【摘要】 论述了公路桥梁的抗震设防标准在桥梁抗震设计中的重要作用,对公路桥梁设计地震动水平、抗震设防目标、抗震设防分类三方面进行了探讨。在基于性能抗震设计背景下,对我国公路桥梁的抗震设防标准的制定提出以下建议:针对我国现行规范中同一地震区不同抗震设防类别桥梁遭遇的地震危险性不一致的问题,建议设计基准期统一取为100年,取超越概率分别为86%、19%、10%和4%的四级设计地震动水平;考虑桥梁震后预期将发挥的使用功能,将其抗震性能水平按正常通行、有限通行、应急通行和禁止通行等功能要求相应地划分为四个等级;抗震设防目标规定为在给定设计地震动水平下结构超过规定的抗震性能水平的条件概率,以期解决我国公路桥梁的抗震设防目标长期没有规定预期的可靠度的问题。更多还原

【Abstract】 The significant role of seismic fortification criteria in seismic design for highway bridges is discussed in this paper. Meanwhile, the design earthquake level, seismic design object and seismic fortification category are explored. In the framework of performance based on seismic design, four earthquake design levels were recommended in terms of the exceeding probability of 86%, 19%, 10% and 4% in 100 years, to solve the inconsistency of seismic hazard for highway bridges with different seismic fortification classification at the same earthquake zone in current Chinese guidelines for seismic design of highway bridges; four seismic performance levels were recommended, i.e. immediately operational, limited operational, emergency traffic only, and closed to traffic respectively, according to the expected functional requirements of highway bridgesafter an earthquake shock;the seismic performance objective is expressed as the conditional probability of exceeding a specified performance level at the given earthquake design level, to solve the problem that the reliabilities of seismic fortification goals of highway bridges have not been specified更多还原