Question

explain the significance of piers and pier caps to the substructure of a bridge system.

Answer 1

Piers

The piers are vertical structures used to support deck or the bearings provided for load transmission to underground soil through foundation. These structures serve as supports for the bridge spans at intermediate points.

The pier structure has mainly two functions:

1. Load transmission to the Foundation
2. Resistance to the horizontal forces

Most of the cases, piers are designed to resist the vertical loads alone. In areas which lie in the seismic zone, it is recommended to design the pier for lateral loads also.

Most of the piers are constructed using concrete. Steel for the construction of pier is used in very few cases till now. Use of composite columns i.e. steel columns filled with concrete is used as new technology of pier construction.

The pier is a vertical member that resist the forces by means of shear mechanism. These forces are mainly lateral forces. The pier that consist of multiple columns are called as bent.

Pier Cap / Headstock

Pier Cap / Headstock is the component which transfers loads from the superstructure to the piers. Pier cap provide sufficient seating for the Bridge girders and disperse the loads from the bearings to the Piers.