flac3d模拟煤炭采空区的算例，很实用！-flac3d simulated coal gob example, very practical!

FLAC3D 煤矿采空区命令流用，FLAC 3D 模拟煤矿垮落法和充填开采影响的命令流。-(Command Flow in Goaf of FLAC3D Coal Mine .With FLAC3D simulation of coal caving method and the impact of mining backfill command stream.)