Wick drains for soil consolidation, Mexico airport
Location of work/project:
Mexico, Nuevo Aerpuerto Internacional de Ciudad de Mexico
The wick drains enable to facilitate the evacuation of the water present in the soil in order to consolidate it and reduce subsequent settlements. The wick drain consists of a prefabricated vertical drain formed of a 9.5 cm wide HDPE core, surrounded by a non-woven geotextile which filters the water flow.
The quality of land in Mexico City makes the construction of its new airport (NAICM) a challenge. Founded on Lake Texcoco, the clays that make up the subsoil have high water content, high plasticity and compression rates that can exceed 10 times the normal value. These are ideal conditions for the development of differential settlements in the middle / long term.
In order to control this complexity and increase global load capacity, the prefabricated wick drains are installed along the length and width of the runways. This solution precedes an overload that is carried out on the area to be consolidated, with the objective to accelerate the settlement thanks to its weight. The accelerated settlement allows the vertical evacuation of the flows through the wick drain.
The installation of the wick drains is done through a machine designed to drive the drains into the ground. Each wick drain can go up to 50 meters deep (usually 20 to 30 m) and they are separated on average 1 meter from each other.
In many cases, this solution can be an alternative to gravel columns as accelerated consolidation / settlement systems.