ALEC’s MD, Barry Lewis, talks about how they conquered the engineering complexities of the “iconic” One Za’abeel project
ALEC’s managing director Barry Lewis sits down with Construction Week’s editor Ashley Williams to reveal how the One Za’abeel project is continuing to put Dubai on the map
Regarded as the next iconic project to take shape in Dubai, One Za’abeel – the twin-tower development near the Dubai World Trade Centre – is among a pipeline of developments attempting to break world records for its architecture and engineering excellence in the UAE.
Featuring Michelin-starred restaurants, a 500-room luxury hotel, executive offices, and an infinity pool, the mixed-use project is being developed by property giant, Ithra Dubai, which is wholly-owned by the Investment Corporation of Dubai (ICD).
But among the most eye-catching parts of the project is ‘The Link’ - a panoramic sky concourse that connects the two towers of One Za’abeel and is expected to be the longest cantilevered building in the world, floating 100m above the ground.
The project marked a significant milestone in October 2020 with the completion of the final lift of the 900-tonne second section of The Link.
The Link is 226m-long and has been constructed of seven steel modules – named Assembly A- G – that were slid into place before they were lifted into their final position on the building.
The lift of the 192m-long first section of ‘The Link’, which is one of the heaviest lifts in the region with a total weight of 8,720 tonnes, took place in September 2020 and was carried out over a period of 12 days.
Stakeholders of the One Za’abeel twin tower development include industry leaders ALEC as the main contractor, who said that the concept of the mixeduse development is being designed on the basis of a Japanese gate which represents “the gateway into Dubai”.
Speaking exclusively to Construction Week, ALEC’s managing director for construction, Barry Lewis, explains how the contractor has managed to navigate through engineering obstacles faced at the One Za’abeel project and how they initially wanted to conduct the lift of The Link in one go.
“It’s been a lot of years of planning and it was visualised many years ago from a concept stage, but the engineering that has gone into making this a reality has been quite significant. The piece that we have lifted now is a small section, and is only 30m long and 900 tonnes,” says Lewis.
“We came up with a robust engineering solution where the proof is now in the pudding as The Link is now up in the air. The last section has around 45 days of welding that needs to take place to ensure the structure is effectively fused together.”
He adds: “It’s a significant lift and in order to do this, it took thousands of manhours of engineering, validation and verification. By using heavy jacks and strands, we were able to design the lift of The Link through a series of leavers, which transfers the forces back into the permanent structure.
“In order to make that happen, we had an obligation to ensure that we engineered our construction sequence considering all temporary conditions, ensuring that at all times the permanent structure was never compromised.”
The verification and validation of the temporary and permanent conditions was a huge task and one of the biggest challenges, Lewis admits.
“The loads incrementally increased as the construction develops. The Link that has been lifted is only 30% of the final load that is actually in the air,” Lewis explains. “We have to put the balance of the
structure, place a façade on it and finishes, as well as fill the infinity pool.”
He adds: “All these loads will be systematically introduced and because it’s a steel structure, we have to design it with sufficient tolerance to allow for the settlement as the various loads are imposed. We have to theoretically model the load transfer that we’re expecting to take place, so that eventually when the building is fully loaded, it comes back to a neutral or flat condition.”
Both concrete towers were built with a camber of 1.5mm per level to allow for the
deflection, which will take place when the load of the lift is introduced.
“We’ve achieved a significant milestone in terms of getting The Link bridge up into position. We have around two months left of consolidation of the bridge in terms of welding and making sure The Link is complete,” says Lewis.
“We still have another 35 floors to add onto Tower A and a couple of floors on Tower B. It’s a mixed use facility, which is very complex, high-end and iconic. It’s got a way to go, but we are pushing as hard as we can.”
ALEC has around 5,500 people onsite and 250 engineers working on the project collectively with the firm’s subcontractors, according to Lewis.
Lewis also discusses how constant monitoring of its workforce has allowed them to continue working on the project during the COVID-19 pandemic.
“One of the biggest challenges for us is that we are moving a lot of people every day at several times of the day. Logistics, even without COVID-19, is a massive challenge,” says Lewis. “Our initial planning for the One Za’abeel site was without COVID-19 and in terms of moving people vertically, we have lost capacity.”
“In order to deal with that loss in capacity, we have had to create further shifting to allow workers to be more staggered. Between our own direct workforce and sub-contractors, there is a lot more scheduling that takes place and we use software that assists us with that.”
He adds: “It is constant monitoring
“WE HAVE AROUND
TWO MONTHS LEFT OF CONSOLIDATION OF THE BRIDGE IN TERMS OF WELDING AND MAKING SURE THE LINK IS COMPLETE”
and reinforcement to make sure people are doing the right things and having sufficient stations so workers can sanitise on a regular basis. It’s not been without its challenges, but contractors are quite resilient and we come up with ways to make sure we can keep pushing on with the project.”
Lewis, who has headed up construction activities for the One Za’abeel project, reflected on what the project meant for the business and his personal career.
“For ALEC, One Za’abeel is a fantastic project to have on its books and we will always cherish the opportunity to do something that is unique and bespoke as it puts you up there with the best,” Lewis grins.
“For me personally, I’ve built many fantastic projects in this region. From a technical and iconic point of view, the One Za’abeel is right up there with the best. This project will enhance Dubai’s reputation in terms of achieving the unthinkable.”
Concluding the conversation, Lewis remained optimistic about the future of ALEC after recently announcing that they have opened an office in Saudi Arabia for the first time to support the Kingdom’s rapidly changing landscape.
ALEC’s office in Riyadh will be led by by general manager, Darrell Bergesen, who has more than 28 years of international experience in the construction industry across South Africa, the UK and the Middle East.
Bergesen will be responsible for overseeing the growth and expansion of the company. Bergesen previously worked with ALEC from 2007 until 2017, and has re-joined the company after delivering the largest and most complex ‘brownfield’ mall in South Africa.
“We are optimistic that ALEC will continue to grow and pick up the landmark projects that Dubai and Abu Dhabi has to offer. We are excited about the endless possibilities that will arise with the opening of our new office in Saudi Arabia,” concludes Lewis.
“We are committed to helping revolutionise the region’s construction industry, and with our team of industry experts we look forward to creating value for our partners and stakeholders in the Kingdom.”