近场与远场地震动作用下单层柱面网壳结构易损性分析

与远场地震动不同，近场速度脉冲型地震动具有瞬时能量大、幅值大、脉冲周期长等特点，但目前少有学者关注其对网壳结构的影响。以三向网格型单层柱面网壳为研究对象，采用40条近场速度脉冲型地震动及40条远场地震动作为输入，对9例网壳结构进行增量动力分析，基于分析结果建立网壳结构的概率地震需求模型及抗震能力模型，获得网壳结构的易损性曲线，并对比研究两组地震动作用下网壳结构的极限状态失效概率。结果表明：与远场地震动相比，近场速度脉冲型地震动会造成单层柱面网壳结构更为严重的损伤，且损伤指数的离散性更大；近场速度脉冲型地震动作用下单层柱面网壳结构的极限状态失效概率要显著大于远场地震动作用下的极限状态失效概率。

Analyses of seismic fragilities of single-layer cylindrical reticulated shells #br#under near-fault and far-field ground motions

Different from the far-field ground motions, the near-fault pulse-like ground motions have the characteristics of high transient input energy and long pulse periods, however, very few researchers have currently focused on their effects on the reticulated shells. In this paper, the incremental dynamic analyses are performed on nine three-way grid single-layer cylindrical reticulated shells, subjected to a set of 40 near-fault pulse-like ground motions and the other set of 40 far-field ground motions, respectively. The probabilistic seismic demand models and capacity models are developed using the incremental dynamic analysis results, and then the fragility curves are obtained. Finally, the comparison analyses on these results due to the two sets of ground motions are made. It can be concluded that, when compared to the far-field ground motions, the near-fault pulse-like ground motions will lead severer damages to the single-layer cylindrical reticulated shells and bigger dispersion of the damage index; besides, the probabilities of failure to the limit states of this type of reticulated shells under near fault pulse-like ground motions are also higher than that under far-field ground motions.