What makes geotechnical engineering so interesting and challenging?
- Everything is unique, the soil structure is nowhere exactly the same
- The behavior of soil is non-linear and heterogeneous: it is therefore labor-intensive to model properly
- Unpredictability: you never know exactly what is underground and what its properties are. You often only really find out how the soil behaves during the construction process.
Due to these circumstances, it is not for nothing that the greatest risks in construction projects often have to do with geotechnics. Nor do these seem ideal conditions for automated / parametric design. Everything is different so little rehearsal. Or maybe it is?
In this article I will explain why I believe that it is precisely because of these properties that a lot can be achieved with the help of digitization. In this article I will discuss:
- The problem: changes
- What is parametric design?
- How do you apply this in geotechnics?
- What is the impact of these types of tools?
- Is there still room for human interpretation?
- How do you ensure that you can use this on projects?
- What is your contribution?
The problem: changes
One of the major challenges during projects is that changes occur along the way. The bigger the project, the greater its impact. The change can be caused by external factors, for example from the customer or by additional soil investigation. But often changes also simply occur because a design process does not run linearly, but in parallel. All kinds of different disciplines gather more information, so that the intended solution no longer works, or that an opportunity is found for a better solution.
In order to mitigate this risk, the strategy is often chosen to record as much as possible as early as possible. We try very hard to ensure that no changes occur. “First time right” is a popular saying. But is this really possible? Isn’t progressive insight inherent in a complex design process? And don’t we miss a lot of opportunities for optimization if we record a lot too early in a process?
I believe that you should turn it around: make sure you organize your processes so that you can deal with changes correctly. Assume that the customer will come up with a change 20 times, the soil investigation will turn out differently or that ideas will gradually arise to arrive at a more optimal design. This is where parametric design comes into play.
What is parametric design?
With parametric design, one quickly thinks of the parametric creation of a geometric model. For example, you can define a beam based on three parameters: length, width and height. For more complex constructions you can do this with more parameters. Besides geometric parameters, there are a lot of other parameters involved in a design. Think of soil parameters, loads, requirements and preconditions.
By setting up a model parametrically, you ensure that when changing a parameter, the impact of this is immediately transparent. You achieve this by automating process steps.
How do you apply this in geotechnics?
Example: During a project, a geotechnical consultant made a large number of models to do settlement calculations for different cuts for a soil body. Gradually, additional soil research shows that the soil parameters are different than assumed. The geotechnical consultant now has to manually adjust all models and redetermine the required increase to meet the residual settlement requirement.
How can this be improved through parametric design? There is then one central place where the soil parameters are recorded. The geotechnical consultant now only has to adjust the parameter, after which the models can be updated with the push of a button. Subsequently, the required increment can be determined automatically, using an algorithm that iteratively makes several sums.
The principle is quite simple: centralize the input, link the various calculations and present the results clearly.
What is the impact of these types of tools?
With VIKTOR we have already developed many applications according to this principle, for example for dikes, pile foundations, soil bodies and sheet piling. These applications have now proven their value on all kinds of projects. Often links are made for this purpose with geotechnical software, such as the D-series or Plaxis.
The main results of the tools are:
- Time savings on “boring” work, more time to deploy expertise
- Flexibility with changes
- Risk reduction through more calculations, sensitivity analyzes and less chance of errors
- Optimal design, because more iterations or cuts can be calculated
Is there still room for human interpretation?
I often notice that geotechnical consultants (like all engineers, by the way, apparently this is in our blood) are skeptical about automation. This is a very healthy and understandable response. Geotechnics is a field in which human interpretation and experience is essential: you do not put this knowledge into a computer or an algorithm. For example, the automatic interpretation of CPTs to a soil structure is very difficult to get right in 100% of the cases. It will not be possible to automate a geotechnical design process from A to Z in the foreseeable future.
I often notice that an idea for automation is being thrown off this. Because a few steps in the process cannot be automated, nothing is automated. This is a shame: you don’t go all the way from Rotterdam to Arnhem on foot, because you have to change trains in Utrecht. Despite that walk you are still 15 times as fast in Arnhem, then those two parts by train are a bonus.
You can also look at a design process in this way. Where is the repetitive (“boring”) work, and where is human interpretation and expertise essential? The repetitive steps in the process often lend themselves very well to automation. A computer is very good at doing stupid work very quickly. Despite the fact that certain steps are still carried out by humans, you can speed up the process drastically.
When these types of tools are properly developed, it gives the consultant more insight, instead of becoming a black box. Consider, for example, the ability to perform sensitivity analyzes or to calculate many more cuts. Then here too the combination of people and computer ensures the strongest team.
How do you ensure that you can use this on projects?
Developing these types of applications naturally takes time and money. Development time is often limited because a project has to be planned. This makes it challenging: the development initially requires an investment. Not only from developers, but also from a specialist who (in a Product Owner role) must give direction to the development. So extra effort is required in the beginning compared to the traditional design process. The role of the geotechnical consultant is also changing: you will develop part of your time, or work together with a developer to achieve a good application. The planning will have to be adapted to this process change. The involvement of the specialist in the development is also crucial to remove the black box feeling: the specialist understands what has been programmed.
Of course, it also helps to ensure that you don’t start developing an application from scratch when a project starts. You can do this by developing applications outside of projects that can be used on different projects. Or by developing building blocks that you can quickly assemble or expand on a project.
We have noticed that different parties need the same kind of applications. From this point of view, the initiative arose to develop tools together with various parties: the first application that was jointly developed for soil bodies. In this way, the investment is divided among different parties and the business case for automation is stronger.
In addition, we have taken the initiative from VIKTOR to develop a number of basic tools for geotechnical consultants, under the name GeoTools. The first version was created based on input from various geotechnical consultants. With this application you can:
- Interpret CPTs to a soil structure with different methods
- Visualize the CPTs on a map and in 3D
- Define the soil parameters in a central place
- Create transverse and longitudinal profiles based on the CPTs
- Generate D-Series models based on the profiles and soil parameters
There is of course much more to be said about parametric design within geotechnical engineering. That is why we would like to take you further into the topic:
- Colleague Roeland Weigand has written a blog about an improved filter algorithm that he has developed which enables geotechnical consultants to gain a better insight into the actual soil structure
- Together with Jacco Haasnoot (CRUX), Ritchie Vink (CEMS, sister of CRUX) and Rob van Putten (Waternet), I contributed to an article about digital building blocks in geotechnical engineering. By making domain knowledge accessible and smartly combining it with digital technology, we achieve better results faster.
- Kevin van Giessen has written a blog about the development and operation of the GeoTools application about which I have already told you something above.
These articles will be published in the coming weeks.
We are looking for input!
We strive to be able to provide a valuable tool with the GeoTools, which makes the work of every geotechnical consultant easier and more fun. For this we need input from specialists. So if you are interested in the application, you can contact me directly via a personal message.
I am also very curious about the experiences you have with parametric design and automation within geotechnics. If you have feedback, experiences or ideas, please send me an email: firstname.lastname@example.org.