基于相对可靠度思想的DDBD抗震设计方法  

DIRECT DISPLACEMENT-BASED SEISMIC DESIGN METHOD BASED ON RELATIVE RELIABILITY CONCEPT

作　　者：简斌[1] 谢县[1] 廖平平[1] 

机构地区：[1]重庆大学土木工程学院,重庆400045

出　　处：《工程力学》2015年第4期138-144,共7页Engineering Mechanics

基　　金：重庆市科委攻关项目(CSTC;2011AC4067);重庆市建设科技计划项目(城科字2009第70号)

摘　　要：以我国现行规范设计结构隐含的性态目标的平均可靠度水准为基础,在DDBD方法中建立了相对可靠度理论体系,并提出了具体方法。在该文所提具体方法中,对于任一性态目标,均转化为以多遇地震作为预期地震风险水平进行可靠度计算,且DDBD法可靠度是通过与现有基于力抗震设计方法可靠度的比值形式体现的,既保持了与现行规范可靠度的传承,又避免了一般情况下可靠度的复杂计算。同时,论证了在多遇地震下DDBD方法所得基底剪力计算值与现行规范基于力方法基底剪力计算值理论上相等,并对其实际存在的计算误差进行修正,确定了DDBD方法截面承载力计算公式。最后,通过算例对比分析初步验证了此理论思路的有效性、优越性。Based on the average reliability level of structures designed according to the current Chinese force-based codes, a relative reliability theory was established and a specific method for Direct Displacement-Based Design(DDBD) is presented. In this method, for any seismic performance objective, the expected seismic risk level is always transformed into a frequent earthquake to calculate relative reliability, which is expressed in a ratio with the reliability of structures designed according to the current codes. This method preserves the reliability level of current codes and avoids complex calculations. After presenting the method, it is demonstrated that the base shear calculated by the DDBD method is theoretically equal to current code method for frequent earthquakes, so the section bearing capacity expression in current codes is adopted for the DDBD method, and a modified coefficient is introduced to account for errors in actual calculation. Finally, two examples are analyzed to identify the method's effectiveness and advantages compared to the current force-based method.

关 键 词：直接基于位移 可靠度 性态目标 抗震设计方法 框架结构 

分 类 号：TU352.11[建筑科学—结构工程]