新型减隔震装置在高速铁路桥梁中的应用研究

Application Research on the New Elastic-plastic Limit Seismic Isolation Device in High-speed Railway Simple Supported Girder Bridges

研究目的:针对铁路简支梁桥的抗震设计特点,提出一种适用于高速铁路简支箱梁的新型软钢阻尼器———弹塑性限位减隔震装置,该装置可与常规桥梁支座共同作用,组成一种新的减隔震体系。以某高速铁路双线32 m简支箱梁为计算实例,结合试验研究成果,采用滑移三折线恢复力模型输入弹塑性限位减隔震装置的力学特性,利用非线性时程分析方法,对弹塑性限位减隔震装置的减隔震性能进行分析。研究结论:(1)采用滑移三折线模型,可以很好地模拟弹塑性限位减隔震装置的非线性特征,装置计算输出的滞回曲线与试验研究结果可以很好地吻合;(2)弹塑性限位减隔震装置可显著延长桥梁的自振周期,并通过装置的塑性变形耗能能力可以大幅降低桥墩的地震力,对于不同墩高的32 m简支箱梁桥,弹塑性限位减隔震装置均可以发挥良好的减隔震效果,罕遇地震下的减震率在55%以上,减震效果优良;(3)新型弹塑性限位减隔震装置,构造简单、施工方便、性能可靠,在工程造价有限增加的情况下,能以较小的代价将高速铁路常规简支梁桥的抗震设防等级由多遇地震提高到罕遇地震,社会与经济效应显著;(4)弹塑性限位减隔震装置可以有效地降低结构关键部位在地震作用下的位移,减小结构构件的地震力,确保结构在地震下的安全,在高速铁路桥梁抗震领域中将会有广阔的前景。

Research purposes:According to the seismic design features of railway simply-supported girder bridges,a new type of soft steel damper,elastic-plastic limit seismic isolation device,was designed for the simple-supported box girder of high-speed railway.The device worked together with conventional bridge bearings to form a new shock-absorbing system.Taking a 32 m simple support box girder of a high speed railway as an example,combined with the experimental research results,the mechanical properties of the elastic-plastic limit seismic isolation device were input by using the restoring force model of the slip three-fold line,and the nonlinear time-history analysis method was used.The seismic isolation and isolation performance of the device was analyzed.Research conclusions:(1)The slip three-fold model can well simulate the non-linear characteristics of the elastic-plastic limit isolation device,and the hysteretic curve calculated by the device is in good agreement with the experimental results.(2)The elastic-plastic limit isolation device can significantly prolong the natural vibration period of the bridge and dissipate energy through the plastic deformation of the device.The capacity can greatly reduce the seismic force of piers.For 32 m simply supported box girder bridges with different pier heights,the elastic-plastic limit isolation device can play a good role in reducing and isolating earthquake.Under rare earthquakes,the rate of vibration reduction is over 55%,and the effect of vibration reduction is excellent.(3)The new elastic-plastic limit isolation device is simple in structure,convenient in construction and reliable in performance.With the limited increase of engineering cost,the seismic fortification level of conventional simple-supported girder bridges on high-speed railway can be improved from frequent earthquakes to rare earthquakes at a small cost,with remarkable social and economic effects.(4)Elastic-plastic limit isolation device can effectively reduce the displacement of key parts of the structure under earthquake,reduce the seismic force of structural components,and ensure the safety of the structure under earthquake.It will have broad prospects in the field of seismic resistance of high-speed railway bridges.