Strong foundations, solid future

From pile foundations to retaining walls, injection works and soil improvements: with more than a century of experience and know-how, Franki Grondtechnieken is the expert in vibration-free foundation techniques.

The success story of Franki Grondtechnieken begins in 1908, when Edgard Frankignoul acquired the patent for the very first Franki pile. This large-footed driven pile was used to carry out numerous prominent projects in a short time. It also built a global empire with subsidiaries and franchises in foundation engineering and general construction, which was split up in the 1980s. Since then, Franki Grondtechnieken, founded in 1934, has focused entirely on foundation engineering. The company is part of Franki Foundations Belgium, which has been part of the BESIX Group since 2008.

The basis for complex projects

Whether it is an expansion of an operational petrochemical plant or hospital, a parking garage or high-rise building in the middle of the city or a large-scale infrastructure project with tunnels and bridges: it is mainly the complex and specialised works where Franki Grondtechnieken shows its added value. "With our vibration-free techniques, we literally lay the foundations for these projects," explains Managing Director Jan-Wim Verhoeff. "An illustrative example is the Spoorzone in Delft, where a 2,300-metre-long railway tunnel with underground station and space for four tracks was built in almost 10 years. For this underground facility, a tunnel had to be excavated. As inserting and pulling sheet piling would cause too much vibration and noise nuisance, a vibration-free alternative from Franki was chosen. We dug trenches as deep as 25 metres, into which concrete was pumped from below to make panels formed in the ground. The 7.50-metre-wide panels created in this way eventually formed a stable wall that was excavated and into which the tunnel was realised. Similarly, we dug the walls for the stations of Amsterdam's North/South Line. And we also laid the foundations for the underground car parks at Lammermarkt and Garenmarkt in Leiden."

From foundations to complete construction pits

Franki's vibration-free drilled piles also form the foundation of high-rise project The Student Hotel, built next to Eindhoven Central Station. But also of residential tower OurDomain Rotterdam Blaak (formerly: Bright), which was the last project in the reconstruction of Rotterdam. "That we also carry out complete construction pits in addition to foundation techniques, we prove, for example, with the RIVM tower in Utrecht," says Verhoeff. "In this project, we installed building pit walls including anchoring. Moreover, we drove piles with a diameter of no less than 2 metres and a depth of 60 metres into the ground to meet the vibration requirement. We sealed the soil using soil injection, after which we excavated the entire construction pit. This allowed the contractor to start construction immediately."

Most of Franki's foundation techniques are formed in the ground. "If required, we can also make combinations of drilled piles and precast elements, resulting in a vibration-free and high-quality element. This technique is being used, for example, on project 'A16 Rotterdam', between the A16 and A13, where we are putting some 10,000 combi piles into the ground in a foundation combination with Voorbij Funderingstechniek."

Own engineering department

Based on building type, size, location and soil conditions, among others, Franki's in-house engineers are happy to design a customised foundation for each project. "In addition, we stand in for a piece of advice. For example, when an alternative piling system can be used to build cheaper, faster and/or quieter," Verhoeff concludes. "We have more than 100 of our own and hired machines, from mega-sized to super-small, which means we can literally get to work on any construction site."