If memory serves me correctly, I believe Jonathan Rosenblum cites in his biography of Rav Yaakov Kamenetsky a story where Rav Yaakov complained that someone had placed a sefer on an arm of a bench rather than stand it up on the seat, to avoid the halachic prohibitions of Yoreh Deah 282 of sitting on the same surface as a Torah.
Accordingly, what are the halachically required minimum dimensions of shelves upon which printed Torah sefarim may be placed (i.e. minimum elevation from ground, width and depth)?
Does it matter if the sefarim are standing vs. lying down?