目的目的小净距多线隧道在轨道交通工程中应用广泛,但由于施工步骤繁多且掘进过程中影响因素较多,需设计合理的小净距多线隧道并行掘进方案。方法方法采用2种不同开挖顺序的并行掘进方案,通过建立三维有限元数值仿真模型,比较2种方案的隧道围岩应力与位移发展规律,分析现场监测数据,对比模型的准确性,确定掘进方案的可行性。结果结果结果表明,开挖顺序对围岩间相互作用影响明显,中隧应力和变形受影响最大。中隧先挖法可以较好地避免应力较为集中现象,2种开挖方式的变形值均在安全范围内;依次开挖法和中隧先挖法拱腰处水平应力的变化规律基本一致,依次开挖法的拱顶处垂直应力比中隧先挖法的大40%左右;中隧先挖法的拱腰水平变形和拱顶沉降值分别比依次开挖法的增大23%,26%,但中隧先挖法开挖初期的沉降值较少;中隧先挖进度较快,应力和沉降控制能力优于依次开挖法,数值模拟方法能较好反映真实施工情况,现场监测结果也表明中隧先挖法适用于小净距隧道进口段施工。结论结论综合考虑衬砌结构应力、变形和施工工期,现场可采用中隧先挖法进行施工。研究结果可为类似小净距多线并行隧道工程设计与施工提供理论参考。

Objectives Closely spaced multi-line tunnels are widely used in rail transit engineering but pose challenges due to complex construction procedures and numerous influencing factors during excavation. Therefore, it is crucial to design a rational parallel excavation scheme for closely spaced multi-line tunnels. Methods This study evaluates two parallel excavation schemes with different excavation sequences by estab‑lishing a three-dimensional finite element numerical simulation model. The stress and displacement evolu‑tion patterns of the surrounding rock are compared, and the simulation results are validated with field moni‑toring data to assess model accuracy and scheme feasibility. Results The excavation sequence significantly impacts the interaction between the surrounding rock, with the middle tunnel experiencing the greatest stress and deformation. The “middle tunnel first” method effectively mitigates stress concentration, with de‑formation values under both methods remaining within safety limits. For horizontal stress at the arch haunch, the variation patterns of the sequential and “middle tunnel first” methods are generally consistent, while the vertical stress at the arch crown in the sequential method is approximately 40% higher. Compared to the sequential method, the “middle tunnel first” method exhibits a 23% increase in horizontal deforma‑tion at the arch haunch and a 26% increase in settlement at the arch crown but shows lower initial settle‑ment. The “middle tunnel first” method progresses faster and demonstrates superior stress and settlement control. Numerical simulations closely reflect actual construction conditions, and field monitoring confirms the suitability of the “middle tunnel first” method for the entrance sections of closely spaced tunnels. Con⁃clusions Considering the stress,  deformation of lining structures, and construction timeline, the “middle tunnel first” method is recommended for on-site implementation. These findings offer valuable guidance for the design and construction of similar closely spaced multi-line parallel tunnel engineering.