Seismic Pounding and Protection Measures of Simply-Supported Beams Considering Interaction between Continuously Welded Rail and Bridge
Seismic Pounding and Protection Measures of Simply-Supported Beams Considering Interaction between Continuously Welded Rail and Bridge
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DOI：
10.2749/101686613x13439149157191
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发表时间：
2013-02
影响因子：
1.1
通讯作者：
B. Yan;G. Dai
中科院分区：
文献类型：
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作者：
B. Yan;G. Dai
摘要简支梁之间的碰撞效应会对桥梁造成破坏，甚至导致桥梁倒塌。然而，以往的碰撞研究没有考虑地震时无缝线路的影响，从而高估了铁路桥梁的地震反应，产生不经济的设计，忽略了地震碰撞对轨道力的影响。因此，本文的主要重点是研究无缝线路对桥梁碰撞的影响，通过数值模拟。仿真中采用非线性杆单元模拟轨道纵向阻力。采用大质量法获得多点激励，采用Kelvin模型模拟梁的碰撞。此外，还考虑了支座的非线性特性、桥墩的弯矩-曲率关系以及桩土相互作用等具体影响。以沪昆线3跨32 m简支箱梁为例，研究了温度荷载、列车制动荷载、行波效应、线路阻力、轨道伸缩装置、缓冲装置和梁连接装置等对桥梁碰撞效应和桥墩受力的影响。数值计算结果表明，轨道可以显著减轻桥梁的碰撞效应。行波效应会显著增加轨道和桥梁的受力，从而导致碰撞。如果高速铁路列车在地震中在桥上制动，则可能在桥台位置附近破坏钢轨。轨道伸缩装置和小阻力扣件的使用可能会导致相邻梁之间的碰撞效应，而缓冲装置和梁连接装置的使用可以减轻碰撞效应，最终减少桥墩上的力。
Abstract The pounding effect between neighboring simply-supported beams can damage a bridge and even cause collapse of a beam. However, previous pounding studies did not consider the influence of the continuously welded rail (CWR) during earthquakes, thus overestimating the seismic response of the railway bridge, yielding uneconomic design and neglecting the influence of seismic pounding on track forces. Therefore, the main focus of this paper is to investigate the influence of CWR on bridge pounding through numerical modeling. In the simulation, nonlinear bar element was used to model longitudinal resistance of the track. Large-mass method was used to obtain multi-support excitation and the Kelvin model was applied to simulate the beam pounding. In addition, a number of detailed effects were taken into account, including the nonlinear behavior of the bearing, the moment–curvature relationship of the pier and the interaction of the piles and soil. Taking the three-span 32 m simply-supported box beams on the Shanghai–Kunming line as an example, this paper also studies the influence of temperature loads, train braking load, traveling wave effect, line resistance, track expansion device, buffer device and beam connection device on the bridge pounding effect an d the pier force. The numerical results showed that the track can significantly mitigate the pounding effect of the bridge. The traveling wave effect could significantly increase the force in track and bridge, which can result in pounding. If the high-speed railway train brakes on the bridge during an earthquake, the rail may be destroyed near the location of abutment. The use of track expansion devices and small resistance fasteners could result in the poundi ng effect between the neighboring beams while the use of buffer device and beam connection device can mitigate the pounding effect and eventually reduce force on the pier.