The first phase of the infrastructure project consisted of more than 82 km of underground lines and 25 underground stations. The Red Line, or "Coast Line" as it is also known, traverses the Emirate from north to south and is the main line in Qatar's public transport system.
Having worked on the Doha Metro Red Line back in February 2015 for the elevated and at-grade sections under the joint venture of RLR, Doka Qatar was delighted to secure its second contract on the line, this time to deliver the extension under Iris Construction Tourism lndustry and Trade WLL.
The Red Line, also known as the Coast Line celebrated its limited launch in May 2019, with 13 out of the total 18 stations being opened to the general public. Dubbed as the Doha Metro Red Line, the functioning section runs from Al Wakra to Al Qassar, however will eventually terminate in Lusail once fully delivered.
Operating under the project name of Al Khor Expressway Package 4C -Qatar Rail Tunnel, Doka Qatar beat off competition to secure the contract having demonstrated a clear understanding of the client's requirements, while providing an innovative solution for the traveller; an essential element in the scope of work.
Running a total length of 1,039 metres, Doka needed to deliver a formwork solution for this tunnel which included a wall casting height of up to 11.20 metres, a top slab thickness of between 1.0 -1.80 metres and a foundation thickness of between 1.0 - 2.0 metres. In addition to finding a suitable engineering solution, the project window was only six months meaning a wall cycle of eight days, top slab of 12 days and foundation of seven.
Having assessed the project in great detail, Doka's team presented a Top 50 system in conjunction with D3 shoring and an SL-1 Traveller unit. By using the traveller, cycle times could be met while ensuring minimal crane usage while a Trolley TT was used for shifting top slab D3 shoring.
Challenge:
Project solution:
"The traveller system is by far the most time-efficient solution when working on either underpasses or tunnels. lt's also cost-effective as you avoid the requirement of using cranes. Once the Doka formwork instructor and design team had completed the assembly, the site team thoroughly appreciated the thought that had gone into it and work progressed quickly. Particular thanks must go to the Doka site supervisor whose consistent support made the project flow with ease."
Muammer Sezgin, Project Manager, Iris Construction Tourism lndustry and Trade WLL
Country
Qatar
Town or city
Doha
Realization
Qatar Rails
Structure
Tunnel
Wall formwork + traveller
Formwork system:
Top 50, D3 Traveller
Casting length: 30.0m
No of sets: 2 sets
Wall height: 8.10-11.0m
Wall thickness: 1.0/1.40/1.80m
Tunnel length: Approx. 1.0km
Wall formwork area: 2,712m2
Slab formwork
Formwork system:
Top 50 decking, D3 load bearing towers
Shifting: Trolley TT
No of sets: 5 sets
Slab thickness: 1.0/1.80m
Shoring height: 7.40/8.0m
Slab decking: 2,191m2
Shoring: 11,145m3