Challenge

Mexico City is the world’s second-largest city and the single largest economic area in Latin America. The country’s vehicle population is growing rapidly, reflecting its economic development. In response, the government has approved a series of major infrastructure works to improve connectivity. This work includes a new tunnel and concrete bridge at Parque la Loma, but to enable its construction, and allow equipment to reach the construction site, a new 5km long dual carriageway was needed, together with a temporary bridge over a ravine.

Solution

When Coordinadora Vía Rápida Poniente, SAPI de CV embarked on the project to construct the new access road and temporary bridge, the challenge facing the installers of the bridge was exacerbated by the soil type at the site, which meant that all vehicles had to be removed at the merest hint of rain, to prevent them getting stuck.

The bridge was to be installed over a ravine with steep sides. The ravine sides were earth, with little exposed rock to restrict the siting of cranes or other plant machinery.

A 15-bay Mabey Compact 200 with anti-skid decks and MLC110W transoms was chosen as the ideal solution, due to its rapid construction and heavy load capability. This suited the client ideally; it had stipulated that the bridge be constructed within a very tight timeframe, of just 8 days.

The construction and lifting-in of the Mabey Compact 200 was undertaken by a subcontractor. The bridge was assembled behind the near abutment using a 20-tonne crane and erection workers. Before assembly of the bridge, the panels were assembled into truss boxes using a 4.8 tonne crane and four erection workers. The bridge was finally lifted-in using a 500-tonne crane, with deck-out taking place after the bridge had been lifted into its final position.

Result

The temporary bridge is now in place, allowing site traffic to progress with the main task of building the new tunnel and concrete bridge. Site traffic is invariably heavy, but the Mabey Compact 200 is providing excellent access for the main contractor. The anti-slip decking adds an extra degree of safety at a site which is frequently wet and muddy, due to the weather and soil conditions.