Joint Network Overview

The Joint Network option in RS2 allows you to generate 2-dimensional networks of joint boundaries, to simulate patterns of natural or induced jointing in rock masses.

Joint networks can be generated according to a variety of statistical or deterministic models. Available options include:

• Parallel Deterministic (i.e. a network of parallel joints at a given spacing and orientation)
• Parallel Statistical (i.e. a network of parallel joints with statistical variation of spacing)
• Cross Jointed
• Baecher
• Veneziano
• Voronoi

Joint networks can be added and edited as described below.

ADD JOINT NETWORK

A joint network is created with the Add Joint Network option. This allows you to generate a joint network in any selected region(s) of the model, using any of the above joint network models. Multiple joint networks can be defined, and different networks can be applied to different regions if desired.

EDIT JOINT NETWORK

After a joint network has been added to the model it can be edited if necessary using a variety of editing options. See the Edit Joint Network topic for information.

JOINT NETWORK CONVERGENCE

Most of models involving complicated joint networks needs to be carefully investigated and requires adjusted convergence criteria (number of iterations and tolerance) so that the results are realistic especially with Shear Strength Reduction (SSR) analysis. In some cases, an excessive number of iterations were employed which resulted in a very long computation time.

A new algorithm has been introduced into the RS2 to improve the convergence of joint and joint network models. The program will automatically calculate the stiffness of a joint as soon as a joint exceeds the tensile or/and shear strength. Using a new algorithm together with the accelerated stiffness, it results in a robust and fast calculation scheme for joint network model. The convergence parameters under Advanced SSR Settings are now able to match the convergence parameters under Stress Analysis Settings with 0.001 tolerance and 500 maximum numbers of iteration. Under SSR Settings, the new convergence type “Absolute Force & Energy” is added, and with this new convergence type, the option of “Accelerate initial stiffness” under Stress Analysis needs to be checked and defined with a min Alpha of 0.2 and a Max Alpha of 5. Please note that all of the settings are the default settings as shown when you open RS2 program.