>To avoid this, in the 1960s builders of apartment blocks in Norilsk began drilling holes up to 100-ft deep and pouring reinforced concrete piles that stuck int

>To avoid this, in the 1960s builders of apartment blocks in Norilsk began drilling holes up to 100-ft deep and pouring reinforced concrete piles that stuck into the permanently frozen soil below. 100ft would be enough for quite some time. From my short stints in the construction industry (specializing in foundations) in Siberia during college summers (“stroyotryad”) 30 years ago I don’t remember anything being done to the full specs and without cutting corners. Using full power of my imagination I still can’t picture somebody doing it 100ft there when 30ft would look the same :)