In the northeast edge of antaibao surface mine were jingyang coal mine shallow mined out areas exploited by the room and pillar mining method.
Roof and pillar mining.
Determination of the pillar and roof optimum parameters for new mining technology with continuous miner was the main aim of the present work.
Since the rock roof of shallow mined out areas was easily weathered the stratified rock roof would distort and decline and roof failure would occur under the gravity and the overlying strata load with the passage of time.
Pillar and roof span stability are two essential prerequisites for safe working conditions in room and pillar mines.
Room and pillar variant of breast stoping is a mining system in which the mined material is extracted across a horizontal plane creating horizontal arrays of rooms and pillars.
When the distance between connecting drifts is the same as that between the parallel drifts then a.
Room and pillar is an underground mining method that has applications to a wide variety of hard rock deposits worldwide.
In this system a series of parallel drifts are driven with connections made between these drifts at regular intervals.
The most common mining system is room and pillar.
Unstable pillars can result in rock sloughing from the pillar and can lead to the collapse of the roof if one or more pillars should fail.
It is commonly classified as an open stoping method meaning that development involves mining out underground cavities while leaving the surrounding un mined waste or ore as primary support.