本文選題：異型拱橋　切入點：內力　出處：《沈陽建筑大學》2014年碩士論文

【摘要】：拱橋是一種歷史悠久的橋梁形式,隨著科技的發(fā)展,基于美學方面的考慮使得現(xiàn)代拱橋正向著大跨度、復雜體系方向發(fā)展,因此作為主要受壓的構件,拱橋的穩(wěn)定問題越來越突出,成為制約其發(fā)展的主要因素。拱橋拱肋在承壓的同時還承受一定的彎矩、扭矩和剪力的作用,受力形式復雜,因而在施工及運營過程中存在的穩(wěn)定問題較突出。本文以某“M”形異型拱橋為例主要研究內容如下：(1)、分析橋梁結構體系,根據該橋結構特點和實際情況采用橋梁結構專業(yè)軟件MIDAS CIVIL建立全橋有限元模型,并對實際施工過程進行仿真模擬。通過對該橋進行成橋狀態(tài)的靜力分析,對橋梁內力、應力、位移及吊桿索力進行設計、驗算,最終保證橋梁施工的順利進行,及成橋后高速行車的舒適度和安全性。(2)、對全橋進行內力應力以及位移的計算分析,得出拱肋各截面所受應力情況以及鋼混結合段與索梁結合處的彎矩剪力變化。分析了全橋各構件的位移變化和吊桿受力特性與吊桿的安全系數。(3)、對全橋進行兩類穩(wěn)定性分析,其中第一類穩(wěn)定為特征值的問題,對實際工程有重要的指導意義。但其理論意義很大,但實際中由于結構的初始缺陷及材料自身存在的問題,研究其理論意義不大,故對其進行第二類失穩(wěn)分析,所以在分析時考慮了幾何非線性的影響,這樣才會得出對工程有現(xiàn)實意義的結果。本文以某“M”形拱橋為工程背景,通過第一類穩(wěn)定性分析,研究了影響這種橋型穩(wěn)定性的各種結構參數,掌握了各種結構參數變化對拱橋穩(wěn)定影響的規(guī)律。同時也對Ⅱ號拱肋進行了幾何非線性穩(wěn)定的穩(wěn)定分析。計算結果表明,全橋穩(wěn)定安全儲備較高,穩(wěn)定性薄弱位置為Ⅱ號拱肋,其拱肋因拱頂橫撐的存在所以失穩(wěn)形式主要以面內失穩(wěn)為主,工況一作用下穩(wěn)定系數為38.73。在復雜體系橋梁中幾何非線因素對穩(wěn)定分析影響較大,必須加以考慮。文中對某異型拱橋的進行了穩(wěn)定性分析,結果表明施工過程穩(wěn)定性達到安全標準。(4)、分析了影響異型拱橋穩(wěn)定的幾點因素,包括吊桿件間距的大小,矢跨比的影響以及拱肋的傾斜角度的影響,計算分析結果表明,拱肋的穩(wěn)定系數隨著吊桿間距的增大而呈現(xiàn)遞減趨勢,增大吊桿間距可以節(jié)省材料,減少工程造價,但是卻降低了結構的穩(wěn)定性,所以在設計選擇吊桿間距時應綜合考慮,矢跨比在1/3.5—1/5之間為最優(yōu),當矢跨比大于1/3.5時,結構的穩(wěn)定系數隨之增大而增大。拱肋傾斜角度在0°-16°時穩(wěn)定性隨之增加而增大,16。之后基本保持不變。所以在選擇傾斜角度時應按實際所需選取最優(yōu)角度。
[Abstract]:Arch bridge is a kind of bridge form with a long history. With the development of science and technology, modern arch bridge is developing towards the direction of long span and complex system based on aesthetic considerations. The stability problem of arch bridge is more and more prominent and becomes the main factor restricting its development. The arch rib of arch bridge is subjected to bending moment, torque and shear force at the same time, and the force form is complex. Therefore, the stability problems in the construction and operation process are prominent. This paper takes a "M" shaped shaped arch bridge as an example to analyze the bridge structure system as follows: 1. According to the characteristics of the bridge structure and the actual situation, the finite element model of the whole bridge is established by using the bridge structure professional software MIDAS CIVIL, and the actual construction process is simulated. Through the static analysis of the bridge state, the internal force and stress of the bridge are analyzed. The displacement and suspension cable force are designed, checked and calculated to ensure the smooth construction of the bridge, and the comfort and safety of high-speed driving after the completion of the bridge. The internal force stress and displacement of the whole bridge are calculated and analyzed. The stress of each section of arch rib and the change of moment and shear force at the joint of steel concrete and cable beam are obtained. The displacement change of each member of the bridge and the stress characteristics of the suspender and the safety factor of the suspender are analyzed, and two kinds of stability analysis of the whole bridge are carried out. The problem that the first kind of stability is eigenvalue has important guiding significance for practical engineering, but its theoretical significance is very great, but in practice due to the initial defects of the structure and the problems existing in the material itself, it is of little theoretical significance to study it. Therefore, the second kind of instability analysis is carried out, so the influence of geometric nonlinearity is taken into account in the analysis, so that the result of practical significance can be obtained. In this paper, a certain "M" arch bridge is taken as the engineering background and the stability analysis of the first type is carried out. The influence of structural parameters on the stability of the arch bridge is studied, and the influence of structural parameters on the stability of the arch bridge is studied. The geometric nonlinear stability of the arch rib is also analyzed. The results show that the stability of the arch rib is affected by the influence of the structural parameters on the stability of the arch bridge. The stability safety reserve of the whole bridge is high, the weak position of the stability is the 鈪，

本文編號：1672690