Non-Destructive Testing Methods for South Dakota Structural Inspection

Problem Description: Structures are a critical component of the transportation network. As they age,deteriorate, and approach or exceed their operational capacities, effective condition assessment becomesincreasingly vital. Inspections play a central role in identifying rehabilitation needs, monitoringdeterioration, and ensuring safety and long-term performance. Over the past several decades,nondestructive testing (NDT) technologies have emerged as alternative tools for structural inspection.These methods may offer safer and more efficient alternatives for assessing structural integrity, possiblyreducing the time required to detect, analyze, and diagnose a wide range of concerns. While NDTtechnologies have numerous applications for structural inspections, SDDOT has identified two primaryareas where these technologies could offer the greatest benefit during inspections.The first area is the detection of voids adjacent to buried structures. These voids typically form due to soilerosion, settlement, and water movement through the backfill material surrounding the structure. If leftunchecked, they can migrate upward into the roadway base course and surfacing, creating the potentialfor catastrophic traffic incidents such as sinkhole formation or wheel punch-through. Currently, there is noreliable inspection methods available to quantify the void volume or determine the extent of upwardmigration toward the roadway surface. Furthermore, many small structures on the SDDOT system are notroutinely inspected, meaning voids often go undetected until problems arise. A network-level inspectiontool could help identify these issues early and prevent potentially devastating incidents.The second area is the detection of deck delamination. Traditionally, SDDOT bridge inspectors havesupplemented visual inspections with manual techniques such as chain dragging and hammer sounding.While these methods are often considered the “gold standard” for accuracy, chain dragging can besubjective, especially for less experienced inspectors. In high-traffic areas, it can be difficult to distinguishsubtle differences in sound, and inspectors are exposed to hazardous traffic conditions for extendedperiods.SDDOT is interested in exploring additional NDT applications for structural inspection as well; however, thepreviously discussed concerns remain the highest priority. There may be the potential for a single NDTtechnology to address multiple inspection challenges. This could improve efficiency and reduce costs. Forall applications presented, SDDOT seeks guidance on selecting NDT methods that can assess structuralconditions both on a network-wide basis and for individual projects. These methods should complementtraditional inspections and provide engineers with better data for short and long-term planning.Although substantial research exists on individual NDT techniques, uncertainties remain regarding theirdefect-detection capabilities and the reliability of collected data. These challenges complicate adoptiondecisions and lead to variability in how agencies apply NDT in the field. This study aims to clarify how,when, and where State DOTs employ NDT methods for highway structure inspection. The objective is tounderstand current practices, available technologies, identify gaps, and determine which NDT technologieswill provide the greatest benefit to the agency’s inspection program.Proposal Deadline: Proposals are due to the SDDOT by 5:00 pm CDT on Thursday, March 19, 2026. Thisdeadline is firm. Extensions will not be granted.Proposals must be submitted as an e-mail attachment in Portable Document Format (PDF) not exceeding14MB. The email must be addressed to andy.vandel@state.sd.us and margo.mcdowell@state.sd.us.Proposers should send the e-mail using “Delivery Receipt” and “Read Receipt” options to verify successfuldelivery.Proposal Guidelines: Proposals must fulfill the requirements listed in the document entitled RESEARCHPROPOSAL PREPARATION, SUBMISSION, AND EVALUATION and dated October 23, 2025.Proposal Evaluation: Proposals will be evaluated by a technical panel knowledgeable in the problem area.Selection will be made in consideration of criteria listed in RESEARCH PROPOSAL PREPARATION,SUBMISSION, AND EVALUATION.Project Management: Margo McDowell is responsible for the management of this project and can bereached at margo.mcdowell@state.sd.us to answer inquiries