Seismic tomography methods let us read between the walls
Europe is home to an astounding number of important cultural landmarks. Many of these structures were built several centuries, even millennia ago. These landmarks attract both locals and tourists from all corners of the globe. Aiming to ensure the safety of visitors to these buildings, engineers from the University of Pisa in Italy, cleverly applied techniques common to geophysical exploration. Both Non-Destructive Testing (NDT) and Minor Destructive Testing (MDT) methods were employed in order to preserve the structural and aesthetic integrity of the buildings. Cross-hole tomography is often applied to assess the safety of drilled shafts, but in the case of the ONSITEFORMASONRY project it was modified to assess buildings. Pulses generated on one side of a wall are picked up by receivers installed on the other side of the same wall. The signal is fed to a seismograph, analysed and important structural parameters are reconstructed graphically. In addition, the Italian engineers generated triangular sections using Tomographic Seismic Sounding methods and the relevant algorithms. The work culminated in the creation of a new seismic tomography prototype, including sensors, positioning equipment and the necessary software for signal processing and graphical presentation. The prototype can be exploited to examine historic landmarks across Europe, indicating where structural reinforcement may be necessary.
