. Bulletin . ed inthat part of the bed where the seam is closed, and the fracture thusformed may run in a diagonal direction, or be otherwise so irregularthat waste will result. Similarl3\ a very uneven fracture may be formed when an attemptis made to lift a wide block in cross-grained stone. It is well known to quarrymen that a widemass of split rock may beraised with little risk of acrooked break, but withcross-grained rock the frac-ture may run on the in-clined grain and give amost unsatisfactory frac-ture. Wedging to form verti-cal breaks may also resultin the formation of irregu-lar surfa
. Bulletin . ed inthat part of the bed where the seam is closed, and the fracture thusformed may run in a diagonal direction, or be otherwise so irregularthat waste will result. Similarl3\ a very uneven fracture may be formed when an attemptis made to lift a wide block in cross-grained stone. It is well known to quarrymen that a widemass of split rock may beraised with little risk of acrooked break, but withcross-grained rock the frac-ture may run on the in-clined grain and give amost unsatisfactory frac-ture. Wedging to form verti-cal breaks may also resultin the formation of irregu-lar surfaces. The irregular-ities may be due to spacingthe wedge holes too far apart, especially if the run is poor, or to anattempt to break the rock in a direction oblique to the run. Further-more, they may result from the wedge holes being too is in certain sandstones a strong tendency for the rock tobreak in a slanting direction from the bottoms of shallow wedgeholes, as is illustrated in fisnire Figure 15.^—Inclined break thatcertain sandstone blocks whereholes are employed. may occur inshallow wedge MISCELLANEOUS CAUSES OF WASTE. Waste may ensue from quarrying rock so late in the autumn thatit has not sufficient time to season before freezing. In deposits inwhich frost is liable to damage the ledge good rock may also bedestro3^ed if the exposed ledge is not protected during the wintermonths. In certain sandstone deposits which dip toward an excavation at asteep angle and have clay seams interbedded, an overloading with WASTE IN SANDSTONE QUARRYING. 85 debris may cause movement of a bed on the clay seams, resulting inthe formation of irregular destructive fractures. WASTE OF WASTE ELIMINATION. In view of the limited number of uses for which waste sandstonemay be emplo,yed, the elimination of waste is a matter of supremeimportance to the quarryman. To the expense of quarrying materialfor which little or no use may be found is to be added t
Size: 1869px × 1337px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectminesandmineralresou
