In my head I am seeing what you describe as a tent shape. Something like this, but more in line with the Great Pyramid dimensions in the roof.

Magnets are only effective if the metal cables which run through them sync up with north/south. Haven't heard about anyone capturing east/west energy before. But one magnetised cable running north/south through the earth in the middle of the structure with connecting cables to all the legs would work.

Even without the magnets the structure alone cannot avoid having an effect on the environment around it. Especially if there is copper involved.

Has someone tried it? No idea. Probably not! You could be the first ;)

Don't forget to post about it here in this community...