Underground protection underneath a dump

An apparatus for isolating a dump sitting on the ground, the apparatus comprising:

• means for driving a tunnel longitudinally through the ground underneath the dump;
• means for cutting from at least one side of the tunnel with a longwall-mining machine a longitudinally and transversely extending slit having a lower end opening into the tunnel and an upper end opening at ground level;
• means for providing a liquid barrier in the slit underneath the dump;
• means for conveying the material dug by the machine to form the slit downward along the slit into the tunnel and thence along and out of the tunnel;
• and
• means for bringing stowing material into the slit from the upper end thereof and backfilling behind the machine with the stowing material.

A method of isolating a dump sitting on the ground, the method comprising the steps of:

• driving a tunnel longitudinally through the ground underneath the dump;
• cutting from at least one side of the tunnel with a longwall-mining machine a longitudinally and transversely extending slit having a lower end opening into the tunnel and an upper end opening at ground level;
• forming longitudinal grooves in the roof of the slit while cutting same;
• providing a liquid barrier in the slit underneath the dump by installing perforated drainage pipes in the grooves;
• conveying the material dug by the machine to form the slit downward along the slit into the tunnel and thence along and out of the tunnel;
• and
• bringing stowing material into the slit from the upper end thereof and backfilling behind the machine with the stowing material.