混凝土桥梁病害分析与体外预应力加固技术应用研究

发布时间：2018-03-23 23:08

本文选题：病害　切入点：加固　出处：《天津大学》2014年硕士论文

【摘要】：本文以天津某混凝土梁式桥为工程背景，，对混凝土桥梁典型病害及病害产生原因进行了分析，得出桥梁上部结构、桥面系的技术状况评价结果。通过现场实测以及MIDAS建立模型，得出主梁自振频率评定结果。根据天津市某桥梁的实际检测数据，引入桥梁检算系数、截面折减系数、承载能力恶化系数和活载修正系数，分别对极限状态方程中的荷载效应和结构抗力效应进行修正，并通过比较判定了主梁满足原设计荷载的要求。运营周期较长的混凝土桥梁由于荷载、气候、外力破坏等不良因素的影响，都不同程度的出现了各种各样的病害与破损。桥梁承载能力由于病害的影响，不能满足现行规范要求，选择体外预应力的方法补强既有钢筋混凝土梁桥，可改善其使用性能、提高承载能力。由体外预应力加固的特点决定了加固过程基本为带载加固，其设计计算与新建结构最大的区别在于应考虑分阶段受力的影响。本文运用力法原理，推导了在正截面承载力计算中，无转折点的体外预应力筋的应力增量公式，提出了考虑分阶段受力的影响的抗裂性验算方法，给出体外预应力加固设计方案；从预应力钢筋材料性能发挥等方面，阐述了体外预应力加固的技术特点和应用范围。从工程费用、断交施工期等方面，对体外预应力加固方案与实际换梁方案进行对比，推荐方案为体外预应力加固方案。本文的研究成果对既有桥梁的承载力评定、体外预应力加固混凝土梁桥的设计与施工，具有较高的参考价值。
[Abstract]:Taking a concrete beam bridge in Tianjin as the engineering background, this paper analyzes the typical diseases of concrete bridge and the causes of the disease, and obtains the evaluation results of the technical condition of the bridge superstructure and deck system. The model is established by field measurement and MIDAS. The evaluation results of the natural vibration frequency of the main beam are obtained. According to the actual test data of a bridge in Tianjin, the load effect and the structure resistance effect in the limit state equation are revised by introducing the bridge checking coefficient, section reduction coefficient, load capacity deterioration coefficient and live load correction coefficient, respectively. Through comparison, the main beam is determined to meet the requirements of the original design load. Because of the bad factors such as load, climate, external force failure and so on, various kinds of damage and damage appear in the concrete bridge with long operating period. The bearing capacity of the bridge is affected by the disease, and the load bearing capacity of the bridge is affected by the damage. The existing reinforced concrete beam bridge can be strengthened by external prestressing method, which can improve its performance and increase its bearing capacity. According to the characteristics of external prestressing strengthening, the reinforcement process is basically strengthened with load. The biggest difference between the design calculation and the new structure is that the influence of the stage stress should be considered. In this paper, the stress increment formula of the external prestressing tendons with no turning point is derived by using the force method principle in the calculation of the normal section bearing capacity. This paper puts forward a checking calculation method of crack resistance considering the influence of stage stress, gives the design scheme of external prestressing reinforcement, and expounds the technical characteristics and application scope of external prestressing reinforcement from the aspects of exerting the properties of prestressed steel bar and so on. From the aspects of project cost and construction period, the external prestressing reinforcement scheme is compared with the actual beam replacement scheme, and the external prestressing reinforcement scheme is recommended. The research results of this paper have a high reference value for the evaluation of the bearing capacity of existing bridges and the design and construction of concrete beam bridges strengthened by external prestressing.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.7

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