摘要
为研究近断层不同区域地震动工程特性与时频特征,考虑近断层地震动方向性效应、滑冲效应、上盘效应等特性与断层类型的关系,基于PEER强震数据库,选取台湾集集(Chi-Chi)地震作为研究对象,依据断层破裂带与地震动观测台站的相对位置关系,将其近断层地震动划分为破裂前方区域(RFR)、断层上盘区域(HWR)、断层下盘区域(FWR)及破裂后方区域(RBR)4类,对比分析近断层不同空间地震动的三要素特性,并利用希尔伯特-黄变换(HHT)进一步分析其能量在时频分布上的差异。结果表明:1)近断层不同区域地震动PGA、PGV、PGD及PGV/PGA具有显著差异,给结构地震响应带来极大影响;2)RFR区域地震动呈显著的长周期效应,RBR区域地震动具有高频大幅值特点,HWR区域和FWR区域地震动同时具有高频大幅值特点和显著长周期效应;3)在时频域内,RFR、HWR、FWR、RBR区域地震动能量高值都主要集中在0~5.2 Hz的中低频段,其中HWR区域的地震动最大瞬时能量最大,RFR区域的地震动最大瞬时能量最小。
The purpose of this paper is to study the engineering and time-frequency characteristics of ground motion in different regions of near-fault.Considering the relationship between the characteristics of near-fault ground motions,such as the rupture directivity effect,fling-step effect,hanging wall effects,and fault types,the near-fault ground motion of Chi-Chi earthquake in Taiwan is selected as the research object from the database PEER.Its near-fault ground motion is divided into the rupture forward region(RFR)ground motion,the hanging wall region(HWR)ground motion,the foot wall region(FWR)ground motion,and the rupture backward region(RBR)ground motion,according to the relative positions relationship between the fault rupture and the ground motion observing station.Further,we compare and analyze the characteristics of three elements of four types of near-fault ground motions,and analyze the difference of energy distribution in time-frequency by the Hilbert-Huang transform.The results show that:1)The seismic characteristic parameters such as PGA,PGV,PGD and PGV/PGA of RFR,HWR,FWR and RBR are significantly different,leading to great influence on the seismic response of structures.2)The ground motion in RFR region shows significant long-period effect,the ground motion in RBR region has the characteristics of high-frequency and large-scale value,and the ground motion in HWR and FWR shows the characteristics of high-frequency large-scale value and significant long-period effect.3)The high values of ground motion energy in RFR,HWR,FWR and RBR are mainly concentrated in 0 to 5.2 Hz middle and low frequency band,among them,the maximum instantaneous energy in HWR is the largest,and the maximum instantaneous energy in RFR is the smallest.
作者
陈扬
王秋良
秦维秉
张弛
CHEN Yang;WANG Qiuliang;QIN Weibing;ZHANG Chi(Institute of Seismology,CEA,Wuhan 430071,China;Zhejiang Earthquake Agency,Hangzhou 310013,China;China Three Gorges Corporation,Beijing 100038,China)
出处
《大地测量与地球动力学》
CSCD
北大核心
2021年第10期1069-1075,共7页
Journal of Geodesy and Geodynamics
基金
中国长江三峡集团有限公司科研项目(0799216)
中国地震局地震研究所和应急管理部国家自然灾害防治研究院基本科研业务费专项(IS201616251)。
关键词
地震工程
近断层地震动
空间分布
地震动三要素
时频特征
earthquake engineering
near-fault ground motion
spatial distribution
three key elements of seismic motion
time-frequency characteristics
