Projects
LONG-TERM SECURE SEALING OF THE ASSE SHAFTS NOS. 2 AND 4, GERMANY
The project involved the step-by-step shortening of the hoisting system, the removal of the shaft furniture and the long-term secure sealing of the Asse Nos. 2 and 4 shafts. The auxiliary hoisting system was dismantled and shaft pipelines installed. In addition, sealing elements were installed in the shafts and bulkheads were erected.
A cavern 10.000 m³ in size at the bottom of the Asse Shaft No. 4 was backfilled with a stable, settlement-free column of gravel. The gravel was tipped from surface in a 250 mm shaft pipeline installed in Shaft No. 2, down to the 925 m level and transported from there to the cavern with a conveyor belt. The shaft hoisting system was shortened several times and the shaft fittings were cleared section by section. In addition, the shaft was partially backfilled.
