近断层地震脉冲效应对大跨度桥梁地震响应的影响
|
摘要
历次震害表明,近断层地震的脉冲效应(滑冲fling step和前导方向性forward rupturedirectivity)使得大量土木工程结构产生灾难性的破坏。大跨度桥梁的动力特性决定了这两种不同的脉冲效应都将对其地震响应产生影响。通过选取具有典型脉冲效应的近断层地震记录,检查了三座不同类型的大跨度桥梁的地震响应,并探讨了脉冲效应的影响。结果表明:滑冲效应在长周期的大跨度桥梁关键部位产生数倍于一般地震的位移和内力响应,而加速度脉冲效应可能对位移响应并无太大影响,却对其内力响应具有与滑冲效应同等程度的影响;对于周期较短的拱桥结构,虽然滑冲效应对其部分长振动周期结构的位移响应具有较大的影响,但加速度脉冲对结构内力的影响更为显著。
Earthquake disasters indicate that fling step and forward rupture directivity effects of near fault ground motions(NFGM) have caused disastrous damages for many civil engineering structures.The characteristics of long span bridges determine the fact that these effects may have different impacts on their seismic responses.Typical NFGMs with pulses were selected to evaluate the impacts of 3 long span bridges.Results show that fling step can induce several times of large displacements than ordinary earthquake wave does at key locations of bridges with really long periods,while for arch bridge with comparably shorter period,fling step effect may have impact on its partial structures with long vibration period,but forward rupture directivity affects more on its seismic forces.
Earthquake disasters indicate that fling step and forward rupture directivity effects of near fault ground motions(NFGM) have caused disastrous damages for many civil engineering structures.The characteristics of long span bridges determine the fact that these effects may have different impacts on their seismic responses.Typical NFGMs with pulses were selected to evaluate the impacts of 3 long span bridges.Results show that fling step can induce several times of large displacements than ordinary earthquake wave does at key locations of bridges with really long periods,while for arch bridge with comparably shorter period,fling step effect may have impact on its partial structures with long vibration period,but forward rupture directivity affects more on its seismic forces.
引文
[1]Tirca,Lucia Dana,Foti,et al.Response of middle-rise steel frames with and without passive dampers to near-field ground mo-tions[J].Engineering Structures,2003,25:169-179.
[2]Alavi,Babak,Krawinkler,et al.Behavior of moment-resisting frame structures subjected to near-fault ground motions effects[J].Earthquake Engineering and Structural Dynamics,2004,33:687-706.
[3]Malhotra P K.Response of buildings to near-field pulse-like ground motions[J].Earthquake Engineering and Structural Dynam-ics,1999,28:1309-1326.
[4]Somerville,Paul.Characterizing near fault ground motion for the design and evaluation of bridges[C].//The3rd National Con-ference and Workshop on Bridges and Highways.Portland Oregon:[s.n.],2002.
[5]Makris,Nicos,Black,et al.Evaluation of peak ground velocity as a“good”intensity measure for near-source ground motions[J].Journal of Engineering Mechanics,2004,130(9):1032-1044.
[6]Park S W,Ghasemi H,Shen J P G,et al.Simulation of the seismic performance of the bolu viaduct subjected to near-fault ground motions[J].Earthquake Engineering and Structural Dynamics,2004,33:1249-1270.
[7]Kalkan,Erol and Kunnath,Sashi K.Effects of fling step and forward directivity on seismic response of buildings[J].Earth-quake Spectra,2006,22(2):367-390.
[2]Alavi,Babak,Krawinkler,et al.Behavior of moment-resisting frame structures subjected to near-fault ground motions effects[J].Earthquake Engineering and Structural Dynamics,2004,33:687-706.
[3]Malhotra P K.Response of buildings to near-field pulse-like ground motions[J].Earthquake Engineering and Structural Dynam-ics,1999,28:1309-1326.
[4]Somerville,Paul.Characterizing near fault ground motion for the design and evaluation of bridges[C].//The3rd National Con-ference and Workshop on Bridges and Highways.Portland Oregon:[s.n.],2002.
[5]Makris,Nicos,Black,et al.Evaluation of peak ground velocity as a“good”intensity measure for near-source ground motions[J].Journal of Engineering Mechanics,2004,130(9):1032-1044.
[6]Park S W,Ghasemi H,Shen J P G,et al.Simulation of the seismic performance of the bolu viaduct subjected to near-fault ground motions[J].Earthquake Engineering and Structural Dynamics,2004,33:1249-1270.
[7]Kalkan,Erol and Kunnath,Sashi K.Effects of fling step and forward directivity on seismic response of buildings[J].Earth-quake Spectra,2006,22(2):367-390.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心