Heterogeneous Rock Mass Stability Analysis in K-MINE

In this video, we'll show you how to set up and run a stability analysis for a heterogeneous rock mass.

First, we add any additional parameters we need. In this example, we'll account for groundwater and an additional surface surcharge on the rock mass.

To add groundwater, simply select the corresponding command in the Geomechanics menu and use a polyline to define its approximate position relative to the rock mass. All geometry is created directly on the cross-section and snapped to the objects on screen, so the process requires minimal effort.

Next, we add the surface surcharge by entering its exact value in kilopascals.

From here, we move straight to the stability calculation. The software needs to know which rock types we're working with.

We create a list of rocks and enter their physical and mechanical properties in the available fields. Then, using the layer editor, we assign the objects and specify where each rock type is located.

If necessary, a layer can also be marked as weak, which will directly affect the calculation results.

Next, we initialize the groundwater table. The easiest option is the “By selected objects” method. We use the same approach for the additional load on the rock mass.

Pay particular attention to the parameters available on the Settings tab. There is a wide range of calculation options here, allowing you to obtain results using the method and conditions that are relevant to your analysis.

Next, we create a rectangle that will also be included in the calculation and initialize it as a Search Grid Boundary object.

Once all the parameters are defined, all that's left is to run the calculation. And now for the most interesting part — the results.

The software evaluates thousands of possible slip arcs. For every generated slip surface, it calculates an individual Factor of Safety using the Simplified Bishop Method.

The results are sorted from the least stable case to the more stable ones.

Simply switch the calculation method, and you immediately get a different set of factors — for example, using the Spencer method, Morgenstern-Price, or the algebraic sum-of-forces method.

Along with the factors, the software visualizes the potential failure wedge and its corresponding slip surface. For greater clarity, object visibility can be controlled through the layer editor.

Next, let's look at stability analysis with seismic effects taken into account.

Seismicity can be defined either by acceleration coefficients or by the seismic intensity of the site.

We enter the parameters required for the specific conditions — for example, a weak layer if one is present — define the slope profile and the other necessary inputs, and run the calculation.

The result is similar to the previous example, although there are naturally some differences.

Here too, you can switch between calculation methods and review the corresponding factors. The Factors of Safety, potential failure wedges, and slip surfaces are visualized for the same methods: Spencer, Morgenstern-Price, or the algebraic sum-of-forces method.

Now let's look at a calculation where you define the potential failure wedge and the rock slip surface yourself.

A user-defined surface is useful when:

— its position has been identified through field observations, for example, an existing landslide;

— you need to verify a specific failure scenario;

— you want to compare different calculation methods for exactly the same surface;

— you need to assess stability along a geologically controlled plane of weakness, such as a layer contact, tectonic fault, joint, or similar feature.

For this, all we need is a simple line representing the theoretical position of the slip surface. We assign it in the corresponding settings option.

Then we add surface water, additional loads on the rock mass, the surface profile, and any other parameters needed to bring the model as close as possible to the actual conditions being analyzed.

The defined surface is evaluated using all the methods we've already discussed, but each method produces only one factor.

That's because the result is governed by that specific slip surface and the defined conditions. There is no variation in the surface itself unless you change the other input parameters.

Anywhere in K-MINE where you see a table, you can create a chart from it.

The chart is highly configurable. You can adjust its type, line weight, outlines, data display, additional axes, axis labels, and even the background.

Once configured, the template can be saved and reused whenever you need it.

The line between economy and stability is a fine one — we wish you the right balance.

And this is just one of the approaches available for stability analysis. Experiment, explore the options, and may your pits always be safe. Good luck!