对加固箱梁在压弯荷载作用下的破坏形态进行对比分析。结果表明:灌浆-锚钢加固能有效地提高弯扭剪复合受力下箱梁的压弯刚度及扭转刚度;在压弯荷载作用下,加固梁的最终破坏形态为箱梁底板拉裂至钢筋屈服破坏,顶板混凝土没有被压溃,腹板锚贴钢板基本无损坏,但顶板锚贴钢板与混凝土界面发生了剥离现象,钢绞线未被拉断;GB50010—2010、JTG D62—2012、ACI318M-05规范均能较为准确地计算箱梁的抗弯极限承载力,ACI318M-05规范计算试验梁在正常使用极限状态下的跨中挠度值与实测值较为接近,基本能反映预应力混凝土箱梁正常使用极限状态下的变形性能;GB50010—2010规范计算试验梁的最大裂缝宽度和裂缝间距与实测值均较为接近,基本能反映预应力混凝土大比例缩尺箱梁的裂缝特性。In order to study whether a special extra long-span double cable surface concrete cable-stayed bridge with strong torsional damage caused by fire can be repaired and used, the model test research on bending stiffness, torsional rigidity and ultimate flexural capacity of the damaged main girder after reinforcement is carried out. The influence of grouting and anchoring steel reinforcement on bending stiffness and torsional stiffness of main girder is evaluated. Based on the normative formulas, the checking calculation on the ultimate flexural capacity together with the deformation and crack features under serviceability limit state of the box girder is conducted. The applicability of the relative formulas in the specification are assessed, and the failure modes of the reinforced box girder under bending load are comparatively analysed. The research result shows that （1） grouting and anchoring steel reinforcement is effective to improve the compression-flexure stiffness and torsional rigidity under bending, torsional and shearing composite force condition; （2） under the action of bending load, the ultimate failure mode is that the bottom flange of box girder from failed with tensional crack to steel rebar yield failure, the deck concrete of box girder did not crushed and there is no damage to steel plate at the web, while the steel plate anchored on the deck peeled off from the concrete and the steel strands are not snapped; （3） GB50010--2010, JTG D62--2012 and ACI318M -05 specifications are suitable for more accurate calculation of the ultimate bending capacity of box girder, the mid-span deflection of the test beam under serviceability limit state calculated by ACI318M -05 specification is close to the measured deflection, which can reflect the deformation performance of prestressed concrete box girder under serviceability limit state ; （4） the largest crack width and the crack spacing of test beam calculated by GB50010-2010 specification are close to the measured values, which can reflect the cra

关 键 词：桥梁工程 压弯性能 模型试验 混凝土箱梁 扭转刚度 抗弯极限承载力 

分 类 号：U446.1[建筑科学—桥梁与隧道工程]