Finite element analysis of temporary pre-stress system of precast segmental box girder bridge

Wang Yahui,Kang Jiangwei,Yang Zheng,Li Zhongming,H Zhang,H Abdul Aziz

doi:10.1051/e3sconf/202127601015

Abstract

The precast segmental bridge has the advantages of fast construction speed, good economic performance, and small impact on the surrounding environment. In order to study the role of the temporary pre-stressing system in the cantilever assembly process of the precast segment box girder bridge, ABAQUS was used to simulate the assembly process of the standard section of a viaduct. Studying the compressive stress and relative sliding of the joint section under the action of the self-weight and temporary pre-stress, the reasonable number and spatial arrangement of the tension pedestal are determined. The research results show that too few roof pedestals will cause the large area decompression state and too much will cause the construction period to be longer. When the roof symmetrical pedestal is located on the inner side of the web, it will obviously increase the area of the zero-compression stress at the end of the top slab. When the distance between the pedestal and the center of the web is 0.12L, the full section meets the minimum consolidation pressure requirement of the glued joint. The reasonable number of tension pedestals and their spatial arrangement will provide specific guidance and reference to assembling construction of actual precast segment box girder in the future.

Highlights

Precast segmented bridges have the advantages of fast construction speed, good economic performance, and small impact on the surrounding environment[1]
During the cantilever precast assembly process of the precast segmental box girder bridge, according to the design and site construction environment, the test assembly of the box girder segments should be carried out first, and epoxy resin glue[2] should be applied to the joints’ section of the segments, and temporary pre-stress which use high-strength rebar is applied in accordance with the design load requirements[3]
The temporary pre-stressing system plays a vital role in the safety and stability of the cantilever assembly structure during the segment assembly process[5], and it is necessary to conduct a detailed study on the temporary pre-stressing system

Summary

Introduction

Precast segmented bridges have the advantages of fast construction speed, good economic performance, and small impact on the surrounding environment[1]. During the cantilever precast assembly process of the precast segmental box girder bridge, according to the design and site construction environment, the test assembly of the box girder segments should be carried out first, and epoxy resin glue[2] should be applied to the joints’ section of the segments, and temporary pre-stress which use high-strength rebar is applied in accordance with the design load requirements[3]. The purpose of this article is to analyze the stress and deformation performance of the glue joint section during the assembly process of the precast segment box girder, and determine the scientific and reasonable pre-stress tension system, that is, the reasonable number of tension pedestals and their spatial arrangement, so as to provide specific guidance and reference to assembling construction of actual precast segment box girder

Temporary pre-stressed system and finite element model

The number influence of temporary top tensioning pedestals

Tensioning pedestals’ space layout

Conclusion