Estimation of the Mean Trace Length of Discontinuities in an Underground Drift Using Laser Scanning Point Cloud Data

In the drifts of underground metal mines, extraction rock mass discontinuity characteristics from point cloud models generated with laser scanning has become main approach. However, exposure discontinuities is restricted in drifts, and size cannot be measured directly. Therefore, it necessary to use a reasonable sampling tool estimate mean trace length that are mapped model. this paper, method using three-dimensional (3D) model drift (3DM) proposed. Through data obtained 3D scanning, information on surrounding was extracted; then, estimated 3DEC set windows roof sidewall 3DM. By analyzing difference between circular window rectangular simulated cases, estimation results showed measuring 3DM closer true length. Finally, used practical engineering case Jianshan Iron Mine, Panzhihua, Sichuan, China.