极端波浪作用下的桥梁限位控制研究
发布时间：2018-08-06 16:15
【摘要】：飓风伊万和卡特里娜在美国墨西哥湾沿岸造成了大量的低矮跨海桥梁严重损毁。飓风风暴潮和巨型波浪在桥梁上部结构上产生了显著的竖向和水平波浪力,导致桥面板发生位移甚至落梁。针对这一工程灾害问题,目前已有学者开展了波浪对桥梁上部结构作用的研究,主要集中在波浪作用机理以及波浪荷载估计方法上,针对桥梁上部结构受波浪作用防护措施仍缺乏相关研究。钢缆限位器是一种在地震工程中用以防止桥梁落梁的装置,以其简洁、廉价、高效的特点获得了广泛应用。本文针对应用钢缆限位器防止极端波浪引起的桥梁落梁进行了研究,利用数值手段模拟桥梁在极端波浪作用下的响应,对比限位器与其他防护装置的桥梁上部结构位移限制效果,主要内容包括:(1)基于OpenSees软件平台,使用平滑动支承单元替换常用的零长度单元,并考虑钢筋混凝土结构非线性特征以及土体的作用建立了改进的三维桥梁有限元模型。改进后的模型能够更准确的模拟桥梁上部结构受到的水平约束力随竖向波浪荷载的变化过程。(2)利用建成的数值模型,分析比较了无约束、防震挡块约束以及限位器约束时,在极端波浪荷载作用下的桥面板和桥墩的位移响应。分析结果表明应用钢缆限位器可以将桥面板的残余位移减少至无约束结构残余位移的7%;与抗震挡块约束下的结果相比,应用钢缆限位器能够在减小桥梁上部结构位移的同时避免造成下部结构损伤。考虑到跨海桥梁下部结构的建设维护造价较高,使用钢缆限位器能够获得更为理想的结构破坏防护效果。(3)进行了钢缆限位器的参数化分析,对在不同强度的波浪荷载下,限位器的布置根数、夹角和预设间隙的宽度对桥面板位移响应、桥墩内力响应以及限位器内力响应的影响。参数化分析结果表明:限位器的根数只需保证限位器在最大波浪力作用下的变形不超过弹性极限;当限位器与水平方向的夹角较大时,减小预设间隙的宽度可以获得更好的控制效果。
[Abstract]:Hurricane Ivan and Katrina have caused massive damage to low-rise sea bridges along the U. S. Gulf Coast. Storm surges and giant waves have produced significant vertical and horizontal wave forces on the superstructure of the bridge resulting in the displacement of the deck and even the fall of the beam. In view of this engineering disaster problem, some scholars have carried out researches on the effect of wave on the superstructure of bridge, mainly focusing on the wave action mechanism and wave load estimation method. There is still a lack of relevant research on the protection measures for the superstructure of bridge subjected to wave action. Steel cable limiter is a kind of device used to prevent bridge from falling beam in seismic engineering. It has been widely used because of its simplicity, low cost and high efficiency. In this paper, the application of steel cable limiter to prevent bridge beam falling caused by extreme waves is studied, and the response of bridge under extreme wave action is simulated by numerical method. The main contents are as follows: (1) based on the OpenSees software platform, the flat sliding support unit is used to replace the commonly used zero length element. Considering the nonlinear characteristics of reinforced concrete structure and the function of soil, an improved 3D bridge finite element model is established. The improved model can more accurately simulate the variation process of the horizontal binding force on the bridge superstructure with vertical wave loads. (2) using the built numerical model, the unconstrained, anti-shock block and locator constraints are analyzed and compared. Displacement response of bridge deck and pier under extreme wave loads. The analysis results show that the residual displacement of the bridge deck can be reduced to 7% of the residual displacement of the unconstrained structure by using the steel cable limiter. The steel cable limiter can reduce the displacement of the superstructure of the bridge and avoid the damage of the substructure. Considering the high cost of construction and maintenance of the substructure of the bridge across the sea, using the steel cable limiter can obtain more ideal structural damage protection effect. (3) the parametric analysis of the steel cable limiter is carried out, and the wave load of different strength is analyzed. The effects of the layout root number, the angle and the width of the preset clearance on the displacement response of the bridge deck, the response of the internal force of the pier and the response of the internal force of the limiter. The results of parametric analysis show that the root number of the limiter only needs to ensure that the deformation of the limiter does not exceed the elastic limit under the action of the maximum wave force, and when the angle between the limiter and the horizontal direction is large, A better control effect can be obtained by reducing the width of the preset gap.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441;TV139.26
本文编号：2168267
[Abstract]:Hurricane Ivan and Katrina have caused massive damage to low-rise sea bridges along the U. S. Gulf Coast. Storm surges and giant waves have produced significant vertical and horizontal wave forces on the superstructure of the bridge resulting in the displacement of the deck and even the fall of the beam. In view of this engineering disaster problem, some scholars have carried out researches on the effect of wave on the superstructure of bridge, mainly focusing on the wave action mechanism and wave load estimation method. There is still a lack of relevant research on the protection measures for the superstructure of bridge subjected to wave action. Steel cable limiter is a kind of device used to prevent bridge from falling beam in seismic engineering. It has been widely used because of its simplicity, low cost and high efficiency. In this paper, the application of steel cable limiter to prevent bridge beam falling caused by extreme waves is studied, and the response of bridge under extreme wave action is simulated by numerical method. The main contents are as follows: (1) based on the OpenSees software platform, the flat sliding support unit is used to replace the commonly used zero length element. Considering the nonlinear characteristics of reinforced concrete structure and the function of soil, an improved 3D bridge finite element model is established. The improved model can more accurately simulate the variation process of the horizontal binding force on the bridge superstructure with vertical wave loads. (2) using the built numerical model, the unconstrained, anti-shock block and locator constraints are analyzed and compared. Displacement response of bridge deck and pier under extreme wave loads. The analysis results show that the residual displacement of the bridge deck can be reduced to 7% of the residual displacement of the unconstrained structure by using the steel cable limiter. The steel cable limiter can reduce the displacement of the superstructure of the bridge and avoid the damage of the substructure. Considering the high cost of construction and maintenance of the substructure of the bridge across the sea, using the steel cable limiter can obtain more ideal structural damage protection effect. (3) the parametric analysis of the steel cable limiter is carried out, and the wave load of different strength is analyzed. The effects of the layout root number, the angle and the width of the preset clearance on the displacement response of the bridge deck, the response of the internal force of the pier and the response of the internal force of the limiter. The results of parametric analysis show that the root number of the limiter only needs to ensure that the deformation of the limiter does not exceed the elastic limit under the action of the maximum wave force, and when the angle between the limiter and the horizontal direction is large, A better control effect can be obtained by reducing the width of the preset gap.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441;TV139.26
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，本文编号：2168267
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