지렛대 원리로 무거운 콘크리트 맨홀 뚜껑 열기 현장 노하우 #worker #process #leverage #construction #manhole

Ajouté : 2026-05-25

This video demonstrates how to safely open heavy concrete manhole covers using the lever principle by inserting a pickaxe into the cover's hole, placing a metal pipe as a fulcrum beneath the pickaxe handle, and pressing down on the handle to generate sufficient force to lift the cover, then sliding it aside.