The New Bullards Bar Dam, managed by the Yuba Water agency in Marysville, California, is a 645-foot-tall concrete-arch dam on the North Yuba River at the edge of Tahoe National Forest. It was built more than 50 years ago to reduce flood risk, generate clean hydropower and ensure a reliable water supply for surrounding populations. It’s the second tallest in California and the fifth tallest in the country.
The New Bullards Bar Dam had a legacy system that posed safety hazards with accessing the dam site, but it also had limited survey points and could not fully monitor the dam.
The condition of the dam data was manually collected, which was a time-consuming process. It exposed the survey team to challenging, remote and difficult-to-access terrain and a fall hazard that necessitated additional training in rope access and fall protection in high-risk locations.
The solution to these issues was the creation of a digital twin of the dam from Bentley Systems.
Dustin Parkman, vice president of transportation at Bentley Systems, said estimates of global water levels rising in the future, dams are a critical barrier to protect towns and cities from flooding.
In 2021, the global sea level set a new record high, 3.8 inches above 1993. And the global sea level rise rate continues to accelerate, doubling from 0.06 inches per year throughout most of the twentieth century to 0.14 inches per year from 2006–2015, according to the NOAA.
“The average current lifespan of a dam is approximately 100 years, and so maintenance and upkeep is a constant challenge,” said Parkman in an email interview. “One small crack or water leak could indicate the dam is becoming unstable and could lead to disaster.”
Parkman adds that time is critical, with inspections often taking weeks or months.
With the digital twin, Parkman says the agency was able to cover the entire face of the dam and monitor movement and behavior of the dam structure over time and as the structure is exposed to different elements.
“Drones have been a popular addition to damage inspections, but combing information gathered by drones with digital twins, you can start to see damage in incredible detail and analyze it from the comfort of our office desk,” adds Parkman.
With the New Bullards Bar Dam digital twin, the Yuba Water Agency collected the monitoring data remotely, with automated alerts based on predetermined early warning thresholds and automated reporting. “The software created a 3D reality mesh from drone data to represent the dam in a digital twin view and to perform crack detection.”
Parkman adds that the secure cloud-based system locks access to the total station when monitoring is inactive.
“With the digital twin of the New Bullards Bar dam, the agency was able to accomplish reduced risk, improved safety and a reduction in downtime and failures,” said Parkman. “And 1,000 times more monitoring data points compared to previous manual methods including a 50% improvement in data accuracy in Automated Total Station compared to manual data collection.”
A trifecta of technology
Parkman says sensors, digital twins and IoT data provide insights into how assets perform in the real world with greater accuracy over time.
“Understanding existing geological conditions and asset conditions heavily influences how engineering data from the past can inform and enable better decisions in the future,” said Parkman. “This also provides a deeper understanding of how geotechnical data influences the built world by measuring that data and incorporating it into a digital twin, which informs engineering and construction to predict how infrastructure will behave in the built world.”
“We need this to inform design better, build and operate changes to assets leading to better-informed decisions, which allow you to optimize changes for better results including fiduciary, performance and safety,” said Parkman.
Parkman says engineering data starts as a representation of the as-designed and then as-built specifications. However, maintaining engineering data in an operating context is difficult once that is in operation.
“Typically, when engineering changes are made once in operation, it can take months to update engineering records,” said Parkman.
So, what happens between making a change and updating records?
“Processes are prone to errors, and this puts the asset, people and environment at higher risk,” said Parkman. “A digital twin or digital representation of the asset increases the value of engineering and geotechnical data by keeping the engineering data evergreen, providing an accurate and up-to-date representation of the asset.”
Parkman says an excellent example of this is a bridge design that may need to be altered to accommodate expected changes in the weather. “These engineering changes can be reflected in the digital twin, and a visual representation of the asset is invaluable for engineering and operations to speed up training and troubleshoot problems.”
“There is always cost savings when design change reviews and approvals are required because they can be done online via the digital twin,” said Parkman. “Digital twins greatly enable remote collaboration and communication.”
The future digital twin
Parkman says that as digital twins become the norm, more data points become available, allowing for the simulation of all relevant data. “As different form factors become available – e.g., wearables and mixed reality – these tools become more of a commodity and offer newer ways to consume information,” said Parkman.
But Parkman says there is still one hurdle to cross.
“That hurdle is proprietary data challenges between engineering firms and their customers,” said Parkman. “Who owns the digital twin? Should a digital twin always be handed over to the owner-operator of the asset as a standard deliverable?”
“For safe and reliable asset operation and maintenance, teams need a living digital twin model of the asset, and even in decommissioning, they need one to make it faster and easier with a complete understanding of the as-operated asset,” said Parkman. “We are seeing more and more collaboration between engineering firms and owner-operators, some engineering firms seeing this as an opportunity to provide operational services since they have the know-how of the infrastructure asset design and recommended operational practices to start.”
But in a more dire outlook, Parkman says that with digital twins down the road, you would continue to get performance gains in design, build and operate workflows the industry needs to keep up with demands. “This would lead to a status quo of sluggish improvement in the overall performance of the world’s infrastructure.”
“Without digital twins — looking 10 to 20 years out — cities and their taxpayers will pay more than they should to monitor bridges and dams relying on people and antiquated inspection methods requiring scaffolding,” said Parkman.
“We are already in crisis mode with a shortage of skilled workers, so imagine the chaos ten years from now if we do not act and adopt technology like digital twins and IoT,” said Parkman. “City and water agency staff will lose more people to careers that are going digital. More schools and colleges are teaching the technologies, and digital natives (Gen Z onward) demand the tools they used in school when they start their careers.”
Parkman says that IoT can replace humans in dangerous and hard-to-reach areas; the time it takes to inspect is exponentially longer than it should be and can be delayed if there is severe weather. “Imagine this in the midst of climate change.”
“We need drones and reality modeling to visualize and give context for IoT data such as detecting cracks; we need digital twins for overall asset visualization and automated analysis and support for early warnings, fast and more accurate decisions than human input alone,” added Parkman.
“A growing number of dams are approaching their design service life (50+ years) and subject to increasing performance challenges related to climate change, seismic activities and aging assets,” said Parkman. “We foresee that in the future infrastructure, digital twins will play an even larger roll in the sustainability and resilience of existing and new infrastructure such as dams and bridges.”
Parkman adds that IoT data from sensors and drones will be implemented into digital twins to drive energy efficiency and waste reduction.
“The insights provided by digital twins contribute to sustainable practices, minimize the environmental impact, and increase safety,” said Parkman.
Read the full article here
