The difference of mechanical response between geostress and mining-induced stress has been obtained, which can be a theoretical support for safe mining such as reasonable gas drainage, prevention of coal gas outburst and gas over-limit.
A list of important ventilation parameters including the air quantity supplied to the mine working face, the negative ventilation pressure in the roof roadway for gas drainage and reasonable distributed airflow quantity in tailgate roadways, are investigated.
Combining a reasonable and efficient gas-drainage method and system can enable efficient gas drainage to be simultaneously realized.
To determine reasonable distance of gas pre-drainage drillings in coal seams, a solid gas coupling model that takes gas adsorption effect into account was constructed.
The results show that a constant vacuum pressure boundary condition can be enough to describe a perforated pipe surrounded by drainage gravel with a reasonable value of well radius, such as half the radius of gravel fill.
Any pot or recycled container will do for your sowing as long as it has drainage holes (imperative) and a reasonable depth (at least 5cm).
In general, the techniques used for mapping tile lines gave reasonable results and are useful to detect drainage extent from aerial image in large areas.
In order to avoid the breakout of the coal seam around hydraulic fracture during drainage process, the model of the reasonable bottom hole pressure is also built.
Adult venous drainage is far more interconnected and could conceivably be a reasonable distribution for the observed pattern of facial PWS.
