Citation: Chavan, V.S.; Chen, S.-E.; Shanmugam, N.S.;Tang, W.; Diemer, J.; Allan, C.; Braxtan, N.; Shukla, T.; Chen, T.; Slocum, Z. Modeling of Progressive Scouring of a Pier-on-Bank. CivilEng 2022, 3, 365–384. https://doi.org/10.3390/ civileng3020022 Academic Editor: Francesco D’Annibale Received: 24 March 2022 Accepted: 20 April 2022 Published: 22 April 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Article Modeling of Progressive Scouring of a Pier-on-Bank Vidya Subhash Chavan 1, *, Shen-En Chen 2 , Navanit Sri Shanmugam 1 , Wenwu Tang 3 , John Diemer 4 , Craig Allan 4 , Nicole Braxtan 2 , Tarini Shukla 1 , Tianyang Chen 4 and Zachery Slocum 4 1 INES (Infrastructure and Environmental Systems) PhD Program, Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; nshanmug@uncc.edu (N.S.S.); tshukla@uncc.edu (T.S.) 2 Department of Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; schen12@uncc.edu (S.-E.C.); nbraxtan@uncc.edu (N.B.) 3 Center for Applied Geographical Information Sciences (CAGIS), Department of Geography and Earth Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; wtang@uncc.edu 4 Department of Geography and Earth Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; jadiemer@uncc.edu (J.D.); cjallan@uncc.edu (C.A.); tchen19@uncc.edu (T.C.); zslocum@uncc.edu (Z.S.) * Correspondence: vchavan1@uncc.edu Abstract: Scour, caused by swiftly moving water, can remove alluvial sediment and soil, creating holes surrounding a bridge component and compromising the integrity of the bridge structure. Such problems can be equally critical for bridges with piers-on-bank bridges subjected to severe storm and flooding issues. In this paper, the Phillips Road Bridge over Toby Creek (35 ◦ 18 ′ 28.2 ′′ N 80 ◦ 44 ′ 16.6 ′′ W, Charlotte, NC, USA), a pier-on-bank bridge with critical/significant local scour holes and deep riverbank erosion cuts was selected as case study bridge. To investigate the scour effect on the bridge with pier-on-bank performance, the scoured area around a single pier is first quantified using a terrestrial laser and then modeled using nonlinear finite element (FE) analysis, where the local scour is modeled as progressive mass losses using the Element Removal (ER) technique. The FE results are compared to the design loading scenario and the results substantiated that the local scouring could cause large deflection and increased bending moment on the bridge pier. Keywords: local scour; lidar scan; bridge piers; finite element 1. Introduction Scour is a critical condition change for a bridge hydraulic system, especially during storms and high water. Scour, caused by swiftly moving water, can remove alluvial sediment and soil, creating holes surrounding a bridge component and compromising the integrity of a structure [1]. Scour associated with bridge piers usually starts out as local scour(s) and is often associated with acceleration of flow and resulting turbulent vortices. Local scour typically starts as a scour hole surrounding the bridge pier [2]. If not addressed, local scours can worsen and result in enlarged mass losses surrounding the bridge supports. The danger of bridge scour failures lies in the fact that they can occur without prior warning. Thus, there is a need for an effective monitoring strategy to identify scour problems surrounding a bridge structure. The geography of North Carolina falls in three divisions—The western Appalachian Mountains, the central Piedmont Plateau and the eastern Coastal Plain. This diverse landscape resulted in a significant number of bridges with the unique design of piers-on- bank. Figure 1 shows several examples of piers-on-bank bridges from the central Piedmont area, North Carolina. CivilEng 2022, 3, 365–384. https://doi.org/10.3390/civileng3020022 https://www.mdpi.com/journal/civileng