复杂地层下大型泥水盾构隧道掘进关键技术研究——以珠海隧道为例

Key Technologies for Large-Scale Slurry Shield Tunnel Excavation in Complex Geological Formations—Taking Zhuhai Tunnel as an Example

摘要: 本文依托珠海隧道工程，综合运用数值模拟与理论分析方法，重点探讨了泥水盾构在穿越淤泥质粉质黏土等复杂地层时的两个关键技术问题：一是盾构掘进引起的隧道承载力及地层变形规律；二是掘进过程中开挖面的支护压力范围与稳定性控制。研究通过Abaqus有限元模拟软件建立了四种典型地质断面的二维模型，模拟分析了不同工况下的隧道结构收敛与地表沉降情况。同时，基于土体破坏理论，计算了不同地层条件下的泥水支护压力上下限。研究结果表明：隧道埋深与下卧土层特性是影响管片收敛变形和地表沉降的主要因素，S2断面(深埋、下卧层薄弱)的收敛变形与沉降值最大，但仍在规范允许范围内；泥水支护压力的安全区间与地层性质(黏性土或砂性土)及覆土厚度密切相关，砂性地层中的操作空间显著小于黏性地层。

Abstract: This paper, based on the Zhuhai Tunnel Project, comprehensively employs numerical simulation and theoretical analysis methods to focus on two key technical issues concerning slurry shield tunneling through complex formations such as muddy silty clay: first, the tunnel bearing capacity and deformation patterns induced by shield advancement; second, the range of support pressure at the excavation face and stability control during tunneling. Using Abaqus finite element simulation software, two-dimensional models of four typical geological cross-sections were established to simulate and analyze tunnel structure convergence and ground settlement under various operating conditions. Concurrently, based on soil failure theory, the upper and lower limits of slurry support pressure were calculated for different geological conditions. The results indicate that tunnel burial depth and underlying soil properties are the primary factors influencing segment convergence deformation and ground settlement. Section S2 (deep burial depth, weak underlying layer) exhibited the greatest convergence deformation and settlement values, though still within allowances. The safe range of slurry support pressure is closely related to soil properties (clay or sandy soil) and overburden thickness, with significantly less operational margin in sandy formations compared to clay formations.