预应力混凝土连续刚构桥裂缝分析及加固研究
发布时间：2019-06-25 20:01
【摘要】：预应力混凝土连续刚构桥梁以其合理的受力和良好的行车性能在我国桥梁领域众多桥型里占据数量上主导地位,对我国公路交通运输业发挥着极其重要的作用。大跨径预应力混凝土连续刚构桥具有较大的跨越能力和较强的适应性的优势,广泛应用于我国高原山区。然而,由于其材料本身、环境因素以及载荷条件的变化,使得连续刚构桥在运营阶段出现不同程度损伤。根据对现有预应力混凝土连续刚构桥梁病害的调查分析,主要损伤病害为中跨挠度变形量过大和梁体不同部位裂缝,裂缝分布形式和分布位置对主梁截面的刚度也有一定的削弱作用,进而促使桥梁下挠,故梁体裂缝和挠度之间息息相关的。本文以云南省大保高速公路一座预应力混凝土连续刚构桥为依托工程。首先,运用有限元分析软件Midas Civil对运营阶段引起裂缝产生的主要因素进行分析,研究活荷载、预应力收缩、温度作用以及收缩徐变对桥梁结构内力和应力的影响规律。其次,根据以上因素对内力的影响规律,结合桥梁所在地的运营环境和交通量,对桥梁实际运营情况的受力状态进行近似模拟。再次,根据有限元理论分析结果并结合该桥梁外观检测报告,选取裂缝分布密集的梁段运用有限元分析软件ABAQUS建立有限元模型进行细部分析,以梁块最不利裂缝为基础运用混凝土断裂力学知识计算梁段在外荷载作用下裂缝的断裂力学参数,定量分析裂缝的受力特性,定性的判断裂缝的表现形式,进而可以评估裂缝对桥梁结构的影响,为桥梁加固提供依据。最后,结合依托工程分析以体外预应力钢束为例的主动加固法,得出不同位置的体外预应力钢束对结构承载力和裂缝控制的作用是不同的,进而对加固效果性进行评价。通过计算裂纹断裂参数及其扩展情况,计算桥梁结构在使用荷载作用下结构的损伤状况,根据分析结果选择适当的加固方法,并对此桥提出加固方案建议,为桥梁结构维修加固提供经济性与安全性的依据。
[Abstract]:Prestressed concrete continuous rigid frame bridge plays an important role in the highway transportation industry of our country because of its reasonable force and good driving performance, which occupies a dominant position in the number of bridges in the field of bridges in our country. Long-span prestressed concrete continuous rigid frame bridge has the advantages of great leapfrogging ability and strong adaptability, and is widely used in plateau mountainous areas of China. However, due to the change of material itself, environmental factors and load conditions, the continuous rigid frame bridge is damaged to varying degrees in the operation stage. According to the investigation and analysis of the existing prestressed concrete continuous rigid frame bridge diseases, the main damage diseases are excessive deflection deformation in the middle span and cracks in different parts of the beam body. The crack distribution form and distribution position also weaken the stiffness of the main beam section to a certain extent, and then promote the bridge deflection, so the crack and deflection of the beam body are closely related. This paper is based on a prestressed concrete continuous rigid frame bridge of Dabo Expressway in Yunnan Province. Firstly, the finite element analysis software Midas Civil is used to analyze the main factors causing cracks in the operation stage, and the effects of live load, prestressed shrinkage, temperature and shrinkage and creep on the internal force and stress of the bridge structure are studied. Secondly, according to the influence of the above factors on the internal force, combined with the operating environment and traffic volume of the bridge location, the stress state of the actual operation of the bridge is approximately simulated. Thirdly, according to the results of finite element theory analysis and combined with the appearance detection report of the bridge, the beam section with dense crack distribution is selected and the finite element analysis software ABAQUS is used to establish the finite element model for detailed analysis. Based on the most unfavorable cracks in the beam block, the fracture mechanical parameters of the beam section under external load are calculated by using the knowledge of concrete fracture mechanics, the stress characteristics of the cracks are quantitatively analyzed, and the manifestation of the cracks is judged qualitatively. Furthermore, the influence of cracks on bridge structure can be evaluated, which provides the basis for bridge reinforcement. Finally, based on the engineering analysis, taking the external prestressed steel bundles as an example, it is concluded that the external prestressed steel bundles in different positions have different effects on the bearing capacity and crack control of the structure, and then the reinforcement effect is evaluated. By calculating the crack fracture parameters and their propagation, the damage condition of the bridge structure under the action of service load is calculated, according to the analysis results, the appropriate reinforcement method is selected, and the reinforcement scheme of the bridge is put forward, which provides the economic and safety basis for the maintenance and reinforcement of the bridge structure.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.72;U448.23
本文编号：2505963
[Abstract]:Prestressed concrete continuous rigid frame bridge plays an important role in the highway transportation industry of our country because of its reasonable force and good driving performance, which occupies a dominant position in the number of bridges in the field of bridges in our country. Long-span prestressed concrete continuous rigid frame bridge has the advantages of great leapfrogging ability and strong adaptability, and is widely used in plateau mountainous areas of China. However, due to the change of material itself, environmental factors and load conditions, the continuous rigid frame bridge is damaged to varying degrees in the operation stage. According to the investigation and analysis of the existing prestressed concrete continuous rigid frame bridge diseases, the main damage diseases are excessive deflection deformation in the middle span and cracks in different parts of the beam body. The crack distribution form and distribution position also weaken the stiffness of the main beam section to a certain extent, and then promote the bridge deflection, so the crack and deflection of the beam body are closely related. This paper is based on a prestressed concrete continuous rigid frame bridge of Dabo Expressway in Yunnan Province. Firstly, the finite element analysis software Midas Civil is used to analyze the main factors causing cracks in the operation stage, and the effects of live load, prestressed shrinkage, temperature and shrinkage and creep on the internal force and stress of the bridge structure are studied. Secondly, according to the influence of the above factors on the internal force, combined with the operating environment and traffic volume of the bridge location, the stress state of the actual operation of the bridge is approximately simulated. Thirdly, according to the results of finite element theory analysis and combined with the appearance detection report of the bridge, the beam section with dense crack distribution is selected and the finite element analysis software ABAQUS is used to establish the finite element model for detailed analysis. Based on the most unfavorable cracks in the beam block, the fracture mechanical parameters of the beam section under external load are calculated by using the knowledge of concrete fracture mechanics, the stress characteristics of the cracks are quantitatively analyzed, and the manifestation of the cracks is judged qualitatively. Furthermore, the influence of cracks on bridge structure can be evaluated, which provides the basis for bridge reinforcement. Finally, based on the engineering analysis, taking the external prestressed steel bundles as an example, it is concluded that the external prestressed steel bundles in different positions have different effects on the bearing capacity and crack control of the structure, and then the reinforcement effect is evaluated. By calculating the crack fracture parameters and their propagation, the damage condition of the bridge structure under the action of service load is calculated, according to the analysis results, the appropriate reinforcement method is selected, and the reinforcement scheme of the bridge is put forward, which provides the economic and safety basis for the maintenance and reinforcement of the bridge structure.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.72;U448.23
【参考文献】
相关期刊论文 前1条
1 余学芳;;混凝土结构裂缝分析中断裂模型的研究现状[J];浙江水利水电专科学校学报;2006年03期
相关硕士学位论文 前5条
1 陈付雷;桥梁加固设计关键技术研究[D];长安大学;2011年
2 王慰军;基于ABAQUS的裂纹扩展仿真软件及应用[D];浙江大学;2006年
3 刘磊;裂纹尖端场的有限元分析与裂尖结构演化行为[D];北京交通大学;2008年
4 吕克金;蜗壳外围混凝土裂缝稳定性分析[D];大连理工大学;2009年
5 郑智辉;基于尺寸效应的混凝土结构承载能力研究[D];南京理工大学;2010年
，本文编号：2505963
本文链接：https://www.wllwen.com/kejilunwen/daoluqiaoliang/2505963.html
