Bridges - Tiltmeter Applications In Bridges
Of all structures provided for public use, none are subject to as much wear and tear as bridges. Now, Applied Geomechanics offers money-saving solutions to problems of construction monitoring, structural testing, and bridge inspection and maintenance.
An Extraordinary Level of Awareness
Applied Geomechanics tiltmeters are inertially referenced to the stablest baseline of all, the vertical gravity vector. They provide a precise and dependable record of all angular movements with respect to gravity. And they eliminate the time and expense of locating a stable benchmark or other datum. Simply install the tiltmeters and begin your measurements. Rotations induced by settlement or loading are directly converted to displacements, moduli, moments, and shears using standard engineering formulae.
With sensitivities as great as one part in 10 million, our tiltmeters give you more resolving power than any other instrument. When read manually, Applied Geomechanics tiltmeters provide quick checks of bridge performance under static loading. Connected to our battery-powered data loggers and alarm systems, they provide continuous surveillance and recording of static and dynamic behavior. Used with PC-based real-time monitoring, they give you absolute knowledge of what's happening at any moment.
Construction (Safety) Monitoring
Excessive structural or foundation movement during construction is a precursor to structural failure. Tiltmeters connected to a warning system can trigger alarms when allowable limits are exceeded, permitting corrective action before damage occurs. Continuously recorded data provides a permanent record of events.
Example: A deep excavation for a new highway bridge threatened to undermine a pier of an existing railroad bridge. Two tiltmeters installed on the pier provided continuous surveillance, allowing the project to proceed safely and on schedule.
Design Verification
Deviations from design during construction can result in hidden danger and unsatisfactory bridge performance. Simple load-deflection test performed with tiltmeters can ensure that structural elements are within their elastic range and that beams and trusses have the required stiffness.
Example: A cantilever span of low-density concrete was suspected of having a lower modulus than called for by the design. Tilts measured in response to controlled loads verified this conclusion.
Evaluating Long-Term Performance
Many of the processes that damage bridges occur slowly over months and years. Highly stable, permanently installed tiltmeters measure and record the effects of corrosion, settlement, fatigue and other causes of bridge deterioration.
Example: A bridge operator suspected that riverbed scour was causing pier settlement. Accelerated tilting that occurred during this high runoff season confirmed this conclusion.
Example: A bridge operator suspected that riverbed scour was causing pier settlement. Accelerated tilting that occurred during this high runoff season confirmed this conclusion.
Prioritizing Expensive Repair Work
Tiltmeters rapidly document deflection and recovery under controlled-load or normal traffic conditions. This measured behavior provides an objective basis for allocating scarce repair and maintenance dollars.
Example: The footings of piers that support a 19th century elevated railway system had deteriorated. The operator wished to identify the worst footings and repair them first. Tiltmeters measured roadbed deflections and ranked the piers accordingly. The piers with the weakest footings deflected the most under a test load driven across the pier.
An Extraordinary Level of Awareness
Applied Geomechanics tiltmeters are inertially referenced to the stablest baseline of all, the vertical gravity vector. They provide a precise and dependable record of all angular movements with respect to gravity. And they eliminate the time and expense of locating a stable benchmark or other datum. Simply install the tiltmeters and begin your measurements. Rotations induced by settlement or loading are directly converted to displacements, moduli, moments, and shears using standard engineering formulae.
With sensitivities as great as one part in 10 million, our tiltmeters give you more resolving power than any other instrument. When read manually, Applied Geomechanics tiltmeters provide quick checks of bridge performance under static loading. Connected to our battery-powered data loggers and alarm systems, they provide continuous surveillance and recording of static and dynamic behavior. Used with PC-based real-time monitoring, they give you absolute knowledge of what's happening at any moment.
Construction (Safety) Monitoring
Excessive structural or foundation movement during construction is a precursor to structural failure. Tiltmeters connected to a warning system can trigger alarms when allowable limits are exceeded, permitting corrective action before damage occurs. Continuously recorded data provides a permanent record of events.
Example: A deep excavation for a new highway bridge threatened to undermine a pier of an existing railroad bridge. Two tiltmeters installed on the pier provided continuous surveillance, allowing the project to proceed safely and on schedule.
Design Verification
Deviations from design during construction can result in hidden danger and unsatisfactory bridge performance. Simple load-deflection test performed with tiltmeters can ensure that structural elements are within their elastic range and that beams and trusses have the required stiffness.
Example: A cantilever span of low-density concrete was suspected of having a lower modulus than called for by the design. Tilts measured in response to controlled loads verified this conclusion.
Evaluating Long-Term Performance
Many of the processes that damage bridges occur slowly over months and years. Highly stable, permanently installed tiltmeters measure and record the effects of corrosion, settlement, fatigue and other causes of bridge deterioration.
Example: A bridge operator suspected that riverbed scour was causing pier settlement. Accelerated tilting that occurred during this high runoff season confirmed this conclusion.
Example: A bridge operator suspected that riverbed scour was causing pier settlement. Accelerated tilting that occurred during this high runoff season confirmed this conclusion.
Prioritizing Expensive Repair Work
Tiltmeters rapidly document deflection and recovery under controlled-load or normal traffic conditions. This measured behavior provides an objective basis for allocating scarce repair and maintenance dollars.
Example: The footings of piers that support a 19th century elevated railway system had deteriorated. The operator wished to identify the worst footings and repair them first. Tiltmeters measured roadbed deflections and ranked the piers accordingly. The piers with the weakest footings deflected the most under a test load driven across the pier.