Foundation design for commercial projects can vary greatly depending on soil conditions, structural loads, and budget.
Most commercial foundations will fall into one or more of the following categories.
A mat foundation is generally a thick soil-rock supported foundation that remains the same thickness through the entire footprint of the structure. Foundations of this type are normally thicker and more heavily reinforced than many foundations and are typically associated with extremely heavy loads. This type of foundation can be classified as either a shallow or deep foundation depending on whether the mat is supported by soil/rock or piles.
Spot or continuous footings are commonly used in commercial construction. Spot and continuous footings typically carry columns or grade beams or a combination of both. The footing is generally wider than it is thick and distributes the structure’s load into the soil supporting the foundation. This type of foundation is generally recognized as a shallow foundation, but may sometimes be constructed in conjunction with piles.
A monolithic slab with grade beams is considered a shallow foundation and is generally utilized on structures with lightly loaded foundations. It is constructed by excavating perimeter and interior trenches for grade beams, setting perimeter forms, adding reinforcing, and casting the concrete for the grade beams and floor slab together in one monolithic pour. This foundation design is sometimes used to support column loads, but more often walls that are more uniformly loaded. Piles are sometimes utilized with this type of foundation construction.
Piles supporting grade beams or pile caps represent a deep foundation. The piles can be concrete, steel or wood and can be installed via a variety of ways. A foundation plan will commonly call for single piles at some locations, with multiple piles or groups in other areas. Next, grade beams or caps are formed, reinforced, and cast. Pile caps can receive columns or grade beams to support both column and uniform loads. The same is true for pile supported grade beams.
