Using Ground-Penetrating RADAR to investigate the Internal Structure of Puente del Inca, Mendoza, Argentina

LANNUTTI, E; LENZANO M. G; BARON, JORGE; LENZANO, LUIS

NEAR SURFACE GEOPHYSICS

EUROPEAN ASSOC GEOSCIENTISTS & ENGINEERS

Lugar: Houten (Holanda); Año: 2017 vol. 15 p. 175 - 186

1569-4445

We performed a set of Ground Penetrating Radar (GPR) measurements to study the internal structure of Puente del Inca (Inca Bridge). This natural structure is located in Mendoza, Argentina and its formation is associated with deposition of travertine caused by geobiological processes created by hot mineral springs. The 200 MHz GPR measurements performed on the surface of the bridge allowed us torelate the behavior of the electromagnetic signal with the presence or absence of hot spring activity. We also made GPR measurements at 20 MHz to estimate the propagation velocity and study the bridge?s internal structure. In order to validate the GPR results, we used a soil dielectric sensor to obtain theattenuation and the velocity of the medium. The results showed similar propagation velocities (0.0222 m/ns on average) across the structure and significant attenuation due to the hot spring water, which is the primary element controlling the response of the electromagnetic signals. This paper shows that it is possible to obtain good results using low frequency (20 MHz) GPR. We were able to characterize the bridge?s internal structure despite of the lossy dielectric environment and the limitations imposed by a highly conductive, saturated medium related to hot spring activity.