Taxiway Embankment Construction on Soft Ground Using In Situ Instrumentation and Staged Construction

The Piedmont Triad International Airport (PTIA), Greensboro, NC is undergoing an expansion as a result of the construction of a regional hub for Federal Express. Part of the construction includes an embankment over an alluvial floodplain in a wetlands area. A hybrid ground modification technique was used to stabilize the soft ground, consisting of geogrids, wick drains and rock toe berms. An instrumentation program was implemented to evaluate the changing properties of the alluvial soils, lateral displacements of the embankment foundation soils, settlement of the embankment, determine the fill placement rates or appropriate waiting periods, and to prevent slope failures from occurring. This paper highlights key features of the design and instrumentation system. It describes the project conditions and considerations, the instrumentation system that was installed, the results obtained during construction, and practical issues that were addressed during construction.