Identification of Creep Camber State of 32-m Box Girders on High-Speed Railway and Prediction of Geometry of Track over Girder

Author(s):  
Xiao-Rui Du ◽  
Ya-Qin Yang ◽  
Peng Xu ◽  
Chao Yang ◽  
Xia Wu
2011 ◽  
Vol 90-93 ◽  
pp. 958-963
Author(s):  
Xue Min Li ◽  
Er Yu Zhu ◽  
Yong Zheng Zhou ◽  
Yue Hong Qin

In the process of steam curing to high-speed railway’s simply-supported box girder, there are some problems must be faced such as the difficulty to determine steam curing system and to achieve automatic temperature control. With the construction site conditions of simple-supported box girder in Longwang beam field which is located on Shijiazhuang-Wuhan (Shi-Wu) section of Beijing-Guangzhou high-speed railway, the paper proposes the appropriate steam system for simply-supported box girders, determines the appropriate equipments, explores the temperature control system in the process of steam curing to the simply-supported box girder's concrete, and takes the temperature test of steam curing in the field. Results show that, the steam curing technology in this paper can increase the production efficiency of beam in production site, and effectively guarantee the prefabricated quality of simply-supported box girder.


2012 ◽  
Vol 238 ◽  
pp. 733-737 ◽  
Author(s):  
Wang Fang ◽  
Bing Han ◽  
Shao Kun Yang

Creep will lead to increasing deflection of prestressed concrete girder, which may induce rails uneven, especially to ballastless tracks in high-speed railways. In this paper, two creep models, CEB-FIP90 and ACI209, were used in a finite element model to analyze influences of creep on simply supported prestressed concrete box girders which are used in high-speed railway in China. Sensitivity analysis was carried on towards curing age, secondary dead load, loading time and prestressing method on deformation of the girder. The results show creep should be controlled in engineering to ensure driving security.


2006 ◽  
Vol 92 (20) ◽  
pp. 49-56
Author(s):  
Marco Petrangeli ◽  
Gaetano Usai ◽  
Francesco Magnorfi ◽  
Marco Orlandini ◽  
Giosafatte Geremia

Author(s):  
Kee Dong Kang ◽  
Sunduck D. Suh

The Korean High-Speed Rail Project, Korean Train Express, has 109 km (67 mi) of bridges that comprise about 27% of the entire alignment. The successful construction of these bridges significantly affects overall project progress. To meet tight schedule and quality control standards, in addition to cost savings, contractors proposed the precast span method (PSM) versus the original girder designs on some segments of the line. This first application of PSM to high-speed rail in Korea has posed some challenges: design requirements for high-speed railway bridges are stricter than those for road bridges because of stringent deformation requirements. The adoption of PSM girders has improved the construction quality and schedule. PSM requires no falsework and is not limited by ground and weather conditions, thus being well suited for the construction of long viaducts under stringent budget and construction schedule requirements. With PSM, one full span of a precast-concrete box girder is manufactured in a casting yard, lifted by hydraulic jacks, transported with a special carrier, and placed by the launching girder into the final position. The PSM units are then tied into two or three 25-m (82-ft) or continuous spans using cast-in-place concrete in place of concrete and posttensioning. The contractors manufactured the PSM girders in a temporary manufacturing facility and reduced the installation cycle time for one 25-m (82-ft) long box girder to 11/2 days. The design, fabrication, transportation, and installation of the box girders for the Korean high-speed railway viaducts with PSM are discussed. Project and economic implications of PSM are compared with the movable scaffolding system method.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Wangqing Wen ◽  
Shiwei Li ◽  
Aiguo Yan ◽  
Jiahua Zeng

AbstractTo analyze the time-varying temperature field distribution pattern of ballastless track steel-concrete composite box girders for a high-speed railway at ambient temperature, a numerical model for analyzing the time-varying temperature field of steel-concrete composite box girders was established based on the long-term monitoring data for the internal and external environments of the main girder of the Ganjiang Bridge on the Nanchang-Ganzhou high-speed railway. The influence of factors such as the deck pavement and the ambient wind speed on the time-varying temperature field of the steel-concrete composite box girders were considered. The results showed that there was a significant difference in the vertical temperature gradient patterns on sections at the side web and at the middle web at the same moment in time due to the hindering effect of the track board on the heat exchange between the ambient temperature and the main girder. Increasing the wind speed accelerated the rate of heat exchange between the main girder surface and the environment. In particular, when the internal temperature of the girder was higher than the ambient temperature, the higher the wind speed was, the larger the temperature gradient was. This study lays a foundation for accurate analysis of the structural response of ballastless track steel-concrete composite girder bridges at ambient temperature.


2012 ◽  
Vol 132 (10) ◽  
pp. 673-676
Author(s):  
Takaharu TAKESHITA ◽  
Wataru KITAGAWA ◽  
Inami ASAI ◽  
Hidehiko NAKAZAWA ◽  
Yusuke FURUHASHI

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