I don’t believe ”calota” has anything to do with excavation methods. Please note that Table 2.3 (see link below) refers to “avanço da calota” from x to y meter (several measurements are given). I couldn’t figure out what these different measurements might indicate, though.

https://www.repositorio.ufop.br/bitstream/123456789/6977/1/D...

“Calota” usually translates as “cap” in English. Examples:
calota de automóvel: hubcap
https://www.collinsdictionary.com/dictionary/english-portugu...
calota de gelo: ice cap
https://en.wikipedia.org/wiki/Ice_cap

In this context, I’m almost sure they’re referring to a cap rock. In the same table, see the word “rocha” of different sizes in column 1, then “calota” in column 2 (under “método de escavação”). Two excavation methods are mentioned: “em camada” and “em bancada”. -
My best shot is that “bancada” refers to bench itself or benching (system):

"Benching (Benching system)" means a method of protecting employees from cave-ins by excavating the sides of an excavation to form one or a series of horizontal levels or steps, usually with vertical or near-vertical surfaces between levels. - https://water-research.net/pdf/confinedspace.pdf

In my opinion, the context points to locations to be excavated. Therefore, I don’t think “benching system” would fit in, although I have provided it as an alternative translation in case you think it’s referring to an excavation method.

I hope this helped shed some light on the subject.



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Note added at 17 hrs (2021-03-07 05:43:15 GMT)
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Definition of cap rock:
https://www.worldwaterfalldatabase.com/glossary