Excavation is the process of moving earth, rock or other materials with tools, equipment or explosives. It also includes trenching, wall shafts, tunnelling and underground. It is the preliminary activity of the construction project.
Gridline drawings represents the grids marked in numbers and alphabets whose measurements are shown for site marking out reference. These grid lines are so aligned that the line falls on the excavation and footing.
Excavation drawing represents the length, width and depth of the excavation. Excavation line is marked in dotted line.