Zapatas

Zapatas are a type of shallow foundation used in civil engineering to distribute loads from building columns to the soil. They are typically made of reinforced concrete and are designed to transfer vertical loads while controlling settlement. The size and shape depend on the column load and the bearing capacity of the supporting soil.

There are several configurations: isolated (zapata aislada) for a single column; continuous (zapata corrida) along a line of columns; combined (zapata combinada) for multiple columns close together; and sometimes corner or cantilevered arrangements. In some cases, a deep foundation is used instead of a shallow zapata.

Design considerations include soil bearing capacity, load eccentricities, moments, settlement limits, and safety factors according to local codes. The design must resist punching shear around column edges, avoid excessive differential settlement, and ensure continuity between footings and the superstructure. Reinforcement is arranged to carry the bending moments and shear; concrete strength guidelines and minimum thickness depend on loads and codes.

Construction typically involves compacted soil, formwork, placement of steel reinforcement, pouring concrete, and curing. Where soil conditions are poor, alternative foundations such as piles or pile caps may be used instead of zapatas. Zapatas are widely used in residential, commercial, and light industrial projects in regions where shallow foundations are appropriate.