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 driven pile with large base 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 especially the complex and specialized works in which Franki Grondtechnieken shows its added value. "With our vibration-free techniques, we literally lay the foundation for these projects," explains General Manager Jan-Wim Verhoeff. "An illustrative example is the Spoorzone in Delft, where in almost 10 years a 2,300-meter long railroad tunnel with underground station and space for 4 tracks has been realized. For this underground facility, a tunnel had to be excavated. Because inserting and pulling sheet pile walls would cause too much vibration and noise pollution, a vibration-free alternative from Franki was chosen. We dug trenches as deep as 25 meters, into which concrete was pumped from below to create panels formed in the ground. The 7.50-meter-wide panels created in this way eventually formed a stable wall that was excavated and in which the tunnel was realized. Similarly, we dug the walls for the stations of the Amsterdam North/South Line. And we also laid the foundation for the underground parking garages on the 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 the Central Station in Eindhoven. 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," Verhoeff said. "In this project, we installed building pit walls including anchoring. In addition, we drove piles with a diameter of no less than 2 meters and a depth of 60 meters into the ground to meet the vibration requirement. We sealed off 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 on projects such as 'A16 Rotterdam', between the A16 and A13 motorways, where we are putting some 10,000 combi piles into the ground in a foundation combination with Voorbij Funderingstechniek."

In-house engineering department

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