Chapter Thirteen

Rock Mechanical Properties and In Situ Stresses


This chapter opens with basic definitions of Young’s modulus, Poisson’s ratio, fracture toughness, and brittleness and fracability ratios. Next, vertical and minimum and maximum horizontal stress, and Biot’s coefficient are explained. This chapter continues with various states of stress and ends with detailed discussions on transverse and longitudinal fractures. Different examples in each subsection on calculating the rock mechanical properties and in situ stresses are provided.


Young’s modulus; Poisson’s ratio; fracture toughness; brittleness; fracability ratios; in situ stresses; fracture reorientation


In general, rock mechanics is a branch of geomechanics ...

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