DOP Submersible dredge pumps

Deepest Dutch underground parking constructed using DOP dredge pump 200

PROJECT SUMMARY

Location: Underground car park at Lammermarkt in Leiden, the Netherlands

Period : Q3-4,2015

Product type : DOP200 with leveller head

Contractor : Verbond Maasland for Combinatie Dura Vermeer – BESIX

The DOP200 was hung in a wire crane and was driven by the crane’s hydraulic power. With plenty of jetwater to fluidise the sand, a layer of 12 m of sand was pumped out of the pit.

Right in the city centre of Leiden, the Netherlands, the deepest Dutch underground car park is being constructed. The 7-storey car park is designed as a cylindrical construction housing 525 parking spots. This immense construction brings along an impressive maximum dredging depth on which the pit had to be delivered: -25.4 m. The job was done using a DOP200 submersible dredge pump.

The DOP dredge pump 200 was hung in a wire crane and was driven by the crane’s hydraulic power. With plenty of jetwater to fluidise the sand, a layer of 12 m of sand was pumped out of the pit. The DOP200 pumped the mixture using another DOP and a booster over 5 km to the spoil field.

DOP Submersible Dredge Pump 200 is used as booster station on a pontoon

The DOP200 was used because of a number of reasons: using the DOP, the dredging process was a continuous one. Moving the same amount of soil by truck would require 100 truck movements a day. Moreover, due to the limited size of this dredging tool, was able to manoeuvre between the 500 anchors in the pit bottom, which were there to hold the concrete. And the DOP was put to another good use once the dredging job was done: by a slight modification to the jet nozzles, it was able to spray the walls of the building pit clean.

Clay was dug out and pumped to the spoil field using a DOP dredge pump

The multi functional use of the DOP and the straightforward mobilization were a bonus in this intricate inner city project. The project had all characteristics of a job well done: the pit bottom had a minute tolerance of only 6 cm upon delivery.