本文選題：空心薄壁墩 + ABAQUS��； 參考：《南華大學》2015年碩士論文

【摘要】：在地震作用下,常常發(fā)生橋墩破壞使整座橋梁發(fā)生倒塌的工程事故。橋墩地震響應的研究,對整個橋梁工程抗震研究起關鍵作用。西部地區(qū)地勢險要、深山溝壑,需要修建較高的橋墩才能跨越山區(qū)。橋墩越高,需要的截面尺寸越大,為了節(jié)約成本、減輕自重、增強柔性,一般情況下采取空心截面形式。在大震作用下,大部分橋墩進入彈塑性變形階段,采用完全彈性理論進行結構分析和設計已經(jīng)難以滿足實際需要,因此,對橋墩結構進行彈塑性地震分析就顯得越來越重要。本文采用大型有限元軟件ABAQUS,對空心薄壁橋墩的地震反應進行研究,為完善我國橋梁抗震設計規(guī)范具有非常重要的意義。本文通過理論分析與數(shù)值模擬相結合的方法,對典型空心薄壁橋墩的抗震性能進行研究,主要研究內容為:(1)本文對6個大比例空心薄壁橋墩在低周反復水平荷載作用下進行仿真分析,探討橋墩在復合受力下的滯回特性、骨架曲線、位移延性和耗能能力,并分析縱向配筋率、配箍率、軸壓比對橋墩承載能力和延性性能的影響。結果表明:1)位移延性系數(shù)介于1.99-4.42之間;影響空心薄壁橋墩抗震性能的主要因素是體積配箍率,隨其值的增加,承載力略微提高,但延性顯著增大;2)隨著軸壓比的提高,其承載力提高,延性下降,對高配筋率影響較大;3)配筋率能夠提高結構的承載能力,但變形能力降低;在較大軸向壓力作用下,配筋率對空心薄壁橋墩的影響較為明顯;4)空心薄壁墩抗震性能符合一般鋼筋混凝土構件,但能節(jié)省材料,降低成本。(2)建立4個大比例有限元模型,研究在相同配箍率(不計重疊部分箍筋體積)情況下,不同箍筋配置形式下的延性和強度,得出結論:在鋼筋混凝土中配置一定數(shù)量的箍筋,有利于提高混凝土的強度和延性,增加耗能能力;當配置復合(重疊)箍時,產(chǎn)生較大的塑形變形,延性最好,混凝土極限應變達到0.00871,相比不配置箍筋情況下提高5.29倍,相比配置直拉結箍筋情況下提高了0.482倍;增加對角拉結箍筋時,延性略微提高,但不便于施工;空心薄壁墩的四個內外角受力較大,在施工條件允許情況下,角部應做成一定形式的倒角。(3)運用靜力彈塑性分析(Push-over)方法的原理和實現(xiàn)方法,建立能力譜和地震需求譜曲線,評估空心薄壁矩形橋墩在不同地震作用下的反應。
[Abstract]:Under the action of earthquake, the failure of pier often results in the collapse of the whole bridge. The research on the seismic response of pier plays a key role in the seismic research of the whole bridge project. The western region has a dangerous terrain and deep mountains and gullies, so it is necessary to build high piers to cross the mountains. The higher the pier is, the larger the section size is. In order to save cost, reduce weight and enhance flexibility, hollow section is adopted in general. Under the action of large earthquakes, most piers have entered the stage of elastoplastic deformation, and it is difficult to use the theory of complete elasticity to analyze and design the structure. Therefore, it is more and more important to carry out the elastoplastic seismic analysis of the pier structure. In this paper, the seismic response of hollow thin-walled piers is studied by using the finite element software Abaqus, which is of great significance to improve the seismic design code of bridges in China. In this paper, the seismic behavior of typical hollow thin-walled bridge piers is studied by combining theoretical analysis with numerical simulation. The main research content is: (1) in this paper, six large proportion hollow thin-walled bridge piers are simulated and analyzed under low cyclic and horizontal loads, and the hysteretic characteristics, skeleton curves, displacement ductility and energy dissipation capacity of the pier under composite loading are discussed. The effects of longitudinal reinforcement ratio, hoop ratio and axial compression ratio on the bearing capacity and ductility of piers are analyzed. The results show that the displacement ductility coefficient is between 1.99-4.42. The main factor affecting the seismic performance of hollow thin-walled bridge piers is the volumetric hoop ratio. With the increase of the ratio, the bearing capacity increases slightly, but the ductility increases significantly with the increase of axial compression ratio. The bearing capacity is increased, the ductility is decreased, and the reinforcement ratio can increase the bearing capacity of the structure, but the deformation ability is decreased, and under the action of large axial pressure, the reinforcement ratio can increase the bearing capacity of the structure. The effect of reinforcement ratio on hollow thin-walled bridge piers is obvious. 4) the seismic behavior of hollow thin-walled piers conforms to the general reinforced concrete members, but it can save materials and reduce the cost. 4 large scale finite element models are established. The ductility and strength of different stirrups are studied under the same ratio of stirrups (excluding the volume of overlapping stirrups). It is concluded that a certain number of stirrups in reinforced concrete can improve the strength and ductility of concrete. The maximum strain of concrete is 0.00871, which is 5.29 times higher than that without stirrups, and 0.482 times higher than that in the case of Czochralski stirrups. The ductility of hollow thin-walled piers is increased slightly, but it is not convenient for construction. The four inner and outer angles of hollow thin-walled piers are subjected to greater forces, and if the construction conditions permit, the ductility of the hollow thin-walled piers is very large. The angle should be made into a certain form of chamfer. 3) the principle and realization method of static elastic-plastic analysis (Push-over) method is used to establish the capacity spectrum and seismic demand spectrum curve to evaluate the response of hollow thin-walled rectangular pier under different earthquakes.
【學位授予單位】：南華大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U442.55;U443.22

【參考文獻】

相關期刊論文 前1條

1 關向陽,王彥;Push-over分析法淺析[J];東北電力學院學報;2005年02期

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本文編號：1948101