4 Rock discontinuities 4.1 INTRODUCTION “Discontinuity” is a general term denoting any separation in a rock mass having zero or low tensile strength. It is the collective term for most types of joints, weak bedding planes, weak schistocity planes, weakness zones, and faults (ISRM, 1978c).
How many types are there of discontinuous rocks?
Discontinuities can be separated into five groups: fractures, shears, faults, shear/fault zones and shear/fault disturbed zones based on the mode of discontinuity movement and the scale of the discontinuities.
What are the different types of discontinuities?
There are two types of discontinuities: removable and non-removable. Then there are two types of non-removable discontinuities: jump or infinite discontinuities. Removable discontinuities are also known as holes. They occur when factors can be algebraically removed or canceled from rational functions.
What is fracture or discontinuity in a volume of rocks?
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Faults may also displace slowly, by aseismic creep. A fault plane is the plane that represents the fracture surface of a fault.
What do you mean by discontinuities?
Definition of discontinuity 1 : lack of continuity or cohesion. 2 : gap sense 5. 3a : the property of being not mathematically continuous a point of discontinuity. b : an instance of being not mathematically continuous especially : a value of an independent variable at which a function is not continuous.
How do you describe discontinuity?
Discontinuities can be classified as jump, infinite, removable, endpoint, or mixed. Removable discontinuities are characterized by the fact that the limit exists. Removable discontinuities can be “fixed” by re-defining the function. Jump Discontinuities: both one-sided limits exist, but have different values.
How discontinuities are formed geology?
Structural discontinuities are defined by a pair of surfaces, or fracture walls, that have been displaced (by opening or by shearing) from their original positions. For example, a crack or joint is open between its two walls (Fig.
What is a discontinuity in a function?
Discontinuous functions are functions that are not a continuous curve – there is a hole or jump in the graph. In a removable discontinuity, the point can be redefined to make the function continuous by matching the value at that point with the rest of the function.
What are the 3 types of discontinuities?
There are three types of discontinuities: Removable, Jump and Infinite.
What fault is caused by compression?
reverse fault
Compressional stress, meaning rocks pushing into each other, creates a reverse fault. In this type of fault, the hanging wall and footwall are pushed together, and the hanging wall moves upward along the fault relative to the footwall. This is literally the ‘reverse’ of a normal fault.
What is fracture discontinuity?
Fracture-discontinuities are classified and described in several ways using a variety of nomenclature, such as: joints, fracture, fault, shear, gash, fissure, vein. Generally, the term fracture is used synonymously with joint, implying a planar crack or break in the rock without any displacement.
How do you find the discontinuity of a function?
Start by factoring the numerator and denominator of the function. A point of discontinuity occurs when a number is both a zero of the numerator and denominator. Since is a zero for both the numerator and denominator, there is a point of discontinuity there. To find the value, plug in into the final simplified equation.
What is discontinuity in geology?
•Discontinuity- General term for any mechanical discontinuity in a rock mass. Discontinuities include all types of mechanical break or plane of weakness in rock mass such as joints, bedding plane, fractures and shear zones that weakened the strength of rock masses.
How does the roughness of rock discontinuities affect their mechanical properties?
The surface roughness of rock discontinuities plays an important role in the mechanical properties of rocks, including the shear strength and deformation [ 1 – 4 ], and can also directly affect the seepage behaviors of discontinuities [ 5, 6 ].
What are parallel discontinuities in rock mass?
A rock mass typically includes many discontinuities, come of which are parallel. This is the case on this figure with the horizontal discontinuities and the vertical discontinuities. The distance between discontinuties taken perpendicular from the discontinuity plane is called spacing.
What is discontinuity spacing?
Discontinuity spacing is one of the important parameters in describing the quality of a complete rock mass. Discontinuity surveys are carried out in the field by examining recovered drill-core to estimate possible distributions for discontinuity geometry parameters of rock masses.
