| 摘要 |
A mining support pillar adapted to provide support between the floor and the roof of a mine, includes particulate material within an envelope of synthetic plastics sheet material, and a plurality of layers of reinforcing material of ductile metal at different elevations in or between layers of the particulate material. The ductile metal has an elongation of at least one-sixth, and preferably more than one-fifth, say, one-quarter or more. The particulate material may be in the form of a plurality of building elements arranged in successive courses on top of one another. The layers of reinforcing material may be provided within at least some of the building elements, or between at least some of the courses. The building elements, singly or in groups, are sheathed or wrapped in synthetic plastics sheet material.
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