UBC Theses and Dissertations
The piezometer cone penetration test Gillespie, Donald G.
Deep quasi-static cone penetration tests in saturated soils can develop large excess pore pressures. The level and sign of the excess pore pressures depend on the volume change characteristics, the strength and the permeability of the soil. The recent addition of pore pressure measurements during cone penetration testing adds a new dimension to the interpretation for geotechnical parameters. This report shows how the pore pressure measurements enhance the stratigraphic logging abilities of the cone penetration test. Calibrations performed on the cone penetrometer are used to show the importance of correcting bearing and friction measurements for pore pressure effects. As well as pore pressure effects the importance of procedure and equipment is discussed. The use of pore pressure dissipations recorded while penetration is halted is illustrated. Theoretical solutions for pore pressure decay rates are illustrated and results predicting the coefficient of consolidation are compared to laboratory measured values. The coefficient of consolidation predicted from decay rates is shown to compare well with laboratory measured values for the soil in the overconsolidated state.
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