We literally lay the groundwork!

Where previously there was a lot of pile driving in inner-city areas, people are increasingly switching to vibration-free foundation techniques. Jan-Wim Verhoeff, director at Franki Grondtechnieken BV, has also noticed this. His company, a specialized foundation contractor, offers a complete package of optimal foundation solutions for small, large and especially complex projects.

From the old box: Rotterdam - piling of Franki piles.

Technology, knowledge and support

Franki Grondtechnieken's clients come from all sectors "No matter what project it is, we always want to get to know the client's needs and provide an appropriate solution." Verhoeff continues: "Our company has an awful lot of different techniques for realizing foundations, renovation, retaining walls, injection works and soil improvement works. We also have a very extensive range of machinery. From the most powerful to the most versatile machines, adapted to all environmental and/or soil conditions." It is clear that Franki not only performs foundation engineering, but also brings the necessary know-how and offers support. "Sometimes as a subcontractor, but our capacity and experience also allows us to act as a general contractor or partner in large projects."

Franki also placed the diaphragm walls for the underground parking garage on the Lammermarkt in Leiden.

Ground displacement

Because of their location, large parts of the Netherlands have weak soil. So in the Netherlands, piles have long been driven for the foundation of buildings. Nowadays, pile driving and vibrating sheet pile walls, especially within urban areas, are no longer possible. "But also no longer necessary," Verhoeff adds. "As a specialist in underground construction, we have vibration-free techniques that we can put to full use." For example, Verhoeff mentions soil displacement pile systems, in which piles are drilled but the soil does not have to be removed. "This reduces logistical inconvenience for local residents as well as CO₂-emissions."

For the underground parking garages in Leiden at Lammermarkt and Garenmarkt, the foundation was laid by Franki.

Deep Walls

Digging diaphragm walls is one of the company's specialties. "As part of Franki Foundations Belgium -with several branches throughout Europe- our market area is larger so we have a lot of experience with this technique This experience and expertise we can use in Dutch projects." Franki Grondtechnieken can make diaphragm walls vibration-free and low-noise to great depths.

Major challenges

"Of course, sometimes we also face big challenges," Verhoeff says. "That requires a high degree of improvisation and solution-oriented thinking. But that is precisely where our strength lies! Because we have many techniques in-house, we can switch quickly and always search for the most optimal solution together with the customer."

Franki applies soil displacement screw piles at project Bright Rotterdam.

In practice

Verhoeff gives some wonderful practical examples: "During the construction of the RIVM tower in Utrecht, we set up a complete construction pit with construction pit walls including anchoring and piles with a diameter of no less than 2 meters were driven into the ground a depth of 60 meters. This was necessary to meet the vibration requirement. At `Spoorzone Delft', Franki installed vibration-free diaphragm walls as deep as 25 meters for the tunnel and a garage. Using a diaphragm wall gripper, deep trenches were dug into the ground into which bentonite was simultaneously pumped to prevent collapse. Franki also laid the groundwork for the underground parking garages in Leiden at Lammermarkt and Garenmarkt. Finally, Verhoeff points us to a project they are currently working on: the junction of the A16 with the A13: together with partner Voorbij Funderingstechniek, 'De Groene Boog' is being realized here where some 10,000 piles are being driven into the ground. Verhoeff concludes, "You don't see our work as soon as the project is in place, but its importance is incredibly high."