Creep Effects on Simply Supported Prestressed Concrete Box Girder of High-Speed Railway with Ballastless Tracks

2012 ◽  
Vol 238 ◽  
pp. 733-737 ◽  
Author(s):  
Wang Fang ◽  
Bing Han ◽  
Shao Kun Yang
Keyword(s):  
Prestressed Concrete ◽  
High Speed ◽  
Element Model ◽  
Dead Load ◽  
Box Girders ◽  
Box Girder ◽  
High Speed Railway ◽  
Simply Supported ◽  
Creep Models ◽  
Curing Age

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.

Research on the Key Technology in Steam Curing for 32m Simple-Supported Box Girder of High-Speed Railway

2011 ◽  
Vol 90-93 ◽  
pp. 958-963
Author(s):  
Xue Min Li ◽  
Er Yu Zhu ◽  
Yong Zheng Zhou ◽  
Yue Hong Qin
Keyword(s):  
Temperature Control ◽  
High Speed ◽  
Production Efficiency ◽  
Temperature Control System ◽  
Box Girders ◽  
Steam Curing ◽  
Box Girder ◽  
High Speed Railway ◽  
Simply Supported ◽  
Steam System

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.

Simply supported prestressed concrete deck for high speed railway bridges

2003 ◽  
Vol 87 (11) ◽  
pp. 57-63
Author(s):  
Maja Della Vedova ◽  
Luigi Evangelista ◽  
Francesco Sacchi
Keyword(s):  
Prestressed Concrete ◽  
High Speed ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Simply Supported ◽  
Concrete Deck

Mathematical Logarithmic Model for Predicting Noise of Simply-Supported PC-Box Girder in High-Speed Railway

2012 ◽  
Vol 204-208 ◽  
pp. 1870-1874
Author(s):  
Xiao Zhen Li ◽  
Jin Feng Wu ◽  
Xun Zhang ◽  
Quan Min Liu ◽  
Zhi Jun Zhang
Keyword(s):  
Noise Level ◽  
High Speed ◽  
Field Tests ◽  
Field Measurements ◽  
Box Girder ◽  
High Speed Railway ◽  
Double Line ◽  
Simply Supported ◽  
Significant Difference ◽  
Logarithmic Equation

When a train runs across a bridge, vibration energy is transmitted from the track structure into the bridge deck and other components which act as different size of ‘sounding boards’. These ‘sounding boards’ also radiate noise, namely, re-radiated noise, which results in ‘hot spots’ in noise maps for bridge sections. Based on the field tests on the noise of 32m double line simply-supported PC-box girder serviced in Chengdu-Dujiangyan High-speed Railway (CDHR) in China, mathematical logarithmic equation for predicting the equivalent A-weighed noise level (LA,eq) is proposed. Predicted results are compared with field ones and the non-parametric tests including two-related samples Wilcoxon and two-independent samples Kolmogorov–Smirnov are carried out, indicating satisfactory results and verifying the reliability of theoretical model. Analysis shows that equivalent A-weighed noise level detects no significant difference between the model predictions and the field measurements at the confidence level of 95%.

Experience with the Precast Span Method on the Korean High-Speed Rail Project

2003 ◽  
Vol 1825 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Kee Dong Kang ◽  
Sunduck D. Suh
Keyword(s):  
High Speed ◽  
Precast Concrete ◽  
Cost Savings ◽  
Weather Conditions ◽  
Box Girders ◽  
High Speed Rail ◽  
Box Girder ◽  
High Speed Railway ◽  
Economic Implications ◽  
Railway Bridges

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.

scholarly journals Mechanical Performance of a Ballastless Track System for the Railway Bridges of High-Speed Lines: Experimental and Numerical Study under Thermal Loading

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2876
Author(s):  
Yingying Zhang ◽  
Lingyu Zhou ◽  
Akim D. Mahunon ◽  
Guangchao Zhang ◽  
Xiusheng Peng ◽  
...  
Keyword(s):  
High Speed ◽  
Thermal Loading ◽  
Mechanical Performance ◽  
Track Structure ◽  
Box Girder ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Track System ◽  
Girder Bridge ◽  
Track Slab

The mechanical performance of China Railway Track System type II (CRTS II) ballastless track suitable for High-Speed Railway (HSR) bridges is investigated in this project by testing a one-quarter-scaled three-span specimen under thermal loading. Stress analysis was performed both experimentally and numerically, via finite-element modeling in the latter case. The results showed that strains in the track slab, in the cement-emulsified asphalt (CA) mortar and in the track bed, increased nonlinearly with the temperature increase. In the longitudinal direction, the zero-displacement section between the track slab and the track bed was close to the 1/8L section of the beam, while the zero-displacement section between the track slab and the box girder bridge was close to the 3/8L section. The maximum values of the relative vertical displacement between the track bed and the bridge structure occurred in the section at three-quarters of the span. Numerical analysis showed that the lower the temperature, the larger the tensile stresses occurring in the different layers of the track structure, whereas the higher the temperature, the higher the relative displacement between the track system and the box girder bridge. Consequently, quantifying the stresses in the various components of the track structure resulting from sudden temperature drops and evaluating the relative displacements between the rails and the track bed resulting from high-temperature are helpful in the design of ballastless track structures for high-speed railway lines.

Prefabrication and Erection Technology of Wide Box Girders in Cross-Sea Bridge

2014 ◽  
Vol 1065-1069 ◽  
pp. 882-888
Author(s):  
Yue Huang ◽  
Xing Fa Wu
Keyword(s):  
Great Influence ◽  
Dead Load ◽  
Box Girders ◽  
Box Girder ◽  
Technical Problems ◽  
Line Segments ◽  
Temperature Load ◽  
Quanzhou Bay ◽  
Research Show ◽  
Better Than

In the approach spans of Quanzhou Bay Cross-sea Bridge, these standard spans are 50m or 70m , width is 20.05m.The approach spans have been built by using short Line segments precast and erection method. This is the first application in the cross sea bridges. According to characteristics of this project, the research on prefabrication and erection technology of wide box girders has been carried out to solve the technical problems in the process of construction. The research show that: 1)In precasting process , the vertical deformation of wide box girder is very small under dead load and temperature load etc. so the influence of prefabrication and erection accuracy can be ignored; 2)The temporary anchor using prestressed steel strand better than planished steel; 3) When using epoxy gasket to adjust geometric line shape, the thickness of cemented layer has a great influence on the linear adjustment;4)The epoxy gasket and bridge erecting machine should be used together, Alignment adjustmen could obtain satisfactory results.

Experimental Study on the Dynamic Deformation of Simply Supported Beam in Chinese High-speed Railway

2018 ◽  
Author(s):  
Gonglian Dai ◽  
Meng Wang ◽  
Tianliang Zhao ◽  
Wenshuo Liu
Keyword(s):  
High Speed ◽  
Structure Design ◽  
Dynamic Coefficient ◽  
Bridge Structure ◽  
High Speed Railway ◽  
Simply Supported Beam ◽  
Vertical Stiffness ◽  
Simply Supported ◽  
Speed Up ◽  
Design Speed

<p>At present, Chinese high-speed railway operating mileage has exceeded 20 thousand km, and the proportion of the bridge is nearly 50%. Moreover, high-speed railway design speed is constantly improving. Therefore, controlling the deformation of the bridge structure strictly is particularly important to train speed-up as well as to ensure the smoothness of the line. This paper, based on the field test, shows the vertical and transverse absolute displacements of bridge structure by field collection. What’s more, resonance speed and dynamic coefficient of bridge were studied. The results show that: the horizontal and vertical stiffness of the bridge can meet the requirements of <b>Chinese “high-speed railway design specification” (HRDS)</b>, and the structure design can be optimized. However, the dynamic coefficient may be greater than the specification suggested value. And the simply supported beam with CRTSII ballastless track has second-order vertical resonance velocity 306km/h and third-order transverse resonance velocity 312km/h by test results, which are all coincide with the theoretical resonance velocity.</p>

scholarly journals Influence of end Contsrains on the Global Behaviour of a Box Girder

2016 ◽  
Vol 6 (1) ◽  
pp. 7-15
Author(s):  
Daniela Mihaela Boca ◽  
A. Faur ◽  
A. Boca
Keyword(s):  
Prestressed Concrete ◽  
Transport Infrastructure ◽  
Box Girders ◽  
3D Fem ◽  
Important Data ◽  
Box Girder ◽  
Fem Model ◽  
Global Behaviour ◽  
Applied Forces ◽  
Precast Prestressed Concrete

Abstract This study aims to presents the importance of end constrains, boundary conditions and position of the applied forces regarding the design of precast/prestressed concrete box girders. The study is based on a destructive test which was performed on a 37.1 m span single-cell prestressed concrete box girder. The scope of the test was to certify the usage of such girders for the new Transylvania motorway bridges. The test is numerically reproduced through a full 3D FEM model implemented in SAP2000. The influence of the end diaphragms is considered by analysing the beam’s behaviour to six loading conditions: one of which is replicating the loadings during the test, while the others are conceived as real vertical and horizontally loading scenarios. The results obtained for the girders with and without end constrains are compared. The performances of both design solutions in the presence of prestressing are highlighted where applicable. It is considered that the results of this study may provide very important data if considering that Romania has an urgent need to realize a modern and an adequate transport infrastructure.

scholarly journals Numerical Analysis of Dead Load Shear Force Distribution in Webs of Multicell Inclined Web Box-Girder Bridge

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xingwei Xue ◽  
Meizhong Wu ◽  
Zhengwei Li ◽  
Peng Zhou
Keyword(s):  
Load Distribution ◽  
Shear Force ◽  
Cell Number ◽  
Force Distribution ◽  
Distribution Factor ◽  
Dead Load ◽  
Bridge Design ◽  
Box Girders ◽  
Box Girder ◽  
The Dead

Moment and shear load distribution are important in bridge design. Most existing studies have focused on the distribution of girders under vehicle loading, neglecting the dead load distribution between the webs of multicell box-girders. Through the “Sum of Local Internal Forces” function, the shear force of each web in the multicell box-girder 3D finite element model was extracted and analysed using the dead load shear force distribution factor. The research parameters include the slope of the web, support condition, and cell number with respect to the dead load shear force distribution factor. The results indicate that the dead load shear distribution in the webs of multicell box-girders is uneven. The outermost inclined web bears a shear force greater than the average shear force, which must be considered in bridge design.

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