【作者】 李东超；

【导师】 张喜德；

【作者基本信息】 广西大学 ， 结构工程， 2007， 硕士

【摘要】 随着混凝土箱梁及薄壁箱梁结构在桥梁建设中不断推广应用，该桥型在施工和使用过程中也出现了较多的病害，但对该病害产生原因以及加固措施的研究目前仍处于进行阶段。本文首先分析导致该类型桥梁出现病害的一般原因，结合南宁邕江大桥试验检测数据，具体分析该桥病害原因并指出加固方向。对比分析了英国、德国和我国相应规范中关于箱梁翼缘有效分布宽度的计算方法，通过建立空间有限元模型以及研究邕江大桥实际裂缝分布，提出规范计算中有活载横向分布系数考虑不足的缺陷，该缺陷是导致结构前期翼腹连接处出现过早出现裂缝的主要原因。论文深入研究了对薄壁箱梁加固较为适用的体外预应力加固技术，重点分析体外预应力加固的预应力损失、极限状态下应力增量、分批张拉以及加固计算、体系防腐和减震等方面。经过对邕江大桥加固方案的设计与对比表明，体外预应力加固技术能够较好的满足该类型桥梁的加固要求。在此基础上，通过有限元法对部分加固效果进行对比分析，计算表明加固效果较好，同时提出优化预应力束纵向布筋方式，提高了加固效果。更多还原

【Abstract】 Along with the increasing application of box girder and thin-walled boxgirder of concrete in bridge building, there are more and more diseases in thistype of bridge during building and using. But the study of the causation of thediseases and strengthening methods is still on the march. Firstly this dissertationanalyzes the common causations of this type of bridge and the special causationof YongJiang Bridge in NanNing City based on the test data, and indicates thepoints of strengthening. The approach to the effective width of flange of boxgirder in English, Germany and China is analyzed contrastively, and thelimitation is put forward through building 3-D FEM model and studying thecrack distribution of YongJiang bridge, which is the primary reason to theappearing of cracks in the joints of flanges and webs. This paper research themethod of external pre-stressing particularly, which is more suitable forreinforcing the bridge with thin-walled box girder, including pre-stressing lose,stress increment in ultimate state, batched tension, calculation, anticorrosion andvibration damper and so on. The designing and comparing of reinforcing plansindicate that the external pre-stressing method can fit in with the need of thistype of bridge more better. On the base of this, this paper analyzes and compares the result of reinforcing effect with the method of finite element, and theanalysis data shows that the effect is well. Meanwhile, the optimization designof lengthways external tendon is put forward, which improves the reinforcingeffect.更多还原