Below is a complete narrative that you can paste directly into the presenter notes or hand‑out accompanying Slide 3 of a Rocscience‑focused presentation.
The content is organized as a speaker script, a slide‑view (what the audience sees), and a technical appendix for anyone who wants a deeper dive into the underlying mechanics and how Rocscience software implements the concept.
The term "Crack Link" refers to the coupling mechanism between the structural geometry and the hydraulic conditions. In a standard analysis, a crack may be modeled as a void. However, in a hydraulic analysis, the Crack Link dictates how water pressure is applied to the walls of the discontinuity.
The effective normal stress ($\sigma'_n$) on a failure plane is governed by: rocscience slide3 crack link
$$ \sigma'_n = \sigma_n - u $$
Where:
If a crack is "linked" to the water table or a hydraulic field, Slide3 calculates the pressure head at the centroid of the crack faces. This pressure acts as an external load, pushing the crack faces apart. This significantly reduces the frictional resistance along the crack, as described by the Mohr-Coulomb failure criterion:
$$ \tau = c' + \sigma'_n \tan(\phi') $$
By linking the crack to the hydraulic model, the shear strength ($\tau$) is reduced due to the decrease in effective stress, often leading to a lower Factor of Safety (FoS).
“Crack links transform a scattered fracture cloud into a deterministic failure pathway – Rocscience lets you generate, detect, and analyse them in minutes.” Below is a complete narrative that you can
In Slide3, a Crack is defined as a planar surface or a polygonal volume that bisects the mesh. Unlike a simple material boundary, a Crack introduces a discontinuity in the displacement field. The software treats the interface as a potential failure plane where slip can occur independently of the surrounding rock mass.