scholarly journals Key Construction Monitoring Technology for Long-Span Continuous Girder Bridge

CONVERTER ◽  
2021 ◽  
pp. 220-231
Author(s):  
Fei Zhang, Yan Wang
Keyword(s):  
Shape Control ◽  
Interpolation Method ◽  
Correction Method ◽  
Solar Thermal ◽  
Long Span ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Cantilever Construction ◽  
Main Girder

This paper integrates a monitoring practice for the construction of a long-span continuous girder bridge to explore strain measurement and geometric shape control technology. In doing so, the actual stress of the bridge in the cantilever-construction stage is identified, and the influence of ambient temperature on the geometric shape control of the main girder is eliminated. According to linear creep theory, a strain correction method based on the superposition principle is proposed to remove the strain induced by concrete shrinkage and creep. By identifying the pattern of the solar thermal effect on the main girder geometry, a double in-situ measurement interpolation method is proposed to predict the adjusted value of formwork erection elevation. The results show that the deviation between the measured and corrected stress values on the root section of the main girder under the maximum cantilever state of the main girder is 16%–23%, which verifies the necessity of strain correction. The corrected values of measured stress on each controlled section are essentially identical to the calculated values, and both have consistent change patterns throughout the construction process, which verifies the validity of the strain correction method. During the cantilever-construction stage, the vertical deformation of the main girder owing to the solar thermal effect is parabolic and significant; hence, the main girder geometry should be measured prior to sunrise. The double in-situ measurement interpolation method can effectively eliminate the adverse effects of solar thermal when lofting the vertical formwork elevation in a non-ideal period.

scholarly journals Effect of Shear Creep on Long-Term Deformation Analysis of Long-Span Concrete Girder Bridge

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yanwei Niu ◽  
Yingying Tang
Keyword(s):  
Superposition Principle ◽  
Three Dimensional ◽  
Deformation Analysis ◽  
Computation Method ◽  
Shear Creep ◽  
Long Span ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Concrete Girder

The purpose of this paper is to report on the development of a three-dimensional (3D) creep calculation method suited for use in analyzing long-term deformation of long-span concrete girder bridges. Based on linear creep and the superposition principle, the proposed method can consider both shear creep and segmental multiage concrete effect, and a related program is developed. The effects of shear creep are introduced by applying this method to a continuous girder bridge with a main span of 100 m. Comparisons obtained with the nonshear case show that shear creep causes long-term deformation to increase by 12.5%. Furthermore, the effect of shear creep is proportional to the shear creep coefficient; for a bridge with different degrees of prestress, the influence of shear creep is close. Combined with the analysis of a continuous rigid bridge with a main span of 270 m, the results based on the general frame program suggest that shear creep amplification is multiplied by a factor of 1.13–1.15 in terms of long-term deformation. Moreover, the vertical prestress has little effect on shear creep and long-term deformation. The 3D creep analysis shows a larger long-term prestress loss for vertical prestress at a region near the pier cross section. The relevant computation method and result can be referenced for the design and long-term deformation analysis of similar bridges.

scholarly journals High-Speed Train-Track-Bridge Dynamic Interaction considering Wheel-Rail Contact Nonlinearity due to Wheel Hollow Wear

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Chao Chang ◽  
Liang Ling ◽  
Zhaoling Han ◽  
Kaiyun Wang ◽  
Wanming Zhai
Keyword(s):  
High Speed ◽  
Synthesis Method ◽  
Dynamic Interaction ◽  
High Speed Train ◽  
Train Track ◽  
High Speed Railway ◽  
Long Span ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Track Bridge

Wheel hollow wear is a common form of wheel-surface damage in high-speed trains, which is of great concern and a potential threat to the service performance and safety of the high-speed railway system. At the same time, rail corridors in high-speed railways are extensively straightened through the addition of bridges. However, only few studies paid attention to the influence of wheel-profile wear on the train-track-bridge dynamic interaction. This paper reports a study of the high-speed train-track-bridge dynamic interactions under new and hollow worn wheel profiles. A nonlinear rigid-flexible coupled model of a Chinese high-speed train travelling on nonballasted tracks supported by a long-span continuous girder bridge is formulated. This modelling is based on the train-track-bridge interaction theory, the wheel-rail nonelliptical multipoint contact theory, and the modified Craig–Bampton modal synthesis method. The effects of wheel-rail nonlinearity caused by the wheel hollow wear are fully considered. The proposed model is applied to predict the vertical and lateral dynamic responses of the high-speed train-track-bridge system under new and worn wheel profiles, in which a high-speed train passing through a long-span continuous girder bridge at a speed of 350 km/h is considered. The numerical results show that the wheel hollow wear changes the geometric parameters of the wheel-rail contact and then deteriorates the train-track-bridge interactions. The worn wheels can increase the vibration response of the high-speed railway bridges.

scholarly journals The Application of the Grey Neural Network in the Deflection Control of PC Rigid Frame Continuous Box Girder Bridges

2014 ◽  
Vol 8 (1) ◽  
pp. 416-419
Author(s):  
Lifeng Wang ◽  
Hongwei Jiang ◽  
Dongpo He
Keyword(s):  
Neural Network ◽  
Prestressed Concrete ◽  
Control Process ◽  
Construction Control ◽  
Box Girder Bridges ◽  
Girder Bridges ◽  
Rigid Frame ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Cantilever Construction

Deflection control is the crucial procedure in construction control of cantilever prestressed concrete continuous girder bridge. This paper summarizes the advantages of Grey theory’s poor information processing and abilities of Neural Network’s self-learning and adaption, and the combinational algorithm of grey Neural Network is applied to the prestressed concrete bridge cantilever construction control process. Firstly, GM (1, 1) model and BP artificial Neural Network algorithm to predict the elevation of construction process are introduced respectively. In addition, the elevation prediction model of rigid-framed-continuous girder bridge is established. By practicing in the construction control project of LongHua Bridge, the method is testified to be feasible. The results indicate that, the combinational algorithm of Gray Neural Network to predict the construction elevation has higher reliability and accuracy which can be an effective tool of construction control for the same type bridges.

scholarly journals Study on temporary support of continuous girder bridge in construction

2017 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Chun Ming Xu
Keyword(s):  
Great Influence ◽  
Engineering Practice ◽  
Rigid Support ◽  
Structural System ◽  
Fixed Bearing ◽  
Long Span ◽  
Temporary Support ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Supporting Force

The reasonable design of the temporary support of the continuous girder bridge is a safe guarantee for the smooth closing. According to the characteristics of temporary support of the closed section, the corresponding calculation method is put forward, and then several kinds of temporary support locking devices colmmonly used in engineering practice are discussed. Based on the engineering example, the paper discusses the selection and design of the temporary support form of the construction of the continuous girder bridge. The results show that the transition of the structural system has great influence on the temporary supporting force, and it is feasible to use the external rigid support when the long - span continuous girder bridge decouples the temporary fixed bearing restraint.

Shaking Table Test of a Long-Span Continuous Girder Bridge

2012 ◽  
Vol 446-449 ◽  
pp. 242-246
Author(s):  
Yan Jiang Chen ◽  
Da Xing Zhou ◽  
Wei Ming Yan ◽  
Zhen Yun Tang
Keyword(s):  
Shaking Table Test ◽  
Shaking Table ◽  
Long Span ◽  
Continuous Girder Bridge ◽  
Girder Bridge

Shaking Table Test of a Long-Span Continuous Girder Bridge

2012 ◽  
Vol 446-449 ◽  
pp. 242-246
Author(s):  
Yan Jiang Chen ◽  
Da Xing Zhou ◽  
Wei Ming Yan ◽  
Zhen Yun Tang
Keyword(s):  
Seismic Design ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Technology Study ◽  
Long Span Bridges ◽  
Long Span ◽  
Test Technology ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Support Excitation

Compared with middle-span bridges, seismic response of long-span bridges is more complicated, and so is seismic design. For example, influence of high order modes is obvious, as well as multi-support excitation, all kinds of nonlinear factors and soil and structure interaction (SSI). It is necessary to study on seismic behavior of a long-span continuous girder bridge. With the help of shake table array and substructure test technology, study on seismic performance of a long-span continuous girder bridge has been done and some useful conclusions have been got.

Analysis of the Causes of the Formation of Crack in Inclined Web of Prestressed Concrete Continuous Girder Bridge in Cantilever Construction

2012 ◽  
Vol 256-259 ◽  
pp. 1614-1617
Author(s):  
Li Hua Lu ◽  
Peng Tian ◽  
Tao Yu
Keyword(s):  
Prestressed Concrete ◽  
Paper Analysis ◽  
Additional Stress ◽  
Different Temperatures ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Cantilever Construction ◽  
The Way

The crack in inclined web of the prestressed concrete continuous girder bridge which is constracted by the way of cast-in-place cantilever method that become one problem that should be more cared about[1-2]. This paper analysis the bridge in three different conditions which are according to the pratical and special engineering to find the causes of the formation of crack in inclined web of prestressed concrete continuous girder bridge in cantilever construction. The results of the analysis show that the additional stress caused by the different temperatures between internal and external components leads to the formation of the crack in inclined web of the bridge.

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