Monitoring the Health of Aging Structures
By Marcus Lehner, MS, BSCE, Project Manager
Much of the infrastructure across the United States is approaching or exceeding its original design life. The average bridge is now over 40 years old, with many highway overpasses approaching or exceeding their original design life of 50 years. Large suspension bridges, while often designed for longer lifespans, also face increasing maintenance demands as key components age and traffic loads grow. At the same time, buildings and dams constructed decades ago are operating under higher loads and greater environmental stress.
In this environment, waiting for visible damage is no longer a practical approach. Proactive monitoring provides a more reliable path forward.
Monitoring the health of aging infrastructure is important for several reasons. First, it helps prevent catastrophic failures, such as bridge collapses or structural breakdowns, by identifying issues before they reach critical levels. Second, insurance providers rely on accurate risk assessments when underwriting policies, and real performance data improves their ability to evaluate exposure. Third, asset owners must actively manage risk by balancing safety, maintenance costs, and operational continuity, making timely information essential for decision making.
Proactive monitoring involves the continuous or periodic measurement of how a structure behaves over time. Unlike traditional inspections that rely on scheduled visual checks, modern systems use sensors and data tools to provide ongoing insight. This allows engineers to identify small changes before they develop into serious problems.
Crack monitoring is one of the most common techniques. By tracking the width and progression of cracks, engineers can determine whether a condition is stable or worsening. This is especially important in concrete structures, where crack growth may point to deeper structural concerns.
Vibration monitoring offers another layer of insight. Each structure has a natural vibration pattern. When that pattern changes, it can indicate damage, material fatigue, or loss of stiffness. These shifts often occur before issues become visible, making vibration data a valuable early warning signal.
Deflection and movement monitoring focus on how structures respond to loads and environmental conditions. Sensors can measure displacement, tilt, and settlement with high precision. Unexpected movement can signal foundation problems or overstressed components, allowing for early intervention.
Together, these approaches provide a clearer picture of structural health. The result is earlier detection, reduced maintenance costs, improved safety, and more informed decision making.
As infrastructure continues to age, proactive monitoring is becoming a critical part of effective asset management. Organizations that invest in these systems are better equipped to extend asset life, manage risk, and avoid costly disruptions.
About The Author: Marcus Lehner is a Project Manager with Beacon Consulting Group working out of the company's Medford, MA office. Marcus holds a Masters of Science in Structural Engineering from Northeastern University, as well as a Bachelor of Science in Civil Engineering. Marcus has twelve years of progressive experience working on a broad range of construction consulting assignments, including projects in all of the following sectors: Educational, residential, commercial, transportation, utilities, marine, and municipal infrastructure.
Marcus has extensive experience managing day-to-day operations of construction projects, including handling submittals, transmittals, RFIs, RFQs, closeout documents, and construction management oversight. Drawing upon his years of experience, Marcus helps assist Beacon's Surety clients to efficiently handle a wide range of matters related to bond-default issues including cost-to-complete analyses, payment bond claims review, and assembly of completion bid packages.
Marcus also has significant experience working on Construction Defects claims assignments. His academic background in structural and civil engineering is particularly helpful related to construction defects consulting and root cause analysis.
