【摘要】：橋梁作為交通運輸線上的關(guān)鍵工程,在整個交通運輸線上起著至關(guān)重要的作用,如果受到強烈地震的破壞導(dǎo)致交通中斷,帶來的人員傷亡和經(jīng)濟損失將十分慘重,并且使得大地震后的搶險救災(zāi)和重建工作無法順利進(jìn)行,后果將不堪設(shè)想。伴隨著我國當(dāng)前大力擴展和改造鐵路基礎(chǔ)建設(shè),鐵路懸索橋的修建勢在必行。高烈度區(qū)需要修建的鐵路懸索橋有跨度大、恒載和列車活載較大等特點,其地震響應(yīng)分析和抗震設(shè)計方面的深入研究亦迫在眉睫。本文借助有限元計算軟件Midas Civil,對某高烈度區(qū)鐵路懸索橋建立三維空間有限元模型,用梁單元、只受拉單元和板單元建模,對懸索橋的結(jié)構(gòu)動力特性進(jìn)行數(shù)值分析。采用線性和非線性時程分析法,分別在四種地震荷載組合下對該鐵路懸索橋進(jìn)行地震響應(yīng)分析,并對計算結(jié)果進(jìn)行對比,主要考察的結(jié)構(gòu)體系的響應(yīng)指標(biāo)包括：梁端順橋向位移、跨中豎向位移、主塔塔頂位移、主塔塔底軸力和彎矩等。還運用非線性時程分析對主梁重量不同的鐵路懸索橋進(jìn)行地震響應(yīng)分析。研究結(jié)果表明：(1)鐵路懸索橋自振周期較長,結(jié)構(gòu)柔性特性顯著；(2)對比線性與非線性時程分析結(jié)果,以非線性時程分析得出的結(jié)論進(jìn)行鐵路懸索橋的設(shè)計和研究偏于安全,亦即非線性特性對鐵路懸索橋地震響應(yīng)影響比較明顯；(3)在地震荷載工況組合中加入豎向地震力后,對梁端順橋向位移、塔頂順橋向位移和塔底彎矩的最大值影響很小,而對跨中豎向位移和塔底軸力的最大值影響較大,鐵路懸索橋設(shè)計時,豎向地震力的影響不能忽略；(4)鐵路懸索橋地震響應(yīng)對于主梁重量的變化并不敏感,雖然主梁重量改變時,鐵路懸索橋地震響應(yīng)指標(biāo)會按一定趨勢變化,但變化幅度不大。
[Abstract]:As a key project on the transportation line, bridge plays a vital role in the whole transportation line. If the damage caused by a strong earthquake results in traffic disruption, the casualties and economic losses will be very heavy. And make the rescue and reconstruction work after the earthquake can not be carried out smoothly, the consequences will be unthinkable. With the expansion and reconstruction of railway infrastructure, the construction of railway suspension bridge is imperative. The railway suspension bridges needed to be built in high intensity areas have the characteristics of long span, large dead load and large live load of trains, so it is urgent to study the seismic response analysis and seismic design of railway suspension bridges. In this paper, a three-dimensional finite element model of a railway suspension bridge with high intensity is established by means of the finite element calculation software Midas Civil,. The dynamic characteristics of the suspension bridge are numerically analyzed by using the beam element, only the tensile element and the plate element. The linear and nonlinear time-history analysis methods are used to analyze the seismic response of the railway suspension bridge under four kinds of seismic loads, and the calculated results are compared. The main response indexes of the structural system are as follows: bridge displacement, mid-span vertical displacement, top displacement of main tower, axial force and bending moment at bottom of main tower, etc. The nonlinear time history analysis is also used to analyze the seismic response of railway suspension bridges with different main girder weight. The results show that: (1) the natural vibration period of railway suspension bridge is longer and the flexible characteristic of the structure is remarkable; (2) compared with the results of linear and nonlinear time-history analysis, the design and research of railway suspension bridge is more safety based on the conclusion of nonlinear time-history analysis, that is, the nonlinear characteristic has obvious influence on the seismic response of railway suspension bridge; (3) after adding vertical seismic force to the combination of seismic load conditions, the maximum value of beam end bridge displacement, tower top forward bridge displacement and tower bottom bending moment is very small, but the maximum value of span center vertical displacement and tower bottom axial force is more significant. In the design of railway suspension bridge, the influence of vertical seismic force can not be ignored. (4) the seismic response of railway suspension bridge is not sensitive to the change of main beam weight, although the seismic response index of railway suspension bridge will change according to a certain trend when the main girder weight changes, but the change range is not large.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U442.55;U448.25

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 張國民,李麗,馬宏生,汪素云,張曉東;中國大陸地震震源深度及其構(gòu)造含義[J];科學(xué)通報;2002年09期

相關(guān)博士學(xué)位論文 前1條

1 趙巖;橋梁抗震的線性/非線性分析方法研究[D];大連理工大學(xué);2003年

，

本文編號：2365254