AGING DAMS, CLIMATE CHANGE AND EARTHQUAKES – HOW CAN MONITORING HELP TO PREVENT DISASTERS?

  • 15 Jan 2024
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Devastating climate change, including killer heat waves and severe flooding, adversely affects the infrastructures our communities rely on. Dams in particular become increasingly more vulnerable to climate change due to aging. Rapidly rising water levels and frequent floods add extra stress to dams, reservoirs and waterways, pushing them to their design limits. A failure to upgrade dams in response to deterioration in structural health may result in a catastrophic impact on the people and environment.

The most recent examples are the failed Edenville and Sanford Dams in Midland, Michigan due to rapidly rising waters after days of heavy rain. The collapsed Edenville Dam, constructed in 1924, was rated in unsatisfactory condition in 2018, while the Sanford Dam, which was built in 1925, was given a fair condition rating by the State.

In 2017, major flooding from the damaged Oroville Dam in Northern California forced the evacuation of nearly 200,000 Californians. The Oroville Dam was completed in 1968, toward the end of the golden era of dam construction. This was a wakeup call for owners of aging dams across the country, as climate change continues to add stress to these structures.

California has additional challenges due to active earthquake faults, including the Hayward and San Andreas faults, which scientists predict are due for a large earthquake. Among the dams now considered to be at risk are the Anderson Dam and the Calaveras Dam, both close to fault lines in Silicon Valley. According to the NY Times, California’s most troubled large dam is at Lake Isabella. This dam was built on the Kern River near Bakersfield by the Army Corps of Engineers in the 1950’s on what was thought to be an inactive fault. However, this fault has been active since then.

Another major threat to dams is scouring. Numerous aging dams have experienced severe erosion of their unlined spillways. This erosion can lead to damage and even failure of dams and consequently can threaten public safety, properties, infrastructure and the wider local environment.

There are a number of unfortunate examples of dams failing due to earthquakes, flooding or scouring where early signs of deficiencies might have been detected if a proper structural health monitoring (SHM) system had been in place.

Introducing SMARTDAM

QuakeLogic is the only company using a cloud-based, AI-powered technology platform to perform continuous, autonomous assessments using data from sensors on the dam structure.

QuakeLogic’s Sensor data Management, Assessment and Repository Technology (SMART) platform transforms a dangerous, aging dam into a SMART dam able to alert officials to critical deterioration. It also significantly reduces needed search and inspection efforts following any seismic or other impact event such as settlement, scouring, etc.

The SMART platform integrates manually and digitally read sensor recordings into a fully automated unified monitoring system. It facilitates the acquisition and analysis of critical sensor data needed by the dam operators for proper operation and maintenance, and most importantly, for the safety assessment of the dam. It routinely collects, organizes and evaluates sensor data, and sends immediate notifications with ACTION PLANS upon exceedance of programmed thresholds, generating PDF reports regularly and on-demand.

The SMART platform is a cutting-edge system that works with various types of sensors such as accelerometers, tiltmeters, potentiometers, strain gauges, thermocouples, weather stations, piezometers and seepage monitors. Comprehensive analytic information is visible in real-time on the mobile-friendly dashboard, providing proof and PEACE OF MIND that a dam is performing as expected.

In addition to our SMART platform, our proprietary earthquake early warning (EEW) alerts provide a window of opportunity for action before earthquake shaking begins at the site. It can even trigger automated actions such as opening spillways, closing roads, etc. – when every second counts.

Easy-to-understand, engineering-quality information on the real-time health of the dam together with the ACTION PLAN support operators to make informed decisions. Whether planning maintenance activities, or prioritizing critical response actions, QuakeLogic has you covered.

QuakeLogic’s monitoring system instantly detects any issue that could impact the structural integrity of the dam, allowing corrective measures to be implemented and avoiding a potential future disaster.

For details, contact us at info@quakelogic.net

ON THE IMPORTANCE OF MONITORING TUNNELS FOR PROPER SEISMIC SAFETY ASSESSMENT AND RISK MANAGEMENT

  • 15 Jan 2024
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Monitoring tunnels for vibrations and deformations is not only critical during the construction phase but also their service life.

In 2012, the Tokyo-bound Sasago Tunnel suffered significant damage when nearly 150 concrete ceiling panels collapsed and crushed three vehicles, including a van carrying six people that caught fire. The deficiencies in mounting components of the ceiling panels were to blame.

But, are tunnels safe during an earthquake?

A common belief that underground structures are safer because they move with the soil, while structures above ground sway back and forth during the earthquakes appears to be misleading. The impact of earthquakes on tunnels can be severe due to ground failures such as liquefaction, strong ground shaking, and fault crossing.

Liquefaction takes place when saturated soft soil deposits loose load-carrying capacity during strong shaking. This phenomenon can cause the ground surrounding tunnels to deform and shift, with potentially severe impacts. The slope instability and fault crossings may also create permanent deformations leading to a collapse of the tunnel.

After the 1906 San Francisco earthquake, the Wrights railway tunnel in southern Santa Cruz mountains was closed for more than a year due to the collapse of approximately 100-m-long part crossing the San Andreas Fault Zone. Another railway tunnel crossing the White Wolf Fault was seriously damaged during the 1952 magnitude 7.5 Kern County earthquake associated with this fault (Kontogianni and Stiros, 2003).

In 1999 a magnitude 7.2 hit the Duzce region in Turkey. Close to the fault rupture, twin highway tunnels on the major highway connecting Ankara to Istanbul were under construction. The tunnels were partially collapsed due to intense pulses of earthquake motion (near-fault effects) as their lines cross the shear zone of the North Anatolian Fault.

The excavation process during tunnel construction may itself trigger microearthquakes. The vibrations, therefore need to be monitored to identify such seismic activity whether they create any movements or cracks on the tunnel surface. The monitoring vibrations is also needed to estimate the rock formations ahead of the tunnel face to optimize the excavation parameters. Besides, the infrastructure surrounding the tunnel including buildings must be monitored especially in case of construction of new subway (metro) lines.

Structural health monitoring (SHM) system is essential for the seismic resilience of tunnels. A robust real-time SHM system not only allows for assessment of accelerations and deformations (displacements and strains) in tunnel linings but also facilitates the implementation of adaptive risk management. Such a system can assist the officials to make informed and timely decisions to protect people (such as drivers or construction workers) from life-threatening conditions. For example, the highway tunnel can be closed to traffic before any severe consequences take place. Such pro-active actions would not only save lives but also avoid liabilities.

QuakeLogic is the only company providing cloud-based AI-powered disaster risk management solutions to prevent and reduce human and economic losses risen during and after earthquakes. Our cutting-edge technology platform performs real-time autonomous structural assessments using sensor data and sends rapid notifications after an event with the level of shaking intensity and whether structural integrity is compromised. For tunnels, our platform provides meaningful and easy-to-understand information immediately after an earthquake. This timely and critical information helps the officials to plan their emergency response. We also provide a web-based display where the sensor information can be monitored in real-time. This solution can provide great benefits especially for tunnels under construction phase.

For emergency measures and safety of tunnels, QuakeLogic provides advanced monitoring systems together with real-time and autonomous data analytics.

PROPER MONITORING CAN PROVIDE EARLY DAMAGE DETECTION AND INTERVENTION FOR DAMS

When disaster strikes, we are all at risk! The unprepared ones will get hit the hardest. Today, at least 1,680 dams across the U.S. rated in poor or unsatisfactory conditions. These dams pose potential risks according to the Associated Press article. Without urgent action, aging dams (dams in the U.S. are on average over 50 years old) may not be able to adequately handle the intense rainfall and floods of a changing climate or imminent earthquakes. Because the housing developments are often located nearby these dams, they may fail to protect people.

The significance of structural health monitoring (SHM) for dam safety is widely acknowledged. There are a number of unfortunate examples of failed dams where early signs of deficiencies might have been monitored and detected if a proper SHM system had been in place. A robust SHM system can provide timely information that is needed for an understanding of the performance of a dam. The SHM system, including instrumentation and data analytics, can provide dam owners with the knowledge that a dam is performing as expected, and the ability to detect a change in its integrity. This knowledge and ability are critical for the dam owners because they are directly responsible for the consequences of failure. Because of these reasons, a robust safety monitoring system should be a fundamental part of every dam owners risk management progra

QuakeLogic provides the most comprehensive structural health monitoring solution for dams. We are the only company with a cloud-based, AI-powered technology platform performing autonomous structural assessments using sensor data. After an earthquake occurs, our platform sends rapid notifications to our users. These notifications include the level of shaking intensity and whether the structural integrity of the dam is compromised. This system not only monitors earthquakes but also utilizes data from various sensors such as potentiometers, strain gauges, thermocouples, weather stations, piezometers and seepage (weirs & flumes).

QuakeLogic’s intelligent structural health monitoring platform generates meaningful and easy-to-understand information. This timely and critical information helps the dam owners to give informed decisions and plan their responses appropriately.

We provide “peace of mind” to dam owners. To learn about our risk management solutions, please contact us at info@quakelogic.net