大氣腐蝕條件下中等跨徑公路鋼箱梁橋受力性能評估
發(fā)布時間：2018-09-18 21:06
【摘要】：鋼箱梁橋隨服役時間的增加將不可避免地出現(xiàn)各種結(jié)構(gòu)損傷,會嚴(yán)重影響鋼箱梁橋的使用性能,本文以紹興一座匝道鋼箱梁橋?yàn)橐劳泄こ?從腐蝕的角度出發(fā),結(jié)合實(shí)地調(diào)研、理論分析和數(shù)值模擬等方法,研究大氣均勻腐蝕和局部腐蝕對中等跨徑公路鋼箱梁橋受力性能的影響,為在役中等跨徑公路鋼箱梁橋承載能力的評估和檢測提供科學(xué)依據(jù),以便更好地彌補(bǔ)現(xiàn)有評估方法的不足。本文的主要研究工作和相關(guān)結(jié)論如下:(1)結(jié)合依托工程所使用鋼材的化學(xué)成分和所處地區(qū)的環(huán)境因素,得出了依托工程中鋼箱梁外部和內(nèi)部的腐蝕深度預(yù)測公式分別為0.762C?0.036t外和0.587C?0.049t內(nèi)。隨后,以依托工程為背景,采用有限元數(shù)值模擬技術(shù),定量分析了在大氣均勻腐蝕作用0~100年內(nèi),鋼箱梁橋受力性能隨服役時間增長的變化規(guī)律。研究結(jié)果表明:大氣均勻腐蝕會造成鋼箱梁各部件厚度減小,但一直能保持較好的整體性,且滿足剛度與強(qiáng)度的設(shè)計要求;大氣均勻腐蝕會造成鋼箱梁橋的極限承載能力成線性減小,當(dāng)腐蝕時間為100年時,下降為無損傷階段的87.5%左右。(2)在分析以往鋼橋腐蝕損傷作用下實(shí)際檢測數(shù)據(jù)的基礎(chǔ)上,結(jié)合依托工程所處的具體環(huán)境,得出腹板兩端和底板跨中為嚴(yán)重腐蝕區(qū)域,并指定每種區(qū)域最大腐蝕深度分別為原有部件厚度的50%,然后采用數(shù)值模擬技術(shù)定性分析了不同腐蝕區(qū)域在不同腐蝕程度的情況下對鋼箱梁橋整體受力性能的影響。研究結(jié)果表明:在指定腐蝕深度范圍內(nèi),局部腐蝕狀態(tài)下的鋼箱梁橋能滿足剛度與強(qiáng)度的設(shè)計要求;局部腐蝕對鋼箱梁橋極限承載能力影響較為明顯,當(dāng)腐蝕深度為原有部件厚度的50%時,極限承載力下降到無損傷階段的60%~70%之間。(3)通過對鋼箱梁橋在各種腐蝕作用下應(yīng)力和位移進(jìn)行分析,研究了鋼箱梁橋在遭受均勻腐蝕和局部腐蝕過程中的應(yīng)力關(guān)鍵區(qū)域和位移變化規(guī)律。研究結(jié)果表明:頂板在與腹板相接位置出現(xiàn)了明顯的剪力滯后現(xiàn)象;底板跨中區(qū)域以及底板邊緣與腹板相接位置應(yīng)力較大;腹板兩端靠近橫梁區(qū)域?yàn)閼?yīng)力和變形的關(guān)鍵區(qū)域;橫隔板在彎扭耦合作用下,在過人通道的角點(diǎn)處易發(fā)生應(yīng)力集中現(xiàn)象。
[Abstract]:With the increase of service time, various kinds of structural damage will inevitably appear in the steel box girder bridge, which will seriously affect the performance of the steel box girder bridge. In this paper, based on a ramp steel box girder bridge in Shaoxing, from the point of view of corrosion, combined with field investigation, Theoretical analysis and numerical simulation are used to study the effect of uniform and local corrosion of atmosphere on the mechanical performance of medium span highway steel box girder bridge, which provides a scientific basis for the evaluation and detection of the bearing capacity of medium span highway steel box girder bridge in service. In order to better compensate for the shortcomings of existing evaluation methods. The main research work and related conclusions are as follows: (1) combined with the chemical composition of the steel used in the supporting project and the environmental factors in the region, The external and internal corrosion depth prediction formulas of the steel box girder in the backing engineering are obtained respectively in 0.762C?0.036t and 0.587C?0.049t. Then, based on the engineering background, finite element numerical simulation technique is used to quantitatively analyze the variation of the mechanical behavior of steel box girder bridges with the increase of service time during the 0-100 years of uniform atmospheric corrosion. The results show that uniform atmospheric corrosion will reduce the thickness of the components of the steel box girder, but it can keep a good integrity and meet the design requirements of stiffness and strength. Uniform atmospheric corrosion will reduce the ultimate bearing capacity of steel box girder bridge linearly. When the corrosion time is 100 years, it will decrease to 87.5% of the non-damaged stage. (2) on the basis of analyzing the actual detection data of steel bridge under the action of corrosion damage, Combining with the concrete environment of the supporting project, it is concluded that the two ends of the web and the middle span of the bottom plate are the seriously corroded areas. The maximum corrosion depth of each region is designated as 50 of the original component thickness, and then the influence of different corrosion zones on the overall mechanical performance of steel box girder bridge is analyzed qualitatively by numerical simulation technique. The results show that the steel box girder bridge under local corrosion can meet the design requirements of stiffness and strength in the specified corrosion depth range, and the local corrosion has a more obvious effect on the ultimate bearing capacity of the steel box girder bridge. When the corrosion depth is 50% of the original component thickness, the ultimate bearing capacity decreases to between 60% and 70% of the non-damage stage. (3) the stress and displacement of the steel box girder bridge under various corrosion conditions are analyzed. The stress critical region and displacement variation of steel box girder bridge under uniform and local corrosion are studied. The results show that the shear lag appears in the joint position of the roof and the web, the stress in the middle region of the bottom plate and the edge of the bottom plate is large, and the two ends of the web are the key areas of stress and deformation near the cross beam area. Under the coupling of bending and torsion, the stress concentration is easy to occur at the corner of the passage.
【學(xué)位授予單位】：江蘇科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U441;U448.213
本文編號：2249101
[Abstract]:With the increase of service time, various kinds of structural damage will inevitably appear in the steel box girder bridge, which will seriously affect the performance of the steel box girder bridge. In this paper, based on a ramp steel box girder bridge in Shaoxing, from the point of view of corrosion, combined with field investigation, Theoretical analysis and numerical simulation are used to study the effect of uniform and local corrosion of atmosphere on the mechanical performance of medium span highway steel box girder bridge, which provides a scientific basis for the evaluation and detection of the bearing capacity of medium span highway steel box girder bridge in service. In order to better compensate for the shortcomings of existing evaluation methods. The main research work and related conclusions are as follows: (1) combined with the chemical composition of the steel used in the supporting project and the environmental factors in the region, The external and internal corrosion depth prediction formulas of the steel box girder in the backing engineering are obtained respectively in 0.762C?0.036t and 0.587C?0.049t. Then, based on the engineering background, finite element numerical simulation technique is used to quantitatively analyze the variation of the mechanical behavior of steel box girder bridges with the increase of service time during the 0-100 years of uniform atmospheric corrosion. The results show that uniform atmospheric corrosion will reduce the thickness of the components of the steel box girder, but it can keep a good integrity and meet the design requirements of stiffness and strength. Uniform atmospheric corrosion will reduce the ultimate bearing capacity of steel box girder bridge linearly. When the corrosion time is 100 years, it will decrease to 87.5% of the non-damaged stage. (2) on the basis of analyzing the actual detection data of steel bridge under the action of corrosion damage, Combining with the concrete environment of the supporting project, it is concluded that the two ends of the web and the middle span of the bottom plate are the seriously corroded areas. The maximum corrosion depth of each region is designated as 50 of the original component thickness, and then the influence of different corrosion zones on the overall mechanical performance of steel box girder bridge is analyzed qualitatively by numerical simulation technique. The results show that the steel box girder bridge under local corrosion can meet the design requirements of stiffness and strength in the specified corrosion depth range, and the local corrosion has a more obvious effect on the ultimate bearing capacity of the steel box girder bridge. When the corrosion depth is 50% of the original component thickness, the ultimate bearing capacity decreases to between 60% and 70% of the non-damage stage. (3) the stress and displacement of the steel box girder bridge under various corrosion conditions are analyzed. The stress critical region and displacement variation of steel box girder bridge under uniform and local corrosion are studied. The results show that the shear lag appears in the joint position of the roof and the web, the stress in the middle region of the bottom plate and the edge of the bottom plate is large, and the two ends of the web are the key areas of stress and deformation near the cross beam area. Under the coupling of bending and torsion, the stress concentration is easy to occur at the corner of the passage.
【學(xué)位授予單位】：江蘇科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U441;U448.213
【參考文獻(xiàn)】
相關(guān)期刊論文 前5條
1 姜竹生;瞿濤;呂磊;吉伯海;;鋼箱梁典型病害分析及其檢測與維護(hù)技術(shù)研究[J];防災(zāi)減災(zāi)工程學(xué)報;2011年05期
2 鄧國軍;;基于振動的既有橋梁評估方法的探究[J];湖南交通科技;2012年02期
3 李子元;石晉華;;基于可靠度理論的橋梁評估[J];交通標(biāo)準(zhǔn)化;2014年07期
4 程軍;;鋼橋的腐蝕及其防護(hù)措施探析[J];鐵道建筑;2008年07期
5 梁彩鳳,侯文泰;合金元素對碳鋼和低合金鋼在大氣中耐腐蝕性的影響[J];中國腐蝕與防護(hù)學(xué)報;1997年02期
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