Soil stratification using the dual-pore-pressure piezocone test

Among in situ testing techniques presently used in soil stratification and identification, the electric quasistatic cone penetration test (QCPT) is recognized as a reliable, simple, fast, and economical test. Installation of pressure transducers inside cone penetrometers to measure pore pressures generated during a sounding has added a new dimension to QCPT - the piezocone penetration test (PCPT). In this paper, some of the major design, testing, de-airing, and interpretive problems with regard to a new piezocone penetrometer with dual pore pressure measurement (DPCPT) are addressed. Results of field investigations indicate that DPCPT provides an enhanced capability of identifying and classifying minute loose or dense sand inclusions in low-permeability clay deposits.