再议既有建筑结构可靠性抽样方案

Another discussion on reliability sampling scheme of existing building structure

针对现行标准和已有文献在既有建筑结构抽样检测方案研究上的不足,分别介绍了建筑结构计数抽样和计量抽样的基本原理,在此基础上比较了现有的既有建筑结构可靠性抽样方案,最后结合中国现阶段的经济水平和工程结构的建设要求对既有建筑结构可靠性抽样方案提出了几点建议。主要结论如下:《建筑结构检测技术标准》(GB/T 50344—2019)给出的计数抽样方案是基于连续取样模式制定的,样本量很大、抽样准则宽松,不利于既有建筑结构的质量把控;受构件受载荷条件、施工质量、维护保养等因素的影响,既有建筑结构计数检验批的组成更接近于孤立批的概念,因此建议采用孤立批的抽样方案和判定数,这样可提高计数抽样的效率,并使得抽样准则更为严格;建议《建筑结构检测技术标准》(GB/T 50344—2019)明确给出适用于既有建筑结构的计量抽样方案;建议在实际的检测、鉴定过程中允许采取随机抽样与工作经验相结合的方法。

In view of the shortcomings of standards and literatures in sampling testing schemes of existing building structures,this paper introduced the basic principles of sampling by attributes and sampling by variables respectively.On this basis,the reliability sampling schemes of existing building structures from different standards were compared.Finally,some suggestions were put forward for the reliability sampling schemes of existing building structures according to the current economic level and construction requirements in China.The main conclusions are as follows:Sampling by attributes schemes from existing Chinese standard Technical standard for inspection of building structure(GB/T 50344—2019)are developed by continuous sampling pattern and the sampling size is large while the sampling criteria is loose which are adverse to the quality control of existing building structures.Affected by load conditions,construction quality and maintenance,the components in existing building structures are closer to the concept of isolated lots in current standards.It is suggested that the sampling schemes and determination number of isolated lots should be adopted which can improve the efficiency of sampling schemes by attributes and make the sampling criteria more strict.For sampling by variables schemes,it is suggested that sampling schemes should be provided clearly in Technical standard for inspection of building structure(GB/T 50344—2019)for existing building structures.The method of combining random sampling schemes with work experience should be adopted in the actual testing and identification process.