【摘要】 郑（州）-万（州）高速铁路湖北段隧道工程是我国钻爆法隧道实现全工序机械化施工的典型案例。该工程具有开挖面积大、开挖进尺长以及施工效率高的特点，因而与传统小型机械分部开挖模式下的隧道施工力学行为和时空效应存在显著差异。采用数值计算及现场测试方法，研究机械化大断面法隧道施工力学行为及时空效应。研究结果表明，大断面开挖降低了掌子面的稳定性（预收敛变形最大值增大40%），空间效应减弱，通过超前支护有效控制掌子面的稳定性对于大断面法施工隧道尤为重要；大断面法施工隧道支护一次成型，且封闭较快，可以有效抑制初期支护的整体沉降（最终收敛变形减小22.5%）。相同施工条件下，相比于C30普通喷射混凝土，采用C30早高强喷射混凝土支护可使隧道收敛变形减小20.1%，表明随着空间效应的减弱和开挖进尺的增大，支护结构在初期阶段迅速获得较强的承载性能可有效控制隧道变形。更多还原

【Abstract】 The tunnel projects in Hubei section of Zhengzhou-Wanzhou High-speed Railway represents a typical case of fully mechanized drill and blast method tunnelling in China. Characterized by large excavation area, extended advance length, and high construction efficiency, it demonstrates significant differences in mechanical behaviors and spatiotemporal effects compared to traditional small-scale mechanical partial excavation methods. Through numerical simulations and field tests, this study investigates the mechanical behaviors and spatiotemporal effects in mechanized construction of large-section tunnels. Key findings include:(1) Large-section excavation reduces face stability(40% increase in maximum pre-convergence deformation) and weakens spatial effects, making advanced support crucial for face stability control;(2) The single-stage support system with rapid closure in large-section construction effectively restrains overall settlement(22.5% reduction in final convergence deformation);(3) Under identical conditions, C30 early-high-strengh shotcrete reduces tunnel convergence deformation by 20.1% compared to C30 ordinary shotcrete, demonstrating that rapid development of high bearing capacity of support structure in early stages could effectively control deformation as spatial effects diminish and advance lengths increase.更多还原