The future of managing structural risk
With advances in structural monitoring technology, it is now possible to identify early warning signs of structural damage or weakness in real-time. Dynamic structural monitoring technology known as STRAAM (Structural Risk Assessment and Management) collects data on how a building moves, which can be used to initiate repairs or renovations sooner, limit the risk of further damage, better manage occupant safety and support possible litigation.
It works by monitoring the tiny vibrations in a building, or its ‘heartbeat’, to create a unique dynamic signature. Like an electrocardiograph, which shows how the human heart beats and performs, a building’s structural-cardiogram or dynamic signature illustrates the almost imperceptible vibrations that happen every day.
These movements occur in all structures and are normal. Even as monolithic structures look immovable, they are constantly vibrating and shifting in response to any number of environmental factors – like temperature changes, winds, traffic movements (including people walking or using lifts, for example), nearby construction, earth tremors and, of course, earthquakes.
It’s important to understand the building’s heartbeat, or normal vibrations, to identify abnormal responses that are indicative of structural damage or weakness. A full analysis of a building’s movements makes it possible to detect potential issues faster and can help to pinpoint the cause and location of the damage.
Dynamic structural monitoring is unique technology that measures a building’s dynamic structure. STRAAM uses non-destructive ground monitors to conduct a Structural-Cardiograph (SCG) to measure the vibrations in a building. This provides real-time reports that accurately assess the stiffness of a structure and changes in its capacity.
These reports provide ‘big data’ on how a building is moving in response to external factors (such as neighbouring construction or the weather) and enable facility managers to pinpoint structural weaknesses quickly, rather than relying on in-person engineering assessments that may take days. Because the technology is also extremely sensitive and accurate, it can detect even minor movement early.
Dynamic structural monitoring technology means facility managers can quickly and easily assess the habitability of buildings following events such as earthquakes or construction. This lets them make decisions regarding building evacuations and re-entry sooner, minimising cost and inconvenience to occupants.
For example, STRAAM was used during the construction of a new building in New York to monitor the impact of the works on a nearby school site and manage related risks.
During foundation works, occupants of neighbouring properties could feel vibrations. STRAAM identified that these vibrations exceeded the intensity levels prescribed by the code and needed modification. Together the project manager, construction company and school used STRAAM to help mitigate serious damage and certify the school fit for use during construction without danger to students.
Similarly, an apartment building in New York was being monitored using STRAAM to monitor its response to nearby excavation for a new subway station. Although the results indicated that the building was responding as planned to the construction works, an alarm was triggered for movement coming from higher up in the building. On investigation, building management found the façade had begun to deteriorate and was in danger of partial collapse. This early warning enabled them to take swift action before the damage worsened.
Facility managers can also conduct continuous monitoring (depending on environmental conditions) to understand the building’s ongoing performance. This can provide evidence-based insights to support decisions regarding the timing of repairs or renovations, limiting the risk of further damage.
Continuous monitoring is also particularly useful in conditions where the ground moves regularly; for example, in seismic zones or heavy construction environments. This can be used to monitor how a building responds to regular changes in movement and vibrations and track its performance over time.
Real-time structural analysis can indicate causes of structural damage, the likely risk of further damage and overall structural stability. This provides crucial information for facility managers, who can use the data to prepare insurance policies and claims, enhance occupant safety, navigate litigation, improve asset management, and help to make communities and buildings more resilient to natural disasters.
Tim Pope is the chief operations officer at Mainmark. He is a leader in the ground engineering construction industry, having held various executive and senior management roles globally. He has broad technical skills, corporate experience and a disciplined approach to risk management.
This article also appears in the February/March issue of Facility Management magazine.