基于三维激光扫描点云数据的地下巷道岩体结构面识别及稳定性分析

巷道围岩中发育的结构面对巷道稳定性有很大的影响，开展地下巷道的工程地质调查，精确获取地下巷道围岩结构面信息是巷道稳定性分析的关键。以云南大红山铁矿775 m 中段运输巷道为研究对象，采用三维激光扫描仪获取围岩结构面点云数据，并利用点云数据处理软件进行误差处理、坐标校正、结构面数据提取、点云拼接和过滤抽稀等内业数据处理工作，基于处理结果开展了统计分析；利用离散元软件3DEC建立了离散结构网络模型与地下巷道合成岩体模型，并对该巷道在自重及爆破振动作用下的失稳概率进行了数值模拟。结果表明：三维激光扫描技术可较好地获取巷道围岩的结构面信息，结合离散块体单元计算软件对巷道岩石块体的稳定性进行进一步分析，所分析区域的围岩自稳能力较好，但在爆破振动影响下失稳概率大幅增加，研究结果可为巷道的支护设计提供理论指导。

Recognition and Stability Analysis of Underground Tunnel Rock Mass Structural Plane Based on 3D Laser Scanning Point Cloud Data

The surrounding rock of the underground tunnel is distributed with structural planes of different occurrences and sizes. The structural planes determine the deformation characteristics and stress-strain mode of the rock mass to a certain extent，which weaken the stability of the rock mass locally，which has a significant impact on the safety of the tunnel engineering. It is very necessary to carry out the engineering geological survey of the underground tunnel and the quantitative analysis of the rock mass structure. To get the structural plane information of the underground tunnel accurately and do stability analysis for the surrounding rock of the tunnel，a three-dimensional laser scanner was used to obtain the point cloud data of the surrounding rock structural plane in the 775 m level drift of the Dahongshan iron mine in Yunnan. A series of work such as correction，structure surface data extraction，point cloud splicing，filtering and thinning，etc.，carried out statistical analysis based on the processing results. According to this statistical result，the discrete element software 3DEC is used to establish the discrete structure network model and a coupling model of an underground tunnel，and numerical simulation of the instability probability of the tunnel under its own weight and blasting vibration is carried out. The results show that the 3D laser scanning technology can better obtain the rock mass discontinuities information of the drift，and the discrete block unit calculation software can further analyze the stability of the drift rock block. The self-stabilizing ability of the surrounding rock in the analyzed area is good，but the instability probability increases greatly under the influence of blasting vibration. The research result can provide theoretical guidance for the support design of the tunnel.