| 摘要 |
The tracing and finally the clearance takes place in a number of interruptable phases. The total number of phases for unexploded explosives lying at a greater depth is five. The first phase involves what may be termed a quick-scan, marking out the area, accessibility, collection of data, reference clarification, air photographs, map material and further historical material, proposed investigation method and advice concerning the introduction of the tracing investigation to the instructing entity. Other phases involve the complete investigation of extent and depth of the problem, formulation of the project, technical and financial aspects, work preparation, compilation of a definitive plan for ground investigation together with cost indications. Ground investigation takes place in accordance with a detection method, based on the disturbance of the magnetic field on site. |
