结构安全性设计的广义方法  

A general method for structural safety design

作　　者：姚继涛[1] 宋璨[1] 刘伟[1] 

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《建筑结构学报》2017年第10期149-156,共8页Journal of Building Structures

基　　金：国家自然科学基金项目(50678143;51278401)

摘　　要：基于概率的分项系数法是结构可靠度通用设计方法,也是我国现行结构设计规范的重要基础,但在30多年的实际应用中,该方法已逐渐显现出广义性和可靠度控制精度不足等缺陷。借鉴国际标准ISO 2394:2015中设计值法的基本思路,根据前期提出的结构安全性设计的广义表达式和标准灵敏度系数的取值方法,提出结构安全性设计的广义方法,并对其进行了必要的简化。该方法可在设计中直接考虑基本变量概率特性、目标可靠指标和设计使用年限变化对设计结果的影响,基于作用和结构性能的新近统计结果,建立新材料、新型结构的可靠度设计方法,并允许业主选取不同的目标可靠指标和设计使用年限,具有良好的普适性,较国际标准中的设计值法也更具有实用性。理论和实例分析结果表明:广义设计方法采用了利用解析优化提出的标准灵敏度系数建议值,可更好地实现对可靠度的控制;该法较目前的分项系数法和设计值法具有更高的可靠度控制精度。Partial factors method based on probability is a generally accepted method for structural reliability design in the world and the important bases of current structural design standards system in our country. However, in the history of more than 30 years, it has been uncovered that the method lacks of enough generality and precision of reliability control. According to the principle of design-value method proposed in international standard ISO 2394：2015, based on the general expressions for structural safety design and assignment method of standard sensitive coefficients proposed before, a general method of structural safety design is put forward and simplified. It allows in design to take directly into account of the influences of variety of basic variables probabilistic properties, target reliability index and design working life on design results, to apply directly the statistical results of actions and structural properties, to establish the reliability design methods of new material and new kind structures, and to select flexibly the target reliability index and design working life by owners. The method is not only of good generality, but also of more practicality than design- value method proposed in international standard. The results of theoretical and case analysis show that the general design method adopts the recommended value of the standard sensitivity coefficient proposed by analytic optimization, which can better control the reliability. Compared with the current partial factors method and design value method, it has higher reliability control precision.

关 键 词：结构可靠度 分项系数法 设计值法 结构设计 

分 类 号：TU318[建筑科学—结构工程]