發(fā)布時間：2018-01-30 22:42

  本文關(guān)鍵詞： 斜拉橋 施工風險分析 層次分析法 蒙特卡羅理論 RBF神經(jīng)網(wǎng)絡(luò) 單索面　出處：《重慶交通大學》2014年碩士論文　論文類型：學位論文

【摘要】：單索面鋼桁梁斜拉橋?qū)儆诙啻纬o定結(jié)構(gòu)，索、塔、梁的連接構(gòu)造復雜，設(shè)計計算難度大，高空作業(yè)較多，索力大且集中，，單索鋼絞線數(shù)量大，抗扭能力差，斜拉索的均勻性和索力調(diào)整不易控制，且國內(nèi)外對該種類型橋梁理論認識不足，施工控制難度大，因而在施工期間存在著較大的風險。為了提高工程質(zhì)量，減少工程事故的發(fā)生，對單索面鋼桁梁斜拉橋施工期間進行風險分析并建立風險評估系統(tǒng)是十分必要的。 本文依托于千廝門大橋，結(jié)合橋梁的具體施工特點，運用層次分析法-灰色關(guān)聯(lián)理論-有限元模型-蒙特卡羅理論-RBF神經(jīng)網(wǎng)絡(luò)綜合評價法對大跨徑單索面公軌兩用鋼桁梁斜拉橋施工風險進行系統(tǒng)研究。 由于大橋體系復雜，結(jié)合層次分析法層次分明、可將定性問題定量化的特點，利用層次分析法對橋梁施工過程中的風險源進行全面辨識，確定橋梁施工期間主要風險源及其相對重要性權(quán)重，建立橋梁風險因素排序表。 由于千廝門大橋結(jié)構(gòu)形式的選取具有灰色系統(tǒng)的特征，采用灰色關(guān)聯(lián)分析法結(jié)合層次分析法證明了千廝門大橋采用單索面結(jié)構(gòu)形式的風險可控性。 結(jié)合有限元分析、蒙特卡羅理論、RBF神經(jīng)網(wǎng)絡(luò)提出風險的綜合評價方法，對千廝門大橋最大懸臂狀態(tài)懸臂端的豎向位移進行定量分析，通過建立有限元模型，確定大橋在確定工況及參數(shù)條件下的懸臂端位移。為使材料參數(shù)達到統(tǒng)計規(guī)律要求，因而引入徑向基神經(jīng)網(wǎng)絡(luò)，對橋梁懸臂端位移進行定量分析，結(jié)合蒙特卡羅理論，確定風險發(fā)生的概率，使得風險分析可信度增加 本文附錄中列舉了千廝門大橋較高權(quán)重風險因素的預防措施。 本文根據(jù)層次分析法-灰色系統(tǒng)理論-有限元模型-蒙特卡羅理論-RBF神經(jīng)網(wǎng)絡(luò)建立大跨徑單索面斜拉橋施工風險定量分析模型，并基于此對橋梁施工期的風險進行評估，提高了風險分析的客觀性，可信度較高。這在橋梁定量風險分析上是一種新的探索，希望能為大跨徑單索面鋼桁梁斜拉橋施工期風險分析理論的發(fā)展提供參考。
[Abstract]:Single cable plane steel truss girder cable-stayed bridge belongs to many statically indeterminate structure, the connection structure of cable, tower and beam is complicated, the design and calculation is difficult, the aerial work is more, the cable force is large and concentrated, the single cable steel strand quantity is large, the torsional ability is poor. The uniformity and cable force adjustment of stay cables is not easy to control, and the theory of this type of bridge is not well understood at home and abroad, and the construction control is difficult, so there is a great risk during the construction period, in order to improve the quality of the project. To reduce the occurrence of engineering accidents, it is necessary to carry out risk analysis and establish a risk assessment system for steel truss girder cable-stayed bridges with single cable plane during construction. This paper is based on the Qiansimmen Bridge, combined with the specific construction characteristics of the bridge. The comprehensive evaluation method of analytic hierarchy process (AHP), grey relation theory, finite element model, Monte Carlo theory and RBF neural network is used to study the construction risk of large-span steel truss bridge with common rail with single cable plane. Because of the complexity of the bridge system and the distinct hierarchy process, the qualitative problems can be quantified and the risk sources in the process of bridge construction can be fully identified by the analytic hierarchy process. The main risk sources and their relative importance weights during bridge construction are determined and the ranking table of bridge risk factors is established. Because the selection of structural form of Qiansimimen Bridge has the characteristics of grey system, the risk controllability of Qiansimimen Bridge using single cable plane structure is proved by using the grey relational analysis method and the analytic hierarchy process. Combined with finite element analysis, Monte Carlo theory and RBF neural network put forward a comprehensive risk evaluation method to quantitatively analyze the vertical displacement of the maximum cantilever end of Qianshuomen Bridge. By establishing finite element model, the cantilever end displacement of the bridge under certain working conditions and parameters is determined. In order to make the material parameters meet the requirements of statistical law, radial basis function neural network is introduced. The quantitative analysis of bridge cantilever end displacement and the Monte Carlo theory are used to determine the probability of risk occurrence, which increases the reliability of risk analysis. In the appendix of this paper, the preventive measures of high weight risk factors of Qianshuimen Bridge are listed. In this paper, the quantitative analysis model of construction risk of long-span cable-stayed bridge with single cable plane is established based on the analytic hierarchy process (AHP), grey system theory, finite element model-Monte Carlo theory and RBF neural network. Based on this, the risk of bridge construction period is evaluated, which improves the objectivity and credibility of risk analysis, which is a new exploration in bridge quantitative risk analysis. This paper hopes to provide a reference for the development of risk analysis theory of long span single cable plane steel truss girder cable-stayed bridge during construction.
【學位授予單位】：重慶交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U445

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本文編號：1477429