Rock Slope Engineering: Civil and Mining (4th Edition)
Duncan C. Wyllie, Christopher W. Mah
Format: PDF / Kindle (mobi) / ePub
The stability of rock slopes is an important issue in both civil and mining engineering. On civil projects, rock cuts must be safe from rock falls and large-scale slope instability during both construction and operation. In open pit mining, where slope heights can be many hundreds of meters, the economics of the operation are closely related to the steepest stable slope angle that can be mined.
This extensively updated version of the classic text, Rock Slope Engineering by Hoek and Bray, deals comprehensively with the investigation, design and operation of rock slopes. Investigation methods include the collection and interpretation of geological and groundwater data, and determination of rock strength properties, including the Hoek Brown rock mass strength criterion. Slope design methods include the theoretical basis for the design of plane, wedge, circular and toppling failures, and design charts are provided to enable rapid checks of stability to be carried out. New material contained in this book includes the latest developments in earthquake engineering related to slope stability, probabilistic analysis, numerical analysis, blasting, slope movement monitoring and stabilization methods. The types of stabilization include rock anchors, shotcrete, drainage and scaling, as well as rock fall protecting methods involving barriers, ditches, nets and sheds.
Rock Slopes: Civil and Mining Engineering contains both worked examples illustrating data interpretation and design methods, and chapters on civil and mining case studies. The case studies demonstrate the application of design methods to the construction of stable slopes in a wide variety of geological conditions. The book provides over 300 carefully selected references for those who wish to study the subject in greater detail. It also includes an introduction by Dr. Evert Hoek.
stability of a slope can be expressed in one or more of the following terms: (a) Factor of safety, FS—Stability quantiﬁed by limit equilibrium of the slope, which is stable if FS > 1. (b) Strain—Failure deﬁned by onset of strains great enough to prevent safe operation of the slope, or that the rate of movement exceeds the rate of mining in an open pit. (c) Probability of failure—Stability quantiﬁed by probability distribution of difference between resisting and displacing forces, which are each
information that can be obtained by diamond drilling may be somewhat different from surface mapping information. While surface mapping is the primary means of obtaining information on geological structure, in drill 3.6.1 Diamond drilling equipment Figure 3.1 shows a typical diamond drill. The major components of the drill comprise a motor, usually gasoline or diesel powered, a head to generate torque and thrust to the drill rods, a mast to support the wire line equipment, and a string of drill
50 1 + 1 n 2 3 4 5 6 7 Shear displacement, 8 9 s i1 0.5 1 2 3 0.25 s 250 200 150 100 89 50 0.05 0.1 1 − n kn Normal displacement + n – s Figure 4.17 Results of direct shear test of ﬁlled discontinuity showing measurements of shear strength, roughness (i), and normal stiffness (kn ) (modiﬁed from Erban and Gill, 1988). 90 Rock strength properties and their measurement slightly lower, residual shear stress. The sample was initially undisplaced, so exhibited a difference
exposed to weathering processes such as wetting and drying, and freezing and thawing cycles. Rock types that are particularly susceptible to degradation are shale and mudstone, which usually have a high clay content. The degradation can take the form of swelling, and the time over which weakening and disintegration can occur after exposure may range from minutes to years. The effect of degradation on slope stability can range from surﬁcial sloughing and gradual retreat of the face to slope
water pressure by means of piezometers installed in boreholes. Because of the important inﬂuence of water pressure on slope stability, it is essential that the best possible estimates of the likely range of pressures should be available before a detailed stability analysis is attempted. There are a large number of factors that control ground water ﬂow in jointed rock masses, and it is only possible in this book to highlight the general principles that may apply. If detailed studies of ground