美标高桩码头抗震计算位移法的对比

从原理和适用性的角度对美标高桩码头抗震计算方法进行对比,着重研究了位移法及其中的替代结构法。对替代结构法中推覆曲线的双折线化方式、阻尼比计算、反应谱衰减等影响因素进行分析。通过推覆分析和替代结构法计算变形能力和地震位移、复核码头抗震性能。结合实际案例,采用反应谱法和替代结构法对某高桩码头结构进行抗震分析。结果表明反应谱法趋于保守,不能反映塑性后的荷载衰减,相比而言替代结构法更为准确。而对于替代结构法,不同的等效阻尼比会较大程度影响地震位移结果。

Comparison of displacement-based seismic design approach in US standards for pile-supported wharf

Seismic design methods in US standards for pile-supported wharf are compared from their principle and adaptability.The displacement-based approach and its substitute structure method are focused on.Effects such as bi-linear approximation of pushover curve,damping ratio,and response spectrum attenuation are reviewed for the substitute structure method.Through pushover analysis and substitute structure method,the deformation capacity and seismic displacement are calculated,and the seismic performance of wharf is rechecked.Combined with practical cases,response spectrum analysis and substitute structure method are used to analyze the seismic behavior of a pile-supported wharf structure.The results show that the response spectrum method tends to be conservative and cannot reflect the load attenuation at plastic stage,and the substitute structure method is more precise.For the substitute structure method,different effective damping ratios will significantly affect the displacement calculation.