【摘要】：隨著國家的改革建設,道路建設的總長度越來越大,橋梁的建設也愈發(fā)重要,各種結構類型的橋梁應用而生。鋼桁架結構拱橋以其材料用量少、結構自重輕、受力鮮明以及美觀大方等特點廣受工程師采納。地震的強大破壞力不僅給國民經(jīng)濟造成巨大損失,對人類生命安全也造成傷害。當前的橋梁工程研究學者們的主要課題目標是探究如何提高橋梁的抗震能力。因此,鋼桁架對于上承式鋼拱橋的地震反應分析具有明顯的工程實用價值和意義。本論文研究的工程案例是一座上承式鋼桁架拱橋,基于ABAQUS有限元軟件對其建立空間模型,研究在強震下的反應。文中的主要研究內(nèi)容概述如下:(1)利用有限元軟件建立模型,得出鋼桁架拱橋在十二階振動模態(tài)中的振型,研究分析得出該拱橋的第一階振型均為全橋的豎向反對稱撓曲振動,高階振型對該類橋梁的影響不可忽略,尤其在對這一類型橋梁進行反應譜抗震設計時需要謹慎注意;(2)對拱橋進行地震波反應譜分析以及罕遇地震動作用下的縱橋向和橫橋向的彈塑性時程分析,從研究中得知,縱向地震作用下的拱橋整體結構基本屬于彈性階段,橫橋向地震作用下,拱橋的地震響應比縱橋向大很多,且橋邊墩間的支撐處于彈性階段或出現(xiàn)屈曲現(xiàn)象,滯回性能較差;(3)以JRT-NS波為例,對文中案例拱橋進行縱橋向+2/3豎向和橫橋向+2/3豎向地震動輸入,研究探討了案例鋼拱橋在豎向地震輸入時的抗震性能影響;再進行縱橋向+豎向地震激勵作用下和縱橋向地震激勵下的關于拱腳軸力、拱肋截面、拱頂以及梁跨中截面處的增加幅度比較;行波效應下分析得知增加幅度較大處是拱肋軸力。以上問題的分析研究,清楚認識到上承式鋼桁架拱橋的振動模態(tài)中的振型、地震波下時程分析反應以及最不利地震波的輸入,得出結論并對類似的橋梁結構的抗震設計給予合理的設計建議。
[Abstract]:With the reform and construction of our country, the total length of road construction becomes larger and larger, and the construction of bridges becomes more and more important. Steel truss arch bridge is widely accepted by engineers because of its few materials, light weight, bright force and beautiful appearance and so on. The strong destructive power of the earthquake not only causes huge losses to the national economy, but also damages the safety of human life. At present, the main task of bridge engineering researchers is to explore how to improve the anti-seismic ability of bridges. Therefore, steel trusses have obvious practical value and significance for seismic response analysis of steel arch bridges. The project case studied in this paper is a steel truss arch bridge. Based on the finite element software ABAQUS, the spatial model of the arch bridge is established and the response to strong earthquakes is studied. The main research contents in this paper are summarized as follows: (1) the model of steel truss arch bridge is established by finite element software, and the vibration modes of steel truss arch bridge in twelve-order vibration modes are obtained. The results show that the first vibration mode of the arch bridge is vertical anti-symmetric flexure vibration of the whole bridge, and the influence of higher-order vibration mode on this kind of bridge can not be ignored, especially in the seismic design of this type of bridge with response spectrum. (2) the seismic wave response spectrum analysis of arch bridge and elastic-plastic time history analysis of longitudinal bridge direction and transverse bridge direction under rare ground motion show that the whole structure of arch bridge under longitudinal earthquake basically belongs to elastic stage. Under transverse earthquake, the seismic response of arch bridge is much larger than that of longitudinal bridge, and the bracing between piers on the side of bridge is in elastic stage or buckling phenomenon, so the hysteretic performance of arch bridge is poor. (3) taking the JRT-NS wave as an example, the seismic performance of the steel arch bridge in the case is studied by the vertical and transverse seismic input of the case arch bridge in the vertical and transverse direction, and the influence of the steel arch bridge on the seismic performance of the arch bridge under the vertical seismic input is studied. Then, the increases of axial force of arch foot, arch rib section, arch roof and middle section of beam span under longitudinal and longitudinal seismic excitation are compared. According to the analysis of traveling wave effect, the axial force of arch rib is the main part of the increase. The analysis and research of the above problems have clearly recognized the vibration modes in the vibration mode of the steel truss arch bridge, the response of the time history analysis under the seismic wave and the input of the most unfavorable seismic wave. The conclusion is drawn and reasonable design suggestions for similar bridge structures are given.
【學位授予單位】：安徽建筑大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：U442.55;U448.22

【參考文獻】

相關期刊論文 前10條

1 王占飛;邢宇s，

本文編號：2454221