In Colorado, the consistency and general make up of the earth ranges widely. Geographically speaking, the eastern portion of Colorado contains flat grasslands that transition rather dramatically to towering rocky peaks. The result is patches of clay, rock, sand and soil. The moisture content varies greatly as well, from very dry to very wet conditions.
So as architects, civil engineers and structural engineers one of the first things we have to gather information on about a particular site for a project is the type and consistency of the soil. Even within the footprint of a proposed building location the soil conditions can be variable and it is typically not feasible to know all the conditions until excavation has begun. However, design for a building begins well in advance of excavation taking place so we rely on a geotechnical analysis, or soils report to provide detailed information for the type and consistency of a soil sample taken from the site. The soils report also recommends for us what type of foundation and the required strength of the concrete needed as a result of the soil quality.
