PSI - Issue 62

Stefano Stacul et al. / Procedia Structural Integrity 62 (2024) 185–192 Stefano Stacul and Nunziante Squeglia / Structural Integrity Procedia 00 (2019) 000 – 000

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Previous experiences of the Authors with ERT have highlighted the good ability of this method in identifying the foundations of some historic masonry buildings in Pisa (Squeglia et al., 2015) as shown in Figure 5. Therefore, their use in the case of masonry bridges will certainly be taken into consideration.

Fig. 5. ERT results (San Paolo Church in Pisa)

4. Concluding remarks In this contribution main available methods for the identification of the foundation system and depth in case of existing bridges have been briefly described showing their basic principles, testing procedures, capabilities, and limitations. Parallel Seismic and Dual-sensor Impulse-Echo tests likely represent the best options for existing structures. Also, ERT seems to have a good potential in identifying the foundation depth. Nevertheless, the most appropriate approach according to the Authors opinion is to perform at least two different methods to provide a proper assessment of the foundation system and depth. References ASTM D5882, 2016. Standard Test Method for Low Strain Impact Integrity Testing of Deep Foundations. American Society for Testing of Materials, West Conshohocken, PA, USA. ASTM D6760-16, 2017. Standard Test Method for Integrity Testing of Concrete Deep Foundations by Ultrasonic Crosshole Testing. American Society for Testing of Materials, West Conshohocken, PA, USA. ASTM D8381-21, 2021. Standard Test Methods for Measuring the Depth of Deep Foundations by Parallel Seismic Logging. American Society for Testing of Materials, West Conshohocken, PA, USA. Baker, C.N. Jr, Drumwright, E.E., Briaud, J-L., Mensah-Dumwah, F., Parikh, G., 1993. Drilled Shafts for Bridge Foundations, FHwA Publicatio Number FHwA-RD-92-004, Federal Highway Administration (FHwA), Washington, DC, USA. Binley, A., Kemna, A., 2005. DC resistivity and induced polarization methods. In Hydrogeophysics (pp. 129-156). Dordrecht: Springer Netherlands. Cardoso, G. A. F., Lopes, B. D. C. F. L., 2022. ERT Feasibility Study to Assess Unknown Bridge Foundation Depth. Journal of Bridge Engineering, 27(7), 06022002. Davis, A.G., 1995. Nondestructive Evaluation of Existing Deep Foundations. ASCE Journal of the Performance of Constructed Facilities, 9, 57– 74. Glanville, W.H., Grime, G., Fox, E.N., Davies, W.W., 1938. An Investigation of the Stresses on Reinforced Concrete Piles During Driving, Technical Paper No. 20, United Kingdom Department of Scientific and Industrial Research, Building Research, Watford, UK. Hertlein, B., Davis, A., 2007. Nondestructive testing of deep foundations. John Wiley & Sons. Institution of Civil Engineers, 2016. Specification for piling and embedded retaining walls. ICE Publishing. Ministry for Sustainable Infrastructure and Mobility (MIMS), 2022. Ministerial Decree 204 on 01.07.2022. Guidelines for the Classification and Management of Risk, the Safety Assessment and the Monitoring of Existing Bridges. Italy. G.U. Serie Generale n.196, 23-08-2022. NF P94-160-1, 2000. Sols: reconnaissance et essais - Auscultation d'un élément de fondation - Partie 1: méthode par transparence. AFNOR. NF P94-160-2, 1993. Sols: reconnaissance et essais - Auscultation d'un élément de fondation - Partie 2: méthode par réflexion. AFNOR.