【作者】 张峰；

【导师】 李丽； 刘韬；

【作者基本信息】 西华大学 ， 工程硕士（专业学位）， 2022， 硕士

【摘要】 上世纪90年代以来,大跨径连续刚构桥在公路桥梁建设中占据了很大比例。近年来随着交通量的剧增、车辆超载等因素的影响,出现了很多的病害,诸如梁体开裂、主梁结构持续下挠以至超限等,亟需进行检测评估和加固。本文针对此类情况,研究既有病害连续刚构桥的检测、评估工作,在此基础上,对其加固方案及加固效果进行研究。论文以贵州省某主跨径162m连续刚构公路桥梁为工程依托,进行结构检测、动静载试验、技术状况评定、加固方案研究等工作,以期对同等类型的病害桥梁的检测评估、维修加固工作,给出参考和借鉴。论文的主要研究内容如下:(1)分析大跨径连续刚构桥梁主要病害特点及病害原因。介绍连续刚构桥梁一般检测、静载试验及动载试验等检测评估手段和内容,据此确定桥梁技术状况等级与承载能力等级。(2)对大跨径连续刚构桥相关维修加固方案进行研究和比较,阐述其各自优缺点及适用范围,重点研究体外预应力加固方案。(3)以贵州省某主跨径162m连续刚构公路桥梁为工程依托,在前述研究的基础上,对其进行桥梁技术状况评定、静载试验、动载试验工作,检测及评定结果表明本桥梁体下挠超限,承载能力校验系数过大,需要加固。(4)在技术评定结果的基础上,提出以体外预应力加固为主,粘贴钢板加固为辅的加固方案。采用Midas Civil 2020对加固前后的结构状况进行有限元模拟计算,研究在加设体外预应力钢束情况下,主梁应力、变形的改善情况。(5)对连续刚构桥进行加固后荷载试验,试验结果与桥梁加固前相关数据进行对比研究。该桥采用体外预应力加固方案加固后,梁体的校验系数、相对残余应变、相对残余挠度等明显降低,均小于规范规定值,安全系数充足,结构的承载能力满足规范要求,动力特性也有了一定的改善。更多还原

【Abstract】 Since the 1990 s,long-span continuous rigid-frame bridges have occupied a large proportion in the construction of highway bridges.In recent years,with the influence of factors such as the sharp increase in traffic volume and the overloading of vehicles,many diseases have appeared,such as beam cracking,continuous downward deflection of the main beam structure,and overruns.Aiming at this kind of situation,this paper studies the detection and evaluation of the existing diseased continuous rigid-frame bridge,and on this basis,studies its reinforcement scheme and reinforcement effect.Based on a continuous rigid-frame highway bridge with a main span of 162 m in Guizhou Province,the thesis carries out structural inspection,dynamic and static load test,technical condition evaluation,and reinforcement plan research,in order to detect and evaluate the same type of diseased bridges,maintenance and reinforcement work,giving references and references.The main research contents of the paper are as follows:(1)Discuss and study the main disease characteristics of long-span continuous rigid-frame bridges and the analysis of the causes of the disease.This paper introduces the testing and evaluation methods and contents of general testing,static load test and dynamic load test for continuous rigid frame bridges,and determines the technical condition grade and bearing capacity grade of the bridge accordingly.(2)Research and compare the related maintenance and reinforcement schemes of large-span continuous rigid frame bridges,discuss their respective advantages,disadvantages and application scope,and focus on the external prestress reinforcement scheme.(3)Relying on a continuous rigid-frame highway bridge with a main span of 162 m in Guizhou Province,on the basis of the aforementioned research,the bridge technical condition evaluation,static load test and dynamic load test were carried out.The inspection and evaluation results showed that The lower deflection of the bridge body exceeds the limit,the bearing capacity verification coefficient is too large,and reinforcement is required.(4)On the basis of the technical evaluation results,the external prestressing reinforcement scheme is proposed.Midas Civil 2020 was used to carry out finite element simulation calculation of the structural conditions before and after reinforcement,and to study the improvement of the stress and deformation of the main beam when external prestressed steel beams were added.(5)Carry out the post-reinforcement load test on the continuous rigid-frame bridge,and compare the test results with the relevant data before the bridge is strengthened.After the bridge is reinforced with the external prestressing reinforcement scheme,the calibration coefficient,relative residual strain and relative residual deflection of the beam body are significantly reduced,all of which are less than the specified values in the specification,the safety factor is sufficient,the bearing capacity of the structure meets the requirements of the specification,and the dynamic characteristics also have some improvement.更多还原