Mine heading machine balancing - using concrete mix bags placed between broken rock and retracted machine shoes for wetting using water injection lance

摘要

Force transmission and balance as between a mine heading machine and the surrounding rock, are obtained by flexible containers filled with a dry concrete mix in the space between the broken rock (4) and retracted machine shoes. The containers fill out the space are wetted either singly or in layers as they are inserted. The containers are then compressed by the extended clamping shoes (2), the full load being applied after a waiting period between 20 and 30 minutes. The mixture should be premix concrete with end strength of 520 kP/cm3. An accelerating agent is mixed with the wetting water continuously, the water being injected into the containers preferably using a lance.