Cone tipped cylindrical probe for use in groundwater testing

Abstract

A piezocone for measuring the soil's resistance to penetration and pore water pressure while being advanced into the ground by a rig. The piezocone includes a friction sleeve and a conical tip attached to the lower end of the sleeve. The conical tip develops the cone resistance. The friction sleeve is an isolated cylindrical sleeve which measures the resistance of the soil as the sleeve passes through the soil. The pore water pressure is measured by a porous element mounted in the conical tip of the piezocone and a pressure transducer mounted in the cylindrical friction sleeve of the piezocone. The measurements including pore water pressure, cone resistance and soil resistance are supplied to a computer which includes a Piezocone Dissipation Analysis program for processing data from the measurements to generate dissipation curves for each depth at which the piezocone provides hydrogeologic site characterization data. Soil classification is also provided from a data file stored within the computer. The Piezocone Dissipation Analysis program generates a Hydrostatic Pressure Profile curve and a Hydraulic Conductivity Profile Plot. A water depth below surface estimate is provided using the Hydrostatic Pressure Profile curve zero pressure intercept. The Hydraulic Conductivity Profile Plot may be generated using coefficients of Permeability from a soil classification table.