Every building needs a strong foundation. This foundation can only be laid if you support it with piles. A pile is a cylindrical item, usually made of durable materials, such as concrete. Pilings are pushed into the earth to support building structures.
Piling contractors use piles for foundations in the following circumstances:
- To strengthen a weak layer of soil near the surface. Because this soil cannot support a building’s weight, pilings are placed so the stronger rock or soil beneath can support a building’s loads.
- To support high-rise buildings or structures, such as water tanks or bridges. Pilings are used to support and establish concentrated and heavy building loads.
Pile foundations are used, as they can take higher loads than spread-type footings.
Two Basic Pile Types
Usually, two basic types of pile foundations are featured for use. These piles are either end bearing piles or friction piles. End bearing files represent piles where the bottom end of a pile lies on a layer of rock or soil. The load of a building or structure transfers to the stronger layer. Therefore, this type of piling serves as a type of column. The bottom end lies on a surface that intersects the weaker and stronger layers. As a result, the load bypasses the weaker link and rests on the stronger material.
Unlike end bearing piles, friction piles transfer a building’s load to the soil over the entire height of the pile by friction. The entire surface transfers the load or its forces to the soil. The greater the depth of the pile, the more load can be supported. When friction pilings are used, the amount of load that is supported is directly proportionate to the pile’s length.
For construction purposes, piles can be made of durable materials, such as wood, steel, or concrete. Usually, wood piles are used as foundations for buildings where the soil is weak. The pilings are also used for constructing jetties.
When concrete piles are used, they are precast, and driven by hammering. Steel piles, such as concrete pilings, are driven into the ground. Steel-H piles can hold heavy loads, and can save time, as the casting process is not used. Steel piles do not feature a protective coating, as the soil would scrape away the coating. If the soil is corrosive, typically concrete pilings are used.
When driving piles, experts in the field must take care to make sure that each pile is spaced appropriately. That way, the loads can be distributed more evenly, rather than being concentrated in a few locations.
In many cases, engineers normally group several piles together before topping them off with a pile cap. The cap, which is made of thick concrete, extends over the pile groupings, serving as a base on which a column may be built. The load of the column is distributed to the group of piles.