大跨度连续刚构桥检测评估与加固处治技术研究

发布时间：2018-05-31 07:39

本文选题：连续刚构桥 + 预应力检测　；参考：《清华大学》2014年硕士论文

【摘要】：大跨度预应力混凝土连续刚构桥是我国应用比较广泛的桥型之一,建造规模和数量居世界前列。但随着使用年限的增加和交通量的不断增大,不少桥梁出现了主梁挠度异常增大、腹板和底板出现开裂等病害,引起了工程界的广泛关注。结合几座典型大跨度预应力连续刚构桥的背景工程实例,总结现有预应力刚构桥检测方法,重点介绍预应力体系检测、混凝土内部缺陷检测和长期变形检测方法,给出检测实施过程中的关键点和检测流程,并结合具体检测实例,给出应用示范。对大跨度连续刚构桥出现的跨中下挠、箱梁开裂等普遍性病害,从计算理论、结构设计、施工工艺、环境温度变化等方面进行了原因分析。根据产生病害的原因,提出了采用施加体外预应力、改变结构体系、桥梁减载等方法抑制主梁下挠。某主跨210m预应力混凝土连续刚构桥,通车运营4年后,出现了跨中下挠、箱梁开裂等病害。根据此工程实例,对连续刚构桥的检测内容和检测方法进行阐述,并采用两套评定体系对检测结果进行评定,验证了评定结果的一致性。对大桥下挠的原因进行详细的分析,提出了在箱梁腹板增加8束19Φs15.2mm体外预应力进行加固。计算分析表明,加固效果明显,主跨跨中下挠得到改善,加固后,跨中理论上挠约1.7cm。主梁跨中、顶板的应力状况得到改善,腹板主拉应力也出现不同程度的降低。针对腹板、顶板、底板的开裂原因分析,采用粘贴碳纤维布或粘贴钢板的方法进行加固处理。本文针对大跨度连续刚构桥出现的病害,从现场检测方法、基于检测结果的技术状况评定方法到加固处治方法的成套技术进行了研究。阐述了现有预应力体系的检测方法,推荐了大跨度连续刚构桥预应力体系的检测流程。对比分析了《公路桥涵养护规范》(JTG H11-2004)和《公路桥梁技术状况评定标准》(JTG/T H21-2011)两套评定体系的不同,从应用者的角度给出了使用建议和意见。结合大跨度连续刚构桥的病害原因分析,给出了常用的加固方法,对体外预应力加固方法进行了详细阐述。最后本文通过典型案例对上述成套技术方法进行了分析验证。
[Abstract]:Long-span prestressed concrete continuous rigid frame bridge is one of the most widely used bridges in China. However, with the increase of service life and traffic volume, many bridges have many diseases, such as abnormal deflection of main girder, cracking of web and bottom plate, which has caused widespread concern in engineering circles. Based on the background engineering examples of several typical long-span prestressed continuous rigid frame bridges, this paper summarizes the existing detection methods of prestressed rigid frame bridges, especially introduces the detection of prestressed system, the detection of internal defects of concrete and the detection of long-term deformation. The key points and detection flow in the process of detection are given, and an example of application is given. In this paper, the common diseases of long-span continuous rigid frame bridge, such as mid-span deflection and box girder cracking, are analyzed from the aspects of calculation theory, structural design, construction technology, environmental temperature change and so on. According to the causes of the disease, the methods of applying external prestress, changing the structure system and reducing the load of the bridge are put forward to restrain the deflection of the main beam. A 210m prestressed concrete continuous rigid frame bridge with a main span of 210m has been put into operation for 4 years. There are some diseases such as mid-span deflection and box girder cracking. According to this engineering example, the detection contents and methods of continuous rigid frame bridge are expounded, and two sets of evaluation systems are used to evaluate the test results, which verifies the consistency of the evaluation results. The causes of bridge deflection are analyzed in detail, and the reinforcement of external prestressing force of 19 桅 s15.2mm on the web plate of box girder is put forward. The calculation and analysis show that the reinforcement effect is obvious and the deflection of the main span in the middle of the span is improved. The theoretical deflection of the main span is about 1.7 cm after reinforcement. In the middle of the main beam span, the stress condition of the roof is improved, and the main tensile stress of the web plate is reduced to some extent. In view of the cracking reason analysis of web, roof and bottom, the method of sticking carbon fiber sheet or sticking steel plate is adopted. In this paper, the disease of long-span continuous rigid frame bridge is studied, from the field detection method, the technical condition evaluation method based on the test result to the complete set of technique of strengthening treatment method. This paper expounds the testing methods of existing prestressed system, and recommends the detection flow of long span continuous rigid frame bridge prestressed system. This paper compares and analyzes the differences between the two sets of evaluation systems: the maintenance Code of Highway Bridge and culvert (JTG 11-2004) and the Evaluation Standard of Technical condition of Highway Bridges (JTG / T H21-2011), and puts forward some suggestions and suggestions for application from the perspective of the applicator. Combined with the cause analysis of the disease of long-span continuous rigid frame bridge, the common reinforcement methods are given, and the external prestressing strengthening method is described in detail. Finally, this paper analyzes and verifies the complete set of technical methods mentioned above through typical cases.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U446;U445.72

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