体外束加固稀索钢筋混凝土斜拉桥静力试验  

Static load test on reinforced concrete cable-stayed bridge with rare cables strengthened by external prestressed steel strand

作　　者：孙全胜[1] 于海涛 徐圣奇 SUN Quan-sheng;YU Hai-tao;XU Sheng-qi(School of Civil Engineering,Northeast Forestry University,Harbin 150040,Heilongjiang,China;China Desion Group Co.,Ltd.,Nanjing 210005,Jiangsu,China)

机构地区：[1]东北林业大学土木工程学院,黑龙江哈尔滨150040 [2]华设设计集团股份有限公司,江苏南京210005

出　　处：《长安大学学报（自然科学版）》2021年第1期39-49,共11页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(51708092)。

摘　　要：为研究稀索钢筋混凝土斜拉桥应用体外预应力束加固后的静力性能提升,以穆棱河斜拉桥加固工程为依托,基于斜拉桥的损伤情况和既有加固经验,通过改变索力参数和体外预应力束参数提出了5种不同加固方案。采用MIDAS有限元模型模拟结构损伤状态和各种加固方案,在设计荷载作用下分别以主梁位移、主塔偏位、斜拉索索力、主梁上下缘应力为评价指标,分析最优加固方案。设置静力试验,详细讨论主梁竖向位移、主梁和主塔截面应变、主塔偏位、典型索力增量等在体外束加固后的变化情况,对比实际加固效果。研究结果表明:有限元分析中,体外束加固主梁方案能够显著减小主梁竖向位移和主塔水平位移,同时在一定程度上改善了主梁上、下缘应力,但索力优化效果差异不大;静力试验分析中,斜拉桥加固后的实测应变和位移均小于计算值和加固前实测值,单测点挠度降低幅度最大达37.94%,单测点应变降低幅度最大达43.47%,裂缝宽度满足设计要求;实测索力与计算索力变化趋势大体相符;主梁刚度储备提升最高达33%,主梁强度储备提升最高达31%。加固后斜拉桥整体承载能力提升明显,体外预应力加固技术运用于稀索钢筋混凝土斜拉桥切实可行。研究结果对早期建成的稀索钢筋混凝土斜拉桥加固具有一定的借鉴性。In order to study the improvement of the static mechanical properties of the reinforced concrete cable-stayed bridge with rare cables strengthened by external prestressed steel strand, the reinforcement project of the Muling River Cable-stayed Bridge was considered as an example. Based on the damage situation of the cable-stayed bridge and the existing reinforcement experience, a total of 5 different reinforcement schemes were proposed by changing the cable force parameters and the external prestressed steel strand parameters, and the damage state and different reinforcement schemes were simulated by establishing MIDAS finite element model, the displacement of the main beam, the deflection of the main tower, the cable force of the stayed cable, and the stress of the upper and lower edges of the main beam were used as evaluation indicators to analyze the optimal reinforcement plan under the design load. Then a static load test was set to compare the actual strengthened effect, the vertical displacement of the main girder, the section strain of the main girder and the main tower, the deflection of the main tower, and the typical increment of cable force were discussed in detail after strengthening. The results show that the scheme of main beam that strengthened by external prestressed steel strand can significantly reduce the vertical displacement of the main girder and the horizontal displacement of the main tower, and at the same time improve the stress on the upper and lower edges of the main girder to a certain extent, but the effect of cable force optimization is not much different in finite element analysis. In the study of static load test, the measured strain and displacement of the cable-stayed bridge after reinforcement are less than the calculated value and the measured value before reinforcement, the deflection of a single measuring point is declined by up to 37.94%, and the strain at a single measuring point is declined by up to 43.47%, and crack width meets design requirements. The measured cable forc

关 键 词：桥梁工程 稀索斜拉桥 对比分析 体外预应力加固 静力试验 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]