在役混凝土桥梁结构耐久性评估方法

对在役混凝土桥梁结构的耐久性进行评估是评价其工作性态是否满足设计要求的关键所在.将桥梁结构划分成桥梁结构、桥梁构成、桥梁构件3个层次，提出了桥梁构件划分方法与耐久性关键构件抽样法，并按照不同构件的耐久性劣化影响因素的差异选取了相应的包括构件环境作用因素指标在内的构件耐久性考核指标，从而建立了在役混凝土桥梁结构耐久性的3层次多指标的评估模型.并定义了桥梁结构全寿命周期的5个耐久性典型状态，以5个典型状态来评估桥梁现有耐久性水平，3个层次均划分为5个模糊等级，对应于完好、较好、较差、差、危险5个耐久性状态.基于模糊数学理论，将定性指标给予定量化，采用最优区间型隶属度函数确定构件的耐久性考核指标对各个模糊等级的隶属度，用可信度与频数统计（CMFS）方法确定权重，用综合隶属度评分法进行等级评定.基于以上分析，总结出在役混凝土桥梁结构耐久性评估流程，用Matlab语言编制了评估程序，用该程序对浙江省4座在役混凝土桥梁进行耐久性评估，评估结果与实际情况十分吻合.基于该程序开发的《公路混凝土桥梁耐久性评估软件系统1.0版》，已通过浙江省交通厅的鉴定并初步运用于浙江省公路桥梁管理系统，效果良好.

Method for evaluating durability of existing concrete bridges structures

Evaluating for the durability of existing concrete bridge structures is crucial for appraising whether their performance accords with design requirements.The existing concrete bridges structures are partitioned into four constituents,i.e.,superstructure,substructure,support,and annexes.Farther,the method how to partition every one of these four constituents into members and how to choose the representational form of every kind of member based on key member for durability is proposed.And test indexes including environmental ones for durability of members are chosen according to their factors affecting durability.Thus three-level-multi-index model for evaluating durability of existing concrete bridges structures is built up.And in terms of five typical durability states defined the bridges structures will certainly exist in their life cycles,five fuzzy durability classes are partitioned for every level,which are good,just soso,bad,worse,and dangerous respectively.Based on fuzzy mathematic theory,the optimum interval membership function is used to decide the memberships of test indexes of every durability class of members after the qualitative indexes are transformed into quantitative indexes.The CMFS method based on credibility matrix and frequency statistic method is used to obtain weights and synthetic membership score considered as class judgment standard.Based on the analysis above,the flow chart for evaluating durability is presented and an evaluating program is compiled in Matlab language,which is applied to four actual bridge engineering projects in Zhejiang Province.And the evaluating results according well with actual results prove that the method proposed in this paper for evaluating the durability of existing concrete bridges structures is believable,feasible and in reasonable.Moreover,a software named as system(version number 1.0) for evaluating the durability of existing concrete bridges structures is developed and applied to bridges management system in Zhejiang Province to verify the system efficiency.