U.S. National Report on CPT

SYNOPSIS: Over the two decades since its introduction into the United States, the CPT has now established its position as a routine, reliable, and expedient means for site characterization, stratigraphic profiling, evaluation of soil engineering parameters, and geotechnical design. Piezocones provide measurements of penetration pore water pressures either midface (type 1) or at the shoulder (type 2). The latter is necessary for the proper correction of tip resistance in soft soils, while the former provides better resolution and detailing in
stiff fissured materials.

Most areas of the U.S. are now serviced by specialty firms with cone trucks for optimizing production, penetration depths, and areal coverage. Portable cone systems are available for small projects and remote locations. Research on CPT testing and analysis continues to have high priority within many organizations.

The incorporation of additional sensors has increased cone versatility, thus favoring use of seismic- geophones, resistivity- or conductivity-, natural gamma-, and chemical-cones. This is attractive on geoenvironmental projects for expedient contaminant mapping while minimizing site damage and wastes
generated from testing.