ABSTRACT
227This chapter describes understanding of in-situ stresses in rock mass and various methods for estimating the state of stress, focusing on the hydrofracturing techniques. With a brief description of theory and procedure of the hydrofracturing test, various methods for determining the ambiguous shut-in pressure in hydrofracturing pressure history curves are introduced by numerical analysis. The hydrojacking test is also introduced as an example of application of hydrofracturing techniques.
