Zach Treece

Navigation locks are critical infrastructure components, and their closure for maintenance and repair can have significant impacts on the global economy. The current state of inspection and monitoring of lock components is generally to close the lock and perform a visual inspection. Whereas structural health monitoring of navigation locks is gaining acceptance, automation of the structural health monitoring process is lacking. This paper reports on efforts to develop an automated damage… Show more

Navigation locks are critical infrastructure components, and their closure for maintenance and repair can have significant impacts on the global economy. The current state of inspection and monitoring of lock components is generally to close the lock and perform a visual inspection. Whereas structural health monitoring of navigation locks is gaining acceptance, automation of the structural health monitoring process is lacking. This paper reports on efforts to develop an automated damage detection system for miter gates of navigation locks. The study focuses on using strain gage measurements to identify the redistribution of load throughout lock gates in the presence of damage. To eliminate the environmental variability in the data, a new damage-sensitive feature is introduced, termed here as “slope” and defined as the derivative of the strain with respect to the water levels in the lock chamber. The slopes form a new, stationary time series effectively purged of environmental effects. A principal component analysis, a method of analyzing multivariate, stationary time series, is then used to detect significant changes in the statistics of slopes as an indication of damage. To validate the approach, damage is simulated in a finite element model, and the resulting changes in strain from the finite element model are superimposed on the measured data. The results demonstrate the potential of the proposed approach for detecting damage in navigational lock gates. Show less

This paper focuses on structural health monitoring of the downstream miter gates
on the main channel of Lock and Dam 27 just north of St. Louis, Missouri. Miter gates
are the most prolific gate type employed by the United States Army Corps of
Engineers (USACE), used at more than 75% of all lock and dam sites throughout the
United States. Structural health monitoring of these gates is important, because it
provides a method for detecting damage, including degradation of… Show more

This paper focuses on structural health monitoring of the downstream miter gates
on the main channel of Lock and Dam 27 just north of St. Louis, Missouri. Miter gates
are the most prolific gate type employed by the United States Army Corps of
Engineers (USACE), used at more than 75% of all lock and dam sites throughout the
United States. Structural health monitoring of these gates is important, because it
provides a method for detecting damage, including degradation of boundary
conditions, fatigue cracking, dragging of debris, or discrete occurrences of damage,
such as barge impact, which may otherwise go unnoticed until the damage propagates
and costly repairs become necessary. By knowing in real time the extent and location
of damage, a better informed decision can be made as to whether or not the gate is in
immediate need of repair. The initial Structural Monitoring and Analysis in Real Time
of Lock Gates (SMART Gate) study of Lock and Dam 27 is focused on achieving
several specific condition monitoring targets. The target that will be addressed in this
paper is the ability to detect contact degradation between the lateral edge of the lock
gate and the wall of the lock chamber. Preliminary results from finite element models
show that contact degradation is a localized phenomenon, which is empirically known
to occur over time. Initial field results have revealed seasonal changes in strain
readings as well as non-linear strain behavior during the beginning of a chamber fill
event. This paper presents initial efforts to combine these findings synergistically to
detect contact degradation between the quoin and wall boundary on the downstream
miter lock gates at Lock and Dam 27. Show less