Mauritshuis

Building underground is always difficult, but in such a historically prominent environment it requires even greater precision. Any subsidence can cause cracking. The Mauritshuis and the De Witte Literary Society both already had a basement, but, of course, neither was adequate. To make it suitable, the basement of the Mauritshuis was completely emptied out. By removing the mass, the basement threatened to rise. This was prevented by installing anchor blocks prior to the demolition. CSM walls were used to construct the underground area below the street that connects the entrance plaza with the space below the Literary Society. A watertight underground wall was constructed this way without creating major vibrations. This process involves churning up the ground with a cutter after which it is mixed with cement. Steel profiles are then attached to the wall to absorb the bending forces. The basement below Plein 26 was the most difficult. The existing basement was too low and furthermore its pile foundation was in the way. This is why jet grouts were used to create vertical piles with sufficient overlap to prevent leaks. This technique in fact provided the only possibility of creating a new underground space. It had to be possible for the machines to manoeuvre in the existing basement. It might have been possible to drive the sheet piles, however this would have caused too much vibration. Using hydraulic pressure to drive the steel piles was not possible given the low overhead space. The glass lift takes the visitors from the forecourt to the subterranean foyer. Because of the monumental character of the Mauritshuis, the client had requested an ‘invisible’ lift. Hans van Heeswijk architecten designed the lift, but wondered whether this was feasible. ABT made a structural model to investigate this. The connections in the glass structure required special attention: these connections, which to a considerable extent determine the amount of distortion, had to be consist of soft materials because of their contact with the glass. By modelling the connections in a 3D model, ABT was able to conclude that a glass lift was, in fact, feasible. Within the design team, ABT looked after the constructional and geotechnical design of the renovation and the newly built parts. The design, in all its aspects, took account of risk control and the prevention of damages. Only tried and tested, vibration-free, and low-noise techniques were used. During the execution, the effects on the buildings in the immediate vicinity were continuously monitored by using a monitoring system. During the building phase, ABT was also deployed for its management and supervision. As a result, the knowledge of the design was directly applied to the supervision of its execution.