Research on the Design of Long Span Prestressed Bridge Piers

Abstract

In highway construction, when designing roads intersecting with existing roads at acute angles or running parallel over extensive distances, conventional single-span solutions become impractical for spanning the intersecting roads. As a solution to meet the requirements of bridge span in such scenarios, this study focuses on the design of prestressed framed bridge piers. The research delves into several aspects of prestressed framed bridge pier design, encompassing the overall structural layout, prestressed cap beam design, and cap beam-to-pier connection types. The study yields the following conclusions: (1) For framed piers, the rational structural forms include the length of the cap beam, the position and number of pier columns (two-column, three-column, or multiple columns), and whether the pier is rigidly connected to the cap beam or hinged. Additionally, the dimensions of the cap beam and pier columns, as well as the arrangement of the pier-column-to-beam connections, should be taken into consideration. (2) When using prestressed steel tendons for the bent cap beam, if the bent cap beam is poured with a single drop, a full-length bundle should be selected. If segmented pouring is used, short bundles can be used. (3) Special attention is warranted for the influence of the stiffness of the substructure foundation on the structural behavior. Temperature loads can induce bending moments and prestress secondary moments, with their magnitudes significantly influenced by the stiffness of the foundation.