CPTU SOUNDING

Our offer covers CPTU static sounding. Conducting a static cone penetration test requires pushing a pentameter, which is a cone-shaped probe, into the soil through a set rods. The probe should be pushed in at a constant penetration rate of approx. 2 cm per second. Throughout the duration of the test, the operators constantly monitor cone penetration resistance (qc), friction sleeve resistance (fs) and pore pressure (u2) values.

Electric CPTU piezo-cones are precise measuring instruments, especially designed for geotechnical soil investigations. These probes are equipped with strain gauges that enable measuring the resistance force for cone penetration (qc) and friction sleeve resistance (fs). CPTU piezocones are also fitted with a pressure sensor (u2) that enables in-situ pore pressure measurements during the test. All these parameters are measured constantly and simultaneously. Pressure sensors can also be used to conduct dissipation tests of excess pore pressure.

Cone penetration test is characterized by high measurement accuracy and sensitivity to variable subsoil properties. In addition to CPTU static sounding, we also execute CPT and seismic tests. We use a seismic module for this purpose.

WHAT DOES THE CPTU INTERPRETATION COVER?

CPTU sounding qualitative interpretation covers the determination of:

  • subsoil structure homogeneity,
  • boundaries between different soil strata,
  • boundary between made ground and natural soils,
  • preliminary assessment of cohesive soils pre-consolidation.

Whereas the quantitative interpretation covers the determination of:

  • soil type (most usually based on the Robertson’s chart),
  • index of density (ID) of non-cohesive soils and consistency (IL) of cohesive soils (based on correlations),
  • deformation modulae (M0, E0) and shear strength parameters (Ф’, cu)
  • load-bearing capacity of foundation piles (direct methods).

How does professional subsoil testing using a static probe look like? Find out by watching our video. We invite you to watch it.

 

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