.... A HBM mining operation will be efficient if sub- sidence of the safeguard roof pillar bridging over the excavations does not surpass the limiting size for which the induced stresses exceed the rock mass strength of the roof pillar. Thanks to this method, the final product is of high quality...

... ABSTRACT ABSTRACT: Cemented backfill sill mats are an artificial pillar used to improve recovery by replacing an ore pillar by an artificial equivalent. In the design of a sill mat pillar, one should account for the driving forces in terms of the self weight of the sill mat plus the load...

... of these mines, typically less than 45m (150 feet) below surface, dates back to the early operating years of the mines. As a result, the upper-level stopes and their asso- ciated crown pillars were largely designed in accor- dance with the engineering standards and mining practices of the day. Mining operations...

... and with slightly smaller rib pillar size between the rooms. Several hypothetical case studies were also conducted. 2 THE TEST SITES Figure 2 shows the two test site locations. The test site in Panel 409 was mined in virgin ground. The first four rooms were mined 85 wide, it then follo- wed by mining 65 room until...

...1 INTRODUCTION Underground limestone mines in the U.S. make use of the room and pillar method of mining. Bench mining of the floor between the pillars is sometimes carried out to improve utilization of the reserves. Figure 1 shows an area where bench mining of the floor is underway. The benched...

...) the final stability of each cavity, as well as the stability of the rock salt “pillars” that remain between the cavities, is all the more necessary as the over-lying ground has to be maintained for agricultural use and buildings. metals & mining displacement salt mining Upstream Oil & Gas...

... ABSTRACT ABSTRACT: Doe Run’s Southeast Missouri Mining and Milling Division (SEMO) currently operates six underground room and pillar mines which produce approximately 5.1 million tonnes per year of lead, zinc and copper ore. Pillar extraction represents approximately 34% of this tonnage...

.... This will result in the formation of approximately 4500 rock mass pil- lars surrounding the emplacement boreholes. The stability of pillars in the mining industry is traditionally carried out using empirical methods. It is unknown if these methods are suitable for the de- sign of a borehole emplacement pillar...

... of a thick seam mechanised longwall caving method in India. Figure 1. Extraction of full thickness of a thick coal seam in single lift (section). On the other hand, large numbers of coal seams in the country have been extensively developed with pillars to meet the country s increasing demand for coal. It has...

... of orebodies under shear loading. The primary objective of this study was to provide guidelines for the safe and economic extraction of remnant sill and boxhole pillars in the F-Zone. The guidelines were to include identification of safe and economic distances of drifts (drift layout) for remote access...