Span-by-Span Erection of Precast Segmental Bridges: Introduction

Span-by-span erection is the most common and often the most cost-effective construction method for precast segmental bridges. Initially conceived for in-place casting with advancing shoring, it was soon extended to self-launching gantry erection of precast segmental bridges and span-by-span casting with Movable Scaffolding Systems (MSS). Span-by-span assembly of simply-supported spans is the typical construction method for light-rail transit bridges. Large-scale highway projects combine span-by-span erection with in-place casting of wet joints to achieve full structural continuity, diminish the number of bearings and expansion joints, and control the propagation of the geometry errors of short-line match casting. In 19 pages, the eManual explores the temporary static schemes of span-by-span construction of precast segmental bridges, the corresponding post-tensioning systems and locked-in stresses, the stiffness interactions to consider for the design of bridge piers and superstructures, and staged application of post-tensioning to avoid opening of the epoxy joints and the risk of brittle span failure. The eManual discusses span assembly on shoring towers and the different means and methods to strand-jack into position precast segmental spans delivered on barges. It introduces the different families of self-launching gantries and explores the span assembly operations common to all types of gantries. Introduction Ground assembly of precast segmental spans Self-launching gantry erection of precast segmental spans References The eManual provides an exhaustive introduction to span-by-span construction of precast segmental bridges for bridge owners, designers and construction professionals interested in this construction method. Specific monographs of the eManuals Project explore the different families of self-launching gantries in great detail. The collection Span-by-Span Construction of Precast Segmental Bridges (134 pages) provides exhaustive coverage of span-by-span construction, ranging from segment fabrication by short- and long-line casting to the different types of self-launching gantries used for span erection, and is offered with 10% discount on the cover price of the five eManuals.