Charleston, SC - Work began this week to install 3.5 million feet (662 miles) of wick drains at the port expansion site on the former Navy Base in Charleston, signaling that construction of the new, 280-acre container terminal is moving forward.
The wick drains, also known as prefabricated vertical (PV) drains, provide a channel for water to migrate vertically from sub-surface soils in order for the land to consolidate and the site to settle. This work is a necessary step before any construction may commence, and greatly reduces the destructive effects long-term settlement would have on above-ground pavement and structures.
The wick drains are pushed vertically deep into the silty clay soils. Once the wicks are in place a thick layer of soil (surcharge) is placed over the area to provide weight. The surcharge presses down on the wet soils, causing water to migrate vertically up the wick drains into the horizontal drainage layer above.