Underwater Inspection Technologies and Construction Techniques for Dams
Eligible for 2 PDHs
The average age of dam in the United States is about 60 years. With passing years, underwater structures in dams face integrity issues. These include:
1) Cavities/cracks/defects in the dam face. These defects could impact the integrity of the dam and create a dam safety issue.
2) Leakage / concern of operability of emergency gates and seals
3) Grooves for lowering gates could be corroded and broken
4) Cement lining of penstock could be compromised thus leading to water leakage
5) Over years, silt could have been deposited in the reservoir (and Tail race channel) thus giving the dam owners a deceptive reading of water availability in reservoir
Engineering assessments of existing dams require inspections of submerged structures such as intake structures, gates, valves, waterways, tail races and stilling basins. Underwater manual inspections have been typically performed by divers. Though divers have historically carried out underwater inspections, they are hampered by water depth / bottom time, differential of pressure (Delta P) potentials, and subjective observation. Remotely operated vehicles (ROVs) are gaining popularity for inspection of dams: unaffected by depth, able to be put in harm’s way, able to ‘see’ through turbidity. New technologies in underwater robotic inspections are continually being developed and upgraded.
The first part of the webinar will focus on presenting manned diving as well as remote technologies that are available and been used successfully for performing a variety of underwater inspections. The second part will be devoted to underwater construction techniques utilized to make structural repairs to concrete structures as well as mechanical equipment. The third part will present 3 case histories.
Moderated by Dave Paul