【作者】 杨斌；

【导师】 王磊；

【作者基本信息】 吉林大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 本文首先介绍了国内外桥梁上部结构加固的发展、研究现状及常用的加固方法,在此前提下将加大截面法和体外预应力法进行了有机的结合,衍生出一种新型的有粘结预应力加固方法。本文在清晰地阐述了主要设计理论之后,详细介绍了新型加固体系的强度验算、传力装置的内力分析、传力区混凝土局部受力分析、预应力损失及预应力加固体系的防腐等重要内容。通过对混凝土构件在加固前后分别进行的破坏荷载对比试验验证了新型加固体系的有效性和可行性,得出的试验结果说明了此加固方法的高效性。并根据试验过程初步总结出此方法的操作流程、施工机具、注意事项及使用材料等。更多还原

【Abstract】 The bridge is the most important spanning structures in the field of road transport and has a very significant position in the modern highway system.It is necessary to strengthen and maintain the bridges timely and effectively which have aged,split and damaged.The typical bridge strengthening approaches are: deck reinforcement layer reinforcement methord,outsouring concrete reinforcement methord,gunite concrete reinforcement methord,paste steel reinforcement methord,paste the carbon fiber reinforcement methord,transforming the structural system reinforcement methord and exteral prestressing reinforcement methord.The paper proposes a new brdige bonded prestressing reinforcement methord applicable to the small&medium span bridge,which combines with increasing section reinforcement methord and exteral prestressing reinforcement methord on the basis of the existing bridge reinforcement methords.This methord is not only simple,but also can ensure the integrity of the structures.Old and new systems can work coordinately, and it has overcome the stress hysteresis of other methods.In addition it can also reduce the structural deflection and crack width, improve the structural carrying capacity,the resistance of cracks significantly and the stress state of the structures effectively.The design idea of this method is as follows: thus the tension of the level linear prestressing tendons(high-tensile bolts) under the beam to realize the application of the exteral reinforcement prestressing,use the anchor for anchorage in the anchor-side,make the use of prestressing provided by the vertical tendons(high-tensile bolts) to press the transmisssion equipment behind the anchors on the beam,transfer the level prestressing to the beam rely on friction between the beam and transmisssion equipment,at last,spray the polymer mortar on the bottom of the beam ,the reinforcement has completed at tins point.The paper mainly covers the research not only on the material , mathord of the tension and layout of the prestressing tendons,but also the anchoring device,performance of the polymer mortar and corrosion of the prestressing system.The paper makes a checking on the normal and oblique section separately on the basis of design specification of highway bridges and culverts. The concrete of the transmission region and the transmisssion equipments are calculated in the context of elasticity.All of these provide the theory foundation for the design.On the basis of the theory, the paper also carried out a destructive load comparative experiment on the beams.In the experiment,the new method which is put forward in the thesis is regarded as the core of the strengthening program,the precast hollow slabs which are very staple in the civilian construction are strengthened for use as the carrier, the precast hollow slabs are strengthened by high-tensile bolts,and the destructive tests are separately carried on the slabs which have been strengthened and not.In the tast,the hogging,destruvtive load value and destructive form are registered under the different load.The outcome of the experiment is indicated that the new mothod is feasible and reasonable.The test concludes that:1. the new mothod is effective and feasible;2. the method have the higher reinforcement efficency and can increase the carrying capacity of the structure apparently;3. the new and old system can work together well and have a good combination;4. the new anchor device is effective and can anchor the prestressing tendon effectively;5. it is feasible to regard the high-tensile bolt as the prestressing tendons.Because the new reinforcement method is never used,so this paper mainly do a research on the applicability ang validity of the new way.In addition,there are still some problems need to resolve:1. the object of the new reinforcement mothod is the upper structure of small&medium span bridge,it is worth of verifying that if it applies to the long&medium span bridge;2. it’s need to be confirmed that ultralong high-tensile bolt wtether or not can be produced to meet the needs of the actual reinforcement;3. it is need to opyimize the size of anchoring device;4. the key part of the transmission region is need to have a more accurate counting; 5. the of influence the polymer mortar towards the structure;6. reinforcement system need to be futher optimized and improved.更多还原