土工基础

土工基础 ›› 2025, Vol. 39 ›› Issue (5): 783-789.

• 专题论述 • 上一篇    下一篇

超浅埋软土隧道暗挖联合支护数值模拟研究

韩龙伟1，周书东2，黄泽航3，赵文平1，潘 达2   

  1. （1.中国水利水电第七工程局有限公司，成都 610081;2.东莞市建筑科学研究院有限公司，广东东莞 523820;
    3.华南农业大学，广州 510642）
  • 收稿日期:2025-09-25 修回日期:2025-09-30 出版日期:2025-10-31 发布日期:2025-10-30
  • 作者简介:韩龙伟（1982-），男，高级工程师，研究方向为轨道工程及市政工程。
  • 基金资助:
    广东省住房和城乡建设厅2025年科技创新计划项目（编号：20250304K0010）

Numerical Simulation Study on Combined Support Technology for Ultra-Shallow Buried Tunnels Excavation in Soft Soils

HAN Longwei1, ZHOU Shudong2, HUANG Zehang3, ZHAO Wenping1, PAN Da2   

  1. (1.Sinohydro Bureau 7th Co. Ltd., Chengdu 610081;
    2.Dongguan Institute of Building Research Co. Ltd., Dongguan 523820;
    3.South China Agricultural University, Guangzhou 510642)
  • Received:2025-09-25 Revised:2025-09-30 Online:2025-10-31 Published:2025-10-30

摘要： 针对超浅埋隧道暗挖扩建因覆土浅、易引发拱部失稳和地表沉降，对施工安全构成显著风险等问题，依托深圳市南山区某隧道扩建项目，研究了超前小导管、管棚支护及其联合支护技术在超浅埋条件下的应用效果。通过MIDAS GTS NX建立三维数值模型，对比分析了单一管棚支护、单一超前小导管支护及二者联合支护三种工况下围岩变形响应与地表沉降规律。结果表明，联合支护可充分发挥管棚“梁效应”与超前小导管注浆改良土体的协同作用，能够有效提升支护体系的整体刚度与承载性能。联合支护工况下拱顶最大沉降量为9.44 mm，较单一管棚支护（21.14 mm）和单一超前小导管支护（33.34 mm）分别降低55.3%和71.7%。研究可为类似地质条件下超浅埋暗挖隧道扩建工程的超前支护设计提供理论依据与技术参考。

关键词: 超浅埋暗挖隧道, 超前小导管, 管棚, 联合支护, 数值模拟, 方案比选

Abstract: The underground excavation and expansion of ultra-shallow-buried tunnels pose notable risks to construction safety since the minimal soil cover readily triggers crown instability and excessive ground subsidence. This paper presents a case history of a tunnel expansion project in Nanshan District, Shenzhen. The study evaluates the effectiveness of a combined advanced supporting system that integrates a piped-roof (umbrella arch) with forepoling using pilot small-diameter grouted pipes under ultra-shallow cover conditions. A three-dimensional numerical model was developed by using MIDAS GTS NX to simulate and to compare the deformation of the surrounding rock mass as well as the evolution of the ground subsidence under three supporting conditons: (i) single pipe-roof support, (ii) single advanced forepoling support, and (iii) the combined system. The comparative results indicate that the combined technique can take the advantage of the “beam effect” of the pipe-roof while simultaneously improving the soil using grouting through the forepoling pipes, thereby improving the overall stiffness and the load-bearing capacity of the support system. Quantitatively, the maximum crown settlement achieved with the combined support is 9.44 mm, which corresponds to reductions of 55.3% and 71.7% relative to the single pipe-roof case (21.14 mm) and the single advanced forepoling case (33.34 mm), respectively. These findings, derived from a consistent three-condition comparison within the same modeling framework, substantiate the practical advantages of the combined advance support for mitigating deformation and settlement risks in ultra-shallow settings. The outcomes provide a clear theoretical basis and operable technical references for the design of advanced supporting systems in similar tunnel expansion projects conducted by underground excavation.

Key words: Ultra-Shallow Buried Tunnel Excavation, Pilot Small Pipe Grouting, Pipe Roof, Combined Support, Numerical Simulation, Excavation Methods Comparison

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