connective N1 rare writtenliterary
〜に〜を重ねて — piling ~ upon ~
〜に〜を重ねて ・ にをかさねて
A full written guide for 〜に〜を重ねて is on the way.
This point is mapped in the grammar tree, but its examples, formation table and usage notes haven't been written yet. The fastest way to learn it now is to meet it in real sentences inside Jengo.
See 〜に〜を重ねて in real sentences
Jengo shows 〜に〜を重ねて the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled from published Japanese grammar references. Editorial confidence: low.