{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,22]],"date-time":"2026-08-22T05:22:44Z","timestamp":1787376164338,"version":"build-2736575974"},"reference-count":22,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T00:00:00Z","timestamp":1787184000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41774145"],"award-info":[{"award-number":["41774145"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["41774145"],"award-info":[{"award-number":["41774145"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Imaging"],"abstract":"<jats:p>The conventional parallel seismic test (PST) is a widely used and highly reliable method for determining lengths of in-service bridge pile foundations. However, it relies solely on the manual interpretation of first-arrival in seismic records and often fails to detect, characterize, or geometrically define internal defects within the piles. To overcome these limitations and enable the intuitive identification of internal defects and damage within piles, this study introduces an elastic reverse time migration (ERTM) imaging algorithm based on the spectral element method, achieving high-resolution imaging of existing bridge pile foundations and their defects and damage. To suppress crosstalk between P- and S-waves during the ERTM process, a wavefield decoupling method is employed to separate the elastic wavefield into P- and S-wave components for independent imaging. Two-dimensional numerical testing on a bridge pile model with a necking defect demonstrates that ERTM can effectively image both the pile geometry and its defects, significantly improving the capability of defect detection and characterization. This approach provides more intuitive visualization for assessing the structural integrity of in-service bridge pile foundations.<\/jats:p>","DOI":"10.3390\/jimaging12080395","type":"journal-article","created":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T16:05:19Z","timestamp":1787241919000},"page":"395","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Imaging-Based Parallel Seismic Test for In-Service Bridge Pile Foundations"],"prefix":"10.3390","volume":"12","author":[{"given":"Zhichao","family":"Luo","sequence":"first","affiliation":[{"name":"Guangxi Nanbin Highway Construction and Development Co., Ltd., Nanning 530499, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weibin","family":"Luo","sequence":"additional","affiliation":[{"name":"School of Geophysics and Geomatics, China University of Geosciences (Wuhan), Wuhan 430074, China"},{"name":"Guangxi Traffic Engineering Testing Co., Ltd., Nanning 530299, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peng","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Geophysics and Geomatics, China University of Geosciences (Wuhan), Wuhan 430074, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuan","family":"Gu","sequence":"additional","affiliation":[{"name":"Guangzhou Marine Geological Survey, Guangzhou 511458, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1613-9261","authenticated-orcid":false,"given":"Peimin","family":"Zhu","sequence":"additional","affiliation":[{"name":"School of Geophysics and Geomatics, China University of Geosciences (Wuhan), Wuhan 430074, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"965","DOI":"10.1080\/13632460902859169","article-title":"Reconnaissance report on damage of bridges in 2008 Wenchuan, China, earthquake","volume":"13","author":"Kawashima","year":"2009","journal-title":"J. Earthq. Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2677","DOI":"10.1038\/s41467-019-10442-3","article-title":"A global multi-hazard risk analysis of road and railway infrastructure assets","volume":"10","author":"Koks","year":"2019","journal-title":"Nat. Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"37","DOI":"10.2113\/JEEG16.1.37","article-title":"Determining lengths of reinforcements in bored in situ concrete piles using the magnetic method","volume":"16","author":"Dong","year":"2011","journal-title":"J. Environ. Eng. Geophys."},{"key":"ref_4","first-page":"55\u201359+71\u201373","article-title":"Integrity Testing","volume":"53","author":"Stain","year":"1982","journal-title":"Civ. Eng."},{"key":"ref_5","unstructured":"Olson, L.D. (1996). Nondestructive Testing of Unknown Subsurface Bridge Foundations: Results of NCHRP Project 21-5."},{"key":"ref_6","unstructured":"Olson, L.D., Jalinoos, F., and Aouad, M.F. (1998). Determination of Unknown Subsurface Bridge Foundations: A Summary of the NCHRP 21-5 Interim Report."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.compgeo.2010.10.002","article-title":"Inclination correction of the parallel seismic test for pile length detection","volume":"38","author":"Ni","year":"2011","journal-title":"Comput. Geotech."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1093","DOI":"10.1016\/j.sandf.2012.11.023","article-title":"Improvement and extension of the parallel seismic method for foundation depth measurement","volume":"52","author":"Niederleithinger","year":"2012","journal-title":"Soils Found."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.ndteint.2012.01.006","article-title":"Experimental study for the evaluation of stress wave approaches on a group pile foundation","volume":"47","author":"Huang","year":"2012","journal-title":"NDT E Int."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"299","DOI":"10.2113\/JEEG24.2.299","article-title":"Evaluation of unknown bridge foundations using borehole-based nondestructive testing methods: A case study in urban settings","volume":"24","author":"Coe","year":"2019","journal-title":"J. Environ. Eng. Geophys."},{"key":"ref_11","unstructured":"(1993). Sols: Reconnaissances et Essais. Auscultation d\u2019un \u00c9l\u00e9ment de Fondation: NF P94-160-3 Partie 3: Sismique Parall\u00e8le (Standard No. NF P94-160)."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Whitmore, N.D. (1983). Iterative depth migration by backward time propagation. SEG Technical Program Expanded Abstracts, Society of Exploration Geophysicists.","DOI":"10.1190\/1.1893867"},{"key":"ref_13","unstructured":"Duan, H., Yao, H., Zhu, P., Li, Z., Xu, Z., and Yuan, Y. (2026). An innovative solution for elastic wavefield decomposition by decoupled elastic wave equations with spectral element method. J. Appl. Geophys., under review."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"457","DOI":"10.1109\/PROC.1986.13486","article-title":"Pre-stack reverse-time migration for elastic waves with application to synthetic offset vertical seismic profiles","volume":"74","author":"Sun","year":"1986","journal-title":"Proc. IEEE"},{"key":"ref_15","unstructured":"Maday, Y., and Patera, A.T. (1989). Spectral Element Methods for the Incompressible Navier-Stokes Equations. State-of-the-Art Surveys on Computational Mechanics, American Society of Mechanical Engineers."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1139","DOI":"10.1002\/(SICI)1097-0207(19990730)45:9<1139::AID-NME617>3.0.CO;2-T","article-title":"The spectral element method for elastic wave equations\u2014Application to 2-D and 3-D seismic problems","volume":"45","author":"Komatitsch","year":"1999","journal-title":"Int. J. Numer. Methods Eng."},{"key":"ref_17","first-page":"482","article-title":"Numerical modeling of P-wave and S-wave separation in elastic wavefield","volume":"38","author":"Ma","year":"2003","journal-title":"Oil Geophys. Prospect."},{"key":"ref_18","unstructured":"(2015). Code for Design of Concrete Structures (Standard No. GB50010-2010)."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1147\/rd.112.0235","article-title":"Hyperbolic difference equations: A review of the Courant-Friedrichs-Lewy paper in the light of recent developments","volume":"11","author":"Lax","year":"1967","journal-title":"IBM J. Res. Dev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"S29","DOI":"10.1190\/1.3533914","article-title":"An effective imaging condition for reverse-time migration using wavefield decomposition","volume":"76","author":"Liu","year":"2011","journal-title":"Geophysics"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Shen, P., and Albertin, U. (2015, January 18\u201323). Up-Down Separation Using Hilbert Transformed Source for Causal Imaging Condition. Proceedings of the 2015 SEG International Exposition and Annual Meeting, Houston, TX, USA.","DOI":"10.1190\/segam2015-5862960.1"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"S223","DOI":"10.1190\/geo2021-0372.1","article-title":"Suppressing migration noise in reverse time migration of vertical seismic profiles by multiple stacking estimation","volume":"87","author":"Guo","year":"2022","journal-title":"Geophysics"}],"container-title":["Journal of Imaging"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2313-433X\/12\/8\/395\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,22]],"date-time":"2026-08-22T04:23:05Z","timestamp":1787372585000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2313-433X\/12\/8\/395"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,20]]},"references-count":22,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["jimaging12080395"],"URL":"https:\/\/doi.org\/10.3390\/jimaging12080395","relation":{},"ISSN":["2313-433X"],"issn-type":[{"value":"2313-433X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,20]]}}}