Persistence (discontinuity)
Encyclopedia
Persistence determines the possibilities of relative movement along a discontinuity
in a soil or rock mass in geotechnical engineering
. Discontinuities are usually differentiated in persistent, non-persistent, and abutting discontinuities (figure) .
plane exceeds the shear strength of the discontinuity plane.
is possible, the discontinuity has to extend and break through intact material. As intact material has virtually always far higher shear strength than the discontinuity, a non-persistent discontinuity will have larger shear strength than a persistent discontinuity.
. Abutting discontinuities might continue at the other side of the intersecting discontinuity, however, with a displacement to give so-called ‘stepped planes’. Shear displacement along the discontinuity can take place if the shear strength along the discontinuity plane is exceeded, and the blocks of material against which the discontinuity abuts can move or break.
might be persistent in dip direction but be not persistent perpendicular to the dip direction or vice versa.
Discontinuity (geotechnical engineering)
A discontinuity in geotechnical engineering is a plane or surface that marks a change in physical or chemical characteristics in a soil or rock mass. A discontinuity can be, for example, a bedding, schistosity, foliation, joint, cleavage, fracture, fissure, crack, or fault plane...
in a soil or rock mass in geotechnical engineering
Geotechnical engineering
Geotechnical engineering is the branch of civil engineering concerned with the engineering behavior of earth materials. Geotechnical engineering is important in civil engineering, but is also used by military, mining, petroleum, or any other engineering concerned with construction on or in the ground...
. Discontinuities are usually differentiated in persistent, non-persistent, and abutting discontinuities (figure) .
Persistent discontinuity
A persistent discontinuity is a continuous plane in a soil or rock mass. Shear displacement takes place if the shear stress along the discontinuityDiscontinuity (geotechnical engineering)
A discontinuity in geotechnical engineering is a plane or surface that marks a change in physical or chemical characteristics in a soil or rock mass. A discontinuity can be, for example, a bedding, schistosity, foliation, joint, cleavage, fracture, fissure, crack, or fault plane...
plane exceeds the shear strength of the discontinuity plane.
Non-persistent discontinuity
A non-persistent discontinuity ends in intact soil or rock. Before movement of the material on both sides of a non-persistent discontinuityDiscontinuity (geotechnical engineering)
A discontinuity in geotechnical engineering is a plane or surface that marks a change in physical or chemical characteristics in a soil or rock mass. A discontinuity can be, for example, a bedding, schistosity, foliation, joint, cleavage, fracture, fissure, crack, or fault plane...
is possible, the discontinuity has to extend and break through intact material. As intact material has virtually always far higher shear strength than the discontinuity, a non-persistent discontinuity will have larger shear strength than a persistent discontinuity.
Abutting discontinuity
An abutting discontinuity abuts against another discontinuityDiscontinuity (geotechnical engineering)
A discontinuity in geotechnical engineering is a plane or surface that marks a change in physical or chemical characteristics in a soil or rock mass. A discontinuity can be, for example, a bedding, schistosity, foliation, joint, cleavage, fracture, fissure, crack, or fault plane...
. Abutting discontinuities might continue at the other side of the intersecting discontinuity, however, with a displacement to give so-called ‘stepped planes’. Shear displacement along the discontinuity can take place if the shear strength along the discontinuity plane is exceeded, and the blocks of material against which the discontinuity abuts can move or break.
Anistropic persistence
A discontinuityDiscontinuity (geotechnical engineering)
A discontinuity in geotechnical engineering is a plane or surface that marks a change in physical or chemical characteristics in a soil or rock mass. A discontinuity can be, for example, a bedding, schistosity, foliation, joint, cleavage, fracture, fissure, crack, or fault plane...
might be persistent in dip direction but be not persistent perpendicular to the dip direction or vice versa.
See also
- Discontinuity (Geotechnical engineering)Discontinuity (geotechnical engineering)A discontinuity in geotechnical engineering is a plane or surface that marks a change in physical or chemical characteristics in a soil or rock mass. A discontinuity can be, for example, a bedding, schistosity, foliation, joint, cleavage, fracture, fissure, crack, or fault plane...
- Rock mechanicsRock mechanicsRock mechanics is the theoretical and applied science of the mechanical behaviour of rock and rock masses;also compared to the geology, it is that branch of mechanics concerned with the response of rock and rock masses to the force fields of their physical environment.Rock mechanics itself forms...
- Shear strength (Discontinuity)Shear strength (discontinuity)The shear strength of a discontinuity in a soil or rock mass may have a strong impact on the mechanical behavior of a soil or rock mass. The shear strength of a discontinuity is often considerably lower than the shear strength of the blocks of intact material in between the discontinuities, and...