The GATE project

As part of the GATE (Gas Access To Europe) project conducted in consortium with Italian and Spanish firms Techint and Sener, VINCI Construction Grands Projets and Entrepose Contracting designed and built three liquefied natural gas (LNG) storage tanks, each with a capacity of 180,000 cubic metres. These structures are part of a building program for a regasification terminal with a capacity of 8,000 million cubic metres a year. The project, which was carried out in an Oil & Gas environment that called on the Group’s full experience and expertise, confirms the outstanding synergies that exist within VINCI’s diverse business lines and skilled trades.

Background

In the past, gas deposits were often distant from consumption centres, making gas-related operations challenging to carry out. One of the main obstacles to commercialising gas was its volume in its natural state. Thanks to industrial-scale construction of storage tanks for gas liquefied by cooling (enabling a 600-fold reduction in volume), the gas trade between exporting and importing countries was developed. In addition, the storage capacity of LNG tanks has been continuously increasing. Advances in terms of structural design, ground-reinforcement techniques, and construction methods have led to a considerable increase in storage-tank capacity. Given its ideal location, the port of Rotterdam is western Europe’s leading seaport platform, and home to the GATE project and other dynamic construction initiatives for receiving terminals for northern Europe.

TECHNICAL OVERVIEW

VINCI Construction Grands Projets performed calculations on cracking, which required extensive modelling and led to stringent civil-engineering finishing works. The design office at Entrepose Contracting designed the storage tanks’ mechanical component with an inner chamber made of steel with a 9% nickel content and a perlite insulating layer, highly resistant to very low temperatures. In addition, Freyssinet deployed high-tech prestressed cryogenic concrete, developed for the nuclear industry, which can retain its ductility at minus 163°C. The strength of our consortium was its ability to adapt to changes in the field. For instance, VINCI Construction Grands Projets was able to modify the civil engineering for the storage tank domes during the course of the project. Each load-bearing post/beam structure located 52 metres above the ground was developed using precast concrete components, rather than poured on site. As a result, they could be assembled and fastened to the dome in two months, independently of weather conditions, with a minimal number of employees working at height. This resulted in a big gain in terms of safety and time-savings.
To be more specific, the storage tanks’ external envelope consisted of a foundation slab 90 metres in diameter, a prestressed concrete shell 40 metres high, and a reinforced concrete dome. Concrete protects and insulates the main inner chamber.
Each foundation slab, of varying thickness, required 1,000 tonnes of reinforcement. The added presence of a network, several kilometres long, of heating pipes in the slab was designed to prevent the ground below the slab to freeze during the operational phase and, thereby, lose its load-bearing capacity.
Implementing the shells 40 metres high required the use of successive lifts by increments of 3.65 metres. A solution consisting of climbing formwork for three platform levels, combined with the use of high-load-capacity tower cranes, allowed us to optimise lifting and panel-sealing operations.

The policy of “zero accidents” was promoted at the worksite. It was led by five people whose role was to raise all labourers’ awareness of safety practices.

IMPACT

The GATE project in the port of Rotterdam marks a dynamic renewal in the construction of new receiving terminals for northern Europe. Currently, this structure is the largest of its kind in Europe.
Throughout the project, safety was a priority and constant concern – as befits a critical petrochemical site where more than 400 employees from fifteen different countries worked together at peak periods.
Top management is committed to making LNG projects compliant with sustainable development. In offices, most paper is recycled and printing cartridges are reused, that is, they are collected and sent to a recycling facility. The same policy applies to batteries. Selective sorting was implemented at the worksite. Clearly identified containers helped in the sorting of waste products. Wildlife and vegetation were also major concerns. Measures to protect bird-nesting sites were taken; in this regard, we worked in partnership with companies specialising in this area. Local environmental authorities also took an active part in the project. Managers aware of environmental issues took a more active role in the worksite and devised innovative practices. For instance, all personnel used bicycles for personal transport at the worksite. This initiative prevented several tonnes of CO2 from being released into the environment, which earned us thanks from the client and from our consortium partners.

Project participants

Client
Gate Terminal Bv

Key figures

Implementation dates
January 2008 to September 2011

Concrete
46,500 m3

Steel
10,000 t

Formed surfaces
65,000 m2

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