基于不同激励方法的大跨度连续梁桥地震响应分析

发布时间：2018-01-05 05:24

本文关键词：基于不同激励方法的大跨度连续梁桥地震响应分析　出处：《辽宁工程技术大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年来,我国地震多发给人民生命和财产带来严重威胁,桥梁结构是道路交通系统的重要结构,是交通运输系统的枢纽工程,桥梁结构的破坏,不仅导致很大的直接经济损失,而且还会影响灾后的重建和生产恢复工作。本文以六库怒江大桥为研究背景,从结构的自身动力特性、地震动的输入方式、桥梁结构的动力响应三个方面出发,应用有限元分析方法,采用有限元软件MIDAS/CIVIL,建立三跨混凝土连续梁桥有限元模型,分别进行反应谱一致激励、时程一致激励和时程多点激励,得出相应的桥梁结构的地震响应,对反应谱一致激励、时程一致激励和时程多点激励进行对比分析,得出以下结论：1.不同的地震波对桥梁结构的内力和位移影响较大,在进行桥梁结构抗震分析中必须根据桥梁结构所处的实际桥址所处的场地条件选择与其一致的地震波。2.反应谱法建立在一致激励的基础上,不能考虑地震动的时空效应,只能得出最大响应。时程一致分析法可以得到桥梁结构任意时刻的地震响应,也无法模拟地震动的时空效应,对于大跨度连续梁桥来讲,在进行抗震分析时,进行时程多点激励更加符合实际地震动的输入模式。3.为了更为准确进行反应谱一致激励与时程一致激励进行对比,必须对所选取的时程波进行调整,使其调整为与反应谱法相等的有效峰值,这样便于对反应谱一致激励与时程一致激励进行对比分析。4.在时程多点激励中,由于采用了不同的视波速,这样使得不同视波速的地震波到达各个墩底的时间就存在一定的时间差,那么在不同的时差进行输入的情况下,大跨度桥梁结构的地震响应存在着很大的不同的,这样使得时程多点激励与一致激励相比各点的振动发生很大的变化,当视波速不是很大时(速度一定大时,时差可以忽略),则地震动的行波效应不能被忽略的。5.反应谱一致下桥梁结构的各支点剪力和弯矩均大于时程一致激励,其中反应谱一致激励时支点剪力是时程一致激励的1.071-1.278倍,各跨中弯矩的1.109-1.243倍,然而时程一致激励的位移均大于反应谱一致激励。
[Abstract]:In recent years, the earthquake sent to people's lives and property in China brings serious threat, bridge structure is an important structure of road traffic system, is the hub of transportation system, the destruction of bridge structure. Not only lead to great direct economic losses, but also affect the reconstruction and production recovery after the disaster. This paper takes Liukunjiang Bridge as the research background, from the structure's own dynamic characteristics, the input mode of ground motion. Based on three aspects of dynamic response of bridge structure, the finite element model of three-span concrete continuous beam bridge is established by using finite element analysis method and Midas / CIVIL-based finite element software. Response spectrum consistent excitation, time-history consistent excitation and time-history multi-point excitation are carried out respectively, and the corresponding seismic response of bridge structure is obtained. The response spectrum consistent excitation, time-history consistent excitation and time-history multi-point excitation are compared and analyzed. The following conclusions are drawn: 1. Different seismic waves have great influence on the internal force and displacement of the bridge structure. In seismic analysis of bridge structure, the seismic wave should be chosen according to the actual site condition of bridge structure. 2. The response spectrum method is based on consistent excitation. The time-history consistent analysis method can get the seismic response of bridge structure at any time, nor can it simulate the space-time effect of ground motion. For long-span continuous beam bridges, seismic analysis is carried out. In order to compare the response spectrum consistent excitation with time-history consistent excitation, the selected time-history wave must be adjusted in order to carry out the time-history multi-point excitation more in line with the actual ground motion input mode .3.In order to more accurately compare the response spectrum consistent excitation and the time-history consistent excitation, the selected time-history wave must be adjusted. It is easy to compare and analyze the response spectrum consistent excitation and time-history consistent excitation. 4. In the time-history multi-point excitation, due to the use of different apparent wave velocities. In this way, there is a certain time difference when the seismic waves with different apparent wave velocities reach the bottom of each pier, so in the case of different time difference input. The seismic response of long-span bridge structure is very different, which makes the vibration of each point change greatly compared with the consistent excitation, when the apparent wave velocity is not very large (when the velocity is certain to be large. If the time difference can be neglected, the traveling wave effect of ground motion can not be ignored. 5. The shear force and bending moment of bridge structure at each fulcrum are larger than that of time-history consistent excitation under the same response spectrum. The fulcrum shear force is 1.071-1.278 times as much as the time-history uniform excitation, and 1.109-1.243 times of the mid-span moment when the response spectrum is consistent. However, the displacement of time-history consistent excitation is larger than that of response spectrum consistent excitation.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55

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