既有城市隧道衬砌结构的损伤评价计算方法探究

Research on a Calculation Method for the Damage Evaluation of the Existing Urban Tunnel Lining Structure

既有城市隧道衬砌结构的损伤严重影响城市公共交通运营安全,并减少既有隧道的使用寿命,因此快速准确地对隧道衬砌结构进行损伤评价具有重要意义。文章通过调研分析既有城市隧道衬砌结构的损伤评价方法,拟将对既有损伤城市隧道的宏观评价与衬砌结构材料的损伤机理相联系,其中,宏观评价方面选取规范评定法对衬砌结构进行损伤评价,并对隧道健康等级F的划分进行优化;损伤机理方面选取基于弹性模量的损伤变量,并引入弹性模量折减率η的概念,进而提出并建立既有城市隧道健康度与损伤度的函数假定关系,为既有城市隧道衬砌结构的损伤评价与计算提供了一条新思路。

The operation safety of the public transport is seriously threaten by the occurrence of defects and damages in existing urban tunnels, which affects the quality of traffic, and will shorten the service life of urban tunnels. Therefore, it is of great significance to evaluate the damages of the tunnel lining structure quickly and accurately. The damage evaluation methods of the existing urban tunnel lining structure are investigated and analyzed in this paper, and a combination method of the macroscopic evaluation of the existing damaged urban tunnel and the damage mechanism of the lining structural material is proposed. Among them, the assessment method specified in the national criterion is selected to evaluate the damages of the lining structure for the macroscopic evaluation, and the classification of tunnel health levels is optimized. Meanwhile, the damage modulus based on the elastic modulus is selected, and the concept of elastic modulus reduction rate is introduced for the mechanism of damage. Furthermore, the assumed function relationship between the health level and the damage degree of existing urban tunnels is proposed and established, which provides a new idea for structural damage assessment of existing urban tunnels.