基于双参数的强震断层耦合作用设计地震动选取与调幅

Design ground motion selection and scaling based on two parameters considering strong earthquake-faulting coupling effect

  • 摘要: 跨断层结构的破坏往往是活动断层错断和强地震动共同作用的结果。为了在跨断层工程的地震响应分析中考虑断层位错-强地震动的耦合作用,提出了一套基于地震动双参数调幅的强震断层耦合作用设计地震动选取与调幅方法。将断层永久位移和峰值加速度作为选取目标参数,分别基于断层位移和地震危险性概率分析确定罕遇、极罕遇地震作用下的目标参数值。在永久位移型近断层地震动数据集中,初选与目标值匹配程度最优的地震动记录,经峰值加速度调幅和基于目标永久位移的地震动基线校正处理后,得到满足双参数设计需求的强震断层耦合作用设计地震动。算例分析表明,相较于单一参数的设计地震动处理方法,基于峰值加速度和永久位移的双参数强震断层耦合作用设计地震动选取与调幅方法实现了选取参数与对应设计目标需求的协同和匹配,保证了强震断层耦合作用设计地震动的有效性与合理性。

     

    Abstract: Damage to fault-crossing structures is often caused by the coupling effect of active fault dislocation and strong ground motion. To consider this coupling effect in seismic response analysis of fault-crossing engineering, a design ground motion selection and scaling based on two parameters considering strong earthquake-dislocation coupling effect is proposed in this paper. Permanent displacement and peak ground acceleration are selected as the target parameters, and the corresponding target values under rare and extremely rare earthquakes are determined by the probabilistic fault displacement hazard analysis and the probabilistic seismic hazard analysis. In the near-fault ground motion database with permanent displacement, the ground motion record with the best matching degree to the target values is selected initially. After amplitude modulation based on peak ground acceleration and baseline correction based on target permanent displacement, the design ground motion that meets the two-parameter design demand, which considers the strong earthquake-dislocation coupling effect, is obtained. Case analysis shows that compared with the single-parameter processing method, the two-parameter design ground motion selection and scaling based on peak ground acceleration and permanent displacement achieves the matching between the selected parameters and the corresponding design demand, and ensure the effectiveness and rationality of the design ground motion considering strong earthquake-dislocation coupling effect.

     

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