长期服役长隧洞衬砌裂缝分布规律与仿真分析  

Distribution law and simulation analysis of lining crack in long-distance tunnel of long service period

作　　者：李翔宇 李军[1] 王海军[1] 张继勋[2] 汤雷[1] 王倩 LI Xiangyu;LI Jun;WANG Haijun;ZHANG Jixun;TANG Lei;WANG Qian(Nanjing Hydraulic Research Institute,Nanjing 210029,Jiangsu,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,Jiangsu,China;Lingcheng District Water Conservancy Bureau,Dezhou City,Dezhou 253500,Shandong,China Dezhen Liangcheng District Water Conservancy Bureau,Dezhou 253500,Shangdong,China)

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]河海大学水利水电学院,江苏南京210098 [3]德州市陵城区水利局,山东德州253500

出　　处：《水利水电技术（中英文）》2023年第1期108-118,共11页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金重点项目(51739008);国家重点研发计划项目(SQ2021YFC3000080)。

摘　　要：【目的】由于已建输调水隧洞工程均埋于地下,盲运时间较长,随着服役时间的增长,隧洞衬砌产生裂缝病害,严重影响运行安全,因此研究衬砌裂缝发生的规律极为重要。【方法】对某运行20 a的隧洞素混凝土衬砌裂缝进行现状调查和现场检测,基于现场检测数据分析,揭示该素混凝土衬砌病害发生的部位、类型、裂纹密集程度等规律,并进行初步成因分析。为进一步揭示该隧洞裂缝病害的成因和主控因素,基于Flac3D软件,开展典型洞段衬砌结构的三维数值仿真分析,得到了初始地应力、衬砌厚度、外水压力等对衬砌工作性态的影响,揭示了裂缝密集程度的主控因素。【结果】结果显示:(1)裂缝是该素混凝土隧洞衬砌中最为广泛的病害;(2)单位隧洞长度下的裂缝密集程度从高到低,依次为Ⅱ、Ⅲ、Ⅳ、Ⅴ类围岩洞段;(3)衬砌厚度、地应力、外水压力是影响单位隧洞长度下的裂缝密集程度不同的主要因素。【结论】数值模拟计算结果反映了衬砌裂缝密度差异的原因与现场检测结果一致。研究结果为水工隧洞建设与长效运维提供了参考。[Objective] As all the existing water transfer-conveyance tunnels are buried underground with long blind operation time, the engineering disease of crack in the lining can seriously impact the operation safety along with the increase of the service time, and then it is quite important to study the occurrence law of the lining crack. [Methods]The cracks of plain concrete lining of a diversion tunnel which has been in operation for 20 years have been detected on site. Based on the analysis of the in-situ detecting data, the laws of the occurrence location and type as well as the crack density of the lining disease occurred in the plain concrete are revealed, while the causations are preliminarily analyzed as well. In order to further find out the causations and dominant factors of the crack disease of the tunnel, a 3-D numerical analysis on the lining structure of typical tunnel section is made with the software of Flac3D, from which the influences from initial ground stress, lining thickness and external water pressure on the working behavior of the lining are obtained and then the dominant factors of the density of cracks are revealed. [Results] The results show that(1) crack is the most widespread disease in the plain concrete tunnel lining;(2) the crack density per unit tunnel length is from high to low with the sequence of the tunnel sections with the surrounding rock classifications of Ⅱ, Ⅱ, Ⅳ and Ⅴ respectively;(3) the lining thickness, ground stress and external water pressure are the dominant factors to affect the difference among the crack densities under unit tunnel length. [Conclusion] The numerical simulation results reflect the reason for the difference in the density of the lining cracks, which is consistent with the field test results. The study results can provide the relevant references for both the construction and the long-acting operation and maintenance of hydraulic tunnel.

关 键 词：引水隧洞 长期服役 素混凝土衬砌 裂缝分布规律 三维数值仿真 

分 类 号：TV554[水利工程—水利水电工程]