Putting the grandure back

There has been a hotel on the San Stefano site in Alexandria, Egypt, since 1887. By 1920 it was one of the world’s ‘Grand’ hotels but it has fallen into disrepair along with much of the Corniche. Today, the Corniche is undergoing a renaissance, and the Stan Stefano is being redeveloped with the use of a sophisticated formwork system.

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By  Colin Foreman Published  December 13, 2003

The San Stefano project|~|san_stefano_200w.jpg|~|The crescent-shaped 30-storey tower will be the tallest building in Alexandria. The sea-facing tower will include a 17 floor Four Seasons hotel.|~|The San Stefano project is situated on Alexandria’s waterfront, is bound to the north by the corniche and to the south by Abdel Salaam Aref Street. On its eastern boundary is the 14 m wide Hamman Al Sayyidat Street and on the opposite side, the 22 m wide Casino Street. The project comprises a three-level basement car park with parking for up to 2000 cars; a lower ground and ground floor topped by a five-storey podium.

The project also features two crescent-shaped high-rise towers that, at 26 and 30 storeys, respectively, make them the tallest in Alexandria and amongst the tallest in Egypt.

In addition to providing 800 high quality apartments ranging in size from 131 m2 to 1272 m2, the complex will also include a luxury five-star 127 bedroom and suite Four Seasons International hotel, a cinema complex and commercial properties. It will also feature its own private 600 m long beach and marina; connected to the hotel by a pedestrian subway.

The San Stefano dates back to 1854 when Count Zizinia, a wealthy contractor and a close friend of Mahamed Ali Pasha, Governor of Egypt, purchased the land, becoming the first foreign resident of the district of Ramleh in Alexandria. A hotel, named after a small chapel dedicated to San Stefano on the site, opened on the 26th June 1887. By the 1920s the hotel San Stefano was recognised as one of the ‘Grand Hotels’ of the Alexandria River and one of the oldest hotels in Egypt.

With the subsequent demise of the waterfront properties along the historic corniche throughout the 1960s and 1970s, the new San Stefano project today forms an integral part of the city’s beautification scheme for Alexandria to regain its former splendour and elegance.

Today’s San Stefano project occupies a similar area of 30 000 m2 as its predecessor with a sea frontage of 170 m. Excavation of the site, piling and fabrication of the diaphragm walls around the site had been completed in an earlier contract by Egyptian contractor ACC, together with the concrete pour for the first 26 500 m2 basement slab.

ACC also constructed the retaining wall up to the P3 basement level and slab. At this stage, with South African contractor Murray & Roberts tendering for construction of the superstructure in joint venture with its partners, it was awarded contracts for basement levels P1 and P2. With a variety of basement heights across the complex up to 5 m high and between 400-700 mm thickness, Murray & Roberts introduced Doka Formwork’s single-sided Frameco system for construction of the retaining walls.||**||Formwork|~|formwork_200w.jpg|~|Throughout construction of the projects vertical elements, Murray & Roberts are utilising Doka’s Frameco system for heights varying from 0.7 – 3 m.|~|Murray & Roberts International, a leading South African-based contractor with extensive experience of Doka formwork systems, through its projects in the United Arab Emirates, opted to use Doka’s tableform system for the ‘typical’ floor layouts of both towers.

However, while awaiting confirmation of its superstructure tender, the company became involved in construction of the upper layers of the podium structure. “This was certainly not a ‘typical’ layout, with an ever changing variety of slab heights and thickness’ across the podium,” said Al Taher. Slabs varied in thickness’ from 300-500 mm across the floor area with floor heights between 2.7 m – 7.75 m.

“However we took the opportunity of utilising the first shipment of Dokaflex tableform, proving the system can be used for both typical and non-typical layouts,” he added.

This is the first use of the system in Egypt and it has allowed the contractor, a joint venture comprising Murray & Roberts, Habtoor Engineering and SIAC, to reduce planned cycle times from a 22 day cycle to just 12 days. According to project manager Osama Al Taher, this was achieved once the workforce had become skilled in the use of the tableform concept, and, he says, “by a re-evaluation of work and management practises.” As a direct result, the contractor has made-up lost time with earlier delays and is well on schedule for a completion date of October 2004.

As a ready-assembled unit, the Dokaflex table reduces the number of separate items needed for the floor formwork. Large tableforms can be easily shifted in one piece to the next position to be cast without being dismantled. With fewer separate parts formwork erection and striking are greatly accelerated. This ensures the shortest possible forming times for the contractor.

By the time construction had begun on the twin crescent towers, Murray & Roberts, recognising the ease of operation and potential of the Doka tableform system, had placed orders for a total of 10 000 m2 of Dokaflex tableforms and props, including Eurex 550. Additionally, the contractor is also using Doka’s Frameco and Frami wall and column formwork systems ordered through Doka Egypt based in Cairo.||**||Operational|~|more_cranes_200w.jpg|~||~|“Having taken the opportunity to train our staff in using the tableform system where possible in the podium levels, we quickly recognised the ease of operation. This together with a re-evaluation of work practises and management procedures, allowed us to reduce the initially forecast 22 day cycle to just 12 days,” enthused Al Taher.

The 26-storey sea-facing west tower with a floor area of 4650 m2 also includes two open atriums above the podium up to the 17th floor. This means the contractor is effectively constructing three towers within the west crescent during this phase. Both atriums have a total height of 40 m. The central tower formed between the two atriums will be designated for the 17-storey five-star Four Seasons hotel; overlooking the corniche and offering sea views for its guests.

The slightly larger east tower with a floor area of 5330 m2 has also been designed to feature a single central atrium; this time to a height of almost 55 m to the 21st storey. Both towers are connected at the top of the west tower by a five-storey bridge to the full height of the east tower. This will be used as a connecting walkway and plant rooms. Throughout construction of the typical floor layouts, the towers were divided into a total of 11 bays – six on the east tower and five on the west.

One complete set of Doka tableform has been delivered for each slab providing a total area of 10 000 m2. Murray & Roberts is achieving one slab pour on each tower every night. Working to a 12-day cycle ensures 2.5 levels are completed within this cycle totalling approximately 28 slabs/month. Slab thickness on the typical floors is 300 mm.

At the start of basement level P2 up to the 11th storey, the contractor used two main classes of concrete: Class B at 32 mPA, sourced from Alexandria aggregates and Class A at 52 mPA. However, difficulty was experienced in achieving Class A without the use of Suez aggregates, special additives and high-quality cement.

Following extensive trials by Murray & Roberts, the contractor obtained approvals to use Class A for vertical elements up to the 11th storey and Class B above this level.

By early November almost 150 000 m3 of Class A and B concrete had been poured.

The project location in an extremely busy area with considerable traffic congestion meant concrete deliveries and pumping is carried out between 1 a.m. and 7 a.m. each night; when traffic delays into the city and the site are minimum.||**||Deliveries|~|harrung_200w.jpg|~|Left to Right: Harald A. Harrung, Doka General Manager; Osam Al Taher, Project Manager; Hesham El Deed, Doka Project Co-ordinator. These are the men managing the project.|~|Co-ordination of deliveries and off-loading remains a major challenge for the joint venture with the adjacent narrow roads and traffic congestion plus limited site storage space. Daytime deliveries are therefore co-ordinated on a ‘just-in-time’ basis.

According to the Project Manager, the Doka tableform has proved to be a most efficient system, its quick, easy to handle and reduces manpower practices. “It is just perfect,” he says. For the project’s vertical elements, Murray & Roberts are utilising Doka’s Frameco system for columns that vary from 0.7 to 3 m. “The beauty of this system is that we can assemble and make-ready before fixing over the steel reinforcement,” says Al Taher. He adds, “As a result of preassembly, this system from Doka is proving more efficient than other systems I have seen.”

The contractor is also using the Doka Frameco system for fabrication of the project’s core shafts using a special platform designed and ‘cut-to-size’ to suit the shaft dimensions. The platforms comprise angles, channels and decking plus Doka’s ‘push-pull’ struts. “This is a beautiful system; it’s really efficient and never a problem,” says Al Taher. Once assembled, the system is moved to each floor and the platform ‘sits’ on strong gravity pawls inprepared recesses in the already hardened concrete wall.

With typical floor heights of 3 m, the contractor is also using the system to heights of up to 5 m on the non-typical floors. The completed shafts will house either two or three lifts and a shaft is constructed within each of the 11 slabs.

Unusually for hi-rise buildings in the region, the San Stefano project does not include expansion pads. Instead the project designer Technical Consultancy & Design Engineering, opted for central shrinkage pads. Strips up to 1.3 m and 1.7 m are left across the breadth of the slab with the reinforcement bars exposed for a period of 2 months; allowing time for shrinkage and settlement. The gap is then cast and left for a further week. “On reflection,” says Al Taher, “We would have preferred the use of expansion joints since the shrinkage pads technique means that the props are retained in position for two months, then a further week before being struck. This means that we are constantly back-propping over a large number of floors tying up lots of material.” The pads have been constructed throughout all the podium levels together with a total of five joints in the east tower and four joints in the west tower.

Murray & Roberts anticipate completing the structure by the scheduled October 2004 with the exterior sand cement-rendered and painted to a high quality finish.

By completion, the crescent-shaped towers will allow more than 90% of the residential units clear views across the Alexandria Riviera out to sea.

According to the architect, Webb Zirafa, the design concept of the project was invariably to make San Stefano an Alexandria landmark:“a pearl on its shore which will increase in value with time.

“Hence our choice of unique design and integrated components and concern for all the elements of good aesthetics and comfort, employing the most up-to-date techniques, providing every enticement whether for entertainment, sport, culture or shopping.”

For more information please visit www.doka.com||**||

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