在对宝天线105隧道工程地质环境进行详细调研和对隧道裂纹长期监测的基础上,论证了105隧道围岩体是松动岩体,松动岩体长期蠕动是隧道裂纹变形的实质.而应力松弛、地表冲刷、崩坍、滑坡、地下水作用和隧道施工等是隧道裂纹变形的原因.“,”Based on the investigation of the engineering geological environment and the long term monitoring of tunnel cracks, the surrounding rock of tunnel 105 is proved to be a slack rock mass. A long term gradual creep of the slack rock is the essence of the crack deformation of the tunnel, which are resulted from stress relaxation, earth surface scouring, rock collapses, landslides, underground water process and tunnel construction, etc.