發(fā)布時(shí)間：2018-04-21 13:49

  本文選題：徐變 + 鋼管混凝土�。� 參考：《蘭州交通大學(xué)》2015年碩士論文

【摘要】：鋼管混凝土作為一種新型的組合材料,集成了鋼管和混凝土的優(yōu)點(diǎn),目前在大跨度鋼管混凝土系桿拱橋中廣泛應(yīng)用。但是,鋼管混凝土徐變與普通混凝土徐變存在一定的差異,鋼管混凝土徐變會(huì)引起鋼管與核心混凝土發(fā)生內(nèi)力重分布,而且在時(shí)間荷載下徐變也會(huì)對(duì)大跨度鋼管混凝土系桿拱橋的靜力性能產(chǎn)生一定的影響。本文針對(duì)鋼管混凝土徐變數(shù)據(jù)較少而且與普通混凝土徐變差異較大,缺乏明確的鋼管混凝土徐變計(jì)算模型等現(xiàn)狀,對(duì)鋼管混凝土徐變進(jìn)行了室內(nèi)試驗(yàn),并通過試驗(yàn)數(shù)據(jù)對(duì)普通混凝土徐變計(jì)算模型進(jìn)行修正,使其可以應(yīng)用于鋼管混凝土徐變計(jì)算,最終用修正后的鋼管混凝土徐變計(jì)算模型對(duì)某大跨度鋼管混凝土系桿拱橋進(jìn)行數(shù)值模擬分析,系統(tǒng)的研究了徐變對(duì)大跨度鋼管混凝土系桿拱橋靜力性能的影響。主要研究內(nèi)容如下:(1)闡述了鋼管混凝土發(fā)展、特點(diǎn)及其在拱橋中的應(yīng)用,并簡要的介紹了鋼管混凝土收縮徐變的特點(diǎn)及其目前國內(nèi)外的研究現(xiàn)狀;(2)在查閱相關(guān)文獻(xiàn)的基礎(chǔ)上,系統(tǒng)的總結(jié)了混凝土收縮徐變的基本性質(zhì),并簡要的介紹了混凝土收縮徐變的影響因素、計(jì)算理論和計(jì)算模型等;(3)通過不同膨脹劑摻量和含鋼率的鋼管混凝土試件收縮徐變?cè)囼?yàn)和承載力試驗(yàn),得到了鋼管混凝土徐變曲線和鋼管混凝土承載力,分析了不同膨脹劑摻量和含鋼率下鋼管混凝土收縮徐變變化規(guī)律及鋼管混凝土的最優(yōu)膨脹劑摻量;(4)通過最優(yōu)膨脹劑摻量下的鋼管混凝土徐變數(shù)據(jù)與模擬數(shù)值進(jìn)行對(duì)比分析,修正了混凝土徐變計(jì)算模型,并將修正后模型的計(jì)算結(jié)果與實(shí)測數(shù)據(jù)進(jìn)行對(duì)比,證明了該修正模型的合理可靠。(5)以某128m大跨度鋼管混凝土系桿拱橋?yàn)槔?采用Midas-Civil軟件建立三維有限元空間模型,用修正后的鋼管混凝土徐變計(jì)算模型分析了徐變對(duì)大跨度鋼管混凝土系桿拱橋靜力性能的影響,包括拱肋軸力、彎矩、位移以及鋼管與核心混凝土應(yīng)力重分布,系梁彎矩、軸力及位移,吊桿軸力等。
[Abstract]:As a new composite material, concrete-filled steel tube (CFST) integrates the advantages of steel tube and concrete, and is widely used in long-span concrete-filled steel tubular tied arch bridge. However, there are some differences between concrete filled steel tube creep and ordinary concrete creep, and concrete filled steel tube creep will cause the redistribution of internal force between steel tube and core concrete. Moreover, creep under time load will also affect the static behavior of long span concrete-filled steel tubular tied arch bridge. In view of the fact that concrete filled steel tube (CFST) creep data are less and there is a big difference between CFST creep and ordinary concrete creep, the concrete filled steel tube creep calculation model is lacking, so the concrete filled steel tubular creep test is carried out in laboratory. The creep calculation model of ordinary concrete is modified by test data, which can be applied to the creep calculation of concrete-filled steel tube (CFST). Finally, a long-span concrete-filled steel tubular tied arch bridge is numerically simulated with the modified concrete filled steel tube creep model, and the influence of creep on the static behavior of the long-span concrete-filled steel tubular tied arch bridge is systematically studied. The main research contents are as follows: (1) the development and characteristics of concrete-filled steel tubular (CFST) and its application in arch bridges are described, and the characteristics of concrete-filled steel tubular (CFST) shrinkage and creep and the current research situation at home and abroad are briefly introduced. The basic properties of concrete shrinkage and creep are summarized systematically, and the influencing factors of concrete shrinkage and creep are introduced briefly. The creep curve of concrete filled steel tubular (CFST) and the bearing capacity of concrete filled steel tubular (CFST) are obtained by the shrinkage creep test and bearing capacity test of concrete filled steel tube specimens with different amount of expansive agent and steel tube content. The law of shrinkage and creep of concrete-filled steel tube (CFST) under different content of expansive agent and steel content and the optimal quantity of expansive agent of CFST are analyzed. The creep data of CFST under the optimal content of expansive agent are compared with the numerical value of simulation. The calculation model of concrete creep is modified, and the calculated results of the modified model are compared with the measured data. It is proved that the modified model is reasonable and reliable, taking a 128m long span concrete-filled steel tube tied arch bridge as an example. The three-dimensional finite element spatial model is established by using Midas-Civil software. The influence of creep on the static behavior of long-span concrete-filled steel tubular tied arch bridge is analyzed by using the modified creep calculation model of concrete-filled steel tube (CFST), including the axial force and bending moment of arch rib. Displacement and stress redistribution of steel tube and core concrete, bending moment, axial force and displacement, axial force of suspender, etc.
【學(xué)位授予單位】：蘭州交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U441;U448.225

【共引文獻(xiàn)】

相關(guān)期刊論文 前2條

1 王存國;李海泉;向淵;;廣深港客運(yùn)專線連續(xù)剛構(gòu)后期變形預(yù)估研究[J];鐵道標(biāo)準(zhǔn)設(shè)計(jì);2012年10期

2 王存國;黃納新;崔陽華;;廣深港客運(yùn)專線連續(xù)梁拱后期變形預(yù)估研究[J];鐵道工程學(xué)報(bào);2014年02期

相關(guān)博士學(xué)位論文 前1條

1 曹建安;無碴軌道大跨度預(yù)應(yīng)力混凝土橋梁后期徐變變形和控制方法研究[D];中南大學(xué);2011年

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本文編號(hào)：1782704