Foundation footing construction begins even prior to site location. The engineering for the construction site must take into account various soil conditions. Site engineering for a structure always includes engineering considerations for about bearing points of a structure.
After site selection, soils experts are called in to determine the depth and which the foundation must be placed in order in to accommodate all live and dead loads. Dead loads are easily assessed but the live loads are much more difficult to determine. Another consideration during this course of construction would be the relationship between the height of the structure in any prominent dynamic wind loads. Also a consideration would be the flexation of the structure due to wind and other natural forces.
When all data has been acquired the proper concrete formulation may proceed. Adjustments are made to the hardness of the concrete as well as admixtures which would make the concrete that is used more appropriate for the condition of the structure. Additionally, engineering experts will make design accommodation for the type of reinforcement bar to be used with consideration given to all known design elements.
When the engineering of the soil has been completed and certified to be in a corrective state for the excavation of design footings construction experts then proceed to excavate for the design footing. The footing takes into account all of the known engineering elements and is excavated to precise measurements. The concrete reinforcing bar is then placed in accordance with engineering design specifications.
After having completed all of the necessary engineering of soils, structural engineering, concrete design, reinforcement bar design, work may then proceed to the inspection stage were qualified and licensed personnel perform a detailed analysis of the placement of concrete forms and concrete reinforcement bar.