The most common mining system is room and pillar.
Roof and pillar mining.
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.
Determination of the pillar and roof optimum parameters for new mining technology with continuous miner was the main aim of the present work.
In the northeast edge of antaibao surface mine were jingyang coal mine shallow mined out areas exploited by the room and pillar mining method.
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.
To do this rooms of ore are dug out while pillars of untouched material are left to support the roof overburden calculating the size shape and position of pillars is a complicated procedure and is an area of.
In this system a series of parallel drifts are driven with connections made between these drifts at regular intervals.
Other articles where room and pillar mining is discussed.
When the distance between connecting drifts is the same as that between the parallel drifts then a.
The conventional calculation formulas and conditional thickness meth ods were used to determine the room and pillar mining system parameters which guarantee a long term stability.