中小跨径梁桥基于性能的抗震设计方法研究
发布时间：2018-08-20 11:27
【摘要】：板式橡胶支座是我国中小跨径公路梁桥中广泛采用的支座类型,为便于施工和安装,板式橡胶支座通常直接搁置在桥墩墩顶盖梁或垫石上,支座与梁底和墩顶没有连接措施。汶川地震中采用板式橡胶支座的中小跨径公路梁桥震害以主梁移位、支座和挡块破坏为主,桥墩震害率较低。为研究中小跨径公路梁桥的震害机理和合理的抗震设计方法,本文针对采用板式橡胶支座的中小跨径梁桥结构体系,对支座在地震作用下优先发生损伤和“多道设防、分级耗能”的抗震性能设计方法开展了系统研究,主要研究内容和成果如下：1.揭示了桥梁震害与桥梁结构体系的分布规律,发现了汶川地震中桥梁震害率较低的原因。地震作用下,采用板式橡胶支座的桥梁结构体系传力路径中断,减小了传递到下部结构的地震力,支座起到了隔震耗能的作用。在此基础上,提出了考虑板式橡胶支座摩擦滑移的中小跨径桥梁抗震设计方法。2.首次进行了不同锚固条件下板式橡胶支座的抗震性能试验研究。试验结果表明,当板式橡胶支座上下面均锚固时,破坏形式为橡胶层撕裂,极限剪切变形可达到300%~400%,加载位移较大时,支座发生硬化现象；当板式橡胶支座锚固一面时,支座受力可分为两阶段：滑动前和滑动后,其滑移特性与支座所受的竖向荷载和支座规格有关,并且考虑摩擦滑移的板式橡胶支座与铅芯橡胶支座的耗能效果接近。在此基础上,提出了考虑摩擦滑移的板式橡胶支座的等效刚度和等效阻尼比。3.建立了考虑摩擦滑移的板式橡胶支座-桥墩串联体系的刚度比控制方程,该方程综合考虑了轴压比、支座厚度、支座变形、桥墩及支座非线性等的影响,得出了地震作用下支座先于桥墩发生损伤的刚度比限值,并根据限位装置参数对板式橡胶支座桥梁位移控制进行了研究,确定了限位装置合理间隙的取值范围。4.基于能量分析方法,对比分析了考虑摩擦滑移的板式橡胶支座、铅芯橡胶支座桥梁中桥墩和支座的滞回耗能,验证了考虑摩擦滑移的板式橡胶支座具有良好的抗震性能,并分析了影响桥梁抗震性能的因素;通过IDA增量时程分析研究了地震作用下不同桥梁体系中各构件的抗震性能,提出了板式橡胶支座桥梁顺桥向和横桥向合理的损伤模式。5.采用等效线性化概念,建立了考虑摩擦滑移的板式橡胶支座-桥墩双自由度模型的位移设计方法及具有多道防线的桥梁抗震设计方法,提出了不同水准地震作用下桥梁各构件的性能目标和性能要求,并通过一算例,验证了不同水准下多道抗震防线的抗震设计方法的可行性和合理性。
[Abstract]:The plate rubber bearing is widely used in the middle and small span highway girder bridge in our country. In order to facilitate the construction and installation, the plate rubber support is usually placed directly on the top beam or cushion stone of the pier, and there is no connection measure between the support and the beam bottom and the pier top. In Wenchuan earthquake, the earthquake damage of small and medium span highway girder bridge with plate rubber bearing is mainly caused by the displacement of main beam, the damage of support and block, and the low damage rate of bridge pier. In order to study the earthquake damage mechanism and reasonable seismic design method of middle and small span highway beam bridge, this paper aims at the structure system of medium and small span beam bridge with plate rubber bearing, and gives priority to damage and "multi-channel fortification" to the support under earthquake action. The seismic performance design method of graded energy dissipation is studied systematically. The main contents and results are as follows: 1. The distribution law of bridge earthquake damage and bridge structure system is revealed, and the reason of low bridge damage rate in Wenchuan earthquake is found. Under seismic action, the transmission path of bridge system with plate rubber bearing is interrupted, the seismic force transferred to the substructure is reduced, and the bearing plays the role of isolation and energy dissipation. On this basis, the aseismic design method of medium and small span bridge considering friction and slip of plate rubber bearing is put forward. The seismic behavior of plate rubber bearing under different anchoring conditions was studied for the first time. The test results show that when the upper and lower parts of the plate rubber bearing are anchored, the failure form is rubber layer tear, the ultimate shear deformation can reach 300 ~ 400 and the bearing hardening occurs when the loading displacement is large, and when the plate rubber support is anchored on one side, The bearing force can be divided into two stages: before and after sliding, the slip characteristics are related to the vertical load and the bearing size of the bearing, and the energy dissipation effect of the plate rubber bearing with friction slip is close to that of the lead rubber bearing. On this basis, the equivalent stiffness and damping ratio of plate rubber bearing considering friction slip are proposed. The governing equation of stiffness ratio of plate rubber bearing-pier series system considering friction slip is established. The equation considers the influence of axial compression ratio, bearing thickness, bearing deformation, bridge pier and support nonlinearity, etc. The limit value of stiffness ratio of bearing before bridge pier under earthquake action is obtained, and the displacement control of plate rubber bearing bridge is studied according to the parameters of limit device, and the value range of reasonable clearance of limit device is determined. Based on the energy analysis method, the hysteretic energy consumption of the plate rubber bearing with friction slip and the bridge pier and bearing in the lead rubber bearing bridge are compared and analyzed. The results show that the plate rubber bearing with friction slip has good seismic performance. The factors affecting the seismic performance of the bridge are analyzed, and the seismic behavior of each member in different bridge systems under earthquake is studied by IDA incremental time-history analysis, and the reasonable damage mode of the slab rubber bearing bridge is put forward. Based on the concept of equivalent linearization, the displacement design method of plate rubber bearing-pier model with double degrees of freedom and the seismic design method of bridges with multiple lines of defense are established. The performance objectives and performance requirements of each component of the bridge under the action of different leveling earthquakes are put forward, and the feasibility and rationality of the seismic design method of multi-channel anti-seismic lines at different levels are verified by an example.
【学位授予单位】：东南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U442.55
，
本文编号：2193414
[Abstract]:The plate rubber bearing is widely used in the middle and small span highway girder bridge in our country. In order to facilitate the construction and installation, the plate rubber support is usually placed directly on the top beam or cushion stone of the pier, and there is no connection measure between the support and the beam bottom and the pier top. In Wenchuan earthquake, the earthquake damage of small and medium span highway girder bridge with plate rubber bearing is mainly caused by the displacement of main beam, the damage of support and block, and the low damage rate of bridge pier. In order to study the earthquake damage mechanism and reasonable seismic design method of middle and small span highway beam bridge, this paper aims at the structure system of medium and small span beam bridge with plate rubber bearing, and gives priority to damage and "multi-channel fortification" to the support under earthquake action. The seismic performance design method of graded energy dissipation is studied systematically. The main contents and results are as follows: 1. The distribution law of bridge earthquake damage and bridge structure system is revealed, and the reason of low bridge damage rate in Wenchuan earthquake is found. Under seismic action, the transmission path of bridge system with plate rubber bearing is interrupted, the seismic force transferred to the substructure is reduced, and the bearing plays the role of isolation and energy dissipation. On this basis, the aseismic design method of medium and small span bridge considering friction and slip of plate rubber bearing is put forward. The seismic behavior of plate rubber bearing under different anchoring conditions was studied for the first time. The test results show that when the upper and lower parts of the plate rubber bearing are anchored, the failure form is rubber layer tear, the ultimate shear deformation can reach 300 ~ 400 and the bearing hardening occurs when the loading displacement is large, and when the plate rubber support is anchored on one side, The bearing force can be divided into two stages: before and after sliding, the slip characteristics are related to the vertical load and the bearing size of the bearing, and the energy dissipation effect of the plate rubber bearing with friction slip is close to that of the lead rubber bearing. On this basis, the equivalent stiffness and damping ratio of plate rubber bearing considering friction slip are proposed. The governing equation of stiffness ratio of plate rubber bearing-pier series system considering friction slip is established. The equation considers the influence of axial compression ratio, bearing thickness, bearing deformation, bridge pier and support nonlinearity, etc. The limit value of stiffness ratio of bearing before bridge pier under earthquake action is obtained, and the displacement control of plate rubber bearing bridge is studied according to the parameters of limit device, and the value range of reasonable clearance of limit device is determined. Based on the energy analysis method, the hysteretic energy consumption of the plate rubber bearing with friction slip and the bridge pier and bearing in the lead rubber bearing bridge are compared and analyzed. The results show that the plate rubber bearing with friction slip has good seismic performance. The factors affecting the seismic performance of the bridge are analyzed, and the seismic behavior of each member in different bridge systems under earthquake is studied by IDA incremental time-history analysis, and the reasonable damage mode of the slab rubber bearing bridge is put forward. Based on the concept of equivalent linearization, the displacement design method of plate rubber bearing-pier model with double degrees of freedom and the seismic design method of bridges with multiple lines of defense are established. The performance objectives and performance requirements of each component of the bridge under the action of different leveling earthquakes are put forward, and the feasibility and rationality of the seismic design method of multi-channel anti-seismic lines at different levels are verified by an example.
【学位授予单位】：东南大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U442.55
，
本文编号：2193414
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