【摘要】：由于寬箱梁翼緣板較寬,存在剪切滯后的現(xiàn)象,使得寬箱梁縱向正應(yīng)力沿橫向分布非均勻,即剪力滯效應(yīng)。對(duì)于混凝土寬箱梁,如果在設(shè)計(jì)與施工中忽略剪力滯效應(yīng)的影響,有可能出現(xiàn)應(yīng)力集中導(dǎo)致混凝土開裂。因此對(duì)寬箱梁的剪力滯效應(yīng)進(jìn)行研究很有必要。本文依托南京六合跨滁河大橋工程,分析了混凝土寬箱梁的受力特性,重點(diǎn)研究了混凝土寬箱梁的剪力滯效應(yīng)。本文首先綜述了目前研究剪力滯的理論與方法。運(yùn)用Midas/Civil建立斜拉橋空間桿系模型,進(jìn)行受力特性分析,得到了幾種不利狀態(tài)下主梁的內(nèi)力及應(yīng)力分布規(guī)律。該橋主梁在承載能力極限狀態(tài)和正常使用極限狀態(tài)下均滿足規(guī)范要求；主梁在承載能力極限狀態(tài)下,主跨主梁彎矩受拉索影響較大,而邊跨彎矩則主要受移動(dòng)荷載影響。其次,采用Midas/FEA建立了斜拉橋?qū)嶓w單元模型,針對(duì)成橋恒載狀態(tài),通過(guò)提取主要典型截面的縱橋向正應(yīng)力并繪制剪力滯系數(shù)曲線圖,研究了主梁的剪力滯效應(yīng)。由于斜拉橋主梁的剪力滯效應(yīng),使得縱向正應(yīng)力沿橫截面分布不均勻；變截面處頂板的剪力滯效應(yīng)相對(duì)一般截面較強(qiáng)；變截面底板剪力滯效應(yīng)受斜拉索影響較大,隨著與斜拉索距離的增加逐漸減��；主跨和邊跨的剪力滯效應(yīng)的分布規(guī)律相似,但是邊跨的剪力滯效應(yīng)比主跨稍強(qiáng)。最后,用Midas/FEA建立參數(shù)化有限元模型,分析了橫隔板厚度、橫隔板間隔、倒角、頂板厚度、底板厚度、縱向預(yù)應(yīng)力的大小、混凝土強(qiáng)度等主要參數(shù)對(duì)斜拉橋剪力滯效應(yīng)的影響。通過(guò)對(duì)多個(gè)參數(shù)化有限元模型的對(duì)比分析可以看出,增大橫隔板、頂板、底板厚度,減小橫隔板間隔,增加倒角,都能夠減小箱梁頂板的剪力滯效應(yīng)；底板厚度的改變對(duì)箱梁剪力滯效應(yīng)的影響較��；變換以上參數(shù)對(duì)寬箱梁底板的剪力滯效應(yīng)影響均較��；縱向預(yù)應(yīng)力減小了斜拉橋?qū)捪淞旱募袅?yīng),對(duì)結(jié)構(gòu)偏于有利,但是隨著預(yù)應(yīng)力值的加大,剪力滯系數(shù)改變的幅度會(huì)減��；混凝土強(qiáng)度的改變對(duì)于斜拉橋?qū)捪淞杭袅?yīng)幾乎無(wú)任何影響。本文對(duì)獨(dú)塔斜拉橋混凝土寬箱受力特性進(jìn)行了研究,對(duì)類似截面形式的寬箱梁的設(shè)計(jì)和施工均有一定的參考價(jià)值。
[Abstract]:Due to the wide flange plate of the wide box girder and the phenomenon of shear lag, the longitudinal normal stress of the wide box girder is distributed inhomogeneously along the transverse direction, that is, the shear lag effect. If the shear lag effect is neglected in the design and construction of the wide concrete box girder, the stress concentration may lead to concrete cracking. Therefore, it is necessary to study the shear lag effect of wide box girder. In this paper, based on the Nanjing Liuhe Bridge, the stress characteristics of the concrete wide box girder are analyzed, and the shear lag effect of the concrete wide box girder is studied. In this paper, the theories and methods of shear lag are reviewed. The spatial bar system model of cable-stayed bridge is established by using Midas/Civil, and the internal force and stress distribution of the main beam under several unfavorable conditions are obtained. The main beam of the bridge meets the requirements of the code under the limit state of bearing capacity and the limit state of normal use, and the moment of the main girder of the main span is greatly affected by the cable, while the moment of the side span is mainly affected by the moving load under the limit state of the bearing capacity of the main beam. Secondly, the solid element model of cable-stayed bridge is established by using Midas/FEA. Aiming at the dead load state of the bridge, the shear lag effect of the main girder is studied by extracting the normal stress of the longitudinal bridge of the main typical section and drawing the curve of shear lag coefficient. Due to the shear lag effect of the main girder of the cable-stayed bridge, the longitudinal normal stress distributes unevenly along the cross section, the shear lag effect of the roof plate at the variable section is stronger than that of the general section, and the shear lag effect of the variable section bottom plate is greatly affected by the cable. The shear lag effect of the main span and the side span is similar, but the shear lag effect of the side span is slightly stronger than that of the main span. Finally, the parametric finite element model is established with Midas/FEA, and the influence of the main parameters, such as the thickness of transverse partition, the interval of transverse partition, the chamfer, the thickness of roof, the thickness of bottom slab, the size of longitudinal prestress and the strength of concrete, on the shear lag effect of cable-stayed bridge is analyzed. Through the comparison and analysis of many parameterized finite element models, it can be seen that the shear lag effect of box girder roof can be reduced by increasing the thickness of transverse partition, roof and bottom, reducing the interval of transverse partition and increasing chamfer. The influence of the thickness of the bottom plate on the shear lag effect of the box girder is small, the influence of the above parameters on the shear lag effect of the wide box girder bottom plate is small, and the longitudinal prestress reduces the shear lag effect of the wide box girder of the cable-stayed bridge, which is favorable to the structure. However, with the increase of prestressed value, the amplitude of shear lag coefficient will decrease, and the change of concrete strength has little effect on the shear lag effect of wide box girder of cable-stayed bridge. In this paper, the mechanical characteristics of concrete wide box of single tower cable-stayed bridge are studied, which has certain reference value for the design and construction of wide box girder with similar cross-section.
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U448.27;U441

【參考文獻(xiàn)】

相關(guān)期刊論文 前6條

1 蔡華炳,裴若娟;連續(xù)剛構(gòu)寬箱梁剪力滯效應(yīng)的計(jì)算分析[J];長(zhǎng)沙鐵道學(xué)院學(xué)報(bào);2003年03期

2 程翔云;雙室箱梁頂板的有效分布寬度[J];公路;1997年04期

3 張俊平,梅力彪,蔡卡宏;展翅梁結(jié)構(gòu)有機(jī)玻璃模型試驗(yàn)研究[J];廣州大學(xué)學(xué)報(bào)(綜合版);2001年02期

4 李興民;;施工過(guò)程對(duì)箱梁剪力滯效應(yīng)影響分析[J];橋梁建設(shè);2013年01期

5 李艷鳳;梁力;王福春;;單索面斜拉橋活載作用下主梁剪力滯研究[J];沈陽(yáng)建筑大學(xué)學(xué)報(bào)(自然科學(xué)版);2013年02期

6 萬(wàn)臻,李喬,毛學(xué)明;Π型截面主梁斜拉橋剪力滯效應(yīng)試驗(yàn)研究[J];西南交通大學(xué)學(xué)報(bào);2004年05期

相關(guān)碩士學(xué)位論文 前1條

1 余澤;超寬分離式混凝土邊箱梁正截面受力性能研究[D];湖南大學(xué);2011年

，

本文編號(hào)：2156530