大跨徑剛構(gòu)—連續(xù)組合梁橋的行波效應(yīng)理論及地震易損性分析
發(fā)布時間：2018-09-12 20:03
【摘要】：橋梁作為交通建設(shè)中較為重要的工程建筑結(jié)構(gòu),其安全性、適用性和耐久性越來越受到人們的重視。近幾十年來,我國橋梁建設(shè)的不斷發(fā)展,隨著交通發(fā)展的要求,大跨徑連續(xù)梁橋在橋梁工程中也得到了更加廣泛的應(yīng)用,而且大型橋梁的經(jīng)濟性和安全性對國家和人民來說都有著更為重大的影響。本文對大跨徑剛構(gòu)-連續(xù)組合梁橋的行波效應(yīng)進行了研究,在假定橋墩基礎(chǔ)處地震波幅值及頻譜特性不變的前提下,建立該橋動力分析模型。采用動態(tài)時程分析方法研究了縱橋向行波效應(yīng)對橋梁的墩底彎矩以及支座位移的地震響應(yīng)變化。結(jié)果表明：(1)行波效應(yīng)作用下,支座位移的地震響應(yīng)與一致輸入相比較存在放大效應(yīng),工程建設(shè)中應(yīng)當充分考慮行波效應(yīng)帶來的不利影響,支座離墩梁固結(jié)處越遠,放大效應(yīng)越明顯,因而在設(shè)計這一類橋梁時應(yīng)考慮足夠的支座位移預(yù)留；(2)行波效應(yīng)作用下,橋墩墩底彎矩存在放大效應(yīng),橋墩位置的不同,彎矩增大效應(yīng)存在差異,且行波效應(yīng)產(chǎn)生的墩底彎矩具有明顯的方向性,沿地震波傳播方向,墩底彎矩逐漸減小。(3)行波效應(yīng)對大跨徑剛構(gòu)-連續(xù)組合梁橋的影響主要集中在設(shè)置支座的橋墩及其對應(yīng)支座上,而且呈現(xiàn)出地震波傳播速度越小,影響越大的趨勢；而對于墩梁固結(jié)的雙柱式矩形實心墩的影響則較小。本文還針對大跨度剛構(gòu)-連續(xù)組合梁橋的關(guān)鍵位置進行了地震易損性數(shù)值分析,并繪制出其理論地震易損性曲線。首先通過對已有橋梁震害的分析,得出了大跨度剛構(gòu)-連續(xù)組合梁橋的易損部位主要是橋墩和支座,并對該橋的某一個主墩施加20條地震波,確定了橋墩易損的關(guān)鍵位置是墩頂和墩底。對比分析了作為地面運動的強度指標,采用PGA計算結(jié)果的離散性要比采用SA時大得多,因此采用SA作為地面運動強度指標得出的結(jié)果更為準確。本文采用非線性的最小二乘法分別繪制了在縱橋向和橫橋向地震波作用下的橋墩和支座的地震易損性曲線,通過對每個橋墩墩頂和墩底易損性曲線之間的相互比較及對不同橋墩相同部位易損性曲線的比對發(fā)現(xiàn),墩底比墩頂容易受損；橫向地震波作用下的橋墩和支座比縱橋向地震波作用下的更容易受損。
[Abstract]:As an important engineering structure in traffic construction, more and more attention has been paid to the safety, applicability and durability of bridges. In recent decades, with the continuous development of bridge construction in China, with the development of traffic, long-span continuous beam bridge has been more widely used in bridge engineering. And the economy and safety of large bridges have a more significant impact on the country and people. In this paper, the traveling wave effect of long-span rigid-frame-continuous composite beam bridge is studied, and the dynamic analysis model of the bridge is established on the assumption that the amplitude and spectrum of seismic wave at the pier foundation are invariant. The dynamic time-history analysis method is used to study the seismic response of longitudinal bridge traveling wave effect to the bending moment at the pier bottom and the displacement of the support of the bridge. The results show that: (1) under the action of traveling wave effect, the seismic response of support displacement has amplification effect compared with uniform input, and the adverse effect caused by traveling wave effect should be fully considered in engineering construction, and the farther the support is from the consolidation of pier and beam, The more obvious the amplification effect is, the more sufficient support displacement reservation should be considered in the design of this kind of bridge. (2) under the action of traveling wave effect, there exists amplification effect on the bending moment at the bottom of the pier, and the effect of increasing moment on the bridge pier is different with the location of the pier. The bending moment at the bottom of the pier caused by traveling wave effect has obvious directionality and propagates along the direction of seismic wave. (3) the effect of traveling wave effect on long-span rigid-frame-continuous composite beam bridge is mainly concentrated on the pier with bearing and its corresponding support, and the smaller the velocity of seismic wave propagation, the greater the influence; However, the effect of double column rectangular solid pier on the consolidation of pier beam is small. In this paper, the seismic vulnerability of long-span rigid-frame-continuous composite beam bridge is numerically analyzed and the theoretical seismic vulnerability curve is drawn. By analyzing the earthquake damage of existing bridges, it is concluded that the main vulnerable parts of long-span rigid-frame-continuous composite beam bridges are piers and supports, and 20 seismic waves are applied to one of the main piers of the bridge. It is determined that the key position of pier vulnerability is pier top and pier bottom. As the strength index of the ground motion, the dispersion of the calculated results with PGA is much greater than that with SA, so the results obtained by using SA as the index of the intensity of ground motion are more accurate. In this paper, the nonlinear least square method is used to draw the seismic vulnerability curves of piers and supports under the action of longitudinal and transverse bridge seismic waves, respectively. By comparing the vulnerability curves between the top of each pier and the bottom of the pier, and comparing the vulnerability curves of the same part of different piers, it is found that the pier bottom is easier to be damaged than the top of the pier. The bridge piers and supports under transverse seismic waves are more easily damaged than those under longitudinal seismic waves.
【學(xué)位授予單位】：長沙理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U442.55
本文編號：2240084
[Abstract]:As an important engineering structure in traffic construction, more and more attention has been paid to the safety, applicability and durability of bridges. In recent decades, with the continuous development of bridge construction in China, with the development of traffic, long-span continuous beam bridge has been more widely used in bridge engineering. And the economy and safety of large bridges have a more significant impact on the country and people. In this paper, the traveling wave effect of long-span rigid-frame-continuous composite beam bridge is studied, and the dynamic analysis model of the bridge is established on the assumption that the amplitude and spectrum of seismic wave at the pier foundation are invariant. The dynamic time-history analysis method is used to study the seismic response of longitudinal bridge traveling wave effect to the bending moment at the pier bottom and the displacement of the support of the bridge. The results show that: (1) under the action of traveling wave effect, the seismic response of support displacement has amplification effect compared with uniform input, and the adverse effect caused by traveling wave effect should be fully considered in engineering construction, and the farther the support is from the consolidation of pier and beam, The more obvious the amplification effect is, the more sufficient support displacement reservation should be considered in the design of this kind of bridge. (2) under the action of traveling wave effect, there exists amplification effect on the bending moment at the bottom of the pier, and the effect of increasing moment on the bridge pier is different with the location of the pier. The bending moment at the bottom of the pier caused by traveling wave effect has obvious directionality and propagates along the direction of seismic wave. (3) the effect of traveling wave effect on long-span rigid-frame-continuous composite beam bridge is mainly concentrated on the pier with bearing and its corresponding support, and the smaller the velocity of seismic wave propagation, the greater the influence; However, the effect of double column rectangular solid pier on the consolidation of pier beam is small. In this paper, the seismic vulnerability of long-span rigid-frame-continuous composite beam bridge is numerically analyzed and the theoretical seismic vulnerability curve is drawn. By analyzing the earthquake damage of existing bridges, it is concluded that the main vulnerable parts of long-span rigid-frame-continuous composite beam bridges are piers and supports, and 20 seismic waves are applied to one of the main piers of the bridge. It is determined that the key position of pier vulnerability is pier top and pier bottom. As the strength index of the ground motion, the dispersion of the calculated results with PGA is much greater than that with SA, so the results obtained by using SA as the index of the intensity of ground motion are more accurate. In this paper, the nonlinear least square method is used to draw the seismic vulnerability curves of piers and supports under the action of longitudinal and transverse bridge seismic waves, respectively. By comparing the vulnerability curves between the top of each pier and the bottom of the pier, and comparing the vulnerability curves of the same part of different piers, it is found that the pier bottom is easier to be damaged than the top of the pier. The bridge piers and supports under transverse seismic waves are more easily damaged than those under longitudinal seismic waves.
【學(xué)位授予單位】：長沙理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U442.55
【參考文獻】
相關(guān)期刊論文 前2條
1 何慶祥;沈祖炎;;結(jié)構(gòu)地震行波效應(yīng)分析綜述[J];地震工程與工程振動;2009年01期
2 彭天波;李建中;范立礎(chǔ);;能力設(shè)計方法在雙層高架橋梁抗震設(shè)計中的應(yīng)用[J];世界橋梁;2009年01期
，本文編號：2240084
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