Extreme heat, high contact pressure: new sliding material for Dubai
Dubai is known for its extreme and innovative structures – correspondingly high are the requirements of the Roads & Transport Authority. For the bridges of the new Dubai Water Canal structural bearings were requested which could withstand a contact pressure of 40 MPa at a temperature of 60° C.
The Dubai Water Canal is a completely new water link which was built between October 2013 and November 2016. With a length of 3 km and a width of up to 120 m, it reaches from the Business Bay to the Persian Gulf. Four bridges with a clearance of 8 m already span the canal. Along the banks, hundreds of hotels, restaurants and shops shall be built in passageways.
143 bearings installed
The first bridge bearings were delivered in 2014. The installation of all 143 bearings was carried out in 2015. The bearings can accommodate forces of up to 30 MN and display a diameter of ca. 1 m.
Uniquely high requirements
The bridge bearings for the three bridges were supplied by three different companies. However, uniform for all the three companies were the high technical requirements, explains Mr. Raad Hamood, Sales Manager Middle East at MAURER. “In this combination of high contact pressure and high temperature, this requirement was worldwide a first time!”
Bearings must withstand 60° C at 40 MPa
Due to the high temperatures that prevail in Dubai, the sliding material in the bearings must withstand 60° C, and because of the high live load must be proven at a contact pressure of 40 MPa. When these requirements were set by the Roads & Transport Authority (RTA) in 2014, the bearing experts of MAURER were already in the process of enhancing the existing MSM® sliding material. Usually, sliding material is being tested at room temperature. Tests of the new MSM® Plus which were conducted at the material testing institute of Stuttgart University (MPA) were however adapted to the specification of RTA. A so called cold-flow-test was successfully conducted, however in a specially specified combination of temperature and contact pressure. MSM® Plus fulfilled all expectations. According to the test certificate of MPA it can cater for a combination of contact pressure and temperature of 40 MPa and 60° C.
Because all contractors had to comply to this extraordinary specification, but only the new sliding material could fulfill, MSM® Plus was employed in all three bridges, independent of the contractor.
The bridge for which MAURER supplied the bridge bearing is a concrete bridge with four lanes in each direction. The individual bridge sections are connected by way of prestressing elements. The bridge bearings are classical pot bearings – also a special in case of Dubai, because there only pot bearings are specified.
The Water Canal was opened for traffic – thus flooded – in October 2016. The bridges were opened for traffic end of 2016.