we plan the world of tomorrow.
Bridge superstructure for the comprehensive improvements of parallel roads in Dubai
4 KM OF BRIDGES WILL REDUCE TRAFFIC CONGESTION AROUND DUBAI WORLD TRADE CENTER – DECKS WITH CONTINUOUSLY VARIABLE SPANS HAVE BEEN CONSIDERED USING A PARTICULAR SPAN-BY-SPAN SEGMENTAL CONSTRUCTION METHOD.
Location: Dubai – UAE
Client: Salini Dubai Branch
Cost of total Works: 70,000,000 € (bridge superstructure)
Services: Consultancy service for the bridge superstructure design taking into account the construction method and the equipment selected by the Contractor.
The Comprehensive Improvement of The Parallel Roads is considered as the main link of the West Parallel to Sheikh Rashid Road, near the very congested area of the World Trade Center in Dubai. The project is located in the Zabeel area and includes elevated roads involving 19 bridges made of precast concrete extending 4236 meters in length and 14.7-12.7 meters in width.
The consultancy service carried out for the bridge superstructure aims at checking all the segmental decks for the construction loading conditions and giving assistance during construction in case of any unexpected situations.
Due to utility congestion, the spans have constantly variable lengths (between 30-60 m) and thus every continuous bridge (from 3 up to 7 spans each) must be rechecked.
The reference code for all verifications was AASHTO LRFD, with the exception of the evaluation of casting curves and strains due to creep and shrinkage that have been assessed with CEB-FIB Model Code 90.
Bridge decks have been built with the segmental techniques by using precast match-cast segments glued with epoxy. The erection of the segments requires two self-launching gantries (one for each alignment) to cope with the contractual deadlines. Segments have been erected up to 60 m long spans, using a specific span-by-span method. In order to accommodate the construction stages as per contract drawings and to keep within a feasible range the design parameters of the gantries, the Contractor has elaborated an erection sequence which involves the use of short cantilever sections filled with intermediate segments in a second stage. This construction method reduces the number of segments hung to the main trusses of the gantry and enables the erection of a complete span per week.
The average weight of the precast segments is around 100 t, with the maximum value of 200 t for the pier diaphragm segment. The segment height is 2.5 m and is kept constant up to 60 m long spans. The average rate of steel bars is 250 kg/m3 for the diaphragm segments and about 180 for the typical ones.
The assistance activity has covered the entire period of construction. The Parallel Roads Project will open to the traffic by the end of 2013.