Jointed, prestressed columns have been shown to enable accelerated construction and to offer superior seismic performance, as compared with cast-in-place columns without prestressing. During an earthquake, such columns deform primarily through concentrated rotations at the joints, and special detailing at the ends of the columns prevents crushing and spalling. Unbonded prestressing steel, running vertically through the columns, provides a restoring moment that returns the columns to plumb after the ground motion stops. The use of prefabricated substructure elements speeds up the bridge assembly by eliminating building formwork, fixing steel, casting and curing concrete on-site. A variety of detailing strategies have been developed for jointed, prestressed columns, but their fundamental behavior is similar. More importantly, this behavior differs from that of conventional reinforced concrete columns for which current seismic code provisions were developed. This paper develops a displacement-based procedure for designing jointed, prestressed columns that is based on the framework provided by the AASHTO Guide Specifications for LRFD Seismic Bridge Design. To account for the unique characteristics of these systems, the design procedure introduces new performance criteria; it also provides recommendations for proportioning the prestressed and non-prestressed steel, calculating the effective column stiffness, and estimating the column displacement capacity. The focus of the paper is on columns with pretensioned strands and internal energy dissipaters, although the procedure would work for post-tensioned systems and those with external dissipaters as well. This design approach is critically evaluated through comparison to the results of both cyclic tests of cantilever columns and shaking table tests of a two-span bridge system.

与没有预应力的现浇柱相比，已显示接头，预应力柱可加快施工速度并提供出色的抗震性能。在地震期间，此类柱主要通过在关节处集中旋转而变形，并且在柱的端部进行特殊设计可以防止压碎和剥落。垂直穿过柱子的无粘结预应力钢提供了一个恢复力矩，使地面运动停止后，柱子恢复了立柱状态。预制的下部结构元素的使用通过消除建筑模板，固定钢，现场浇筑和固化混凝土来加快桥梁组装速度。已经为连接的预应力柱开发了各种详细设计策略，但是它们的基本行为是相似的。更重要的是，这种行为不同于制定了现行地震规范的传统钢筋混凝土柱的行为。本文基于AASHTO LRFD地震桥梁设计指南规范提供的框架，开发了一种基于位移的过程来设计节理预应力柱。为了考虑这些系统的独特特性，设计程序引入了新的性能标准；它还提供了有关按比例分配预应力和非预应力钢，计算有效柱刚度以及估算柱位移能力的建议。本文的重点是在具有预应力钢绞线和内部耗能器的柱子上，尽管该程序适用于后张紧系统和具有外部耗能器的系统。