PURPOSE: To ensure safety by dividing the length by a specified section using a concrete bulwark and at the same time, filling an abandoned mine which is water-proofed by injecting a ground reinforcing agent, with industrial waste.

CONSTITUTION: The shaft and tunnel 4 of an abandoned mine are filled with industrial waste 2 and the drift is divided by providing a bulwark 3 by a specified section between the inner walls 5, 5 of the drift 4. In this case, the bulwark 3, of concrete, is self-sustaining with a structure and of strength firm enough to prevent any adverse effects from being inflicted to an adjacent section, if a collapse happens to occur in some section. That is, the bulwark 3 is self- sustaining with a foundation I applied to the ground. When filling the drift with industrial waste, it is pressed using a bulldozer. If 70 to 80% of the entire length of one section is filled with the industrial waste, the bulwark 3 with an opening 8 on the top is installed. After this process, the industrial waste is packed into a shallow space in the section through the opening 8. If the filling is completed, the opening 8 is closed tightly.