基于反拱行为的空心板桥横向体外预应力加固模型  

A Lateral External Prestress Reinforcement Model for Hollow Slab Bridge Based on Arching Behavior

作　　者：黄海新 安帅锟 程寿山[2] 

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]交通运输部公路科学研究院,北京100088

出　　处：《公路交通科技》2018年第1期55-63,共9页Journal of Highway and Transportation Research and Development

基　　金：河北省科技计划项目(15215431)

摘　　要：同梁体内纵向预应力增设预拱度的原理,横向体外预应力也会使被加固的桥梁产生"反拱"现象,为明确该现象的产生机理,"反拱"程度的影响因素以及体外横向预应力对桥梁结构恒载和活载支座反力受力状况的评估,需对该加固方式进行进一步研究。针对上述问题文中基于铰接板法,在计入横向体外力产生的附加扭矩的条件下,建立了能获得横向预应力作用下各板反力分布的理论解析式,并采用有限元数值模拟手段,分别对体外预应力的大小、预应力筋布置高度、纵向布置间距、铰缝深度、铰缝损伤程度以及板梁片数等影响因素进行了量化研究,分析了该加固方式对桥梁活载和恒载的影响。结果显示,横向体外预应力作用引起的边板反力增大中板反力减小是"反拱"现象的内在原因,且与横向体外预应力大小、布置高度等加固方式的外在因素相比,铰缝深度、铰缝破坏程度等内在因素对支反力增量的影响程度更大;中板活载作用下,桥梁的反拱现象得到了一定程度的改善,各板受力更为均衡。提出了横向预应力加固方式更适用于大铰缝桥梁、铰缝破坏程度小于50%的桥梁,以及主要活载作用位置靠近中梁的窄桥,弥补了常规加固时仅以荷载横向分布改善状况作为单一指标的不足,为梁桥横向加固设计提供了理论指导。Same as the principle of the camber produced by longitudinal prestressing tendon in the beam body, the lateral external prestressing will also cause the arch phenomenon of the reinforced bridge. In order to clarify the mechanism of the phenomenon and the influencing factors of arch phenomenon, and to evaluate of the support reactions of bridge structure under dead load and live load by external transverse prestress, the reinforcement method should be further studied. In view of the above problem, based on hinged plate method, considering the additional torque generated by transverse external prestressing, we established a theoretical analytical formula about bearing reaction distribution of each slab under the action of the transverse prestressing, quantitatively studied the external prestressing, arrangement height of prestressed tendons and longitudinal spacing, hinge joint depth, hinge joint damage degree and beam slab number and other factors respectively by means of the finite element numerical simulation, and analyzed the influence of the strengthening method on the live load and dead load of the bridge. The result shows that （ 1 ） The internal cause of arch phenomenon is the increase of support reaction of side slab and the decrease of support reaction of central slab. Compared with the external factors of reinforcement such as transverse external prestress, arrangement height, the influence of internal factors such as hinge joint depth and joint damage degree on the increment of support reaction is greater. （2） The arch phenomenon of the bridge has been improved to a certain extent under the action of middle live load, and the force acting on each slab is more balanced. We proposed that the transverse external prestressing reinforcement method is more suitable for the bridge with large hinge joints and hinge joint damage less than 50%, and the narrow bridge with the main live load acting near the middle beam. It compensated for the deficiency of only taking single index as a result of lateral load

关 键 词：桥梁工程 横向加固 有限元分析 装配式空心板桥 体外预应力 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]