9.3: The Tear Type and the Chip Type

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Similar to the derivation of equation (8-127) for the occurrence of tensile failure under atmospheric conditions, equation (9-19) can be derived for the occurrence of tensile failure under hyperbaric conditions. Under hyperbaric conditions equation (9-19) will almost always be true, because of the terms with r1 and r2 which may become very big (positive). So tensile failure will not be considered for hyperbaric conditions.

Screen Shot 2020-08-23 at 11.18.44 PM.png — Figure 9-13: The Tear Type cutting mechanism in rock under hyperbaric conditions.

Screen Shot 2020-08-23 at 11.19.39 PM.png — Figure 9-14: The Chip Type cutting mechanism in rock under hyperbaric conditions.

\[\ \mathrm{c}\cdot \left( \begin{array}{left}\mathrm{\frac{r\cdot \frac{\sin(\beta)\cdot\cos(\delta)}{\sin(\alpha)}+r_2\cdot\frac{\sin(\beta)\cdot sin(\delta)}{sin(\alpha)}}{sin(\alpha+\beta+\delta+\varphi)}}\\ \mathrm{+\frac{+r_1\cdot sin(\alpha+\beta+\delta)}{sin(\alpha+\beta+\delta+\varphi)} }\\ +\mathrm{\frac{-cos(\alpha+\beta+\delta)-sin(\alpha+\beta+\delta+\varphi)}{sin(\alpha+\beta+\delta+\varphi)}}\end{array} \right)\cdot\mathrm{\left(\frac{1-sin(\varphi)}{cos(\varphi)} \right)>\sigma_T}\tag{9-19} \]