中文摘要：

目前对既有结构可靠性的评定主要采用结构可靠度设计中的校核方法,即以分项系数表达的实用设计表达式.虽然在具体的校核过程中,一般会考虑既有结构实际的材料性能、几何尺寸和所承担的作用,但这种评定方法并不完全适用于既有结构的可靠性评定.借鉴国际标准中设计值法的基本思想,在前期工作的基础上,提出既有结构可靠性评定的设计值法.该方法在可靠性评定中直接考虑了基本变量概率特性、目标可靠指标和后续使用年限变化对评定结果的影响,引用既有结构的作用和性能的最新统计结果,建立可靠性评定方法,允许业主自由选取目标可靠指标和后续使用年限,较现有的结构可靠度设计中的校核方法更具有良好的灵活性和通用性.同时,根据此方法确定了现有规范规定的既有结构构件承载能力的鉴定等级与结构构件可靠指标之间的关系.

英文摘要：

Presently,the method about the assessment of the existing structure reliability mainly uses the verification method of structure reliability design,which is the practical design expression with the partial coefficient.The actual material performance,geometry and performed function of the existing structure can be taken account into the process of the specific verification.However,this assessment method is not fully applicable to assess the existing structure reliability.Thus,with the reference from the basic idea of the design value method in international standard,the design value method of assessing the existing structural reliability can be put forward on the basis of previous work.This methodology takes account directly the characteristics of the basic variable probability,target reliability index and design working life on design results into the reliability assessment.Moreover,it can also establish the method of reliability evaluation and allow owners to choose flexibly the target reliability index and design working life with citing the latest statistics of structural functions and performance.Compared with the current verification method of the reliability design,the design value method of assessing the existing structural reliability can possess more excellent flexibility and versatility.Simultaneously,this method can identify the relationship between the identification grade of the structural elements＇ bearing force provided in existing specifications and the reliability index of the structural elements.