Setting out of works
The process of transferring the plan of a structure to the ground for actual construction is known as setting out of works. It involves marking the location and dimensions of the proposed structure on the ground using pegs, stakes, strings, and other tools. 
Setting out of works is necessary to ensure that the construction is carried out according to the design and specifications.
Site clearance 
The process of removing all unwanted materials and vegetation from the site before the start of construction is known as site clearance. It involves clearing the site of trees, bushes, rocks, debris, and any other obstructions that may hinder the construction process. Site clearance is necessary to provide a clean and safe working environment for the construction workers and equipment.
Steps in deep excavations In deep excavations, steps or benches are constructed to prevent the sides of the excavation from collapsing and to provide safe access for the workers and equipment. The depth and width of the steps depend on the type of soil, the angle of repose, and the height of the excavation. Steps in deep excavations are necessary to ensure the stability and safety of the excavation and to provide safe access for the workers and equipment.