Nieuwe MolensGent

What was the customer’s request?

To execute the necessary sheeting and foundation work for the renovation/new building project on the site.

What technical challenges did the project pose?

Before commencement of the project, the first challenge was to anchor the existing basement wall of the classified façade in order to break out the existing basement.

Secondly, construction pit sheeting had to be designed for the realisation of an underground multilevel car park with three floors. A factor to be taken into account was the existing groundwater pollution in the surrounding area. As a result, there was to be no groundwater flow as a result of dewatering. Consequently, the secant pile wall not only needed to be earth-retaining, but  water-inhibiting as well.

How did CVR tackle it?

After a stability study of the existing façade had been carried out, it was possible to determine which anchors were to be drilled into the existing basement wall. As this had to be done before demolishing the ground level floor slab, the working space and the implementation of the anchors was very restricted. Thanks to the use of our Morath 2 anchor drilling machine, which is specially designed for working in small spaces, we were able to implement the anchors in the existing basement without prior demolition and/or strutting.

A detailed dewatering survey was carried out for the construction pit sheeting design. CVR could use this as a basis for the design and stability calculations for executing the secant pile wall, taking account of the soil and groundwater pressures, both in the temporary and definitive states.

What was the end result?

Thanks to the anchoring implemented by CVR, the existing ground floor and basement could be demolished without risking damage to the classified façade.

CVR has also drilled a secant pile wall around the construction pit, which enabled the main contractor to excavate safely and drily with a maximum earth-retaining structure of 8.84 metres. Because the secant pile wall has been dimensioned as a definitive wall, it can remain visible in the definitive state so that no wall lining needs to be installed.