2022年日本福岛Mw7.4级地震的S-net海底场地非线性反应研究OA
Nonlinear response of S-net sites in 2022 Mw7.4 off-Fukushima earthquake,Japan
为探究海底场地的地震非线性反应特征,基于2022年日本福岛海域Mw7.4级地震中S-net的海底地震动记录,分析了峰值加速度(PGA)≥100 cm/s²的强震动与弱震动(20 cm/s²<PGA<100 cm/s²)的水平与竖向(HVSR)谱比,探讨了 DNL、ADNL、PNL 3 个量化场地非线性参数的特征,评估了 148 个台站的场地非线性水平,回归分析了埋置台站和未埋置台站场地的非线性参数与 PGA、峰值速度(PGV)的关系.结果表明,当水平 PGA 超过 100 cm/s²时,S-net 的部分台站场地在地震中出现了明显的非线性特征,包括主频向低频偏移和高频谱比的降低;3 个非线性参数均与 PGA 和 PGV 具有较好的相关性;非线性参数 PNL 更适合用于 S-net 站点的非线性识别,而用于识别海域场地非线性反应的 DNL、ADNL 阈值需要重新评估;台站布设方式对非线性评估具有重要影响,利用埋置台站与未埋台站记录的强震数据判别场地非线性时需分类讨论.
To investigate the seismic nonlinear response of seafloor sites,this study analyzes S-net seafloor strong-motion records from the Mw7.4 off-Fukushima earthquake on March 16,2022.Horizontal-to-vertical spectral ratios(HVSR)are compared between strong motions(PGA≥100 cm/s²)and weak motions(20 cm/s²<PGA<100 cm/s²).Three nonlinear site parameters(DNL,ADNL,PNL)are examined to evaluate nonlinearity at 148 ocean bottom stations(OBSs),and regression analysis is conducted on their relations with PGA and PGV for buried and unburied OBSs.Results show that when horizontal PGA exceeded 100 cm/s²,some OBSs exhibit clear nonlinear features,including dominant frequency shift to lower frequencies and spectral ratio reduction at high frequencies.All three parameters correlate well with PGA and PGV;PNL is more suitable for nonlinearity identification at S-net sites,while DNL and ADNL thresholds for offshore sites require reassessment.The setting condition of OBSs significantly affects nonlinearity assessment,suggesting buried and non-buried OBSs should be analyzed separately.
胡进军;李建华;崔鑫
中国地震局工程力学研究所,黑龙江 哈尔滨 150080||地震灾害防治应急管理部重点实验室,黑龙江 哈尔滨 150080中国地震局工程力学研究所,黑龙江 哈尔滨 150080||地震灾害防治应急管理部重点实验室,黑龙江 哈尔滨 150080中国地震局工程力学研究所,黑龙江 哈尔滨 150080||地震灾害防治应急管理部重点实验室,黑龙江 哈尔滨 150080
建筑与水利
Mw7.4级福岛海域地震海底地震动非线性反应HVSRS-net
Mw7.4 off-Fukushima earthquakeseafloor ground motionnonlinear responseHVSRS-net
《岩土工程学报》 2026 (5)
929-938,10
国家重点研发计划项目(2021YFC3100701,2022YFC3003503)国家自然科学基金项目(52478568)This work was supported by the National Key R&D Program of China(Grant Nos.2021YFC3100701,2022YFC3003503)and National Natural Science Foundation of China(Grant No.52478568)
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