Beyond the Building Code — Compliance and Forensic Failure Analysis of Retaining Walls

Brian Eubanks; Garrett Ryan; Noel Janacek; Joseph Roberts

doi:10.51501/jotnafe.v43i1.1004

Authors

Brian Eubanks Paragon Structural Engineering https://orcid.org/0009-0009-6560-1388
Garrett Ryan Paragon Structural Engineering, LTD. https://orcid.org/0009-0009-0051-8647
Noel Janacek https://orcid.org/0009-0006-7734-2780
Joseph Roberts https://orcid.org/0009-0004-4797-4598

DOI:

https://doi.org/10.51501/jotnafe.v43i1.1004

Keywords:

Retaining Wall Design, Retaining Wall Failure, Analysis, Structural, Slope Management, Mass Walls, Gravity Walls, Cantilever Walls, Pile Walls, Mechanically-Stabilized Walls, MSE, IRC, IBC, Soil Force, Geotechnical, Construction Oversight, Internal Stability, Local Stability, Global Stability, Factors of Safety, Design-Compliance, Active Pressure, At-Rest Pressure, Compliance Analysis, Cosmetic Distress, External Stability, Failure Analysis, Functional Distress, MAss/Gravity Retaining Wall, Mechanically Stabilized Earth, Passive Pressure, Reinforced Zone, Safety Factor, Scarp

Abstract

Retaining walls are structural walls that serve to laterally restrain earth at a desired elevation in order to shape the topography of a site by managing slopes and creating usable spaces for development and construction of the built environment. Common types of retaining walls include mass/gravity walls, cantilevered walls, pile walls, and mechanically stabilized earth (MSE) walls. The design and construction of such walls are not well covered in the International Residential Code (IRC) and/or the International Building Code (IBC). As structural elements subjected to applied soil forces, retaining walls cross engineering disciplines, and a successful design often requires careful coordination between geotechnical engineers and structural engineers. In addition, successful construction often requires field verification of expected geotechnical parameters and construction oversight to ensure compliance with design specifications. This paper will explore the different stability checks (e.g., internal stability, local stability, and global stability), as well as different factors of safety, required for the proper design of a retaining wall. In addition, it will use real-world case studies to explore failures of various retaining walls, highlighting differences between compliance analysis and forensic failure analysis to identify the root cause of the failure and the responsible party.

Author Biographies

Brian Eubanks, Paragon Structural Engineering

Brian C. Eubanks, MSCE, PE, SE, MAC, D-IBFES, DFE, is Senior Principal Engineer and founder of Paragon Structural Engineering, LTD. With over two decades of experience, he leads a multidisciplinary team in the structural design and forensic investigation of residential, commercial, and institutional projects. He is a Board-Certified Diplomate in forensic engineering by the National Academy of Forensic Engineers (NAFE) and the International Board of Forensic Engineering Sciences (IBFES) and holds professional engineering licenses in fifteen states.

Mr. Eubanks has been engineer-of-record on a diverse design portfolio and possesses significant proficiency in forensic investigations. He is recognized for expertise in structural systems, building envelopes, components and cladding, and construction defect evaluation. He is an active member of national and regional engineering committees, has authored numerous industry standards and technical publications, is a frequent expert witness in mediation, arbitration, and court proceedings, and served as an arbitrator. Additionally, Mr. Eubanks regularly presents at engineering conferences and professional seminars, demonstrating his commitment to advancing best practices in engineering and forensic analysis.

Garrett Ryan, Paragon Structural Engineering, LTD.

Garrett T. Ryan, PE, MAC, DFE, is a Principal Engineer at Paragon Structural Engineering, LTD. He leads technical teams in the structural design and forensic investigation of planned and existing structures, with focused expertise in building envelopes, soil-structure interaction, structural system performance, and the evaluation of peril-related damage. Mr. Ryan is a Board-Certified Diplomate in Forensic Engineering by the National Academy of Forensic Engineers (NAFE) and holds professional engineering licenses in seven states.

With more than two decades of experience, Mr. Ryan’s design portfolio spans large custom residences, multi-family buildings, low-rise commercial facilities, and ancillary structures serving as engineer-of-record and designer. He has authored numerous expert reports, stewards quality control for the firm’s forensic reports, and provides testimony in arbitration and court cases. He regularly presents technical education sessions for builders and industry professionals, is an active member of two regional engineering committees, and is recognized for his expertise in diagnosing and resolving building envelope and structural performance issues.

Noel Janacek

Noel W. Janacek, MSCE, PE, DFE, is Engineering Director at Paragon Structural Engineering, LTD. With more than two decades of combined construction and engineering experience, he oversees the firm’s structural design and forensic investigations of new and existing structures. He is a Board-Certified Diplomate in Forensic Engineering by the National Academy of Forensic Engineers (NAFE), Pre-Certified in multiple TxDOT categories, and holds professional engineering licenses in five states.

Mr. Janacek has been engineer-of-record and provided design and technical leadership for projects across transportation, infrastructure, and commercial development while serving as a senior reviewer and technical advisor on major programs. He is recognized for his depth of experience in geotechnical and structural evaluations, his commitment to advancing professional standards, and serves as a consultant and expert witness for mediation, arbitration, and court cases. He has authored technical papers, delivered numerous presentations to industry groups, and led the American Society of Civil Engineers’ Dallas Geo-Institute Chapter as President.

Joseph Roberts

Joseph P. Roberts, MECE, PE, MLSE, MAC, is an Associate Principal Engineer at Paragon Structural Engineering, LTD. He leads a technical team in the structural design and forensic investigation of planned and existing structures, with increased specialization in retaining walls and thermal envelopes. He is Building Envelope Trained and Certified by the Building Envelope Science Institute (BESI), Haag Certified, a Licensed Mold Assessment Consultant, a Model Law Engineer and a Model Law Structural Engineer with the National Council of Examiners for Engineering and Surveying (NCEES) and holds professional engineering licenses in three states.

Mr. Roberts is an Associate Member of the National Academy of Forensic Engineers (NAFE) and has presented at professional seminars. With two decades of experience, he has designed a broad range of structural systems, conducted diverse forensic investigations, authored expert reports for mediation, arbitration, and court cases, provided expert witness testimony, and served as an arbitrator.

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