Universal formwork for 127 million dollar property

The first 400 kV underground electrical power supply system for Dubai

The demand for supplies made by a rapidly growing population is not growing steadily, but also by leaps and bounds: New city sections must be erected on once-empty land, and supply and waste lines must be laid. This applies particularly to Dubai (United Arab Emirates). The most recent project is the 127 million US dollar Mamzar Beach substation, to work for the first time in Dubai with an EHV (extra-high-voltage) 400 kV line running underground. Internationally operating companies, including those from Germany, are involved.

Location

Only six kilometres away from the city of Dubai lies Al Mamzar Beach Park, set up in 1994 and 106 hectares in size, and possibly one of the swankest and most beautiful park and recreation facilities of the Arabic world. Nearby this holiday paradise, the most modern substation in Dubai is under construction. For the first time in this Emirate, the electricity will be supplied underground through 400 kV extra-high-voltage lines (above-ground lines could have a negative effect on the impressions of tourists and the local population). The plant will provide the local power supply for the growing population.

Key data

The first excavation work in this area dominated by desert sands began on Christmas Eve 2009. The groundwater level, influenced by sea water, lies 4.2 m under the earth’s surface. Since it was necessary to go 8.0 m deep into the ground, open dewatering was necessary.

Work on the shell construction began already on January 7th 2010. Because so much effort is being put into the work, this will be finished already in December 2010. The plant is to be handed over, ready for use, in May 2011.

Amounting to 16.5 million US dollars, the construction costs are not out of this world. The total costs, including the electrical systems, run at about 127 million dollars.

The client is the Federal Electricity and Water Authority (FEWA) in Dubai.
The main contractor is Siemens Power Transmission and Distribution (PTD), the division of the enterprise established for energy in 2008, which has a subsidiary located in Dubai.

The sub-contractor responsible for all constructions is Lootah Building & Construction (LBC) founded in 1973, from Dubai, a division of the Lootah Group of Companies.

Use is also made of the consultation services of Électricité de France International.

Working on location are: 1 general manager, 1 construction manager, 1 construction site planner, 1 technical manager, 2 construction site engineers, 3 quality managers, safety engineers, 2 foremen, 100 carpenters, 60 steel fixers, and 20 workers.

The electricity is generated in Al Awir, is transmitted 20 km to Mushrif, and from there 20 km underground to Mamzar Beach.

Constructions

The six construction sections are largely underground. The main components are

• The gas-insulated 400 kV substation including low voltage control centre (LCC relay room)
• The gas-insulated 132 kV substation including low voltage control centre (LCC relay room)
• The building for the 400 kV inter-connecting transformer (ICT)
• The master controller for 132 and 400 kV
• The control building
• The auxiliary buildings with water tank, pump room, collection tanks, etc.

Instead of the terrestrial atmosphere, the gas-insulated substations will contain the artificial gas, sulphur hexafluoride. This is inert, non-toxic and non-corrosive, conducts electricity considerably worse than air, and has the useful advantage that with it, many plants must be only 25% as large as those which contain oxygen. So for a system built within the city this is an unbeatable advantage – to say nothing of the enormous savings in material and construction costs.

Formwork planning

Because of the technology mentioned, the partially underground substation can be viewed as nothing less than small in comparison to plants with similar capacity built according to conventional methods.
It comprises only 24,000 sqm. – but of course it is made of 4850 tonnes of gas-impervious PPC 40/20 concrete, which contains 8% micro silicon. To be integrated in it are around 3000 tonnes of concrete reinforcement.
The base foundations were built using conventional methods.
Above them, MODULAR universal formwork from PASCHAL was used for all vertical surfaces.

In the building for the master controller there were a few problem areas where the heavily reinforced foundation had various height changes. At a depth of eight metres, there was hardly enough space and there were numerous separating walls. Since Modular is virtually indestructible, easy to work with and comparatively light, the formwork was able to satisfy all of these requirements.
The PASCHAL subsidiary in Dubai (PASCHAL Emirates Co. L.L.C., Dubai), under the direction of the construction engineer, Primo Celeste, was responsible for the formwork planning and supply.

MODULAR/GE universal formwork

The name, MODULAR/GE universal formwork, is entirely appropriate because it has proven its versatility and flexibility in use on the widest range of construction sites in over 40 countries, whether in foundations, walls, shafts, polygons, columns or beams.
Work with MODULAR has proven to be faster and easier than that with other products. The strong flat steel frame is easy to clean and work with.
The benefits of MODULAR were quickly recognized on the construction site. One of the reasons for this was the good training provided to the specialized workers by the PASCHAL sales engineers and installers.
Since the cycle planning was very effective, only 1500 square metres of formwork were necessary. Added to this were 200 square metres which formed several sets of, to some extent, double-high column formwork (up to 9.0 m).

Since the cycle planning was very effective, only 1500 square metres of formwork were necessary. Added to this were 200 square metres for the column formwork.

Despite the different wall heights (up to 9.0 m), foundation height changes and a strict schedule on the part of Électricité de France International, the Modular formwork satisfied the requirements with ease.

Outlook

The construction site is well organized according to strict international standards, and the construction materials and machinery are of the best quality. Everything is running according to plan.
This construction site is the first of its kind, and so it also represents a test case for other construction sites in the entire gulf, also in respect to standardized construction methods and the efficient large-scale use of concrete formwork systems. These can be used in similar substations, but also in residential and commercial buildings, and public buildings such as schools, hospitals, hotels and similar.
Today, an on-time opening is already being anticipated with satisfaction.