本文選題：坡橋 + 動力特性　； 參考：《長安大學(xué)》2015年碩士論文

【摘要】：坡橋在我國西南山區(qū)應(yīng)用越來越多,近年來坡橋發(fā)生局部破壞的現(xiàn)象較一般橋梁嚴(yán)重;同時(shí)在長下坡路段為了達(dá)到減速目的,不得不在橋梁上設(shè)置振動減速帶,目前其設(shè)置具有較大的隨意性,關(guān)于坡橋減速帶對橋梁結(jié)構(gòu)動力特性的影響研究較少,因此對坡橋動力特性及車載響應(yīng)展開分析非常必要。以國家自然科學(xué)基金項(xiàng)目《隨機(jī)車載下高墩大跨彎連續(xù)剛構(gòu)橋沖擊系數(shù)研究》的后續(xù)研究及中央高校基金《長大坡橋動力分析》資助項(xiàng)目為依托,運(yùn)用有限元程序?qū)Σ煌露�、不同支座設(shè)置形式下的簡支梁、連續(xù)梁坡橋自振特性展開理論研究,并通過室內(nèi)試驗(yàn)驗(yàn)證了理論研究的正確性�；诂F(xiàn)行《公路橋涵設(shè)計(jì)通用規(guī)范》(JTG D60-2004)對簡支梁、連續(xù)梁坡橋的沖擊系數(shù)展開研究,在此基礎(chǔ)上,利用車-橋耦合振動原理分別研究了連續(xù)縱坡在車輛作用下的撓度、彎矩響應(yīng),得到了橋梁結(jié)構(gòu)在不同車速、不同行駛方向下的時(shí)程曲線,按照傳統(tǒng)計(jì)算方法求解橋梁結(jié)構(gòu)的沖擊系數(shù),分析了單向縱坡、雙向縱坡、橋面不平整度對連續(xù)坡橋沖擊系數(shù)的影響,并和規(guī)范法沖擊系數(shù)進(jìn)行對比分析�；谲�-橋耦合振動原理研究了不同坡度和行駛速度下減速帶設(shè)置數(shù)量、設(shè)置間距、設(shè)置位置對坡橋動力特性及沖擊系數(shù)的影響,并對坡橋減速帶的合理設(shè)置提出建議。研究結(jié)果表明坡橋振型與相應(yīng)平橋相同,支座的布置方式對橋梁的頻率有一定影響,當(dāng)支座水平方向設(shè)置時(shí)坡橋頻率比相應(yīng)平橋的小,當(dāng)支座垂直主梁方向設(shè)置時(shí)坡橋基頻與相應(yīng)平橋相同;坡橋宜將固定支座設(shè)在較低墩臺處。基于規(guī)范法得到簡支梁、連續(xù)梁縱坡坡度對橋梁沖擊系數(shù)影響很小;車-橋耦合振動下單、雙向縱坡形式對連續(xù)梁橋沖擊系數(shù)有一定影響;減速帶的設(shè)置增大了坡橋結(jié)構(gòu)的動力響應(yīng),在條件允許時(shí)建議不設(shè)減速帶;若必須設(shè)置則建議采用8組減速帶、減速帶組間距為,且減速帶距梁端8m為宜。論文研究成果可為坡橋橋梁結(jié)構(gòu)的動力評估及交通設(shè)施安全提供依據(jù)和參考。
[Abstract]:The slope bridge is applied more and more in the mountainous area of southwest China. In recent years, the phenomenon of local damage of the slope bridge is more serious than that of the ordinary bridge. At the same time, in order to achieve the purpose of deceleration, vibration reducers have to be set up in the long downhill section of the bridge. At present, there is much randomness in the design of the bridge, so it is necessary to analyze the dynamic characteristics and the vehicular response of the bridge because of the little research on the influence of the slope-bridge reducer on the dynamic characteristics of the bridge structure. Based on the project of National Natural Science Foundation, "Research on impact coefficient of long span continuous rigid frame bridge with high piers under random vehicle" and the project of "dynamic Analysis of long Slope Bridge" funded by the Central University Foundation, the finite element program is used to analyze the different slopes. The theoretical study on the natural vibration characteristics of continuous beam sloping bridges with simple supported beams with different support forms is carried out and the correctness of the theoretical research is verified by laboratory tests. Based on the current General Code for Highway Bridge and culvert Design (JTG D60-2004), the impact coefficient of simply supported beam and continuous beam slope bridge is studied. On this basis, the deflection of continuous longitudinal slope under the action of vehicle is studied by using the coupled vibration principle of vehicle-bridge. Bending moment response, the time history curve of bridge structure under different speed and different driving direction is obtained. According to the traditional calculation method, the impact coefficient of bridge structure is solved, and the unidirectional longitudinal slope and bidirectional longitudinal slope are analyzed. The influence of deck irregularity on impact coefficient of continuous slope bridge is analyzed and compared with that of code method. Based on the principle of vehicle-bridge coupling vibration, the effects of the number of reducers, the setting distance and the setting position on the dynamic characteristics and impact coefficient of the slope bridge under different slope and driving speed are studied, and some suggestions are put forward for the reasonable setting of the deceleration belt of the slope bridge. The results show that the mode of vibration of the slope bridge is the same as the corresponding horizontal bridge, and the arrangement of the support has a certain influence on the frequency of the bridge. When the support is set horizontally, the frequency of the slope bridge is smaller than that of the corresponding horizontal bridge. The base frequency of the slope bridge is the same as that of the corresponding horizontal bridge when the support is set in the direction of the main beam, and the fixed support should be set at the lower pier abutment. Based on the code method, the simple supported beam is obtained, the longitudinal slope gradient of continuous beam has little effect on the impact coefficient of bridge, the order of vehicle-bridge coupling vibration is given, and the impact coefficient of continuous beam bridge is influenced by the form of two-way longitudinal slope. The installation of the reducer increases the dynamic response of the slope bridge structure, and it is suggested that no reducer should be set when the conditions permit; if necessary, 8 sets of reducers should be adopted, with a spacing of 8 m between the reducers and the end of the beam. The research results can provide the basis and reference for the dynamic evaluation of bridge structure and the safety of traffic facilities.
【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】：U441.3

【共引文獻(xiàn)】

相關(guān)期刊論文 前2條

1 羅川舟;袁向榮;;不同跨徑組合的三跨連續(xù)梁的模態(tài)分析試驗(yàn)[J];實(shí)驗(yàn)室研究與探索;2015年02期

2 胡幫義;袁向榮;楊勇;陳澤賢;劉輝;;4等跨連續(xù)梁模態(tài)試驗(yàn)分析及沖擊因數(shù)研究[J];實(shí)驗(yàn)技術(shù)與管理;2015年08期

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本文編號：2097027