A range of solutions from formwork specialist Peri is helping the contractors complete a 1455-m-long Saadiyat Bridge linking the “island of happiness” to Abu Dhabi.

Developed 500 m off the coast of Abu Dhabi city, Saadiyat Island, which means island of happiness, has been artificially extended through a comprehensive landfill programme.
The project, on the one hand, provides additional space for further development of Abu Dhabi and, on the other, creates an idyllic holiday destination complete with 29 luxury hotels and 8,000 villas over  a 10-year period.
In addition, four museums and a performing arts centre are planned on Saadiyat as the main elements of a new international art and cultural centre.
The technically-challenging bridge, which is over 60 per cent complete, has an impressive width of 60 m, making it one of the widest in the world, providing enough space on one level for 10 car lanes as well as two railway tracks.
Once complete, the bridge should help achieve the reduction of travel time from the city centre to the Saadiyat Island, from more than one hour to just a few minutes.
The project is being carried out by a consortium of Ed Zublin and Saif Bin Darwish Civil Engineering Contractors. Within Ed Zublin, project development is being handled by the company’s subsidiaries, Zublin International, Stuttgart, and Dywidag Bau, Bridge Construction Nuremberg.
“The close co-operation of all those involved together with Peri engineers from Nuremberg, Weissenhorn and Dubai has proved to be extremely constructive, both in the offer phase as well as the construction stage,” says a spokesman for the contractor. “This has meant that even planning changes that are made during construction do present a challenge for everyone but not, however, unsolvable problems.
“Eight foreland piers in the west and a total of 11 on Saadiyat itself serve to support the three pre-stressed concrete hollow boxes with spans ranging between 45 and 135 m, says the spokesman.
“The main bridge has a span of 200 m with an overhead clearance of 26 m in the bridge centre and is carried by two V-shaped, 20-m high sets of triple identical piers per section. The inclination of each of the twelve individual supports is 27.45 degrees.
For the bridgework, Peri has supplied the formwork and scaffolding solution for the inclined individual supports, which includes two sets of Vario GT 24 side formwork, a 7.76-m-wide, forward-inclined Vario formwork element with integrated working platforms as well as a reverse-inclined raised formwork unit. This is based to a large extent on rentable standard material taken from the Vario GT 24 girder wall formwork system and SLS heavy-duty spindles. Due to the large supporting angle, the high concreting loads are carried on the externally-positioned reverse-inclined formwork mounted on Peri UP shoring. Part of the steel girder framework installed by the contractors which cantilevers over the sea – steel profiles over 900 mm high – provides a safe support surface with correspondingly reliable load distribution.
The modular structure and the metric grid dimensions of the Peri UP modular scaffolding system make it possible to optimally adapt the load-bearing construction to the forces which are transferred via the raised formwork unit through the SLS heavy-load spindles. 1.50-m-wide shoring towers are connected to form long supporting frame sections. Short, only 25-cm-long ledgers contribute here to the bundling of the standards at the points where the loads are applied. Thus, the individual load-bearing capacity of 40 kN per leg can be virtually multiplied at will, even for higher loads in the system without any time-consuming coupling of the scaffold tubes, as well as being adapted to the required load size. In connection with the high ledger rigidity of the Peri UP scaffold nodes, the scaffolding sections remain sufficiently stable in all situations. This means large scaffold units can be moved very quickly without their dimensional stability being impaired in any way.
Moving process: The 7 m by 3 m individual supports are constructed alternatively in four climbing steps with concreting heights of 4.7 m – as well as by 2.44 m in an outward direction in each case due to the pier inclination.
“The Peri concept therefore allows that the supporting frame construction is pulled outwards on the steel girders after striking has been completed as though being guided along rails,” says a spokesman for the formwork manufacturer.
“To achieve the required supporting and platform levels, three tower modules each with a 2 m base and a 4.65 m extension height could be subsequently coupled together. The time-saving connection is carried out by means of a standard component taken from the Peri UP programme, the Peri section spindle. The extension units can therefore be accurately adjusted to the required height,” he adds.
Through the extensively dimensioned moving units, using in part special cross-beams for the Vario wall formwork elements, both the formwork and scaffolding can be brought efficiently to the next cycle. This means the altogether 48 casting segments can be very cost-effectively constructed with only four sets of formwork.
“However, Peri’s know-how has been used, for all other construction phases as well – for both abutments, the numerous bridge piers in the foreland area through to the superstructure formwork,” says the spokesman.