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

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.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.238.733 ◽

2012 ◽

Vol 238 ◽

pp. 733-737 ◽

Cited By ~ 1

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.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.204-208.1870 ◽

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%.

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

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1825-03 ◽

2003 ◽

Vol 1825 (1) ◽

pp. 15-21 ◽

Cited By ~ 2

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.

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

Materials ◽

10.3390/ma14112876 ◽

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.

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Defect investigation and replacement implementation of bearings for long-span continuous box girder bridges under operating high-speed railway networks: a case study

Structure and Infrastructure Engineering ◽

10.1080/15732479.2020.1867589 ◽

2021 ◽

pp. 1-16

Author(s):

Fengbo Ma ◽

Huile Li ◽

Shitong Hou ◽

Xuecheng Kang ◽

Gang Wu

Keyword(s):

High Speed ◽

Box Girder Bridges ◽

Box Girder ◽

High Speed Railway ◽

Girder Bridges ◽

Long Span ◽

Railway Networks ◽

Defect Investigation

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

IABSE Conference, Kuala Lumpur 2018: Engineering the Developing World ◽

10.2749/kualalumpur.2018.0637 ◽

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>

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