公路桥梁基于概率的实用抗震性能设计框架

发布时间：2018-06-16 13:50

本文选题：公路桥梁 + 抗震性能设计　；参考：《中南大学学报(自然科学版)》2015年09期

【摘要】：针对公路桥梁提出实用的基于概率的抗震性能设计框架。在该框架中,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 a,取超越概率分别为86%,19%,10%和4%的4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4个等级;抗震性能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;采用一次二阶矩法,建立基于需求-能力系数的抗震性能设计的极限状态方程,该方程同时考虑结构地震需求和抗震能力的不确定性。按照本文所提出的设计框架,结合设计算例演示其设计过程。研究结果表明:本文所提出的设计框架可实际应用于公路桥梁基于概率的抗震性能设计。
[Abstract]:A practical seismic performance design framework based on probability is proposed for highway bridges. In this framework, the seismic hazard of different seismic fortification types of bridges in the same seismic area in the current code of our country is not consistent. It is suggested that the standard period of design should be taken as 100 a, and the design ground motion level of magnitude 4 of 10% and 4% of the transcendental probability should be adopted, respectively; considering the expected use function of the bridge after the earthquake, the seismic performance level of the bridge should be considered as the normal passage and the limited passage. The functional requirements such as emergency passage and forbidden passage are classified into four grades accordingly; the seismic performance objective is defined as the conditional probability of the structure exceeding the specified seismic performance level under a given design ground motion level, In order to solve the problem that the seismic fortification target of highway bridges in our country has not stipulated the expected reliability for a long time, the limit state equation of aseismic performance design based on the demand capacity coefficient is established by using the first-order second-order moment method. The equation takes into account the uncertainty of seismic demand and seismic capacity. According to the design framework proposed in this paper, the design process is demonstrated with a design example. The results show that the proposed design framework can be applied to the seismic performance design of highway bridges based on probability.
【作者单位】：福州大学土木工程学院;
【基金】：高等学校博士学科点专项科研基金资助项目(20113514110003)~~
【分类号】：U442.55

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