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  本文關(guān)鍵詞：混凝土強(qiáng)度不均勻性對懸臂法施工的橋梁結(jié)構(gòu)影響分析　出處：《長安大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 懸臂澆筑 混凝土強(qiáng)度 彈性模量 撓度 應(yīng)力

【摘要】：隨著大跨徑預(yù)應(yīng)力混凝土橋梁的發(fā)展,因懸臂澆筑法具有結(jié)構(gòu)整體性好、施工變形易控制和不受橋下地形限制或通航限制等優(yōu)點而被廣泛采用。在懸臂澆筑施工過程中,混凝土受到配合比和現(xiàn)場養(yǎng)護(hù)條件等因素的影響,不僅使得混凝土強(qiáng)度和彈性模量偏離原設(shè)計值,而且每個節(jié)段的混凝土強(qiáng)度和彈性模量也會出現(xiàn)差異,從而使得橋梁結(jié)構(gòu)受力偏離原設(shè)計值。因此,研究各個節(jié)段混凝土強(qiáng)度和彈性模量的差異對橋梁結(jié)構(gòu)的影響具有重要的理論意義和工程實用價值。本文以某新建鐵路線上預(yù)應(yīng)力混凝土T形剛構(gòu)為工程背景,借助有限元計算軟件,通過合理的參數(shù)假設(shè),研究因混凝土強(qiáng)度和彈性模量差異對橋梁結(jié)構(gòu)的影響。通過修改混凝土的彈性模量,研究彈性模量的變化對成橋階段影響,并通過定性分析給出合理的彈性模量的取值范圍;通過修改各個節(jié)段混凝土強(qiáng)度和彈性模量發(fā)展函數(shù),研究在施工階段對主梁撓度和懸臂根部、跨中和最大懸臂端應(yīng)力的影響。研究結(jié)果表明,混凝土彈性模量的變化對成橋階段的撓度影響較大。當(dāng)混凝土的彈性模量是1.0~1.1倍的設(shè)計值時,撓度變化的離散性較小,變形能得到較好的控制。當(dāng)混凝土彈性模量發(fā)生變化時,對主梁1/4跨至最大懸臂端撓度影響較大。當(dāng)修改混凝土強(qiáng)度和彈性模量發(fā)展函數(shù)時,在施工階段結(jié)構(gòu)體系發(fā)生轉(zhuǎn)變前,對應(yīng)力無影響,而在結(jié)構(gòu)體系發(fā)生轉(zhuǎn)變后,混凝土彈性模量的變化導(dǎo)致?lián)隙犬a(chǎn)生變化,從而使得懸臂根部、跨中和最大懸臂端應(yīng)力發(fā)生變化,并且當(dāng)混凝土強(qiáng)度大于設(shè)計值一個等級時,應(yīng)力偏離設(shè)計值較小。
[Abstract]:With the development of long-span prestressed concrete bridge, the cantilever pouring method has good structural integrity. The construction deformation is easy to control and is not restricted by the terrain under the bridge or navigation restrictions and other advantages are widely used. In the cantilever pouring construction process concrete is affected by mix ratio and site maintenance conditions and other factors. Not only the strength and elastic modulus of concrete deviate from the original design value, but also the concrete strength and elastic modulus of each segment will be different, which makes the force of bridge structure deviate from the original design value. It is of great theoretical significance and practical value to study the influence of concrete strength and elastic modulus on the bridge structure. In this paper, the T-shaped rigid frame of prestressed concrete on a new railway line is taken as the engineering background. By means of finite element calculation software and reasonable parameter hypothesis, the influence of concrete strength and elastic modulus on bridge structure is studied, and the elastic modulus of concrete is modified. The influence of the change of elastic modulus on the bridge stage is studied, and the reasonable range of elastic modulus is given by qualitative analysis. By modifying the development function of strength and elastic modulus of each segment of concrete, the effect of the construction stage on the deflection of the main beam, the root of the cantilever and the stress at the span and the maximum end of the cantilever are studied. The variation of elastic modulus of concrete has a great influence on the deflection of the bridge stage. When the elastic modulus of concrete is 1.0 ~ 1.1 times of the design value, the dispersion of the deflection change is smaller. The deformation can be controlled well. When the elastic modulus of concrete changes, the deflection of the 1/4 span to the maximum cantilever end of the main beam is greatly affected. When the development function of the strength and elastic modulus of concrete is modified. There is no effect on the stress before the structural system transition in the construction stage, but the change of the elastic modulus of concrete leads to the change of deflection after the transformation of the structure system, thus making the cantilever root. The stress changes at the end of the span and the maximum cantilever, and when the strength of concrete is larger than the design value, the stress deviation from the design value is smaller.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U445.466;U441

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本文編號：1402495