Adherence to deadlines, efficiency and completion without interrupting the flow of traffic are the requirements that are of paramount importance during the Sabah Al Ahmad Corridor infrastructure project. For the construction phase on Al Bustan Street South, PERI made use of the PD 8 shoring system and a combination of systems from the PERI UP Flex portfolio in addition to a tailor-made VARIOKIT solution with VST heavy-duty shoring towers. The customer has therefore taken full advantage of the opportunity to procure time-saving formwork and scaffolding systems from a single source.
The timetable for completion of the Sabah Al Ahmad Corridor infrastructure project is demanding: Construction of the unique transport corridor, which will feature the largest intersection, longest bridge and deepest and longest bidirectional tunnel in Qatar, must be completed in time for the start of the 2022 Football World Cup. By then, a total of four roads featuring a multitude of multi-lane motorway bridges will connect the five football stadiums of Doha to the northern and southern areas of the city.
The Al Bustan Street South construction project is one of four parts that make up the infrastructure project and features bridges with a total length of more than 10 km. The existing road, which currently consists of three lanes in each direction, will be extended by one to two lanes on each side. This will ensure a smooth flow of traffic and will optimise the logistical process. As a result, around 20,000 vehicles will be able to use the corridor every hour compared to the current figure of 12,000, thus enabling people to reach nearby urban areas more quickly.
As part of a partnership-based cooperation, HYUNDAI and PERI developed a time-saving engineering solution that could be supplied from a single source using perfectly coordinated formwork and scaffolding systems. All in all, they used around 150,000 m3 of shoring, 13,000 m3 of working scaffold, 13,000 m2 of formwork and VST heavy-duty shoring towers to achieve this. The result: A bridge that consists of an in-situ concrete bridge with 37 piers and a prefabricated concrete bridge with 81 piers. The system solution was tailored to account for the specific circumstances on site. Carrying out the bridge construction work with traffic in full flow posed a significant challenge.
Combining the modular VARIOKIT and PD 8 systems proved to be the ideal approach to establishing the superstructure formwork for the in-situ concrete bridge. Modifying the systems to accommodate the varying thicknesses of the bridge structure, which ranges from 3.2 m to 4.0 m, was a straightforward process. The prefabricated components of the external web and cantilevered formwork were assembled on the ground ahead of time, raised by a single crane to save time and then adjusted to marry up precisely with the angle of inclination of the bridge using articulated couplings and a heavy-duty spindle. PD 8 shoring, which was adjusted quickly and steplessly to the different heights, ensured that loads could be transferred in an optimum manner.
The very first deployment of the VARIOKIT VST heavy-duty towers in the Middle East was a particular highlight. These were used for the erection of the main bridge and the bridge access roads using prefabricated concrete elements. Using mobile hydraulics, the VST heavy-duty shoring towers were also adjusted steplessly to account for the special geometry of the bridge in order to transfer the extremely high loads. This made the formwork process exceedingly efficient and expedited the construction process.
The bridge piers were shuttered using a tailor-made solution involving components from the VARIOKIT engineering construction kit and VT 20 formwork girders. A custom-made coupler was also used as part of this process.
The reliable level of protection on the internal and external sides provided by the lightweight PERI UP Flex system meant it was possible to achieve a high degree of working safety. The versatility of the system components of the PERI UP Flex scaffolding means that they can be used in a huge range of applications. During the Al Bustan Street South construction project, they were used as reinforcement scaffolds, working platforms, stair towers, access points for finishing works and suspended scaffolds.
The project planning for Al Bustan Street South was carried out using the trendsetting method BIM (BIM = Building Information Modelling). In this way, the complex formwork and scaffolding solution was integrated into a 3D construction model in its entirety. This made the project execution process exceedingly efficient and transparent: The customer benefited from the visual representation of the construction project and from the resultant high level of planning security. Thanks to the 3D model, it was possible to simulate and optimise all planning and design variants at an early stage of the project. This made it possible to stick to the demanding construction schedule that was agreed and to reach the project milestones on time.