近断层区的输入能量设计谱及其在基于能量抗震设计中的应用

Energy input design spectra for near-fault regions and application in energy-based seismic design

研究并确定输入能量设计谱是建立基于性能抗震设计和评估能量方法的必要基础。选取断层15km投影距离内的224条强震记录讨论场地类型和断层距等因素的影响,建议了近场地震的输入能量设计谱(EIDS),在与实际记录及日本等国已有抗震规范比较后表明,所建议的设计能量谱能较好地反映近断层区潜在能量需求,在此基础上形成了基于能量的桥梁结构抗震评估设计方法,并用3座实际RC桥墩进行算例验证证明了所建议方法的可行性,表明基于既有抗震规范设计的桥梁结构仍有必要进行考虑近断层效应的耗能能力验算。

The reliable definition of input energy spectra is an essential foundation for energy-based seismic design and evaluation method. Considering the influence of soil type and fault distance, a world-wide ensemble of 224 records within 15km of fault projective distance is selected as a data base. The energy spectra for seismic design have been derived with the shape and amplitude adjustment according to different seismicity groupings. The proposed energy input design spectra（EIDS） are compared with that from the Japanese Building Code（ 1985 and 2001 ） and the actual energy demand of earthquakes that occurred near faults. It＇s proved that the proposed spectra can meet the practical earthquake energy demand. A procedure for energy-based seismic evaluation and design is advised and confirmed by 3 RC bridge piers. Energy-based seismic capacity assessment is needed for structures within near-fauh region.