针对重庆地区泥岩与回填土复合地层中小半径曲线盾构隧道掘进过程的安全问题,本研究通过Midas建立三维数值模型,系统分析了曲线半径、顶推力及不平衡顶推力对地表沉降与围岩变形的影响规律及敏感性。结果表明:随着曲线半径增大变形逐渐减小,但变形量的幅度平缓;顶推力存在临界值,过低引发掌子面失稳,过高则导致土体剪切破坏;不平衡顶推力比例升高会破坏应力对称性,弱推力侧土体流失与强推力侧挤压协同加剧非对称沉降;敏感性分析显示,顶推力对变形控制起主导作用,其次为曲线半径和不平衡顶推力。研究成果可为类似地质条件下小半径曲线隧道的施工参数优化提供参考。
Regarding the safety issues during the excavation process of small radius curved shield tunnels in composite formations of mudstone and backfill soil in Chongqing area, a three-dimensional numerical model was established by Midas. The influencing regularities and sensitivity of curve radius, top thrust force, and unbalanced top thrust force on surface subsidence and surrounding rock deformation were analyzed. The results indicate that: As the radius of the curve increases, the deformation gradually decreases, but the magnitude of the deformation is gentle. There is a critical value for the top thrust, which can cause instability of the palm surface if it is too low, and shear failure of the soil if it is too high. An increase in the proportion of unbalanced thrust will disrupt stress symmetry, and the synergistic effect of soil loss on the weak thrust side and compression on the strong thrust side will exacerbate asymmetric settlement. Sensitivity analysis shows that top thrust plays a dominant role in deformation control, followed by curve radius and unbalanced top thrust. The research results can provide reference for optimizing construction parameters of small radius curved tunnels under similar geological conditions.
[1] Liu Y, Lei H, Shi L, et al. Deformation analysis of ground and existing tunnel induced by overlapped curved shield tunneling[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2025, 17(2): 795-809.
[2] Zhang X, Luo B, Xu Y, et al. Case study of performance assessment of overlapping shield tunnels with a small curve radius[J]. Deep Underground Science and Engineering, 2023, 3(4): 481-496.
[3] 赵秀绍, 魏度强, 于万友, 等. 小曲线半径盾构隧道上穿既有隧道影响分析[J]. 地下空间与工程学报, 2021, 17(4): 1216-1224.
[4] 郝润霞. 软土地区曲线段盾构隧道超挖量与注浆量分析[J]. 地下空间与工程学报, 2013, 9(5): 1132-1136.
[5] 刘书斌, 周立波. 小半径曲线地段盾构施工质量调研与分析[J]. 地下空间与工程学报, 2013, 9(增2): 1936-1939, 1950.
[6] 赵翌川, 颜建平, 张晨光, 等. 小半径曲线盾构隧道施工的地层扰动规律研究[J]. 现代隧道技术, 2022, 59(增1): 243-250.
[7] Wang X, Liu X, Lin Y, et al. Analysis of the effect of pore water pressure on a small radius curve section of a fine sand layer under cyclic metro[J]. Water 2023, 15(5): 981.
[8] Hu Y, Tang H, Xu Y, et al. Ground settlement and tunnel response due to twin-curved shield tunnelling in soft ground with small clear distance[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2024, 16(8): 3122-3135.
[9] 吴迪, 蒋敏敏, 肖昭然. 小半径曲线盾构施工对周边土体位移的影响[J]. 辽宁工程技术大学学报(自然科学版), 2021, 40(4): 318-326.
[10] 孙捷城, 路林海, 王国富, 等. 小半径曲线盾构隧道掘进施工地表变形计算[J]. 中国铁道科学, 2019, 40(5): 63-72.
[11] Yang B, Zhang C Y, Su N, et al. Influence of small radius curved shield tunneling excavation on displacement of surrounding soil[J]. Buildings, 2023, 13(3): 803-803.
[12] Feng X J, Wang P, Liu H F. Mechanism and law analysis on ground settlement caused by shield excavation of small-radius curved tunnel[J]. Rock Mechanics and Rock Engineering, 2022, 55(3): 3473-3488.
[13] 叶雅图, 王世君, 王琪. 小半径上下重叠地铁盾构隧道设计与施工[J]. 地下空间与工程学报, 2008(4): 696-701,733.
[14] 陈洪涛, 王连俊, 李阳. 岩溶软土区高速公路复合地基参数对路基沉降敏感性分析[J]. 公路, 2017, 62(8): 62-64.
