發(fā)布時間：2018-08-12 08:03

【摘要】：鋼桁—混凝土T構組合結構橋梁是混凝土箱梁橋面板與鋼桁架共同受力的一種新型組合結構，因其剛度大、結構自重低、整體穩(wěn)定性好、抗震性能強和行車平順等一系列優(yōu)點，已在各國的公路和高速鐵路中得到廣泛應用。但是在日照或者氣候變化的影響下，鋼桁架和混凝土都會產生不同程度的溫度應力和變形，因此很容易導致混凝土出現(xiàn)開裂的問題。從既有的研究來看，國內外橋梁專家學者針對混凝土箱梁橋的溫度效應做了大量的研究工作，積累了許多寶貴的經驗，但是對于鋼桁—T構組合梁橋溫度效應及開裂問題沒有得到足夠的重視。本文結合新建高速鐵路大同至西安某黃河特大橋主跨部分單T剛構加勁鋼桁組合結構實際工程，深入研究鋼桁—T構組合梁橋溫度場分布規(guī)律，完善溫度效應理論計算和實橋測試研究，分析了鋼桁—T構組合梁橋開裂機理，給出了裂縫控制措施�；谝陨戏治觯疚脑谝酝芯康幕A上利用空間有限元軟件對該單T剛構加勁鋼桁組合橋梁進行計算分析，主要進行了以下工作： 1．通過對鋼桁架結構日照溫度場的監(jiān)測以及氣象資料的分析，得到了鋼桁在日照作用下的溫度分布規(guī)律和極端溫度荷載分布情況。并根據(jù)溫度分布規(guī)律，分析了鋼桁架在日照影響、極端溫度荷載、極端溫度荷載與恒活載組合三種荷載工況。 2．建立某黃河特大橋主跨部分單T剛構加勁鋼桁組合結構空間有限元模型，計算分析了鋼桁架分別在三種工況下橋梁支座豎向反力、桁架應力及混凝土應力與位移變化規(guī)律。得出了在線性溫度荷載作用下，支座豎向反力、桁架應力和混凝土應力均為線性變化；極端溫度荷載作用下，，相互對立的鋼桁架V型斜桿總是一邊受拉一邊受壓，升溫荷載作用使主梁上撓，降溫荷載作用使主梁下?lián)希辉跇O端溫度荷載與恒活載組合作用下，掌握了橋梁最不利情況下的桁架應力以及混凝土主梁應力、撓度變化情況。 3．研究了鋼桁—混凝土T構組合梁橋桁架與混凝土結合處的連接類型，得到了溫度變化對桁架與混凝土連接處受力的影響機理。建立結合點三維實體有限元模型，計算分析了極端溫度荷載作用和組合作用兩種最不利情況，得到了此時全橋混凝土應力最大位置處結合點混凝土的應力以及裂縫情況。 4．本文根據(jù)計算結論結合相關文獻，分析了鋼桁—混凝土T構組合橋梁溫度裂縫的特點以及成因，繼而提出了鋼桁—混凝土T構組合橋梁溫度裂縫的防裂措施，用以指導這類橋梁的設計與施工。
[Abstract]:Steel truss-concrete T-structure composite structure bridge is a new type of composite structure with concrete box girder bridge slabs and steel truss. It has a series of advantages such as high stiffness, low deadweight, good overall stability, strong seismic performance and smooth running, etc. It has been widely used in highway and high-speed railway all over the world. However, under the influence of sunshine or climate change, both steel truss and concrete will produce different degrees of thermal stress and deformation, so it is easy to cause cracking of concrete. From the existing research, bridge experts and scholars at home and abroad have done a lot of research work on the temperature effect of concrete box girder bridge, and accumulated a lot of valuable experience. However, not enough attention has been paid to the temperature effect and cracking of steel truss-T composite girder bridge. In this paper, the temperature field distribution of steel truss composite girder bridge with steel truss is studied in combination with the practical engineering of single T rigid frame stiffened steel truss composite structure in the main span of a new high-speed railway from Datong to a certain Yellow River super large bridge in Xi'an. The theoretical calculation of temperature effect and the test of real bridge are improved. The cracking mechanism of steel truss-T composite beam bridge is analyzed and the crack control measures are given. Based on the above analysis, this paper uses the spatial finite element software to calculate and analyze the single T rigid frame stiffened steel truss composite bridge based on the previous research. The main work is as follows: 1. The temperature distribution and extreme temperature load distribution of steel truss under sunlight are obtained by monitoring the temperature field of steel truss structure and analyzing meteorological data. According to the temperature distribution, the influence of steel truss on the extreme temperature load is analyzed. Extreme temperature load and dead load combination. 2. A spatial finite element model of a single T rigid frame stiffened steel truss composite structure with main span of a Yellow River bridge is established. The vertical reaction force, truss stress and concrete stress and displacement of steel truss are calculated and analyzed under three working conditions. Under the action of linear temperature load, the vertical reaction force, truss stress and concrete stress of the bearing are all linearly changed, and under extreme temperature load, the V-shaped oblique bar of steel truss is always subjected to tension and compression at the same time. Under the combined action of extreme temperature load and dead load, the stress of truss and the stress of main beam of concrete under the most disadvantageous condition of bridge are grasped. 3. The connection type between truss and concrete of steel truss-concrete composite beam bridge is studied, and the influence mechanism of temperature change on the joint force between truss and concrete is obtained. The 3D solid finite element model of the junction point is established, and the two most disadvantageous cases of extreme temperature load and combination action are calculated and analyzed. At this time, the stress and crack of the concrete at the joint point at the maximum stress position of the whole bridge concrete are obtained. 4. According to the calculation conclusion, the paper combines the relevant literature, This paper analyzes the characteristics and causes of temperature cracks of steel truss-concrete T-structure composite bridges, and then puts forward the measures to prevent the temperature cracks of steel truss-concrete T-structure composite bridges, which can be used to guide the design and construction of this kind of bridges.
【學位授予單位】：長安大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U441.5

【參考文獻】

相關期刊論文 前10條

1 陳寶春;劉振宇;;鋼管混凝土拱橋溫度問題研究綜述[J];福州大學學報(自然科學版);2009年03期

2 鐘善桐;鋼-混凝土組合結構在我國的研究與應用[J];鋼結構;2000年04期

3 周良;陸元春;李雪峰;;鋼-混凝土組合梁的溫度應力計算[J];公路交通科技;2012年05期

4 雷昌龍;鋼-混凝土組合橋中新的剪力連接器的發(fā)展與試驗[J];國外橋梁;1999年02期

5 盛洪飛;混凝土箱形截面橋梁日照溫度應力簡化計算[J];哈爾濱建筑工程學院學報;1992年01期

6 樊健生,聶建國,賈維,何萌;鋼-混凝土連續(xù)組合梁的設計方法[J];建筑結構;2003年01期

7 樊小卿;溫度作用與結構設計[J];建筑結構學報;1999年02期

8 邵紅艷,竺潤祥,任茶仙;結構溫度場和溫度應力場的有限元分析[J];寧波大學學報(理工版);2003年01期

9 姜全德,蔣鴻;鋼筋混凝土箱形梁橋日照溫度場和溫度應力平面有限元數(shù)值分析方法[J];橋梁建設;1990年03期

10 何雄君,文武松,胡志堅;鋼管混凝土拱橋溫度荷載分析[J];橋梁建設;2000年01期

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