【摘要】：隨著箱梁寬度的逐漸增大,采用懸臂施工的連續(xù)梁及連續(xù)剛構(gòu)橋,在施工的前數(shù)個(gè)階段中,即施工短懸臂狀態(tài),采用梁單元理論進(jìn)行施工階段驗(yàn)算結(jié)構(gòu)響應(yīng)的不適用性,逐漸引起橋梁界的關(guān)注。在短懸臂狀態(tài),采用梁單元理論得到的應(yīng)力與結(jié)構(gòu)實(shí)際應(yīng)力分布的差別,如何正確模擬后張法預(yù)應(yīng)力鋼筋等問題,亟待形成系統(tǒng)的研究成果。因此,本文以短懸臂狀態(tài)下橋梁在預(yù)應(yīng)力荷載作用下的局部應(yīng)力為研究對(duì)象,進(jìn)行了較為深入的研究,希望進(jìn)一步完善PC箱梁橋的設(shè)計(jì)理論和方法,同時(shí)為施工提供一定的借鑒和參考。本文對(duì)PC箱梁橋的設(shè)計(jì)和分析理論進(jìn)行了系統(tǒng)的論述、對(duì)比與總結(jié),研究表明在施工的短懸臂狀態(tài)采用梁單元進(jìn)行分析是不精確的,亦或是造成橋梁在后期運(yùn)營過程中開裂的隱患�；趯�(shí)體有限元數(shù)值模擬法來實(shí)現(xiàn)后張法預(yù)應(yīng)力作用下PC箱梁橋局段應(yīng)力分析的方法,本文以花卉大橋?yàn)楸尘皩?duì)不同建模方式的要點(diǎn)進(jìn)行了明確的闡述,可為工程建造提供指導(dǎo)性意見。通過采用兩種不同的方式進(jìn)行預(yù)應(yīng)力鋼筋與混凝土單元的節(jié)點(diǎn)耦合建立的AN SYS實(shí)體有限元分析模型與基于初等梁單元的M idas-civil模型數(shù)據(jù)對(duì)比,結(jié)果表明采用初等梁單元進(jìn)行分析不能夠準(zhǔn)確反映截面應(yīng)力的分布,由于截面寬度較大,同一截面高度上應(yīng)力分布是不均勻的。為進(jìn)一步修正初等梁單元模型的誤差,采用有效翼板寬度理論進(jìn)行修正。結(jié)果表明,此理論還是不能用來計(jì)算結(jié)構(gòu)的應(yīng)力水平,腹板縱向正應(yīng)力與實(shí)體單元分析的應(yīng)力吻合較好。為進(jìn)一步驗(yàn)證實(shí)體有限元數(shù)據(jù)的可信度,與花卉大橋?qū)崢虻谋O(jiān)控?cái)?shù)據(jù)進(jìn)行了對(duì)比。研究表明,采用半耦合方式建立實(shí)體單元的有限元模擬更能夠準(zhǔn)確模擬結(jié)構(gòu)的應(yīng)力分布。研究表明采用梁單元理論分析橋梁在預(yù)應(yīng)力荷載作用下的局部應(yīng)力引起的誤差,應(yīng)該引起足夠的重視。
[Abstract]:As the width of box girder increases gradually, the continuous beam and continuous rigid frame bridge constructed by cantilever, in the first few stages of construction, namely, the short cantilever state of construction, adopts the beam element theory to check the inapplicability of structural response in the construction stage. Gradually aroused the attention of bridge boundaries. In the short cantilever state, the difference between the stress obtained by the beam element theory and the actual stress distribution of the structure, how to correctly simulate the pre-stressed steel bars after Zhang Fa, and so on, need to form systematic research results. Therefore, this paper takes the local stress of the bridge under the prestressing force as the research object under the condition of short cantilever, carries on the more in-depth research, hopes to further perfect the design theory and the method of the PC box girder bridge, At the same time, it provides certain reference and reference for construction. In this paper, the design and analysis theory of PC box girder bridge are systematically discussed, compared and summarized. The research shows that it is imprecise to use beam element to analyze the short cantilever state in construction. Or cause the bridge in the later stage of operation in the process of cracking hidden dangers. Based on the solid finite element numerical simulation method, the stress analysis method of the local section of PC box girder bridge under the action of post-Zhang Fa prestressing force is realized. In this paper, the main points of different modeling methods are clearly expounded on the background of the Flower Bridge. Can provide guidance for the construction of the project. The finite element analysis model of AN SYS entity based on the coupling of prestressed steel bar and concrete element is compared with M-idas-civil model based on elementary beam element in two different ways. The results show that the stress distribution of the cross-section can not be accurately reflected by the elementary beam element analysis. Because of the large width of the cross-section, the stress distribution at the same section height is not uniform. In order to further correct the error of the elementary beam element model, the effective fender width theory is used to correct the error. The results show that this theory can not be used to calculate the stress level of the structure, and the longitudinal normal stress of the web is in good agreement with that of the solid element analysis. In order to verify the reliability of the entity finite element data, the comparison is made with the monitoring data of the real bridge of the Flower Bridge. The results show that the finite element simulation using semi-coupled method can simulate the stress distribution of the structure more accurately. The results show that the error caused by the local stress of bridge under prestressed load should be analyzed by beam element theory, which should be paid more attention to.
【學(xué)位授予單位】：湖南科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U441;U448.213

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本文編號(hào)：2469250