1875
Evaluation of diaphragm wall as-built data to determine the risk of leakage for the
Kruisplein car park excavation in Rotterdam, The Netherlands
Evaluation des données de fabrication des murs diaphragmes pour déterminer le risque de fuite
dans le chantier du parking souterrain Kruisplein à Rotterdam, Pays-Bas
Hannink G.
Engineering Consultancy Division, City of Rotterdam, The Netherlands
Thumann V.M.
Seaway Heavy Lifting Engineering B.V, The Netherlands, formerly Engineering Consultancy Division, City of Rotterdam,
The Netherlands
ABSTRACT: In the centre of Rotterdam, the Kruisplein car park is becoming the deepest underground parking facility in the country.
It is being constructed since 2009, and will provide around 760 parking places on a total of five floors, of which the deepest is
reaching to almost 20 m below ground surface. The retaining wall has been designed as a diaphragm wall reaching from ground
surface to approximately 40 m depth. Because of some major leakage incidents in diaphragm wall type excavations in Rotterdam and
elsewhere in The Netherlands, additional effort was raised to define and prepare mitigating measures to reduce the risk of leakage for
the Kruisplein car park project. An extensive evaluation of as-built data of the diaphragm wall was made, including all available field
records of process-parameters. Based on the outcome of the evaluation, it has been concluded that in general the diaphragm walls
were of sufficient quality. No major leakage incidents have occurred to date.
RÉSUMÉ : Dans le centre de Rotterdam, le parking de la place Kruisplein est en train de devenir le plus profond garage souterrain du
pays. Ce parking est en construction depuis 2009 et pourvoira 760 places de stationnement réparties sur cinq niveaux. Le plus profond
d'entre eux atteint plus de 20 m de profondeur sous la surface du sol. Le mur de soutènement a été conçu comme une paroi moulée
atteignant approximativement 40 m de profondeur. À cause de divers accidents majeurs de fuites d'eau survenus dans des excavations
utilisant des parois moulées à Rotterdam et ailleurs dans les Pays-Bas, des efforts supplémentaires ont été fournis pour définir et
préparer des mesures d’atténuation pour réduire le risque de fuite lors du projet du parking Kruisplein. Une évaluation étendue des
données des parois moulées, incluant toutes les données de chantiers enregistrées lors de leur fabrication, est présentée. Il n'y a eu
jusqu'à ce jour aucun incident majeur de fuite sur le chantier de Kruisplein.
KEYWORDS: diaphragm wall, deep excavation, risk of leakage, field records, as-built data, mitigating measures.
1 INTRODUCTION
In Rotterdam diaphragm walls are regularly applied since the
construction of the Willem Railway tunnel in the nineties of the
past century. For underground infrastructural projects, it is an
appropriate building method, because it facilitates deep
excavations under dry conditions. By connecting the diaphragm
walls to the rather impermeable soil layers of the Formation of
Waalre a dry building pit can easily be created. The geological
conditions are favorable for this building method: in the centre
of Rotterdam the rather impermeable layers of the Formation of
Waalre are everywhere present between 35 and 40 m below sea
level (this corresponds to the Dutch reference level NAP).
Diaphragm walls have been applied at several locations of
the metropolitan light rail project RandstadRail in the beginning
of this century. During the extension of metro station CS a
major leak through the diaphragm walls arose when the
excavation inside the building pit was at its maximum depth (14
m below sea level). As a result a huge amount of water and sand
entered the building pit. With a lot of trouble, the leak was
fortunately stopped within two days, and the construction of the
metro station could be continued (Thumann et al. 2009).
In the same period the preparation of the underground car
park Kruisplein was in full swing. The design consisted of 40 m
deep diaphragm walls to make a 20 m deep excavation possible.
A logical question at that moment was, how to minimize the
possibility of a similar incident during the construction of the
car park. This paper describes the mitigating measures taken in
advance, the supervision during the construction, and the
effectiveness of the precautionary measures in practice.
The construction of the Kruisplein car park is part of the
overall project Rotterdam Centraal (Hannink & Thumann
2007). This major project comprises of the building of a large
Public Transport Terminal in the vicinity of the Rotterdam
Central Railway Station. It is designed to facilitate passenger
transfer between (inter)national trains including the high-speed
train, and local public transport like trams, buses and
underground trains. The excavation as required for the
construction works of the Kruisplein car park covers about
5.000 m
2
.
Engineering of the car park Kruisplein, and supervision of
the execution of the project is performed by the Engineering
Consultancy Division of the City of Rotterdam.
Figure 1. Building pit of car park Kruisplein.
