Pier "pier body" is a colloquial title, which is somewhat similar to the title of "person (body)". The actual bridge structure is divided into superstructure, substructure, foundation structure and accessory structure. Pier actually refers to the substructure. The substructure includes pier cap beam, pier column and tie beam. In other words, the pier "pier body" includes pier columns.

There are columns, square columns, rectangular columns and vase piers. , are included in the scope of the substructure, and some can't be called piers, such as hollow thin-walled piers, and some streamlined irregular piers. They mainly bear the upper load. Some are connected with the capping beam, and some are directly consolidated with the upper part.