Clear run to Versoud

The Goal

To build a new bridge over an existing railway line without disruption
A new 1.7-kilometre-long road between Le Versoud and Villard-Bonnot required a bridge over the existing railway line.

With panel sizes up to 3.5m x 2.5m, it is by far the biggest system on the Chilean market. And the fact that it needs so few accessories per square metre significantly boosts productivity.

The Project

Summary:
The new bridge piers were meticulously planned to be constructed in the least disruptive manner for the railway line. 

Challenge:
Avoiding disruption to the railway line was the top priority, so each bridge pier needed to be poured in a single cycle in one day. Due to the location of the piers adjacent to the railway line, the airflow from the passing trains would also affect the stability of the formwork.

At the same time, the cantilevers of the piers had to be integrated during the pour. However, additional decking or heavy shoring would not be possible as they would have obstructed the railway line.

The Solution

1. Expert technical solutions
   To pour each pier in just one day, 350m³ of fresh concrete would need to be poured in ten hours. To avoid large wood fillers, MEVA suggested using STB corner frames, thus allowing the formwork to be created in a shape that corresponded to the pier geometry.

   On the construction site, the Mammut 350 wall formwork was able to make full use of its strengths. The system, which has a capacity of up to 100kN/m², can easily cope with the fresh-concrete pour speed corresponding to a pressure loading of 70kN/m². This made it the perfect choice for the rapid pier construction.
    
    

2. Working safely at height 

   For the cantilevers – which were 79 centimetres long and needed to be poured at a height of 10 metres – access was an issue. To get around this, the SecuritBasic safety system was used in conjunction with the Mammut 350 panels. The working platforms enable safe and cost-effective work at height and can be flexibly adapted to suit the formwork structure. This way, the cantilevers could be poured without infringing upon the railway line below. 

   The complete unit comprising a safety system and wall formwork panels was assembled safely and easily on the ground and moved into position by crane.

The Outcome

The bridge was completed in the summer of 2019, after the forming work was completed without any issues. At the end of 2020, construction was completed and this important transversal road opened to traffic. The improved transport link between the two towns will not only improve local traffic conditions, but also support the expansion of two newly built industrial estates in the area.

Featured Products

• Mammut 350 wall formwork
• SecuritBasic safety system
• STB/SK

Client:
Baudin Chateauneuf

Project:
Bridge

Location:
Le Versoud, France

Principal:
Communauté de commune du Gresivaudan

Engineering & Support:
MEVA Systèmes de Coffrage SNC, France