Faster foundation work on the Maaslijn: “Everyone who works with it is enthusiastic about this innovative technique.”

In early June, Swietelsky made history on the Dutch railway: for the first time, we applied the innovative pipe foundation, specifically on the Maaslijn. Earlier, Ger Wuite took us through the design and preparation. This time, lead contractor for the overhead line, Ben Meerschaert, explains how different this method is. And why he and his colleagues enjoy working with it so much.

Ben has just completed four night shifts, during which he and his colleagues installed 69 pipe foundations. “Everyone is really enthusiastic about this technique,” he says. “Normally, we do about five traditional foundations per shift. Now you can really produce.”

First application on the Maaslijn required careful preparation

Admittedly, for Ben, the concept of the pipe pile was not entirely new. “I come from Belgium, where we already worked with the pipe foundation.” Still, he found that first pile on the Maaslijn quite exciting. “Of course, we did a lot of preliminary research, with ground scans and intersections with cables and pipes. And the pile drivers also received training to work with the new Movax machine. But driving a pipe pile is fundamentally different from placing a concrete block.”

“A pipe is in the ground in ten to twenty minutes”

High-frequency vibrations with the Movax

Ben explains how a traditional foundation works. “We first dig a hole. And determine the exact height and depth and make the hole level. Once the concrete block arrives, it’s a matter of lifting it with the crane and lowering it according to instructions. After that, it’s in place.” How different is it with the pipe foundation? “The Movax, which is attached to the pile driver, grabs the pipe from the side. Then it vibrates it into the ground with high-frequency vibrations. As the pipe goes further into the ground, the machine grabs it a bit higher each time.” The last bit, the Movax pushes the pipe into place from above. Or, if that doesn’t work, a hydraulic block comes into play. “In the end, every pipe is in the ground in about ten to twenty minutes,” Ben indicates.

Millimeter work: precision and monitoring during pipe foundation placement

A major difference with traditional foundations lies in the movement space during placement. “Where you place the pipe, it stays. You have very limited room to adjust once the pipe is in the ground. While with a concrete block, you can still make some adjustments to set it correctly. This requires constant monitoring because you can easily be five centimeters out of plumb.” Although the pipe foundation already existed, the integrated anchors are a new addition. “Our supplier mills parts out of the pipe and places round sleeves in there. The anchors for the overhead line pole are placed in those sleeves. They must also protrude exactly at the right spot.” Therefore, the pile driver constantly monitors the driving on his screen. “And fortunately, we still have the trusty tape measure and level,” Ben laughs. “Trust is good, but control is better.”

“The risk of subsidence is virtually eliminated”

Faster foundation work with minimal disruption: a smart choice with courage

As mentioned, the pipe foundation method uses a Movax with high-frequency vibration. “This allows us to work as vibration-free as possible, a requirement in the immediate vicinity of the railway.” Although the vibration can be slightly more intense for a short time, the disruption is minimal according to Ben because the work pace is high. “Within a few minutes, the installation is already several meters further.” Another important advantage: the pipe foundation reduces the risk of subsidence to almost zero. “This is especially important when working in or near the pressure line of the railway. You want absolute certainty about the stability of the subsoil.”

With a total of two thousand foundations planned, Ben and his colleagues can still be found regularly along the Maaslijn. “Due to the high production we achieve with this method, you can see the work progressing. That’s really nice. It’s great that we took the bold step for this project and found a faster way.”

- Photos for this article were taken by André Bouwfotografie.