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 twenty ton hydraulic cone penetrometer rig. The low pressure piezocone includes a friction sleeve and a conical tip attached to the lower end of friction 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 the soil resistance are supplied to a computer which includes a Piezocone Dissipation Analysis program for processing the piezocone 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 computer uses the Piezocone Dissipation Analysis program to generate a Hydrostatic Pressure Profile curve and a Hydraulic Conductivity Profile Plot. The computer also uses the Piezocone Dissipation Analysis program to provide a water depth below surface estimate which occurs at the Hydrostatic Pressure Profile curve zero pressure intercept.