Santarelli et al. (1986) distinguish between three general types of stress-induced borehole instabilities. Type (a) are “hole size reductions due to ductile yield of the rock”. This type (a) will be subject to a computational analysis in this paper. Type (b), “hole enlargements due to brittle rock fracture or rupture”, will be discussed in a subsequent analysis (Mühlhaus, Lempp in preparation), and the third is type (c) “unintentional hydraulic fracturing induced by excessive mud pressure”. Mechanical models concerning the behavior of brittle material, however, will be advanced in this paper on the basis of mechanical laboratory tests. These model findings will then be considered in the computational evaluation of borehole instabilities of type (b) and (c). Traditional computational analysis will be applied, at this point, to ductile rock mass only (type (a)).
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- Significance of Material Softening for the Analysis of Deep Borehole Stability
- Springer Berlin Heidelberg
Systemische Notwendigkeit zur Weiterentwicklung von Hybridnetzen