附加自锚式悬索桥法加固连续箱梁桥效果分析  

Analysis of Effect of Using Added Self-Anchored Suspension Bridge to Strengthen Continuous Box Girder Bridge

作　　者：张文学[1] 汪振[1] 王鹏亮[1] 陈华婷[1] 

机构地区：[1]北京工业大学建筑工程学院,北京100124

出　　处：《世界桥梁》2017年第6期76-81,共6页World Bridges

基　　金：北京市自然科学基金面上项目(8122007)

摘　　要：针对大跨度预应力连续箱梁桥在使用过程中,由于主梁开裂和下挠等病害所造成的桥梁承载力严重不足问题,提出了一种附加自锚式悬索桥法加固方式。该方法的加固结构由桥塔、主缆、吊杆和组合型钢组成,加固时通过改变桥梁的受力状态达到加固效果。以某严重开裂的(72+120+72)m连续梁桥为背景,采用附加自锚式悬索桥法加固该桥,通过有限元计算,考虑不同荷载组合、预应力损失、超载等因素的影响,对比分析了加固前后桥梁结构的力学特性。研究表明:附加自锚式悬索桥法能有效控制主梁的内力与挠度,并抑制主梁裂缝的发展;但在超载作用下主梁中支点截面上缘主拉应力超限,在桥梁使用过程中车辆超载对其损伤的影响应予以重视。During the service period of the long-span prestressed concrete continuous box gird-er bridge, deteriorations like main girder cracking and downwarping can cause severe loss of the load bearing capacity of the bridge. A method of adding a self-anchored suspension bridge structure to strengthen the bridge of such type is proposed. The strengthening system comprises of towers, main cables, hangers and composite section steel, which can change the load bearing condition of the bridge to realize the goal of strengthening. A continuous girder bridge that suffers severe cracking was taken as the study background. The bridge has three spans of 72 m, 120 m and 72 m and has been strengthened by the method. The finite element calculation was conducted to analyze the influence of different load combination, prestress loss and overloading, and the mechanical be-havior of the bridge before and after the strengthening was contrastively analyzed. The study indi-cates that the added self-anchored suspension bridge can effectively control the internal force and deflection of the main girder, and curb the propagation of the cracks in the main girder. However, the main tensile stress in the upper edge of the central support cross section of the main girder will surpass the limit under the action of overloading, and the influence of the vehicle overloading on the damage of the bridge in its service period should be given enough concern.

关 键 词：桥梁加固 连续箱梁桥 自锚式悬索桥法 预应力损失 有限元分析 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]