Rehabilitation of the West Access to the Americas Bridge
With an approximate cost of 15.6 million Dollars, FCC executed the stabilisation of the western access to the Americas bridge, which was an emergency project requested by the Ministry of Public Works (MOP) to improve slope stability.
The project included an investigation survey to establish its design.
The survey consisted of boreholes with core recovery, testing and installation of clinometers and piezometers.
Both clinometers and piezometers are still being monitored.
This stabilisation, which was carried out over an average time of one year, included the following:
• The Installation of sub-drainage, construction of concrete ditches and basin on the mountain side to channel the underground and surface water of the mountain side basin to the Canal.
• Reconstruction of the existing piping for the water exit, from the mountain side to the Canal. A driven, 24-inch diameter, high-density polyethylene (HDPE) pipeline was installed parallel to the existing one, to guarantee drainage capacity from the mountain side to the area bordering the access highway to Veracruz, with special water-collection boxes.
• Slope stabilisation using two layers of launched reinforced concrete, with subsequent installation of 12-metre passive anchors, in a 4 x 4-metre mesh.
• To achieve deep stabilisation of the embankment, a cut-off wall of 1.20-metre diameter piles was constructed that was contiguous with the Veracruz access highway, followed by a crown beam and a 4.9-metre wall. After filling-in the space between the slope and the wall, the stabilisation of the deep embankment fault was achieved by providing weight on the slope foot. In order to achieve stability of the whole works, two rows of active anchors were executed on the wall, which support 150 tonnes per linear metre, with a length exceeding 50 metres.
• The hidden wall face was waterproofed by constructing a ditch at its foot to collect water underground water circulating through the underground drainage. A ditch was executed along the upper part of the wall to collect surface water.
• Californian drains were installed from the crown beam, with six-metre separation and length exceeding fifty metres, with a five-degree inclination.
• The final wall appearance from the Veracruz roadway was obtained with an apron from the pile cut-off wall crown beam to the water collection ditch at the roadway foot.
• The final access appearance was obtained by injection below the grade line, asphalt paving, together with lesser operations.
• Reforestation and seeding to control erosion.