GNGTS 2015 - Atti del 34° Convegno Nazionale

GNGTS 2015 S essione 3.2 111 Conclusions. The R.Ex. system constitutes an acquisition device aimed at obtaining a huge amount of high quality GPR data in a relatively short time. Furthermore, the integration and joining of multy-frequency antennas is essential to obtain high resolution in the shallower portion of paved roads and detailed information down to 2-3 m below the topographic surface. The methodology described in this work allows to achieve the information that are important for a traffic infrastructure company before maintenance operations planning and after new roads contructions. In Case-1-Test site-1 the interpretation of inhomogeneities of the subgrade let to locate the critical failure points and drive for future maintenance activities; Case-1-Test site 2 and Case 2 report the surveys after pavement and construction works, that has been used as a sort of verification of the layers thicknesses and its analyses between the cores. Future developments have to be addressed to the improvement in the precision (and the speed) of picking horizons. In this regard, a picking method was recently implemented and tested in different fields of application (Forte et al. , 2013; Dossi et al. , 2015a) including pavements (Dossi et al. , 2015b, 2015c). The obtained results are encouraging allowing to achieve a faster and more accurate picking, diminishing at the same time the subjectivity level of the interpretation. Acknowledgments. We gratefully acknowledge Pavenco srl (Eng. F. Picariello), Emaprice srl (Dr. Eng. M. Grippo Belfi), Elletipi srl (Eng. C. Bratti), Acmar scpa (Eng. M. Lenzi) for the availability of using data for research purpose. All the dataset shown have been acquired by Esplora srl. References Al-Qadi I., Lahouar S. And Loulizi A.;2003: Successfull application of GPR for Quality Assurance/Quality control of new pavements . Paper No. 03-3512, proceedings of Transportation Research Board: 82nd Annual Meeting. January 12-16, 2003 Washington, D.C. Benedetto, A.; 2010: ater content evaluation in unsaturated soil using GPR signal analysis in the frequency domain . Journal of Applied Geophysics, 71 (1) , 26–35. Benedetto A. and Pensa S.; 2007: Indirect diagnosis of pavements structural damages using surface GPR reflection techniques . Journal of Applied Geophysics, 62, 107-123. Briggs R.C., Scuillon T., and Maser K.; 1991: Asphalt thickness variation an effect of backcalculation . 2 nd International Conference on Backcalculation. Nashville, USA. Dossi M., Forte E., Pipan M.; 2015a: Automated reflection picking and polarity assessment through attribute analysis: theory and application to synthetic and real GPR data . Geophysics, 80 (5) , H23-H35 Dossi M., Forte E. and Pipan M.; 2015b: Auto-picking and phase assessment by means of attribute analysis applied to GPR pavement inspection . Proceedings of IWAGPR 2015, 3-7 July 2015, Florence, Italy, in press. Fig. 3 – Portion of GPR profile of CASE-2 composed by 2.3 GHz till 25 cm from the surface and 800 MHz from 25 cm to 1.2 m of depth; the lateral variation of thickness of the aggregate layers and of subgrade is evident.