When the Earth Speaks and No One Listens: Learning from Engineering's Deadliest Monitoring Failures
Ali Siamaki
Massive engineering projects, such as dams, deep mines, and complex urban tunnels, are built on and within the earth. Geotechnical instrumentation and monitoring provide a critical "nervous system" for structures, continuously detecting subtle shifts, pressure increases, and hidden stresses. This proactive approach helps to identify potential issues, thereby ensuring the safety and structural integrity of assets throughout their operational lifespan. They generate enormous amounts of data, providing a real-time report on the health of the project.
This article explores a critical and often tragic lesson from the history of geotechnical monitoring: the most devastating failures often happen not from a lack of data, but from a fundamental human failure to correctly interpret, believe, and act on the warnings that data provides. The instruments may be speaking clearly, but if no one is listening or if their warnings are dismissed, disaster becomes inevitable. As one investigation concluded after a catastrophic collapse: "many warnings of approaching collapse were either not taken seriously or ignored."
This article will examine powerful and distinct case studies that illustrate the dangerous gap between data collection and decisive action, drawing on reports and evidence.The collapse of the Fundão Dam in Brazil shows what happens when the right warnings are never even measured. The Vajont Dam disaster in Italy reveals the fatal consequences of misinterpreting clear data through a lens of wishful thinking. And the Nicoll Highway collapse in Singapore serves as a stark reminder that even the most advanced monitoring system is useless if its alarms are actively disregarded.
These three patterns of failure are repeated across our industry, from Brumadinho in Brazil and Merriespruit in South Africa to open-pit mines in Africa and Asia and a tunnel excavation in London. These disasters represent three distinct but related patterns of human and organizational failure that can undermine any engineering project.
Pattern 1: Inadequate Instrumentation (When the Warnings Go Unmeasured)
The most basic failure is when the right data is never collected in the first place because the monitoring system is flawed, insufficient, or simply absent. Critical risks develop undetected, as seen in the catastrophic failure of the Fundão Dam, as it was very poorly instrumented. Monitoring relied on outdated, slow-responding standpipe piezometers unable to detect rapid changes in internal water pressure. The core failure was inadequate instrumentation, as physical tests indicated a dangerously high water table, but no reliable, real-time sensor data confirmed the risk, leading to critical warning signs going completely unmeasured. The consequence was a catastrophic liquefaction failure that released approximately 43-50 million tons/m³ of toxic sludge, killing 19 people, destroying a village, and causing one of Brazil's environmental disasters.
The root of the Fundão disaster was a failure at the most basic level: the monitoring system was simply not up to the task. That danger was rising "pore water pressure". When this pressure gets too high, it effectively pushes the soil particles apart, causing them to lose their solidity in a sudden, liquid-like failure known as "static liquefaction". Because there was "no reliable piezometer data to cross-check this," the engineers were effectively blind. The critical warning signs went unmeasured. With no alarm or early warning, the dam's collapse was sudden and total.
Fundão teaches a serious lesson about the dangers of a "false economy". Skimping on proper, modern instrumentation to save money creates the very conditions for a far more costly disaster. This was not an isolated design flaw. Similar failures in monitoring design, such as piezometers being placed too far from the dam toe or too sparsely distributed to capture critical data, were noted in the investigation of the Mount Polley dam failure in Canada.
This pattern was also seen in the 1994 Merriespruit disaster in South Africa, which claimed 17 lives. The failure was caused by overtopping after rainfall, which led to flow liquefaction. The root cause was clearly inadequate freeboard, highlighting a failure in water management protocols and a lack of adequate monitoring data on the dam's hydraulic response to precipitation. In all these cases, the earth was speaking, but the right instruments weren't in place to listen.
Pattern 2: Flawed Interpretation (When the Data Is Dangerously Misinterpreted)
In the second pattern, the data is successfully collected, but its severity is fatally misunderstood, downplayed, or dismissed by experts due to bias or wishful thinking. The Vajont Dam project in Italy, one of the world's tallest arch dams, was built in a valley beneath the geologically unstable Mount Toc slope. The creeping slope of Mount Toc was monitored with extensometers, survey points, and piezometers, which measured ground movement over time. The core failure was a flawed interpretation of data, as instruments clearly showed the mountainside was moving at an accelerating rate as the reservoir filled, a classic sign of impending collapse. This data was "largely misinterpreted" by the technical team. The consequence was a landslide of approximately 270 million cubic meters crashing into the reservoir, creating a massive wave that overtopped the dam and completely destroyed downstream villages, killing approximately 2,000 people.
Unlike at Fundão, instruments at Vajont were present, and they did detect the danger. This accelerating creep is a textbook warning sign for a catastrophic landslide. The geological flaw was a "weak clay layer creating a slip surface" deep within the mountain. As the reservoir filled, rising water pressure within this layer acted like a lubricant.
The failure was not technological, but human. The team convinced themselves that any landslide would be gradual and small, something they could manage. They saw the data but refused to believe its terrifying implications. Vajont's legacy is a stark directive to all engineers: "trust the data, not wishful thinking". Accelerating ground movement is one of the most reliable indicators of a future large-scale collapse.
This failure to interpret data is a recurring theme. At an Africa Cobalt and Copper Mine in 2016, a slope failure killed seven people. The mine was equipped with ground-based radars that provided extensive data. This data showed a gradual deformation trend that suddenly escalated sharply to 400 mm/day in the three days before the collapse. The monitoring team recorded the numbers, but their report failed to highlight this critical, exponential acceleration. The failure was interpretational: the team lacked the training to understand the significance of the velocity increase, a transition to tertiary creep that signifies imminent failure.
The 2019 Brumadinho disaster in Brazil, which killed 270 people, tells a similar story. Unlike Fundão, this dam did have instruments. However, the expert panel found that standard instruments showed only gradual changes misinterpreted as "benign," and the monitoring system failed to provide any advance warning. The data was available, but its subtle warning signs were overlooked. In fact, later independent analysis using InSAR satellite data found a pattern of accelerating deformation in the months before failure that could have predicted the collapse. The data was there, but the ability to interpret it in real-time was not.
Pattern 3: Organizational Disregard (When the Alarms Are Ignored)
In the third and perhaps most tragic pattern, the data and its correct interpretation are available. Alarms are ringing loud and clear, but they are actively ignored or overridden due to production pressure, poor communication, or a weak safety culture.
The Nicoll Highway project in Singapore involved a 30-meter-deep "cut-and-cover" excavation for a new mass transit tunnel next to a major urban highway. The site was heavily instrumented with thousands of sensors, including inclinometers measuring wall movement, strut load cells, and settlement markers. The core failure was organizational disregard, as instruments showed clear signs of distress, with retaining walls bending excessively (by as much as 400 mm) and support struts overloaded, but these explicit warnings were ignored. The consequence was the failure of the excavation support system, triggering a massive cave-in that killed four workers, destroyed a section of the highway, and led to a project manager being jailed for negligence.
This project represents the ultimate failure of monitoring. The warnings were not subtle. Despite the data showing the system was approaching failure, the contractor continued excavation without adequate reinforcement. This was a textbook failure to use the data for its intended purpose: to stop work and prevent a collapse. Investigators concluded that "many warnings of approaching collapse were either not taken seriously or ignored".
This pattern of disregarding clear warnings is alarmingly common.
At an Asia Coal Mine in 2020, an incident resulted in an operator fatality. Monitoring engineers detected progressive movement one hour before the collapse and alerted the site team via phone, applications, and email. The warning was clear and timely. However, no evacuation was carried out, and operations continued until the slope failed. The failure was purely organizational, as production pressure compromised the will to comply with safety protocols.
Similarly, the 1994 Heathrow Airport Tunnel Collapse was rooted in organizational dysfunction. The tunneling method relied heavily on observational monitoring. Instruments were in place, but the data was "not being promptly correlated to construction decisions". Intense pressure to reduce costs had minimized the monitoring scope. As a result, excavation advances were decided "without checking up-to-date settlement readings". The data existed, but it was not effectively communicated or acted upon in time.
The Systemic Failures Beneath the Surface
These three patterns, inadequate tools, flawed interpretation, and organizational disregard, are the immediate causes of disaster. But beneath them lie deeper, systemic failures of professional judgment, technical craft, and economic logic.
The Economic Failure: Organizations often perceive monitoring as a "cost rather than a critical investment". Conventional cost-benefit analyses often undervalue comprehensive site investigation. However, evidence shows that increasing the scope of site investigation and monitoring results in a less expensive, more stable project overall, especially when the massive probabilistic cost of failure is factored in.
The Technical Failure: Even when an organization invests in monitoring, the technology itself can be undermined by a lack of specialized field craft. The reliability of monitoring systems hinges entirely on correct sensor installation. For example, Vibrating Wire Piezometers (VWPs) can be rendered useless by "hydraulic short circuits," where poorly mixed grout allows water to travel along instrument wires, corrupting the data. In low-permeability rock, sensors can take over 12 months to stabilize, meaning engineers might be making critical decisions based on data that is not yet accurate. Likewise, incorrect pre-assembly or orientation of inclinometer wheels can generate "misinterpreted output data," leading to invalid analysis.
The Judgment Failure: Ultimately, the final failure point is the intellectual gap between receiving data and transforming it into actionable judgment. Engineers require specialized training in Monitoring Data Forensics, the ability to validate incoming data, cross-correlate different sensors, and spot corrupted or "unlogic results". They must be trained not just to read displacement, but to understand the critical significance of velocity and acceleration trends, which signal the onset of tertiary creep and imminent failure.
How to Prevent the Next Disaster
The lessons from Fundão, Vajont, and Nicoll Highway are written in loss of life and environmental ruin, but they provide a clear blueprint for a safer future. For any aspiring engineer, scientist, or project manager, these best practices are non-negotiable.
Install the Right Tools and Keep Them Working Every project has unique risks, and the monitoring system must be tailored to detect them. This means installing a sufficient number of appropriate, modern, and well-maintained instruments, such as rapid-response vibrating wire piezometers instead of slow standpipes in dams. Implement mandatory, hands-on certification for field personnel focusing on specialized best practices, like grout mixing and casing alignment, to prevent data corruption from the start. Skimping on instrumentation is never a valid way to save money; it is a false economy.
Establish and Empower Iron-Clad Action Plans (TARPs) A Trigger Action Response Plan (TARP) is a pre-agreed set of rules that connects data to action. It defines exactly what must be done (e.g., "Stop all work," "Evacuate the area") when a sensor reading hits a specific alert level. This removes ambiguity. But having a plan is not enough; it must be empowered. Implement mandatory, scenario-based crisis simulations for all site management to establish and audit clear lines of authority, ensuring that safety warnings result in immediate, non-negotiable compliance, regardless of production impact.
Train People to Recognize the Signs Engineers and site staff must be thoroughly trained to understand what the data is telling them. This training must go beyond reading a dial. It must include GIM Data Forensics to validate data integrity and Time-Series Deformation Forensics to accurately recognize the exponential velocity increases that signal collapse. This expertise turns raw data into life-saving wisdom.
Foster a "Safety-First" Culture Ultimately, safety rests on culture. Project leadership must empower every team member to halt work when data indicates danger, without fear of reprisal. This culture must be supported by systems, such as integrating GIM hardware into Computerized Maintenance Management Systems (CMMS) to ensure proactive maintenance and using independent experts to audit monitoring data and catch complacency. Production schedules and budgets must never be allowed to overrule clear safety warnings from the instruments.
These cases teach us that the earth almost always provides a warning before a major failure. The challenge is not just to measure these warnings. The challenge is to create systems and cultures prepared to listen and react to what our instruments are telling us, in time to make a difference. The mere presence of data is not enough; its proper understanding and timely use is what truly safeguards against failure.
