Engineering Rock Mechanics
248 Excavation principles (e) detonators: electric detonators consist of an aluminium tube with an electrically activated fusehe ...
Specialized blasting techniques 249 surface. Both of these techniques tend to be used only where it is essential to produce a hi ...
250 Excavation principles the bulk blasting will be optimized through the use of blasting rounds; and the natural stability of t ...
Specialized blasting techniques 25 1 of the adjacent blastholes. Second, there are dynamic and quasi-static effects of the gas p ...
252 Excavation principles (e) Ensure good site management-accurate surveying and setting out of blastholes followed by accurate ...
Specialized blasting techniques 253 c Figure 15.14 Illustration of pre-splitting effect in model tests in Perspex with introduce ...
254 Excavation principles Figure 15.16 A static pre-split formed using expanding grout (Isle of Lewis, Scotland). An extreme exa ...
Mechanical excavation 255 Tangential postsplit) Figure 15.17 Smooth-wall (or 'post-split') blasting. principal stress will be co ...
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Mechanical excavation 257 (a) cutting rate, C: the rate at which the tunnel is constructed when the (b) advance rate, A: the rat ...
258 Excavation principles Table 15.1 Rock cutting devices and associated parameters Cutter type Rock strength Applied forces dra ...
Mechanical excavation 259 T Drag pick Button cutter Disc cutter Jet-assisted cutter Figure 15.19 The action of four primary cutt ...
260 Excavation principles energy cutter spacings No interaction at large spacings I at optimal spacing Distance between cutters, ...
Vibrations due to excavation 261 Figure 15.22 Large tracked-type tractor fitted with ripping attachment. is chosen to match the ...
262 Excavation principles U W v) W 0 a ...
Vibrations due to excavation 263 parameters. Independent parameters in some way control the blast; the dependent parameters rela ...
264 Excavation principles 15.5.2 Evuluution of structurul response The next step in establishing the effects of vibrations due t ...
Vibrations due to excavation 265 0.3 Surface coal and mine blasting I f= principal frequency * 0 Quarry blasting III-III 7 C ...
266 Excavation principles (a) establish the relation between the ground motions due to the blast and scaled distances (cf. Fig. ...
Stabilization 76 principles In the previous chapter on excavation principles, we discussed the idea of taking the rock into the ...
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