2. Subsurface Stresses and Pore Pressure

Similarly to fluid pressure, rock stresses change with depth. Yet, changes in rock stresses depend not only on depth but also on the properties of the rock and tectonic stresses if any. This chapter presents a summary of the calculation of vertical stress (total and effective) and pore pressure with depth. The chapter also reviews the concept of horizontal stress from a phenomenological point of view. The calculation of horizontal stress requires a mechanical model that will be introduced in subsequent chapters.