DaveC426913 said:
I know explicit AI is not allowed, but are Google results disallowed, evn though they're essentialy AI?
I introduced the word "strake" in post #2. I used Google search and was fed results by AI, but I found only references to boat hull "strakes" in my searches. I suspect Google AI has learned from my searches and post, and accepted the new term, being applied to dams. Can you find an original text that uses the term "strakes" that Google AI supplied as the introduction to its search results?
The OP picture, from between 1880 and 1899, is of the Fox River where it flows through Appleton, Wisconsin, USA. That weir was built during the early days of reinforced concrete, and has since been replaced. The massive concrete was pored in blocks. That left a gap between the blocks at the foot of the wall. The strakes may have been cast in place later, to cover the gaps between the blocks, to protect them from the damaging water, falling from above. I would expect blocks cast more recently to not require that protection.
Terminology: Since water flows over the crest, that is not really a dam, it is a barrage or a weir. A barrage has gates to regulate the flow, which reduces that structure to identify as a weir.
The crest height of a weir is used to regulate the level of the river above the weir. A river used for navigation will have locks to raise and lower vessels travelling along the river. The weir ensures the river is navigable, without rapids between locks. Since weirs are specific to navigable rivers, the technology will not be widely used, nor will it apply to higher dam spillways.