Dike reinforcement at Tiel requires application of CSM walls 

Near the historic Grand Café Bellevue building in Tiel, the dike was reinforced with a CSM wall, or Cutter Soil Mix wall. If it were up to Djordy van der Eijnde, project manager at Bodembouw, the entire dike reinforcement at Tiel should have been carried out using this technique. "Because," he says, "using the regular steel sheet pile walls is practically a step back in time."

"Steel sheet pile walls are still standard in levee reinforcement projects. This while CSM walls are much more suitable," Djordy believes. "And no, this is not preaching to your own parish. If we look at steel sheet pile walls, first of all this requires a lot of transport movements to transport the long steel plates of about 18-20 meters each, from Luxembourg to Tiel. Then, on site in Tiel, heavy equipment is needed to lift and install these heavy slabs. This is anything but sustainable, it poses the necessary safety risks and creates a nuisance on the surrounding area."

River beds ideal soil layer

Djordy champions the use of CSM walls for levee reinforcement. "In general, you encounter a lot of sand and gravel in a riverbed where there are dikes. It is a challenge to properly install a sheet pile wall in such a foundation. This often requires heavy vibrating blocks. This foundation leads to risks and delays in execution. Not for nothing did FPH Ploegmakers approach us because they recognized these risks. The sand and gravel soil, as we also saw at Tiel, is perfect for the application of the CSM system." Indeed, unlike a steel sheet pile wall, the CSM wall is installed completely vibration-free and settlement-free, which preserves the dike but also means that historic buildings are not at risk. "Moreover, at a location like Tiel or elsewhere on a narrow dike where space is limited, it is much more practical to install a CSM wall because less machinery and material is required when applying the CSM system."

Constructively possible

"Below the line, this is the best solution," Djordy said. "On all points, sustainability, risk, safety and impact on local residents, the CSM technology scores better than regular steel sheet pile wall construction. In cooperation with engineering firm ABT, we have shown in the dike reinforcement of the city of Tiel that CSM walls are structurally possible in the dike design."