Structural Behavior of a Long-Span Partially Earth-Anchored Cable-Stayed Bridge during Installation of a Key Segment by Thermal Prestressing

Abstract

This study investigated structural behavior of long-span partially earth-anchored cable-stayed bridges with a main span length of 810 m that use a new key segment closing method based on a thermal prestressing technique. A detailed construction sequence analysis matched with the free cantilever method (FCM) was performed using a three-dimensional finite element (FE) model of a partially earth-anchored cable-stayed bridge. The new method offers an effective way of connecting key segments by avoiding large movements resulting from the removal of the longitudinal restraint owing to the asymmetry of axial forces in the girders near the pylons. The new method develops new member forces through the process of heating the cantilever system before installing the key segment and cooling the system continuously after installing key segments. The resulting forces developed by the thermal process enhance the structural behavior of partially earth-anchored cable-stayed bridges owing to decreased axial forces in the girders.

Determination and Implementation of Reasonable Completion State for the Self-Anchored Suspension Bridge with Extra-Wide Concrete Girder

“…However, only one of them is usually chosen as the single control parameter currently, or the target hanger force and tag line position were chosen as the dual control parameters for part of the hanger tensioning process [41]. Moreover, the control accuracy of the hanger tensioning process is affected by the ambient temperature changes, operation errors, and measuring errors [42]. Especially for the later tensioning stages, the influences on hanger force brought by the measuring error of cable displacement are more significant because of the large cable stiffness.…”

Structural Health Monitoring and Time-Dependent Effects Analysis of Self-Anchored Suspension Bridge with Extra-Wide Concrete Girder

“…However, the stable and exact measurement of the stress values of structure details may then only be obtained by the durable and sensitive strain gauges embedded in the structure during the construction phase [27][28][29]. In addition, the influences on the bridge safety brought by the vehicle loads [30,31], seismic loads [32,33], environmental corrosions [34,35], and thermal effects [36] had be investigated widely, and the concrete shrinkage & creep (S&C) effects of the laboratory specimens [37] and simple bridge types [38,39] were also widely reported. However, the field measurement for the complicated self-anchored suspension bridge, including the detailed stress and geometry evolution associated with time-dependent effects were rarely reported, especially for the one having such an extra-wide concrete girder [40,41].…”

FE Model Updating on an In-Service Self-Anchored Suspension Bridge with Extra-Width Using Hybrid Method

“…Meanwhile, with the high increase of the requirement for vehicle throughput of bridge system, many more bridge structures with extra-width appear. For those large-scale and complex engineering structures, the evaluations of situation and behavior of bridges are usually based on finite element (FE) analysis [2][3][4][5][6]. FE analysis is one of the most effective methods used to solve those engineering problems, but due to the complexity of most existing engineering structures, we cannot get a precise model to reflect the behavior of the physical one [7,8].…”