Engineering Rock Mechanics
268 Stabilization principles (c) at the boundary of an excavation open to the atmosphere, any previous fluid pressure existing i ...
The stabilization strategy 269 associated with entire rock blocks moving into the excavation, or whether the rock mass is deform ...
270 Stabilization principles excavation, as determined by the engineering objective. t$ are introduced the rock mass, su excavat ...
Rock reinforcement 271 Figure 16.3 Illustrations of (a) rock reinforcement and (b) rock support. basic principle of rock support ...
272 Stabilization principles Sketch of radially reinforced annulus stabilizing forces within the rock mass e.g. a ring of pre-ca ...
Rock reinforcement 273 this type of analysis provides a rapid means of determining the value of reinforcing continuous rock-whic ...
274 Stabilization principles optimal orientation for the anchor as that which enables the anchor tension to be a minimum, then t ...
Rock support 275 displacements are proportional to the radius of the opening and inversely proportional to Young's modulus. More ...
276 Stabilization principles Curve 1 represents the ‘perfect’ excavation case, in which there is no disturbance of the remaining ...
Rock support 277 be exceeded. This strength may be reached before equilibrium with the ground response curve is attained. Such a ...
278 Stabilization principles between the two (i.e. the pressure remaining to be equilibriated) versus displacement. Equilibrium ...
Stabilization of ‘transitional’ rock masses 279 Zero displacement condition Zero strength - - . Boundary displacement Figure 16. ...
280 Stabilization principles 7 (a) Stresses on excavation boundary There are three basic concepts that permit consideration of t ...
Stabihzation of 'transitional' rock masses 28 1 instability 'f p' will ./, 2 &,change as $i changes /& Figure 16.12 The ...
282 Stabilization principles Regardless of the technique used for determining the tangential stress, the formula above shows tha ...
Further comments on rock stabilization methods 283 Figure 16.14 Underground excavation stabilized by (a) rock bolts and @) rock ...
284 Stabilization principles No support required (a) Single set of discontinuities in strong rock c .- .a > 0 d H fr on stand ...
Further comments on rock stabilization methods 285 before the wheel carries any load, with the effect that the weight of the rid ...
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Surface 77 excavation Many discontinuities, weak rock: effectively a continuum instability Few discontinuities, strong rock: a d ...
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