软土地层大直径地铁盾构隧道承载性能研究
李潇1于博翔2马秀媛2王剑宏2
Bearing Capacity of Large-diameter Metro Shield Tunnel in Soft Soil Layer
LI Xiao1YU Boxiang2MA Xiuyuan2WANG Jianhong2
-
作者信息:1.广州地铁设计研究院股份有限公司， 510010， 广州
2.山东大学齐鲁交通学院, 250002, 济南
-
Affiliation:1.Guangzhou Metro Design and Research Institute Co., Ltd., 510010, Guangzhou, China
2.School of Qilu Transportation, Shandong University, 250002, Jinan, China
-
关键词:
-
Key words:
-
DOI:10.16037/j.1007-869x.20245661
-
中图分类号/CLCN:U451
-
栏目/Col:土建工程
摘要:
［目的］随着地铁盾构隧道施工技术的发展，大直径盾构隧道工程逐渐增多。软土地层大直径地铁盾构隧道的地质条件和隧道结构存在特殊性，有必要对其承载性能进行深入研究。［方法］以深大(深圳机场至大亚湾)城际铁路白泥坑站—大运站区间大直径盾构隧道工程为依托，通过精细化建模和分析，揭示了管片衬砌的承载性能和损伤演化规律，明确了不同直径隧道承载性能的差异。结合现场监测，论证了数值研究的合理性。［结果及结论］随着荷载增大，衬砌结构依次经历拱顶开裂、拱底接缝张开达2.0 mm、拱腰外侧裂缝宽度逾0.2 mm、拱底接头外侧混凝土屈服、拱底螺栓受拉屈服等关键损伤行为。大直径盾构隧道承载阶段可分为4个阶段：弹性受力阶段(收敛变形δ为0~<2.0‰D，D为隧道外径)、轻微损伤阶段(δ达2.0‰D~<5.6‰D)、损伤快速发展阶段(δ达5.6‰D~9.4‰D)、濒临失效阶段(δ达9.4‰D以上)。其中：弹性阶段的结构承载状态良好；轻微损伤阶段的结构耐久性下降，但承载安全性依旧良好；在损伤快速发展阶段，有必要对结构进行修复。
Abstracts:
［Objective］ With the development of metro shield tunnel construction technology, large-diameter shield tunnel projects are gradually increasing. There are special geological conditions and tunnel structure for large-diameter metro shield tunnel in soft soil layer, thus it is necessary to conduct in-depth research on its bearing capacity. ［Method］ Based on the large-diameter shield tunnel project of Bainikeng Station to Dayun Station interval on Shenda (Shenzhen Airport to Daya Bay) Intercity Railway, the bearing capacity and damage evolution law of tunnel segment lining are revealed through refined modeling and analysis, and the bearing performance differences of tunnels with different diameters are clarified. Combined with field monitoring, the rationality of numerical study is demonstrated. ［Result & Conclusion］ With the increase of load, the lining structure experienced arch cracking, 2.0 mm arch bottom joint opening, over 0.2 mm arch waist outer crack width, arch bottom joint outer concrete yield, arch bottom bolt tensile yield and other key damage behaviors. The bearing process of large-diameter shield tunnel can be divided into four stages: elastic stress stage (the convergence deformation δ reaches 0 to ＜2.0‰D, D as the tunnel outer diameter), slight damage stage (δ reaches 2.0‰D to ＜5.6‰D), rapid damage development stage (δ reaches 5.6‰D to 9.4‰D), and near failure stage (δ reaches 9.4‰D or more). Among them, the structure bearing state in elastic stage is good, the structure durability in slight damage stage is reduced, but the bearing safety is still good. So it is necessary to repair the structure in the rapid damage development stage.
过刊浏览
资料下载
友情链接