Natural aging of hydraulic structures occurs with the long-term running of reservoirs&dams, which afford a very heavy burden when water blocking. Structure damage, body missing, cracks, aging, as well as unstable bodies, scouring pits, topography, metal corrosion bring potential risk to dams, especially after experienced an earthquake.
Inspection through water drainage or frogman are mostly used in the early time. But for water drainage method, it probably bring some damage to the surrounding environment, even some high dams could not be drained. For frogman method, the working depth could not exceed 50m for safe consideration. Since the 1950s, underwater robots have become increasingly popular in the water conservancy industry because of the advantage of high safety, high efficiency and high objectivity.
Camera is one of the basic configurations of ROV, including color cameras, black and white cameras, etc., because the imaging effect is greatly affected by the quality of the light source and the water environment, LED light sources are usually introduced. The following are some practical applications of detection of Deepinfar ROV equipped with optical imaging system
Millimeter Crack Cave
Rocks Floodgate Blocked by Debris
When the water quality is poor and clear image could not obtained through camera. There is another way to get the figure of target, which through reflection of sound wave on the surface or internal structure of the object, to discover the hidden dangers of the underwater structure of the reservoir&dam. The following are some 2D/3D sonar image took by Deepinfar ROV
Cave Detected by Sonar Gate of a Hydropower Station
Scour Hole of A Wind Power Station
3D Structure of A Tunnel
Laser Gauge Measurement
Equipped with a laser gauge, ROV could determine the size of dam defects and cracks and output the data through software developed by Deepinfar. Ltd
Laser Gauge Developed by Deepinfar Laser Gauge in Work
Ink Tracking Detection
When the location of the crack is relatively concealed and hard to be confirmed by camera or sonar, the ink tracker, which a new equipment developed by Deepinfar team would work.
Equipped with an ink tracker, the ROV close to the suspected part of dam body and jet ink to it, because of the pressure difference between upstream and downstream, the ink will be draw into the crack if it exited. The motion curve of the ink could be observed by camera, through which the entrance turns out.
“HeTun” in Working Ink Run Out from Crack
Connection Verification Testing
Connection verification testing is very helpful when the crack is complex and extend to the opposite side. Eject the tracer at the upstream and check it at the downstream. The approximate distribution of the leakage channel and the size of the cracks are estimated by the exposure time and tracer volume.
Diagram of Connection Verification Testing
Ink Tracker in Working
Tracker Color Turned Out
Black and white camera
|Long Tunnel Inspection ROV|