As part of the reconstruction of the Amstel junction, construction consortium Amstel Verbindt (Mobilis, Boskalis and Van Gelder), together with its partner Fugro, previously carried out ground investigations beneath the A10 Zuid and the urban road network (see the box at the end of this article). A sounding truck was used for those investigations. This time, however, the work needs to be carried out in the Amstel itself. Fugro has therefore brought in Tonny, a 50-metre-long inland vessel equipped for cone penetration testing. The vessel has a steel measuring rod and four stabilising legs to keep it steady on the water. The investigations will take place from Monday, 27 July until Friday, 31 July.
Peter Bonn of Amstel Verbindt and Casper van Basten of Fugro explain the work in this video
Replacing the Rozenoordbrug in stages
The existing Rozenoordbrug needs to be replaced and will therefore be partially demolished. We are assessing the condition of the bridge so that we can determine exactly how much needs to be removed and which parts can still be reused. Before the existing bridge can be demolished, however, a new bridge must already be in place. This will allow traffic to continue travelling to and from the Amstel junction throughout the construction works. The cone penetration tests now being carried out will provide the information needed to design and build that new bridge properly.
Reconstruction of the Amstel junction
The reconstruction of the Amstel junction is the final major project within Zuidasdok. Construction is scheduled to start in 2028, with completion currently expected in 2037. The project covers the section of the A10 Zuid between the Amstel junction and Europaboulevard. The reconstruction will improve road safety by separating through traffic from local traffic and by adding two extra lanes in both directions. In addition to widening the A10 Zuid, the project includes new connections between the A10 Oost and the A10 Zuid, replacement of the southern Rozenoordbrug bridge, construction of several new viaducts, changes to urban roads and installation of noise barriers.
Load-bearing capacity
Cone penetration testing is a type of ground investigation in which a measuring rod, known as a cone, is pushed vertically into the ground at a constant speed. Sensors in the cone tip measure the resistance of the soil. This information allows us to identify the location of soft soil layers, such as clay; the depth at which load-bearing sand layers begin; and the level at which the foundations can be installed. These findings help determine how long and heavy the new foundation piles need to be and where they should be positioned.
Flowing water
Carrying out cone penetration testing in a flowing river is very different from doing so on an undeveloped site or beneath the A10 Zuid. Despite the current, the cone must enter the riverbed perfectly vertically. Tonny therefore needs to remain precisely in position throughout the work. The vessel’s four stabilising legs are used for this purpose.
Cables and pipelines
There are also cables and pipelines beneath and alongside the Amstel, and these must not be damaged. Their exact positions were mapped in advance so that each test point can be placed safely.
Temporary restrictions on the waterway
Disruption to the surrounding area will be limited. Because the work is being carried out on the water, part of the waterway may occasionally be temporarily restricted. Any restrictions will be announced in advance through the usual channels for shipping. The waterway will not be closed completely. Recreational boats and rowers will always be able to pass.
Noise disturbance
There may also be a limited amount of noise disturbance. Pushing the cone into the riverbed is a relatively quiet process. Most of the noise will come from the machinery and pumps on the platform. The work will take place during the daytime and will only last for a short period at each location. We therefore do not expect continuous disturbance for nearby residents.
Asphalt investigations
From late March until mid-May, we investigated the asphalt beneath the A2, the A10 Zuid and the urban road network for tar content, load-bearing capacity and remaining service life. Fewer sections of road contained tar than expected, which means that more of the asphalt can be reused. There were also no unpleasant surprises in terms of load-bearing capacity or service life. A great deal of time and effort went into planning the investigations. According to Arno Miltenburg, Infrastructure Discipline Lead at Amstel Verbindt, this paid off: ‘By combining as many investigations as possible, we were able to keep traffic disruption to a minimum.’
Share article:
Give your opinion
Get in touch with us