Project characteristics
GEM Bloemendalerpolder CV commissioned Martens en Van Oord to get a section of the future residential area of Weespersluis in the Bloemendalerpolder broadly ready for development. Autumn 2018 saw us make a start on the preparatory work.
Geotechnical challenge
In spring 2019 we will start the design and precompression work. The aim is to achieve a low-subsidence final situation, thus rendering the area ready for construction and habitation. The subsoil is among the worst in the Netherlands and consists of a thick layer of peat. Making it an interesting challenge from a geotechnical perspective.
It will start with a bed of sand being introduced and vertical drainage being inserted into the peat layer to enable the water to be drained from it. Sand will then be introduced in layers to press the peat downwards and compress it. Working layer by layer reduces instability in the subsoil. A total of around 5 metres of sand will be put in. After a subsidence process of roughly six months, the subsoil will have sunk by more than 2 metres and the excess sand remaining will be excavated and incorporated into the preload for ‘De Gouw’ lake.
Thus rendering a total of 10 hectares of future residential area broadly ready for construction. Martens en Van Oord is supplying around 500,000 m3 of sand for this.
‘De Gouw’ lake
In addition to the precompression of the residential plots, ditches will be filled and ‘De Gouw’ lake created. ‘De Gouw’ will be connected up with the River Vecht and will be made suitable for sailing and swimming. The nature of the subsoil makes it impossible to excavate the lake ‘normally’, but as with the residential plots it will be created by introducing a preload of sand that will see to it that the layer of peat is compressed. Once the subsoil has settled at the right depth, the sand will mostly be removed. Half a metre of sand will be left, which will form the bed of ‘De Gouw’ and ensure that the water remains clear.
New district
Weespersluis will be a large residential area encompassing some 2,750 properties. Nature and water will play an important role here. Just one third of the area will be built on, with the rest being reserved for water and plant life. Completion of the subareas is scheduled for the end of 2020.
For further information https://weespersluis.nl/
Corné supervised the entire process. Please contact him or let him know what he can do for you in the form below and he will call you back or email a reply.
