Riyadh Metro: Watertight special solutions for Qasr Al Hokom Station
In 2012, the city of Riyadh in Saudi Arabia had a population of 5.7 million. This figure is expected to increase to 8 million by 2030. Therefore, the infrastructure needs to be adapted to the expected growth in population. In order to reduce traffic congestion and improve the city's air quality, the decision was made to construct a new rapid transit system: The Riyadh Metro.
Construction work on this major project started in April 2014, and the project is expected to be completed by 2018.
Total length of 178 km, six new metro lines with 85 stations
The project will have a total length of 178 km and includes six new metro lines with 85 underground, elevated and at grade stations.
The ArRiyadh New Mobility (ANM) joint venture has been awarded the contract to build Line 3 as well as the Qasr Al Hokom and Western stations. Line 3 is the longest line of the metro project with a final length of 41.58 km. It will run from west to east and will have 22 stations in total.
Concave design for Qasr Al Hokom Station
At the surface, the new Qasr Al Hokom Station has an innovative concave design resembling a bowl. Underground, the blue Line 1 runs above the orange Line 3 at this station.
A deep, completely impermeable pit that was excavated step by step in 3 m deep sections was required for the new station. The excavation walls were stabilized with waler beams that were tied back into the stable soil using an untensioned, passive anchor system. Since the final building also had to be stabilized by the passive anchor system, the system had two functions. On the one hand, it served to stabilize the excavation, and on the other hand, it served as buoyancy control for the building.
For this purpose, DSI Construction Germany produced and supplied 1,183 double corrosion protected tension piles. In addition, to prevent uplift, 997 double corrosion protected micropiles were used in the station floor slab.
Due to the fact that the station had to be completely impermeable, DSI developed watertight special solutions for both systems in cooperation with the contractor.