Advanced Stability Analysis Methods in K-MINE

In this video, we'll show you how to set up and run stability analyses under different conditions and using different methods.

Let's start by coding the block model with stability ratings, an important step in assessing the rock mass as a whole.

Here, all fields in the Complete Rated Rock Class task need to be filled in correctly. When it comes to stability analysis, detailed input data matters. The in-situ conditions of every rock type involved in the assessment should be specified as accurately as possible. Insufficient input parameters can lead to an unreliable assessment.

Once the calculation is complete, the resulting stability values are written to a block model field.

One way to visualize them is with a gradient fill, which provides a clear overview of the entire block model. The color scheme can be configured according to the results you want to highlight.

The updated block model can then be reviewed both in cross-section and as a whole.

The Set Properties command also allows you to display only blocks whose values fall within a selected range. By isolating a specific group of blocks, you can work with them separately, for example, by creating a wireframe and using it in further rock mass design.

Next, let's analyze the stability of part of the pit wall using the block model while accounting for groundwater at different levels.

We will assess the wall across two cross-sections using the Force Polygon method in an anisotropic medium.

For the calculation, we define the block model, the physical and mechanical properties of the rocks, groundwater conditions, the regional seismic activity coefficient, and other required parameters.

After running the calculation, the resulting Factors of Safety are displayed in a table.

An additional construction can also be generated to visualize the Force Polygon for the blocks forming the potential failure wedge.

The diagram shows the driving and resisting force vectors, block weight, reaction on the slip plane, water pressure forces, and the graphical closure of the forces, representing the equilibrium condition.

This vector diagram is built along the slip line and allows the geotechnical engineer to see where the greatest destabilizing forces occur and how those forces are distributed from the upper crest to the bench toe.

For calculations like these, we recommend using the cross-section view, where each calculation element can be examined in detail.

Additional results include the resulting pit wall angle, the width of the potential failure wedge, and the visualized slip surface.

Together, these outputs provide the geotechnical engineer with a clear view of the calculated stability conditions.

For the next example, let's look at the classic Force Polygon method.

We begin by creating two conditional cross-section lines in the areas where stability needs to be assessed. After positioning them near the intersection of the pit crests, we run the Calculate Pit Stability command and select the Force Polygon method.

As usual, we then define the properties of the rocks forming the mass. The existing rock-type library can be reused and expanded whenever necessary.

Groundwater is included by specifying the corresponding layer, after which the calculation can be run.

The calculation provides detailed Factors of Safety for the full list of benches. Each result can be reviewed individually or analyzed as part of the combined result.

The calculation can also be visualized directly on the cross-section. Simply select which elements should be displayed and generate them with a single click.

For a clearer view, we position the section plane along the line used for the calculation.

The cross-section shows the distribution of forces acting on the rock mass, the resulting slope angle of the wall section, the potential failure wedge, the slip surface, and other information required to assess the condition of the rock mass.

The next method is intended for calculating the stable position of dump slopes when the dump is located on a weak foundation.

The workflow is similar to the previous examples. First, we define the physical and mechanical properties of the fill materials, followed by those of the foundation rocks.

We then specify the parameters that determine the number of calculations, including the number of wedges and additional cross-sections, and run the analysis.

The results include the potential failure wedge, the slip surface, and the distance that failure of the unstable part of the dump could reach.

In this example, the calculation indicates that the rock mass is in an unstable state.

The line between economy and stability is a fine one, and finding the right balance is essential.

These are just some of the methods available for stability analysis in K-MINE. Experiment with different conditions and calculation approaches, and may your pits stay safe.