3D assessment of rockfall hazard and risk mitigation

Protection dimensioning

To determine the dimensioning of protection measures (preliminary, operational studies, etc.), the following questions need to be answered

What type of protection?

How many of them?

Where could they be best located?

What should their length be?

What should their height, inclination and capacity be?

What is the confidence level in their design?

To this end, a trajectometric study can help to identify areas at risk from rockfall and provide the information needed to define the mitigation works that may be required in your study areas. Thanks to its many functions, RocPro3D can help you in your daily work, at all stages of protection design.

Identify the optimal location

By viewing the height and energy maps, you can quickly and easily identify preferred zones where protection can be installed and start dimensioning the protection.

Protections can be moved interactively on the maps and envelopes, combining an overall analysis of the zone with a detailed analysis at the protection!

Identification of the optimal location for the protection.

Protection definition

One-click positioning of protections to the topography

In practice, all you need to do is define two points in the 2D view using the mouse. This will create a straight line of protection in the 2D plane view. You can then select the “horizontal” baseline projection, and the protection will fit accurately the topography, which is what you want in most cases.

It is also possible to import protections from RPRO or Shapefile file, which includes both their geometry and properties.

Once you have created the geometry and properties of the protections, you can export them as point files, e.g. for later use in third party software.

Many possibilites for a quick and easy way to position protection accurately!

Types of protection: fictitious, net or embankment

You can define each protection either as:

  • A fictitious protection, used as a data collector, defined by a zero capacity and a fictitious height. This type of protection can be created before or after the calculation and can be moved interactively. This is particularly useful when analysing the results before positioning a real protection such as a berm or net.
  • A net, defined by a capacity and a height. The capacity can be entered manually or selected from one of the ETAG 027 energy classes (MEL or SEL).
  • An embankment (berm), defined by an infinite capacity and a height.

The use of fictitious protection saves time in the pre-sizing (or pre-analysis) phase of a real protection.

Inclined protection

For each type of protection, you can specify an inclination: vertical, perpendicular to the slope or specify the angle of inclination (between 0 and 90°).

You can use inclined protections to make your project more realistic and give you more confidence in your design.

Protection length measurement

The length of each protection is also given as an indication, which is useful for an initial quantification of the corresponding linear protection.

Useful for an initial cost estimate!

Dimensioning protection

Visualize the protection impact

The altimetric profile of the selected protection allows you to visualise the position, energy, height and travel time of the blocks that cross the protection plane: blocks that have flown over, passed through or been stopped by the protection are easily visualised.

This gives you a first visual indication of the influence of the protection on the block trajectories!

Select statistically relevant design parameters

In the graph view, the histogram shows the distribution of energy (or height, velocity, travel time, mass and volume) of the block population intersecting the protection plane, with its empirical cumulative distribution curve (in violet), and the corresponding theoretical cumulative distribution curve assuming a normal distribution (in grey).

One click displays the design statistical parameter shown in red on the graph, and you can make a choice for your dimensioning. 

Confirm the protection design

The dimensioning of a protection is generally based on the choice of a given statistical parameter (confidence limit or quantile) for each analysed result (energy, height…). The value of this statistical indicator varies according to the number of blocks that have reached the protection. The question is then: 

Did I throw enough blocks in my simulation? 

You can check the reliability of this indicator by verifying its convergence as a function of the number of blocks that reached the protection. This is an important point in confirming the protection design.

Check the convergence of the value of the statistical parameter on which the protection dimensioning is based.

All these tools make it possible to define an efficient protection design.