Latest solutions for segment fixing 14 Sep 2017

Optimas Sofrasar News Release

Tunnels form an important part of a rapid transit network, whether for traffic or utilities, and although impressive in their construction, tunnels need many smaller individual components to function effectively.

Optimas plastic dowel segment fixings
Optimas plastic dowel segment fixings

French supplier of fastening solutions for major tunneling construction projects, Optimas Sofrasar has supplied products for pre-cast segment tunneling projects for over 20 years. Recently it has introduced its new segment fixing products to a number of important projects in North America including the SR99 Alaskan Way double deck highway tunnel in Seattle which, once complete, will have the largest diameter of any tunnel in the world.

The new fixings from Optimas enable a quick and secure installation of concrete segments and involve using thermoplastic dowels in circumferential joints which provide stability of the rings under pressure from ground or grout injection and provide a cost effective alternative to the classic bolt system.

Optimas is currently using this new system in several high-profile projects including the New York Rondout Bypass Tunnel in North America, the Los Angeles Westside Subway extension I, the Columbus Blacklick Creek sewer tunnel, the West Trunk Sewer project in Toronto, and they proved a success on the recent Crossrail project in London.

Optimas provides a complete range of bespoke or standardized bolting systems, dowel systems, centering systems and shear dowels, grout-lift sockets, guiding rods and packers plus precast accessories and security systems. All components are designed and developed in-house and backed by a strong supply structure, so even bespoke parts can be delivered at a competitive price.

Optimas stand at the recent RETC conference
Optimas stand at the recent RETC conference

In addition to supplying components Optimas can also help during the concrete segment design phase to save costs and ensure faster production. Highly specialised testing rigs and software are also provided to check mechanical resistance and durability prior to installation on site, assuring contractors that any fastener supplied will offer maximum performance and service life in application. To bolster this, a number of state-of-the-art laboratories where components are independently tested to guarantee performance are operated worldwide.

Optimas recently joined its North American agent David Klug and Associates to exhibit its products and meet professionals of the North American tunneling industry at the RETC conference in June 2017 and will be exhibiting at the FAST Exhibition on September 21 at Duxford, UK.

“While its primary focus is on the North American market, the RETC is a key event for the tunneling industry on a global scale. As a business, we specialize in the design and delivery of components that are engineered for tunneling applications. We were very happy to partner with David R. Klug and Associates to spread the message of our capabilities to the conference delegates,” said Christophe Delus, Tunnel Division Director for Optimas.


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