What is Geostatic pressure?
1. n. [Geology] The pressure of the weight of overburden, or overlying rock, on a formation; also called lithostatic pressure.
What is Lithostatic stress?
lithostatic stress: Rock beneath the Earth’s surface experiences equal pressure exerted on it from all directions because of the weight of the overlying rock. It is like the hydrostatic stress (water pressure) that a person feels pressing all around their body when diving down deep in water.
What causes lithostatic pressure?
Lithostatic pressure is a consequence of overburden stress, whereas hydrostatic pressure is the component of reservoir pressure caused by pore fluid. Lithostatic pressure is a function of rock density and is generally between 22.7 and 25.0 KPa/m (1.0 and 1.1 psi/ft) in coal-bearing successions (McKee et al., 1988).
What is vertical stress?
The principle vertical stress also known as overburden stress is a result of the weight of rock overlying a certain point of measurement. Fractures always form perpendicular to the minimum in-situ stress and in almost all cases, the vertical stress equals the weight of the overburden per unit area.
What is Geostatic?
Definition of geostatic : relating to pressure exerted by earth or a similar substance.
What causes compressional stress?
The stress that squeezes something. It is the stress component perpendicular to a given surface, such as a fault plane, that results from forces applied perpendicular to the surface or from remote forces transmitted through the surrounding rock.
What are the 3 types of stress in rock?
There are three types of stress: compression, tension, and shear. Stress can cause strain, if it is sufficient to overcome the strength of the object that is under stress. Strain is a change in shape or size resulting from applied forces (deformation). Rocks only strain when placed under stress.
How is Lithostatic stress calculated?
The title pretty much says it. I have the formula: P=ρgh where ρ is the density, h is how deep the pressure is in the Earth and g is the gravitational acceleration(?).
What is Boussinesq theory?
BOUSSINESQ THEORY Boussinesq (1885) developed a theory to calculate stresses and deformation due to point load applied at the surface of semi infinite soil mass. Assumptions: 1. Soil mass is elastic continuum having a constant value of modulus of elasticity (E) i.e it obeys Hook’s law.
What is Westergaard theory?
Westergaard’s Theory Assumptions: Elastic medium of semi-infinite extent but containing numerous, closely spaced horizontal sheets of a negligible thickness of an infinite rigid material which permits only downward deformation as a whole without allowing it to undergo any lateral strain.