山区桥墩抗滚石冲击的双腔椭圆偏心包裹结构研究

发布时间：2018-03-06 08:12

本文选题：滚石　切入点：桥墩偏心防护　出处：《工程力学》2017年10期 　论文类型：期刊论文

【摘要】：山区桥梁墩柱因刚性大而抗冲击效果差,常被滚石冲击损毁,但目前还缺乏有效防治措施。为此,在科学解析滚石对桥墩的弹塑性冲击破坏机理的前提下,基于耗能减震理论提出了一种充填泡沫铝的双腔椭圆偏心桥墩包裹抗冲击结构。继而综合MTS试验数据,采用动力有限元技术对滚石冲击下桥墩防护新结构的动力响应进行计算和分析,并优化结构设计。结果表明:定向椭圆偏心包裹泡沫铝层可显著延长冲击历时,降低冲击荷载,其结构形式经济高效;包裹层厚度适当增加有利于控制墩柱对冲击的动力响应,但过厚也会因结构整体性增大而弱化甚至降低防护效果;双腔充填的"外薄外密"模式最利于控制桥墩塑性应变和冲击挠度,耗能效果更好。总体上,新结构可大幅降低滚石的最大冲击力,保证桥墩结构安全运行。
[Abstract]:Because of its large rigidity, the pier column of mountain bridge has poor impact resistance and is often damaged by rolling stone impact. However, there is still a lack of effective prevention and cure measures. Therefore, based on the scientific analysis of the elastoplastic impact failure mechanism of rolling stone on bridge pier, Based on the theory of energy dissipation and shock absorption, a double cavity elliptical eccentric bridge pier encased in shock resistant structure is proposed, which is filled with aluminum foam, and then the MTS test data are synthesized. Dynamic finite element technique is used to calculate and analyze the dynamic response of the new bridge pier protection structure under rolling stone impact, and the structural design is optimized. The results show that the directional elliptical eccentrically wrapped aluminum foam layer can significantly prolong the impact duration and reduce the impact load. The structure form is economical and efficient, the proper increase of the thickness of the cover layer is helpful to control the dynamic response of the pier column to the impact, but the excessive thickness will weaken or even reduce the protective effect because of the increase of the whole structure. The double cavity filling "outer thin and outer dense" mode is most favorable to control the plastic strain and impact deflection of bridge pier, and the energy dissipation effect is better. In general, the new structure can greatly reduce the maximum impact force of the rolling stone and ensure the safe operation of the bridge pier structure.
【作者单位】：中国科学院山地灾害与地表过程重点实验室;中国科学院水利部成都山地灾害与环境研究所;成都理工大学地质灾害防治与地质环境保护国家重点实验室;
【基金】：STS(KFJ-EW-STS-094) 国家自然科学基金项目(41672356,41472293) 十三五重点专项项目(2016YFB0201003) 院百人计划项目(41502334) 省科技厅项目(2017SZ0041;2016SZ0067)
【分类号】：U443.22

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