Or you could make sure that each tech in the web has, within its JSON description, the tech codes of its immediate dependancies, and then draw the web procedurally.
Anyhow, pursuing your web idea further, do you propose a single unified web for each civilisation, with military and economic techs in the same web; several webs for each civ, with one web for economic, one for military, etc; or that each building in the game capable of researching techs should have it own, specific, web?