Geophysical Methods

Another focus of our range of activities is geophysical investigation.

The results of the measurements are optimized by using a combination of different geophysical methods.  We carry out the following geophysical measurements:

Ground-penetrating radar measurements with various antennas and differing penetration depths
Underwater Scuba radar
Microgravity
Electromagnetics
Seismic measurements
Geo-electric measurements
FGM^®/EFT® measurements

Ground-penetrating radar (GPR) is an electromagnetic pulse radiation method. Short electromagnetic pulses are transmitted from the surface into the subsurface and recorded after being reflected from objects or boundaries with different dielectric constants.   Radar measurements are conducted using varying antennas: the higher the frequency of the antenna, the lower the penetration of the pulses into the subsurface. Higher-frequency antennas, however, provide better resolution.

GPR can be used in a variety of media including soil, rock and ice, or closed surfaces such as pavements and other structures. It can detect objects, changes in material, cavities, voids and cracks.

The SCUBA radar technology which was developed by TEXPLOR enables the use of the radar also under water down to depths of approx. 30m. The equipment is lowered onto the lake/river bottom and is pulled by a boat or with the help of divers along the bottom. The depth penetration into the sediment is between 3 and 15 m according to the antenna used (100 MHz or 500 MHz).

Geo-electric measurements (ERT) are carried out to investigate the lithological structures and the geological situation in the subsurface, e.g. clay, sand, gravel. The method is applied non-destructively on the surface.  Geo-electric measurements determine the electrical conductivity of the soil.  The advantages of the modern multi-electrode devices (Electrical Resistivity Tomography – ERT) are the fast performance and the dense measuring data.

Micro-gravimetric measurements are carried out to investigate the horizontal and vertical distribution of the density in the subsurface.  Geologically weak zones and disturbances in the underground can be detected in this way.   The results yield a model of density distribution and its horizontal and vertical changes in kg/m³, displayed in a vertical section.

Dam bodies can be evaluated and anomaly zones detected near large building pits in urban areas with micro-gravimetric measurements.

Please find reference projects of our Geophysical Methods here.