Jump Main Menu. Go directly to the main content

Sección de utilidades

Fin de la sección de utilidades

Sección de idiomas

Fin de la sección de idiomas

You are in:

  1. Viaduct launching and tensioning

Portal / Viaduct launching and tensioning

Start of main content

Launching process

This is a platform construction process that involves the manufacture of platforms by sections (segments) in a fixed location (Manufacturing Park). The platform is then launched with hydraulic jacks that pass on top of the piles with special support elements.

This process is repeated as many times as the number of platform segments or sections, fixing them together with the post-tensioning operations.

Launching equipment

The launching equipment includes horizontal and vertical hydraulic jacks, so that the movement takes place in four phases, whereby the vertical jack lifts the platforms load and it is then pushed by the horizontal jack to move the platform forward. After covering approximately 20 cm, the vertical jack is lowered and the horizontal jack is retracted, repeating the cycle.

The equipment used by Tecpresa has a power rating of 680 Tons during launching operations and 1,570 Tons during lifting operation. These units can push a platform length of more than 1 Km horizontally, with performances of up to 7 m/h.

Post-Tensioning during the launching procedures

This type of viaducts usually involves two different types of Post-Tensioning operations.

The purpose of the post-tensioning operations during the launching or execution activities is to brace segments together to provide the continuity needed by the platform and thus resist the efforts that the structure has to withstand during the launching operations.

Exterior Post-Tensioning of the service

When the whole bridge structure has been launched, the post-tensioning operations are carried out to support the loads of the service viaduct.

Exterior post-tensioning operations have the following advantages:

  • They facilitate the execution of inspection, replacement and re-tensioning operations, in case needed, throughout the working life of the structure, improving its durability.
  • They facilitate the manufacturing of the platform, since they decrease the interference in the concrete pouring activities of beam webs, improving the execution rates.

End of main content

  • Start of content