Incremental Launching for Bridges | MK4 - Mekano4

The concept of the Incremental Launched Method is to cast or assemble successive deck segments of approximately 15-30 meters long in a stationary formwork on concrete bridges (similar to factory conditions or segments of 100-200 meter on metallic viaducts) behind the abutment and then to push/pull the increasing lengths of bridge decks into their final position by sliding the segments over special Teflon-stainless steel devices (temporary or permanent bearings).

For the launching operation special “friction system” using hydraulic lift-push jacks is used. Alternatively, the launching can be done by means of hydraulic pulling jacks using strand or bar temporary tendons. A steel nose is installed on concrete viaducts or a temporary tower with stays on metallic decks.

Construction design / alternative design.
Supply and installation of temporary / permanent post tensioning.
Supply and erection of special formwork and launching steel-nose.
Supply of bearings (temporary/permanent).
Launching operations and equipment.
Supply of special sliding pads and devices.
Bar prestessing for steel-nose and lateral guides attachment to the structure.

The incremental launching method arises from the need to build continuous steel decks in an economical way and with the least possible interference with the valley, river or area over which the structure crosses.

First launch of the Grenland viaduct in the E18 project in Norway