scholarly journals A new Technology for Incremental Launching the Small Curvature Radius Variable Cross-Section Steel Box Girder

2015 ◽  
Author(s):  
Hong Zhang ◽  
Qiang Guo ◽  
Wenxia Wang
Keyword(s):  
Cross Section ◽  
New Technology ◽  
Variable Cross Section ◽  
Curvature Radius ◽  
Variable Cross ◽  
Box Girder ◽  
Small Curvature ◽  
Steel Box Girder

Stability Analysis of Single-Pier Variable Cross-Section Box-Girder Continuous Bridge

2014 ◽  
Vol 989-994 ◽  
pp. 923-926
Author(s):  
Guan Sheng Yin ◽  
Jie Bai ◽  
Jun Jie Feng
Keyword(s):  
Cross Section ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Lateral Stability ◽  
Eccentric Load ◽  
Box Girder ◽  
Factors Affecting ◽  
Safety Coefficient ◽  
Future Design ◽  
Transverse Stability

On the basis of Umansky box-girder torsion theory, the software of ANSYS is applied to simulate related engineering model. In considering a variety of live load conditions, the lateral stability of multi-span single-pier variable cross-section box-girder under torsion eccentric load is analyzed. Analysis results reveal that under different working conditions, the factors affecting the transverse stability of the bridge and the proportion of the value on each, such as gravity, the span ratio and the distance between support are different; When the overload ratio is 2 times larger, the bridge stability safety coefficient decreases along the curve and changes rapidly. In the future design of this kind of bridge, the overall lateral stability should be paid much more attention. Some methods and suggestions about how to prevent the emergence of security and stability problems are put forward in the end.

The Changes of Internal Forces and the Reliability of Curved Bridge Taking the Cross-Sectional Design of Axial Symmetrical

2014 ◽  
Vol 587-589 ◽  
pp. 1631-1636
Author(s):  
Zheng Jiu Zhao ◽  
Jing Hong Gao
Keyword(s):  
Cross Section ◽  
Variable Cross Section ◽  
Radius Of Curvature ◽  
Variable Cross ◽  
Cross Sectional ◽  
Box Girder ◽  
Curved Bridge ◽  
The Cross ◽  
Cross Sectional Design ◽  
Bridge Models

Taking a bridge of 160m long variable cross-section prestressed continuous curved box-girder as the research object and analyzing the cross-sectional design of axis with axial symmetrical or axial non-symmetrical to research the structure forces change of the upper part of bridge in different curvature. In order to test and verify the variable cross-section of prestressed continuous curved box-girder bridge is safe and reliable via cross-sectional design with axial symmetrical instead of axial non-symtrical within a radius of curvature of the interval. Creating the straight bridge and curved bridge models with different radius of curvature in same span by Midas/Civil to compare their structure forces.

Field Test and Numerical Simulation of Cracks in the Box Girder of Long-Span RPC Bridges

2011 ◽  
Vol 383-390 ◽  
pp. 5592-5597 ◽  
Author(s):  
Jin Mei Zhang
Keyword(s):  
Cross Section ◽  
Field Test ◽  
Radial Component ◽  
Curvature Radius ◽  
Element Analysis ◽  
Box Girder ◽  
Small Curvature ◽  
Long Span ◽  
Cantilever Construction

Cracks that occurred in the top slab of a cantilever construction bridge were investigated through field test, which revealed that the cracks were caused by excessive prestress layout and too small curvature radius of tendons. The excessive prestress layout can reduce the forced area of cross-section. Too small curvature radius of tendons may cause the concrete in the flat curve of tendons to withstand great radial component of forces. And, excessive prestressed ducts will in a certain extent affect the quality of concrete between the ducts. In addition, a finite element analysis was performed to evaluate the effects of the tendons. Based on the results, a construction method that prevents the cracks is proposed.

Analysis of Eccentric Load Causing Torsion Effects of Variable Cross-Section Continuous Box Girder during Cantilevered Casting

2012 ◽  
Vol 446-449 ◽  
pp. 1194-1198
Author(s):  
Min Xiang ◽  
Cong Juan Yang
Keyword(s):  
Cross Section ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Construction Process ◽  
Analysis Model ◽  
Box Girders ◽  
Eccentric Load ◽  
Box Girder ◽  
Continuous Beam Bridge ◽  
Beam Bridge

The construction with hanging basket eccentric loading was studied for the cantilever casting of a 32m +48 m +32 m continuous box girder. The calculation of center deflecting angles of cantilever box girders with variable cross-section due to pure torsion was derived, and correspondingly a program was developed to calculate this formula. An analysis model of cantilever casting continuous beam bridge with hanging basket eccentric loading was established based on finite elements software, and the shear stress, the longitudinal normal stress and the combined stress of different section were analyzed under different construction process. The torsional effect due to hanging basket eccentric loading was studied and the results are helpful to guide the construction in practice.

scholarly journals Numerical Testing of Switch Point Dynamics—A Curved Beam with a Variable Cross-Section

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 701 ◽  
Author(s):  
Jerzy Kisilowski ◽  
Rafał Kowalik
Keyword(s):  
Cross Section ◽  
Ritz Method ◽  
Variable Cross Section ◽  
Beam Parameter ◽  
Curvature Radius ◽  
Curved Beam ◽  
Vertical Force ◽  
Variable Cross ◽  
Switch Point ◽  
Rail Vehicle

The article presents mathematical considerations on the dynamics of the springing switch point being an element of the railway junction. Due to the structure of the switch point, mathematical analysis was divided into two stages: The first stage refers to the analysis of the dynamics of the switch point as a beam of variable rectilinear stiffness to which three forces (coming from three closures of switch drives) placed in the initial section of the switch point are applied. The next stage of the analysis concerns an identical beam, but curved, with a variable cross-section. In both cases, the beam is subjected to a vertical force resulting from forces from the rail vehicle. The calculations refer to a switch point of 23 m length and a curvature radius R = 1200 m. The first stage of the switch point analysis refers to the movement of a rail vehicle on a straight track, and the second stage concerns the rail vehicle movement on a reverse path. This article also provides an analysis of mode vibrations of a curved beam with a variable cross-section, and variable inertia and stiffness moments (further in the article the changes will be referred to as beam parameter changes). It is assumed that the beam is loaded with vertical forces (coming) from a rail vehicle. The solution was found by applying the Ritz method, which served to present the fourth-order partial equations as ordinary differential ones. The numerical research whose results are given aimed to define how the changes in beam parameters and vertical load affect mode vibrations of the beam.

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