The seismic vibration sources are magnetostrictive actuators from TdVib, LLC. Depending on the task, one to four magnetostrictive actuators of different sizes and performance levels with adapted amplifier, control and regulation technology are used.
The geophone anchors are based on the rock bolts used in tunnelling and mining, which are used, for example, to maintain the rock strength during construction.
The pneumatic hammers developed at GFZ for underground seismics generate reproducible and energy-rich pulses.
Common seismic data acquisition systems are wired and therefore unsuitable for professional use on tunnel drilling machines.
Four SUMMIT Compact Units with 24 channels each are available for seismic data acquisition.
As part of the Seismic Prediction While Drilling (SPWD) project, the SPWD field prototype was constructed for applications in 8 1/2" and up to 2000 m deep drill hole diameter and depth, according to the SPWD laboratory prototype, but each with a 3K geophone per receiver unit.
As part of the Seismic Prediction While Drilling - SPWD project, the SPWD laboratory prototype of a seismic "predictive" borehole probe was developed for use in horizontal dry wells with a diameter of 8 1/2".
Dr. Rüdiger Giese4.2 Geomechanics and Scientific Drilling