大别山隧道围岩破碎带全断面开挖施工方案研究

以客运专线合武铁路大别山隧道工程大断面施工为背景，在通过隧道施工设计中存在的围岩破碎带时，应用TSP超前地质预报初步确定破碎带的距离和走向，并结合隧道施工现场开挖揭露出的围岩情况，应用离散单元法（UDEC）对围岩破碎带全断面施工开挖、支护方案参数进行数值模拟理论分析。现场实测结果表明，监控量测成果和离散元计算成果中隧道拱顶下沉规律基本一致，且变形量小于设计允许值，证明隧道围岩及初期支护结构处于完全稳定状态。

Study on Full-face Construction Scheme of Fractured Section of Dabieshan Tunnel

Full face construction is conducted for Dabieshan tunnel, which is a large cross section tunnel on Wuhan Hefei passenger dedicated railway. TSP advance geology forecasting is conducted during the construction of the tunnel penetrating through the fractured surrounding rock mass, so as to determine the distance and strike of the fractured zone. On basis of the geological conditions exposed by the tunnel excavation, numerical simulation and theoretical analysis are performed by means of universal distinct element code （UDEC） for the tunnel excavation and reinforcement in the fractured zone. The measured results indicate that the crown settlement pattern obtained through calculations by means of  UDEC coincides well with that obtained through in situ measurement and that the deformation values are lower than the designed allowable values, whichdemonstrates that thesurrounding rock mass and reinforcement structure of the tunnel are stable.