Custom engineering in the installation of sheet piling

Vibration-free and with pond frame

One of the challenges in the Zuidasdok project is the logistical organization. The working space between train tracks, metro tracks, A10 freeway and in the passenger passages of Amsterdam Zuid station is limited, and the surrounding area must be affected as little as possible by the work. At Aannemings- en funderingsbedrijf Kandt BV, they are particularly enthusiastic about such logistical and technical issues. Company manager Willem de Meijer explains how they approach this for the Zuidas.

Two LeKa pile drills, three wire cranes. auxiliary cranes, several hydro dam wall racks and a total of 35 men. Behold the deployment of people and equipment during one of the weekends in which Kandt BV worked hard on, among other things, the construction of the new passenger passage: the Britten Passage of Amsterdam South Station. It is not the numbers, but rather the choice of specific equipment that characterizes the work. "The work on the new Brittenpassage to be built and the current passenger passage Minervapassage mostly involves short periods of execution, think of a weekend, where we have to work with many people and specific equipment in a limited space and a relatively short time frame," explains Willem. "That requires a lot of consultation with Bouwcombinatie Nieuw-Zuid and a good plan of action. It is customized work, exactly what we as a company are strong in. For small and large projects with many 'snags and eyes' and where design and execution are close together, we see it as a challenge to come up with a solution. That requires flexibility and craftsmanship, exactly what makes our profession beautiful."

Specialist customization

Kandt BV is a family business in Nieuwerkerk aan de IJssel with approximately 60 employees. The company began over 45 years ago with earthworks and excavators, after which custom machines were soon built for foundation work. The family business specializes in foundation work, especially work in inner-city areas where the work takes place in limited space. It is engaged in projects for the supply, installation and, if necessary, removal of (anchored or stamped) sheet piling and the vibration, pile driving or drilling of pile structures and LeKa piles. Think of projects such as A9 BaHo (Badhoevedorp - Holendrecht), Groningen ring road and the A16 Rotterdam. "We design and build a significant part of our machinery ourselves, have our own technical service and we also provide our own transport to the relevant construction sites. For example, our hydraulic cranes are of our own design and specially made to be used where space is limited and erection and dismantling must be quick." For the work on the Zuidas, Kandt BV deploys both hydraulic cranes and wire cranes, depending on the length of the sheet piling and the distance to where it is to be placed. At some locations, the sheet piles are pressed in vibration-free with a silent-piler. "For the construction of the new Britten Passage, for example, we installed combi piling below deck. Because we have little space here, less than 3 meters in height, we cannot use high cranes. This is why we install the pipes for the combi wall in pieces of about 1.80 meters. 

In total, they have a length of about 23 meters. We fill the space between the tubes with sheet piles to a depth of about 6 meters. The sheet piles are pushed down by jacks. Once a section of the sheet piling is pushed down, a new section is erected, welded with certified welds and jacked until the desired depth is reached."

Own design pond frame

Because the work on the passages is custom work, Kandt BV devised and built a special construction. "We developed a so-called pond frame for this purpose. We are able to do this because we have a lot of material and fittings, but above all the expertise in-house." Speaking of expertise, you can have good equipment in house, but without the right people you still won't get very far according to Willem. "Nice example of this is drilling through anchors. For this you work with enormously powerful machines. This requires craftsmanship on the part of the operator, because you have to have a feeling for piercing the anchors in the right place. So I always say: good people make the work."

Logistics planning

The work on the Zuidas requires good logistical planning, says Willem. "Especially when you see how many travelers pass through Amsterdam Zuid station every day. Add to that the traffic on the A10, and you're talking about very large numbers. It's the overall scale what makes the project interesting and challenging for us. We are part of the preparation and development of a plan of action. Our people understand their profession, together we form a club with a drive!"