Biggest MSM® Spherical Bearings in Europe: Weighing 21 tons
The Waal Bridge in Ewijk gets a twin, in order to cope with the ever increasing traffic. Maurer Söhne supplies the bridge expansion joints as well as MSM® Spherical Bearings, which, at a vertical load of 220,000 kN, are among the biggest in Europe.
Principally speaking, the existing Waal bridge near Ewijk already is a reference project for Maurer Söhne: in 1997, the largest modular and watertight expansion joints in the Netherlands were installed there. In 1999 all the bridge bearings were replaced.
This "old" bridge is still fully functioning, yet cannot cope any longer with the increasing traffic. The administration authority Rijkswaterstaat, that is in charge of this bridge, therefore decided to construct a second Waal bridge near Ewijk, so that in future traffic can flow in 4 lanes in each direction.
With 1,055 m, the new bridge will be just as long as the existing one, but will be executed as concrete bridge. To be more exact: As a cable stayed bridge with a main span of 270 m.
Main criteria for awarding the contract for the supply of expansion joints and bridge bearings was not only the price, but in particular a proof to be able to deliver in high quality – which was where Maurer had its undeniable strength.
220,000 kN vertical load per bearing
A total of 22 MSM® spherical bearings are to be installed, and their high quality as well as their service life are confirmed by way of a European Technical Approval (ETA). With a diameter of 2,660 mm, the 4 pylon bearings stick out, as they are designed for a vertical load of up to 220,000 kN, weighing each around 21 tons.
These bearings will be installed at the 2 axes of the pylons. The high vertical load results from the stay cables which have to bear the total weight of the bridge. Moreover, new design methods and higher safety factors which have their base in new standards have as effect that the relevant vertical loads have to be increased.
Deciding criteria for the award of this order was that Maurer Söhne counts among the few manufacturers that are at all capable to design and manufacture bridge bearings of this size – and this not only theoretically: based on its experience Maurer Söhne could already prove during the acquisition phase that the special know how is available for designing such challenging bridge bearings.
Watertight Expansion Joints
Also the expansion joints have remarkable dimensions: 20.10 m long and 23 tons heavy. The expansion joints of type XLS900 and XLS700 facilitate a longitudinal displacement of the bridge of 900 mm respectively 700 mm. In addition these expansion joints are watertight and display a low noise emission, having rhombic plates welded on top which reduce noise emission of passing traffic.
The watertight expansion joints protect the substructure in particular in the area of the abutment against surface water and especially against salt which is sprayed in winter. A reduced noise emission was mandatory to protect the exposure of the neighbouring settlements against noise. Moreover the carriageway was executed with an asphalt layer that also reduces noise emission.
The 2 expansion joints were delivered for the 4 lanes of the carriageway in just one unit. Only the footway area of a length of 4 m was delivered separately. In the Netherlands, this "fifth" lane is traditionally separated, for the use of pedestrians, cyclists or for emergency traffic.
The installation of the bridge bearings and expansion joints was carried out in May 2013. Early 2014 the second Waal Bridge was opened for traffic. Meanwhile, Maurer Söhne also received the purchase order for the replacement of the expansion joints of the old Waal bridge.