近断层脉冲型地震动强度指标与高耸结构损伤关联性

Correlation between structural damage of high-rise structures and ground motion intensity measures under near-fault ground motions with pulse-like effect

为了研究近断层脉冲型地震动作用下适用于评价高耸结构抗震性能的地震动强度参数,基于加速度反应谱提出一种同时考虑结构周期延长和高阶振型效应的地震动强度指标。分别以120 m和240 m的钢筋混凝土烟囱结构为研究对象,使用OpenSEES程序,在近断层脉冲型地震动作用下,揭示了高耸混凝土结构的损伤指标(Park-Ang损伤指标、最大层间位移角、最大曲率、最大楼层加速度以及最大顶点位移)与37个地震动强度指标的关联性。研究结果表明:提出的地震动强度指标最适合用于预测高耸混凝土结构在近断层脉冲型地震作用下发生的Park-Ang损伤;与速度相关的地震动强度指标表现出与高耸结构损伤指标的较高的相关性;随着结构周期的增大,位移型的地震动强度指标与损伤的关联性有增长的趋势;此外,地面峰值加速度在表征高耸结构变形破坏方面存在局限性,但是可以用来分析非结构构件的抗震性能。研究结论可为选择合适的地震动强度指标和损伤指标评价高耸混凝土结构在近断层脉冲型地震动作用下的抗震性能提供参考。

To investigate the ground motion intensity measures suitable for evaluating high-rise structures under near-fault ground motions with pulse-like effect,this paper proposes a new ground motion intensity measure considering period elongation effect and higher mode effect based on acceleration spectrum.Taking two high-rise reinforced chimney structures(120 m and 240 m)as research objects,the correlation between damage indices(Park-Ang damage index,maximum inter-story drift ratio,maximum structural curvature,maximum floor acceleration,and maximum roof displacement)of high-rise structures and 37 ground motion intensity measures was studied under near-fault ground motions using OpenSEES.Results show that the proposed intensity measure was the optimal index in predicting the Park-Ang damage of high-rise concrete structures under near-fault ground motions.High correlation between velocity-related intensity measures and structural damage index was observed.As the structural period increased,the correlation between damage indices and displacement-related intensity measures was improved.Besides,peak ground acceleration had limitations in characterizing the deformation and failure of high-rise structures,but it could be used to analyze the seismic performance of non-structural components.The research results can provide reference for selecting proper measures and structural damage indices to evaluate the seismic performance of high-rise structures under near-fault ground motions.