開裂RC橋梁動態(tài)可靠度分析及研究
發(fā)布時間：2018-09-08 17:46
【摘要】：近幾年來,我國交通事業(yè)快速發(fā)展,國家高速公路網(wǎng)逐漸完善,RC橋梁的建設(shè)所占比重也越來越大。但隨著RC橋梁服役時間的增長,人們在RC橋梁上發(fā)現(xiàn)了許多不同類型的裂縫,RC橋梁的開裂大大降低了橋梁的承載能力及耐久性;同時由于近幾年橋梁事故時有發(fā)生,橋梁開裂被認(rèn)為是橋梁破壞前兆,人們對其產(chǎn)生強烈的恐懼感。對開裂RC橋梁的動態(tài)可靠度進(jìn)行研究及對其剩余壽命進(jìn)行預(yù)測,為開裂RC橋梁的維修加固提供理論依據(jù),具有重要的理論價值和現(xiàn)實意義。本文依托福建省交通廳重點科技發(fā)展項目——“福建混凝土橋梁防裂對策及預(yù)防性建養(yǎng)關(guān)鍵技術(shù)研究”,以某一開裂簡支T梁橋為研究對象,對開裂RC橋的荷載效應(yīng)、抗力衰減模型進(jìn)行了研究,并基于驗算點法(JR法)計算RC橋梁動態(tài)可靠度,然后根據(jù)動態(tài)可靠度的計算結(jié)果對該橋的剩余壽命進(jìn)行了討論。主要工作內(nèi)容如下:1、根據(jù)由福建省交通廳組織的對在役混凝土橋梁開裂情況的調(diào)查結(jié)果,分析了各類混凝土橋梁裂縫的分布規(guī)律:(1)鋼筋混凝土T梁橋的開裂情況主要是支座、1/4及1/5跨徑附近翼緣板斜向開裂和翼緣板與腹板交接處的縱向開裂兩種;(2)RC小箱梁橋主要是在在1/5L~1/3L處的底板縱向開裂及橫向開裂、箱梁間濕接縫處的橫向開裂、梁間現(xiàn)澆段段處的豎向開裂三種開裂形式。2、根據(jù)可靠度的基本原理,介紹動態(tài)可靠度的基本概念。并針對工程實例,基于動態(tài)可靠度理論的混凝土碳化深度及鋼筋銹蝕隨時間變化的動態(tài)模型,建立了考慮開裂影響的RC簡支T梁橋荷載效應(yīng)及抗力衰減隨時間變化的動態(tài)模型,討論了結(jié)構(gòu)可靠度隨時間變化的規(guī)律。3、利用MATLAB 2014a數(shù)學(xué)計算軟件編寫驗算點法(JC法)計算動態(tài)可靠指標(biāo)程序,并對某一開裂簡支T梁橋動態(tài)可靠度進(jìn)行求解,根據(jù)計算出的動態(tài)可靠指標(biāo),對其剩余壽命進(jìn)行了預(yù)測與分析,重點分析了超載運行及裂縫進(jìn)一步擴(kuò)展時對橋梁結(jié)構(gòu)動態(tài)可靠度及剩余壽命的影響。相同時間內(nèi),超載運營比正常荷載運營時的可靠度要小,且超載運營時的可靠度下降速率要快,并使RC橋梁結(jié)構(gòu)的使用壽命大大縮減;在相同服役時間段內(nèi)及相同運營狀態(tài)下,橋梁開裂程度越嚴(yán)重,RC橋梁結(jié)構(gòu)的可靠度越小,則表面RC橋梁的正常使用壽命就越短,這樣將嚴(yán)重影響橋梁建設(shè)及交通網(wǎng)線規(guī)劃。4、處理好裂縫問題的關(guān)鍵所在就是正確認(rèn)識混凝土結(jié)構(gòu)的裂縫。只有能夠正確判斷裂縫產(chǎn)生的各種原因以及影響程度,才有可能對裂縫的性質(zhì)及其對結(jié)構(gòu)安全及使用功能的影響做出科學(xué)的判斷,才能采取針對性的措施進(jìn)行更有把握地、更有效地處理。本文最后根據(jù)前面對開裂RC橋梁動態(tài)可靠度的分析研究,提出了一些預(yù)防混凝土橋梁開裂的措施及開裂后的修復(fù)方法。
[Abstract]:In recent years, with the rapid development of transportation in China, the construction of RC bridges in the national highway network is becoming more and more important. However, with the increase of service time of RC bridge, many kinds of cracks and cracks of RC bridge have been found in RC bridge, which greatly reduce the bearing capacity and durability of the bridge, at the same time, because of bridge accidents in recent years, Bridge cracking is regarded as a precursor of bridge damage, and people have a strong fear of it. This paper studies the dynamic reliability of cracked RC bridge and predicts its residual life, which provides the theoretical basis for the maintenance and reinforcement of cracked RC bridge, and has important theoretical value and practical significance. In this paper, based on the key scientific and technological development project of Fujian Provincial Communications Department, "study on crack Prevention Countermeasures and key techniques of Preventive Construction and maintenance of concrete Bridges in Fujian Province", a cracked simply supported T-beam bridge is taken as the research object, and the load effect of cracked RC bridge is studied. The resistance attenuation model is studied and the dynamic reliability of RC bridge is calculated based on JR method. Then the residual life of the bridge is discussed according to the calculation results of dynamic reliability. The main contents of the work are as follows: 1. According to the results of an investigation on the cracking of existing concrete bridges organized by the Fujian Provincial Communications Department, The distribution of cracks in various concrete bridges is analyzed as follows: (1) the cracking of reinforced concrete T-beam bridges is mainly divided into two types: (1) the slanting cracking of flange slabs near the support 1 / 4 and 1 / 5 span and the longitudinal cracking at the junction of flange slabs and web plates; (2) the RC box. Girder bridge is mainly at the bottom of the 1/5L~1/3L longitudinal cracking and transverse cracking, According to the basic principle of reliability, the basic concept of dynamic reliability is introduced. Based on the dynamic reliability theory, the dynamic model of concrete carbonation depth and steel corrosion changing with time is established, and the dynamic model of load effect and resistance attenuation of RC simply supported T-beam bridge with the influence of cracking is established. This paper discusses the rule of structural reliability varying with time .3.Using MATLAB 2014a mathematical calculation software, the program of calculating dynamic reliability index by checking point method (JC method) is compiled, and the dynamic reliability of a cracked simply supported T-beam bridge is solved. According to the calculated dynamic reliability index, the residual life of the bridge is predicted and analyzed, and the influence of overload operation and crack expansion on the dynamic reliability and residual life of bridge structure is analyzed. In the same period of time, the reliability of overloading operation is smaller than that of normal load operation, and the reliability decline rate of overload operation is faster, and the service life of RC bridge structure is greatly reduced; in the same period of service and under the same operating condition, The more serious the cracking degree of the bridge is, the less reliable the RC bridge structure is, the shorter the normal service life of the surface RC bridge is. This will seriously affect the bridge construction and traffic network planning. 4. The key to deal with the crack problem is to correctly understand the cracks of concrete structure. Only if we can correctly judge the causes and the degree of influence of cracks, can we make a scientific judgment on the nature of cracks and their influence on structural safety and use function, and then we can take targeted measures to carry out more sure measures. Deal with it more effectively. Finally, according to the analysis and study of the dynamic reliability of cracked RC bridges, some measures to prevent the cracking of concrete bridges and the repair methods after cracking are put forward in this paper.
【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】：U441
本文編號：2231238
[Abstract]:In recent years, with the rapid development of transportation in China, the construction of RC bridges in the national highway network is becoming more and more important. However, with the increase of service time of RC bridge, many kinds of cracks and cracks of RC bridge have been found in RC bridge, which greatly reduce the bearing capacity and durability of the bridge, at the same time, because of bridge accidents in recent years, Bridge cracking is regarded as a precursor of bridge damage, and people have a strong fear of it. This paper studies the dynamic reliability of cracked RC bridge and predicts its residual life, which provides the theoretical basis for the maintenance and reinforcement of cracked RC bridge, and has important theoretical value and practical significance. In this paper, based on the key scientific and technological development project of Fujian Provincial Communications Department, "study on crack Prevention Countermeasures and key techniques of Preventive Construction and maintenance of concrete Bridges in Fujian Province", a cracked simply supported T-beam bridge is taken as the research object, and the load effect of cracked RC bridge is studied. The resistance attenuation model is studied and the dynamic reliability of RC bridge is calculated based on JR method. Then the residual life of the bridge is discussed according to the calculation results of dynamic reliability. The main contents of the work are as follows: 1. According to the results of an investigation on the cracking of existing concrete bridges organized by the Fujian Provincial Communications Department, The distribution of cracks in various concrete bridges is analyzed as follows: (1) the cracking of reinforced concrete T-beam bridges is mainly divided into two types: (1) the slanting cracking of flange slabs near the support 1 / 4 and 1 / 5 span and the longitudinal cracking at the junction of flange slabs and web plates; (2) the RC box. Girder bridge is mainly at the bottom of the 1/5L~1/3L longitudinal cracking and transverse cracking, According to the basic principle of reliability, the basic concept of dynamic reliability is introduced. Based on the dynamic reliability theory, the dynamic model of concrete carbonation depth and steel corrosion changing with time is established, and the dynamic model of load effect and resistance attenuation of RC simply supported T-beam bridge with the influence of cracking is established. This paper discusses the rule of structural reliability varying with time .3.Using MATLAB 2014a mathematical calculation software, the program of calculating dynamic reliability index by checking point method (JC method) is compiled, and the dynamic reliability of a cracked simply supported T-beam bridge is solved. According to the calculated dynamic reliability index, the residual life of the bridge is predicted and analyzed, and the influence of overload operation and crack expansion on the dynamic reliability and residual life of bridge structure is analyzed. In the same period of time, the reliability of overloading operation is smaller than that of normal load operation, and the reliability decline rate of overload operation is faster, and the service life of RC bridge structure is greatly reduced; in the same period of service and under the same operating condition, The more serious the cracking degree of the bridge is, the less reliable the RC bridge structure is, the shorter the normal service life of the surface RC bridge is. This will seriously affect the bridge construction and traffic network planning. 4. The key to deal with the crack problem is to correctly understand the cracks of concrete structure. Only if we can correctly judge the causes and the degree of influence of cracks, can we make a scientific judgment on the nature of cracks and their influence on structural safety and use function, and then we can take targeted measures to carry out more sure measures. Deal with it more effectively. Finally, according to the analysis and study of the dynamic reliability of cracked RC bridges, some measures to prevent the cracking of concrete bridges and the repair methods after cracking are put forward in this paper.
【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】：U441
【參考文獻(xiàn)】
相關(guān)期刊論文 前3條
1 貢金鑫,仲偉秋,趙國藩;工程結(jié)構(gòu)可靠性基本理論的發(fā)展與應(yīng)用(1)[J];建筑結(jié)構(gòu)學(xué)報;2002年04期
2 王嫻明，趙宏延;一般大氣條件下鋼筋混凝土結(jié)構(gòu)構(gòu)件剩余壽命的預(yù)測[J];建筑結(jié)構(gòu)學(xué)報;1996年03期
3 劉揚,張建仁;鋼筋混凝土橋梁服役期間的可靠性評價[J];中國公路學(xué)報;2001年02期
相關(guān)碩士學(xué)位論文 前2條
1 祁永利;BP神經(jīng)網(wǎng)絡(luò)在斜拉橋換索中的應(yīng)用[D];重慶交通大學(xué);2009年
2 夏強;混凝土簡支梁時變可靠度分析[D];重慶交通大學(xué);2012年
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