薄层炭质板岩地层隧道围岩大变形特征及支护方法研究

Study on Large Deformation Characteristics and Support Paterns of Thin Layer Carbonaceous Slate Tunnel

依托香丽高速海巴洛隧道,针对隧道施工中的大变形以及二衬、仰拱填充开裂情况,结合隧道变形监测数据和FLAC3D数值软件,采用广义Hoek-Brown准则反演围岩参数,开展高海拔地区炭质板岩地层隧道大变形特征分析和支护优化研究。结果表明:高海拔地区薄层炭质板岩隧道围岩变形特征为:初期变形速率大且持续时间长、变形量大、变形在空间上的不对称性以及受开挖扰动影响大。当选取SF5c支护形式,锁脚锚管采用直径Φ42mm,长4.5 m,打设角度45°,注浆范围1 m时,能较好的控制围岩变形,以期为类似工程提供参考。

Based on Haibaluo tunnel in Xiang Li high-speed road,focusing on the large deformation,lining and inverted arch filling crack in tunnel construction,combined with deformation monitoring data and FLAC3D,inverting rock parameters in the generalized Hoek-Brown criterion,this paper has studied the large deformation characteristics and optimization for support pat-tern.It shows that deformation characteristics for thin layer carbonaceous slate tunnel in the high altitude area are that initial large deformation rate and long duration,large amount of deformation,asymmetric deformation in space,which are easily affected by the excavation disturbance.The deformation of surrounding rock can be effectively improved with adopting support pattern SF5 c,the parameters of feet-lock pipes are that 42 mm of diameter,4.5 m of length,45°of installation angle,1.0 m of grouting range.It can provide a reference for similar projects.