Lamar Tower is arguably the stand-out project on Jeddah’s Corniche. The rate of new developments across Saudi Arabia’s Red Sea coast may mean that this will intensify over the next few years, which is good news for developers and contractors looking for opportunities to show their capabilities in this growing economic hub.
A mixed-use project of a type becoming increasingly common in Saudi Arabian cities, Lamar Tower is two towers of residential units sitting atop a curved podium that will, for the first time in the region’s property history, contain a hotel, shopping mall, restaurant, conference centre, ballroom, spa and other facilities. The tallest tower, at 372m, will be the tallest in the Kingdom, with the second tower eventually standing at 293m. The total land covered will be 415,000m2, nestled a pebble throw away from the rolling coastline.
The project has undergone some challenges and changes since it was launched by Cayan Investment & Development and Zahran Property Investment in February 2007, with its deadline for completion extended at least twice, from the end of 2010 to a current target of 2013. Arabian Construction Company had been the original main contractor, only to be replaced in the summer of 2009 by Arabtec.
Both contractors faced the same challenge: how to build something so high on ground that was so close to the sea, with the inevitable difficulty of preventing so much water entering into both the construction site and the finished product. Sources close to the project say Arabtec had to retreat from the project as it had a greater focus on UAE projects and could not provide sufficient technical resources, as well as a bond, to the project, as its focus remained mostly on its UAE activity. By the end of last year, Saudi Lebanese Contracting Company, also known as Tarouk, took up the project, and has been the fulcrum for the project’s swift progress since October 2010.
The project brings together an abundance of high-profile companies, with some specified consultants for different areas. Overseeing all aspects of construction is Turner, complemented by Saudi Diyar Consultants, which has a focus on the engineering strategy to convert the design by RMJM into reality. Tarouk will have additional help from Clink for the shop drawings.
Dulb Trading & Contracting has been lined up for all electromechanical work when the structure is completed, and will receive consultation from Damas. At the same time, it also incorporates some of the biggest sub-contractors. These include Kasktas Arabia, the local arm of the Turkish foundation specialist; Doka, the formwork giant that has been critical in the creation of the podium, tower core walls and slabs; and Saudi Basic Materials, whose huge machines at the back of the project is injecting the structure with its concrete mix.
The design has been a complex concept, and has needed to incorporate new elements along the way, from the provisions against water flooding into the foundations to the specifics of the podium’s interior. Salih Fardour, CEO of Lamar Company, a member of Zahran Holding, explains that the company is still yet to decide which of the three hotel companies that have made it through to the final round of consideration will occupy the hotel space, and that this has an influence on the current construction procedure.
“We are currently discussing with three hotel companies, and we will be nominating the winning company no later than June,” he says in the company’s site office. “These are under review, although we have a study from one of the hotels, and we are trying to bring that study into consideration at the design stage, though we are aware that the other designs from the hotels will be different.”
Fardour explains that the contractor has completed five slabs of tower one, the tallest, and is working on the sixth of tower two. The basement and podium are on the verge of completion, with the services of Kasktas Arabia retained for the moment to continue the dewatering.
Fardour explains that the project has specialist consultants to work with carefully-selected contractors so that each area of construction is on time, with the best methods and quality possible. This produces savings in the long-run, he says, particularly if the project is completed ahead of schedule, even though the initial outlay to employ these consultants may be high.
“The key is engineering and procurement and you do have to have qualified people. The reason that some projects have stalled or stopped is because there is not enough care taken with engineering and procurement. Even if you have a strong main contractor you need to have the right subcontractors.” Between 10% to 15% of a project’s cost can be saved with the right procurement choices and timely finish, he estimates.
The site is teeming with around 4,000 workers across the length and breadth of the project, from steelwork in the areas of the basement that is still exposed to the formwork gripping the core wall at the top of the twin towers.
Standard formwork upholds the podium level on the ground floor. Omer Khawaja, marketing manager at Doka, explains that slipform was used for the G+1 level, and then this was replaced by three systems for the core wall: automatic climbing formwork SKE, climbing formwork MF240, and climbing formwork 150F. Steven Klaas Ulrich, in-house project coordinator for Lamar Company, explains that the climbing formwork is split into two parts, with the left side slightly higher than the right side as you look at the bright yellow belt clinging to the core. Working at slightly different levels, essentially splitting the core wall into two parts, helps speed the construction of the corewall, he explains.
“Tower 1 slabs are being completed in 14 days and tower 2 in eight days,” he says, adding that they are trying to reduce the slab cycle time. “From here [the podium] to the column, we used slip formwork.”
The project is mobilising for its big push of construction into the sky. Ulrich explains that they are currently putting in place a 500t mobile crane to complement the lifting crane that is attached to the core.
It is the building foundations, and what is below them, that has proven to be one of the biggest challenges, and the basis of innovation. Ehab Sobhy Mohamed, construction manager at Turner, says that as the piling was being completed, the company did a detailed study of the potential that any hole in the earth would flood with water from under the shallow land.
“It has been a challenge to prevent water rising up as there are too many cavities,” he says. “What we did was to install a grout blanket, which is comprised of cement and sand, from 18m deep into the ground up to 13m deep, so 5m.”
This blanket, which is comprised of cement and sand, is essentially the foundation under the foundation, and prevent the majority of water entering underground.
However, the foundations only go down 9.6m, so there is only soil between the bottom of the foundation and the top of the grout blanket. This means that some seepage still occurs, keeping Kasktas Arabia busy until further notice.
Mohamed says that the second major challenge is to be able to ensure the verticality of the towers as they get higher. He says that up to the tenth floor the team of contractors can use traditional surveying methods.
Above that level, he says the company is considering deploying technology, namely the Leica GeoMoS monitoring system, a web-based tool that allows users to visualise the upcoming structure and assess changes where necessary. The system can collect data from different parts of the structure and in this way ensure everything is mathematically correct.
“The verticality of the structure is very important, and Tarouk is new to constructing high-rise buildings, so we can help with maintaining the verticality,” he says. “Due to the wind factor and the position of the placing boom, there will be some shifting. So we need to control the structure as it goes up.”
Higher building also implies a growing weight on the basement, and this presents the second geotechnical challenge. “We take the lead from the consultants regarding the uplift of the raft. This is an element of the geotechnical work, in which you are studying the uplift. If you have the same weight pushing up as is pushing down, you are fine; if there is greater weight coming down from the podium and towers, then it is a failure.”
It also implies the challenge for all high-rise builders: how to pump concrete up the structure to complete the slabs. Mohamed explains that the company is going to initiative a simulation test using a special pump and placing boom from Putzmeister.
Essentially Turner will test the consistency and friction of the concrete mix when it reaches the top of the pump – then it will be clear if the top of the building can be constructed with the same consistency as the bottom.
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