基于FLAC3D的深部隧道分区破裂特性研究

深部地层隧道施工期间，其围岩及支护构成一个复杂的承载体系。开挖导致深部岩体中出现的围岩分区破裂、岩爆等现象会给现场带来极大的安全隐患。围绕分区破裂化这一超常现象，依托淮南矿区某深部巷道工程，借助有限差分软件FLAC3D，通过模拟岩体高温、高地应力等特殊环境下，建立其响应模型，研究了原岩应力和内摩擦角对分区破裂化现象的影响。结果表明：不同原岩压力和内摩擦角对围岩分区破裂现象影响显著；当原岩压力在17.3~35.0 MPa内逐渐增大时，间隔破裂区域体积从0增大至25×102 m3；当摩擦角在22~38°区间内逐渐增大时，间隔破裂区域体积则从26.87×102 m3降至0，恢复至浅部隧道传统破坏模式。

Research on Zonal Fracture Characteristics of Deep Tunnels Based on FLAC3D

Due to the fact that, with the surrounding rock and support constituting a complex bearing system, the surrounding rock partition fracture, rock burst and other problems in deep rock mass caused by excavation will bring great potential safety hazards to the site during the construction of deep stratum tunnels. Taking the abnormal phenomenon of zonal fracturing as the research focus, an abnormal response characteristic model has thus been established under the special environment of high temperature, high ground stress, etc. of the deep roadway rock mass, relying on the actual project of a deep roadway in Huainan mining area, and with the help of FLAC3D numerical simulation software, followed by an analysis of the influence of different original rock pressure and internal friction angle on the zonal fracturing. The results show that different original rock pressures and internal friction angles have significant effects on the zonal fracture of surrounding rocks. When the original rock pressure gradually increases within the range of 17.3 MPa and 35.0 MPa, the volume of the interval rupture area increases from 0 to 25×102 m3; when the friction angle gradually increases within the range of 22°and 38°, the volume of the interval rupture area decreases from 26.87×102 m3 to 0, returning to the traditional failure mode of the shallow tunnel.