本文選題：矩形空心墩 + 動水壓力　； 參考：《蘭州交通大學》2010年碩士論文

【摘要】： 近年來,我國橋梁在朝著更大跨度發(fā)展的同時,出現(xiàn)了許多建成和擬建的深水橋梁。目前為止,已建或在建的深水橋梁其橋墩入水深度最深已達百米。深水橋梁在地震作用下,橋墩自身的運動會引起周圍水體的輻射波浪運動,而波浪運動也反過來影響橋墩的運動,這樣橋梁結(jié)構(gòu)的水下部分便產(chǎn)生了動水壓力,從而使橋梁的結(jié)構(gòu)動力特性發(fā)生改變并影響結(jié)構(gòu)的動力響應。若忽略動水壓力,則在計算全橋的動力特性和地震內(nèi)力時會出現(xiàn)較大的誤差甚至錯誤的結(jié)果。 從當前深水橋梁抗震研究的文獻來看,國內(nèi)外對深水橋梁的計算理論及地震響應特性的研究仍較少。本文在查閱大量國內(nèi)外文獻的基礎上,評述了當前關于水與結(jié)構(gòu)相互作用的計算理論、水中結(jié)構(gòu)地震響應的分析方法及相關的研究成果,并針對深水橋梁在地震作用下的動力響應特性開展了以下幾個方面的詳細研究： (1)闡述了深水橋梁考慮動水壓力的必要性,以及動水壓力的研究現(xiàn)狀。 (2)以深水庫區(qū)主跨為220m,墩高為173m的紅旗大橋為例,利用Morison方程所得的圓形墩附加質(zhì)量公式的矩形修正公式模擬水對橋墩的作用,建立了全橋考慮附加質(zhì)量影響的變截面三維有限元模型。 (3)運用有限元方法并結(jié)合JTG/T B02-01-2008《公路橋梁抗震設計細則》中的有關規(guī)定進行了該橋的模態(tài)分析,反應譜和時程反應分析。 (4)分析與討論了不同地震動輸入情況下,動水壓力對該橋地震動響應的影響程度。 研究結(jié)果表明由于動水壓力的作用,不僅使橋梁結(jié)構(gòu)的自振頻率明顯降低,而且隨著頻率階數(shù)的增加,自振頻率總體上的下降率有增大趨勢,即考慮水的附加質(zhì)量后對橋梁高階頻率的影響較大。多工況地震響應的結(jié)果表明,由于附加動水壓力的影響,使得本橋在地震作用下的彎矩、剪力明顯增大,深水橋梁的抗震問題較無水橋梁更為突出。對比反應譜法與時程分析法的計算結(jié)果,可以看出,按反應譜計算得到的內(nèi)力結(jié)果小于按時程響應計算得到的結(jié)果。顯然,就本橋而言,僅采用反應譜進行地震響應分析是不夠的,遵循地震響應分析的多波原則進行時程響應分析是完全必要的。 本文研究方法與所得結(jié)論可為同類橋梁的抗震設計提供參考。
[Abstract]:In recent years, there are many deep water bridges in our country. Up to now, the deep water depth of the bridge piers has reached 100 meters. Under the earthquake, the movement of the pier itself will cause the radiation wave motion of the surrounding water body, and the wave motion will affect the bridge pier movement in turn, so the underwater part of the bridge structure will produce dynamic water pressure. Thus, the dynamic characteristics of the bridge structure are changed and the dynamic response of the structure is affected. If the hydrodynamic pressure is ignored, there will be large errors or even wrong results in the calculation of the dynamic characteristics of the bridge and the seismic internal force. According to the literature of seismic research on deep water bridges, there are few researches on the calculation theory and seismic response characteristics of deep water bridges at home and abroad. Based on a large number of references at home and abroad, this paper reviews the current computational theory on the interaction between water and structure, the analysis method of seismic response of water structure and the related research results. The dynamic response characteristics of deep water bridges under earthquake are studied in detail in the following aspects: (1) the necessity of considering the dynamic pressure of deep water bridges is expounded. (2) taking the Hongqi Bridge with a main span of 220 m and a pier height of 173m in the deep water reservoir area as an example, the effect of water on the pier is simulated by using the rectangular modified formula of the additional mass formula of the circular pier obtained by Morison equation. A three-dimensional finite element model with variable cross-section considering the effect of additional mass is established. (3) the modal analysis of the bridge is carried out by using the finite element method and the relevant regulations of JTG / T B02-01-2008 "detailed rules for Seismic Design of Highway Bridges". Response spectrum and time-history response analysis. (4) the influence of hydrodynamic pressure on the seismic response of the bridge is analyzed and discussed under different ground motion input conditions. The results show that the natural vibration frequency of the bridge structure is obviously decreased due to the effect of hydrodynamic pressure, and with the increase of the frequency order, the decrease rate of the natural vibration frequency on the whole has a tendency to increase. That is to say, considering the additional mass of water, it has a great influence on the high frequency of the bridge. The results of multi-condition seismic response show that due to the influence of additional dynamic water pressure, the bending moment and shear force of the bridge under seismic action are obviously increased, and the seismic problem of deep water bridge is more prominent than that of non-water bridge. By comparing the results of response spectrum method and time history analysis, it can be seen that the results of internal force calculated by response spectrum are smaller than those obtained by time-history response calculation. Obviously, for this bridge, it is not enough to use response spectrum for seismic response analysis, and it is necessary to follow the multi-wave principle of seismic response analysis. The methods and conclusions of this paper can be used as reference for the seismic design of similar bridges.
【學位授予單位】：蘭州交通大學
【學位級別】：碩士
【學位授予年份】：2010
【分類號】：U441.3

【引證文獻】

相關碩士學位論文 前2條

1 馬馳;大理河系桿拱橋的地震響應分析[D];蘭州交通大學;2011年

2 田中旭;抗風纜在劉家峽大橋非一致橫向地震激勵中的影響[D];蘭州交通大學;2012年

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本文編號：2100685