一种新的拟合地震动衰减关系的分步回归法

详细信息

A new step regression approach for fitting groundmotion data with attenuation relation

(Institute of Geophysics, China Earthquake Administration, Beijing 100081,China)

摘要: 提出了拟合地震动衰减关系的一种新的分步回归法．该方法首先确定近场饱和项，再获得距离衰减项，最后确定震级项．作为算例，采用NGA项目美国西部地区的强震观测资料，对基岩场地自由地表加速度反应谱平台高度值衰减关系进行了回归．结果表明，采用此方法对实际资料的拟合不存在系统偏差，结果稳定，能反映强震地震动在近场的距离饱和与震级饱和特性．对远场数据考虑截尾效应，能使回归结果正确反映地震动的远场衰减特征．
- 衰减关系 /
- 地震动 /
- 分步回归 /
- 近场饱和 /
- 截尾效应
Abstract: A new stepregression method for fitting ground motion data to obtain an attenuation relation is suggested in this paper. As an example, this method is applied to find attenuation relation for acceleration response spectra platform level of western U.S.,using strongmotion data supplied by PEER NGA project. Fitted result shows that the final prediction equation is unbiased and stable, and can well characterize the distancesaturation and magnitudesaturation in nearfield with large magnitude. It also shows that in the farfield the attenuation rate of ground motion is correctly predicated by accounting for data truncation.