Platform on new construction, renovation, restoration and transformation
The new train car depot on the NS Treinmodernisering site in Haarlem is supported by more than 1,700 concrete piles. Given the location—right next to the railroad tracks and a short distance from historic (landmark) buildings—it was essential to drive the piles into the ground without causing vibrations and with as little noise as possible. The solution was found in the “Drukpaal” concept, a relatively new foundation technique on the Dutch market.
Initially, the project had been designed using a different type of pile, but while exploring ways to optimize the design, Drukpaal’s technique emerged as the best option. “Our foundation machine uses hydraulic jacks to press a precast concrete pile into the ground in a controlled manner,” explains Menrik Doornbos of Drukpaal. “This results in virtually no vibrations or noise. This was a requirement for this location, where trains pass by just a few meters away and historic buildings stand on the other side of the water.”
The existing hall where train cars are serviced also had to remain accessible throughout the construction work. According to Doornbos, another advantage of the Drukpaal technique is that the precast concrete piles are manufactured in the factory under controlled conditions. “The soil is not excavated during installation, which means that no contaminated soil is drilled up or spread. The groundwater flow also remains intact.”
The engineering work was carried out in close collaboration with the structural engineer and Aveco de Bondt. “By contributing ideas early on regarding pile length, diameter, and quantity, we sought the optimal and most cost-effective foundation design,” says Doornbos. In total, Drukpaal installed more than 1,700 precast concrete piles over a five-month period, each measuring 38 centimeters square and up to ten meters long.
According to Doornbos, Drukpaal’s technology is clearly gaining ground. This is also evident from the investment in a new machine with a pressing capacity of 505 metric tons, compared to 375 metric tons for the current machine. “This paves the way for even larger and more complex projects,” he says.
