Direct Push System inserts

The Direct Push System can be used to obtain extensive geophysical information about the subsurface. The detection of layer boundaries and the detailed structure of the subsurface can be carried out at a high resolution (2 cm) and non-destructively.

For further information on results and scientific publications, please click on the respective image.

The use of different probes enables the measurement of the electrical resistance (reciprocal conductivity), the pore volume, the sediment strength by means of peak pressure and the frictional resistance (so-called skin friction).

By using a seismic module, information about wave propagation and seismic reflection behavior can also be obtained.

By evaluating the parameters, a detailed evaluation and interpretation can be carried out at the investigated site.

The Direct Push system is based on the Geoprobe 540 MT system (Geoprobe, Salina, KS, USA) which is adapted to a Nordmeyer system (model RS 0/2.3, Nordmeyer, Peine Germany).

CPT (Cone Penetrating Test)

The CPT probe (Cone Penetrating Test, type Geotech probe NOVA – Geotech, Askim, Sweden) is pressed into the subsoil at a constant speed of 20 mm/sec. A depth logger is used to determine the exact depth to the millimeter. During probing, the parameters peak pressure (qc), skin friction (fs) and pore pressure (u) are determined in parallel. The strength, grain size and water saturation of the sediment are the main factors that influence the parameters and, in combination, allow detailed conclusions to be drawn about the stratigraphic structure of the subsurface.

HPT (Hydraulic Profiling Tool)

The HPT (Hydraulic Profiling Tool) Direct Push System is fed by a water pump with a flow rate of approx. 250 ml/min. While the probe is hydraulically pushed into the subsoil, the water pressure and the line pressure are determined at 2 cm intervals. Furthermore, the groundwater level can be determined as well as the porosity of the sediment.
The probe has 4 linearly arranged electrodes at the lower end, which are controlled as standard with a Wenner or dipole-dipole configuration to determine the electrical conductivity. At a distance of 2 cm, the electrical conductivity is determined from the ratio of the injected current and the measured potential difference.

OIP system

The OIP system (Optical Image Profiler) offers the possibility of creating images in true color by using an active illumination source and a CMOS detector. The images are generated at a constant repetition rate of 30 fps and saved every 2 cm.

Analysis of direct push data

The classification and the combination of the geophysical parameters of the direct push system with closed boreholes allow a comprehensive and transferable interpretation. The example (see Fig. 3) clearly shows stratigraphic changes and the input of coarse clastic sediments. The combination of methods allows a safe, fast and non-invasive exploration of the subsurface structures and their interpretation.

The Direct Push System can be used for a wide range of questions thanks to a variety of probes and ensures fast and reliable scientific data.

Range of applications and cooperation

The advantages of the Direct Push system are its high time efficiency, non-invasive and non-destructive prospection and the fact that it works independently of groundwater. With these possibilities, the system can be used for a wide range of scientific questions:

• Soil investigations
• Archaeological issues
• Groundwater detection
• Landscape changes (paleogeography)
• Structure of the near-surface subsoil
• Determination of vertical and lateral changes in the subsurface
• Soil tests

Cooperation request

Please contact Prof. Dr. Andreas Vött if you have any questions about supporting scientific projects and collaborations.