基于限位索的简支梁桥减震防碰研究

发布时间：2018-07-27 09:21

【摘要】：摘要：强震作用下,简支梁桥支座容易发生破坏导致相邻梁体和梁台间发生碰撞,从而造成梁体的损坏或者落梁。严重的碰撞会直接会导致桥梁交通中断并且短时间内无法恢复交通通行能力,不仅造成直接经济损失,而且给后续的救灾带来很大不便,故需要采取合适的控制措施。限位索作为一种原理清晰、布置方便、形式简单的梁体位移控制措施,在国外已有应用,然而在国内研究却相对较少。本文以公路简支梁桥为工程背景,在梁体间和梁台间引入限位索,开展防碰撞研究,主要内容和成果如下： (1)利用有限元软件ANSYS建立了一座四跨(4×30m)公路简支梁桥全桥碰撞有限元模型。其中,采用Kelvin模型来模拟梁间碰撞,采用非线性弹簧单元来模拟支座。 (2)分析了简支梁桥分别在调幅加速度峰值为0.15g、0.30g、0.60g的EL-Centro波、Taft波、Takochi-oki波和天津波等地震波激励作用下的碰撞效应,结果表明：地震响应与结构振动特性、地震波谱特性有关；随加速度峰值增大,响应加剧。 (3)进行了碰撞效应参数分析,通过改变相邻桥墩墩高比、邻梁间距、碰撞单元阻尼等参数,获得了不同参数变化对碰撞效应的影响规律,结果表明：墩高越高,位移响应越大；碰撞力和碰撞次数随邻梁间距增大而减小。 (4)在邻梁和梁台间引入限位索,开展了简支梁桥防碰撞研究,分析了拉索数量变化和不同地震激励作用下的结构响应。限位索可有效减小梁体位移,避免邻梁和梁台间发生碰撞,降低落梁几率；且随拉索数量增加防碰减震效果越明显。
[Abstract]:Absrtact: under the action of strong earthquake, simply supported beam bridge supports are easily destroyed, resulting in the collision between adjacent beam body and beam platform, which results in the damage or fall of beam body. Serious collision will directly lead to the interruption of bridge traffic and the inability to restore traffic capacity in a short time, which not only causes direct economic losses, but also brings great inconvenience to the subsequent disaster relief, so appropriate control measures should be taken. As a kind of beam displacement control measure with clear principle, convenient arrangement and simple form, limit cable has been applied in foreign countries, but it has been studied less in our country. In this paper, based on the engineering background of highway simply supported beam bridge, the limited cable is introduced between beam body and beam platform, and anti-collision research is carried out. The main contents and results are as follows: (1) A four-span (4 脳 30m) finite element model for the impact of a four-span (4 脳 30m) highway simply supported beam bridge is established by using the finite element software ANSYS. The Kelvin model is used to simulate the collision between beams. The nonlinear spring element is used to simulate the support. (2) the collision effect of the simply supported bridge under the excitation of seismic waves such as Takochi-oki wave and Tianjin wave is analyzed under the excitation of the EL-Centro wave with the peak amplitude modulation of 0.30g / 0.60g. The results show that the seismic response is related to the structural vibration characteristics and the seismic spectrum characteristics, and the response intensifies with the increase of the peak acceleration. (3) the impact effect parameters are analyzed, by changing the height ratio of the adjacent piers and the distance between adjacent beams. The effects of different parameters on the impact effect are obtained. The results show that the higher the pier height, the greater the displacement response. The impact force and the number of collisions decrease with the increase of the distance between adjacent beams. (4) by introducing limited cables between adjacent beams and beam abutments, the anti-collision research of simply supported beam bridges is carried out, and the structural responses under different earthquake excitation and the number of cables are analyzed. The limit cable can effectively reduce the displacement of the beam, avoid the collision between the adjacent beam and the beam abutment, and reduce the probability of falling beam, and with the increase of the number of cables, the more obvious the anti-collision effect is.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55;U448.217

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