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.

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.

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.

Numerical Model Updating Technique for Estimating Load Carrying Capacities of High Speed Railway Bridges

2016 ◽  
Vol 106 (8) ◽  
pp. 490-497
Author(s):  
Dong-Uk PARK ◽  
Jae-Bong KIM ◽  
Nam-Sik KIM ◽  
Sung-Il KIM
Keyword(s):  
Numerical Model ◽  
High Speed ◽  
Model Updating ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Load Carrying

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.

scholarly journals A Fuzzy Optimization Model for High-Speed Railway Timetable Rescheduling

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Li Wang ◽  
Yong Qin ◽  
Jie Xu ◽  
Limin Jia
Keyword(s):  
Optimization Model ◽  
High Speed ◽  
Fuzzy Optimization ◽  
Soft Constraints ◽  
Accurate Approximation ◽  
Total Delay ◽  
High Speed Rail ◽  
High Speed Railway ◽  
Tolerance Approach ◽  
Rail Line

A fuzzy optimization model based on improved symmetric tolerance approach is introduced, which allows for rescheduling high-speed railway timetable under unexpected interferences. The model nests different parameters of the soft constraints with uncertainty margin to describe their importance to the optimization purpose and treats the objective in the same manner. Thus a new optimal instrument is expected to achieve a new timetable subject to little slack of constraints. The section between Nanjing and Shanghai, which is the busiest, of Beijing-Shanghai high-speed rail line in China is used as the simulated measurement. The fuzzy optimization model provides an accurate approximation on train running time and headway time, and hence the results suggest that the number of seriously impacted trains and total delay time can be reduced significantly subject to little cost and risk.

Design of High-Speed Railway Bridges with Earthquakes in the United States

2018 ◽  
Vol 29 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Yinghong Cao ◽  
Todd Ude ◽  
Daniel Getter ◽  
Brendan Gill
Keyword(s):  
United States ◽  
High Speed ◽  
The United States ◽  
High Speed Railway ◽  
Railway Bridges
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