Preliminary Evaluation of the Bump at the End of the Railway Bridge

Author(s):  
Jennifer E. Nicks ◽  
Jean-Louis Briaud

Bumps often develop at the interface between the bridge deck and the approach embankment of a railway bridge. The differential track movement at this transition zone creates higher impact loads, reduced bridge and embankment life, possible safety hazards, and higher maintenance costs. This study investigates the extent of the problem, typical maintenance expense, reasons behind the bump, and possible solutions. Based on a survey conducted to evaluate current practice, the bump problem affects about 50% of all railroad bridges and costs each railroad company an estimated $2,550,000 on maintenance. The typical slope for current bumps is equal to approximately 1:150. Using LS-DYNA, a 3-D, non-linear finite element program, a simple, rigid system was simulated to find the range of impact forces resulting from different bump slopes. A parametric study will be conducted in the future to examine the components involved and to optimize various solutions, such as approach slabs. The results from the entire study will help to minimize the bump at the end of the railway bridge.

2011 ◽  
Vol 675-677 ◽  
pp. 1175-1178
Author(s):  
Ling Kun Chen ◽  
Li Zhong Jiang ◽  
Peng Liu

Basin rubber bearings are frequently used in high-speed railway bridge or passenger special line railway bridge, lead rubber bearings (LRB) are infrequently used in those railway bridges nowdays, the study on earthquake-resistant capability of railway bridge fabricated isolation bearing - the intelligent and functional structure - would be beneficial in engineering practices. Elasto-plastic earthquake responses of high-speed railway bridges fabricated LRB are studied by means of the finite element program, earthquake responses of railway bridges under high-speed vehicles and different earthquake action fabricated and unfabricated isolation bearing are calculated respectively. The results show that: plastic hinge will develop at the bottom of piers in regard to railway bridges with mid-high and low pier; LRB can reduce displacement and inner forces of structures and improve earthquake-resistant capability of structures effectively.


2011 ◽  
Vol 50-51 ◽  
pp. 100-104
Author(s):  
Chang Yong Zhang ◽  
Tie Yi Zhong ◽  
Ke Jian Chen ◽  
Yun Kang Gong

In this paper, based on the finite element program ANSYS, the model of a simply supported railway bridge with and without isolation using lead rubber bearing is established. Seismic response time-history analyses of the bridge subjected to high-level earthquakes are carried out considering and not considering train live loads. Through the comparison and analyses of the results, the effects of train live loads on seismic calculation of non-isolated railway bridges and isolated railway bridges are obtained. The results of the research will support the further study on seismic design and isolation design of simply supported railway bridges.


2007 ◽  
Vol 347 ◽  
pp. 173-178 ◽  
Author(s):  
Chun Sheng Wang ◽  
Yue Xu ◽  
Ai Rong Chen ◽  
Wei Zhen Chen

According to the fatigue damage failure mechanism of riveted members, a riveted member probabilistic fatigue failure model (RMPFFM) was proposed, and a fracture finite element program is developed to calculate the geometry function of RMPFFM. Furthermore, a system fatigue damage reliability model of riveted bridges was proposed, and based on Monte-Carlo method, a large system fatigue damage reliability analysis program was developed to calculate the system fatigue failure probability. Then the system evaluation model was used to predicate the system fatigue damage reliability of Ganjiang Railway Bridge. According to assessment results, the probabilistic remaining fatigue life, safe inspection intervals and maintenance strategy are determined, which can control and avoid fatigue failure accident and reduce the contingent disaster in bridge service life.


2003 ◽  
Vol 154 (8) ◽  
pp. 305-313 ◽  
Author(s):  
Roman Eyholzer ◽  
Martin Baumann ◽  
Rolf Manser

Faced with the challenging task of balancing forest interests and wildlife, the Swiss Forest Agency initiated the pilot programme«Game and Forest», which is committed to a philosophy of goal-oriented management practice and a redesign of forestry subsidizing. Within this programme the diverse goals of forestry and hunting have been amalgamated to a superimposed goal and set out in a corresponding contract. The Game-Forest-Management-Tool (GFMT) has been divised to simulate the effect of various strategies to deal with the complex problems of forest-wildlife. Optimal contract-fulfilling procedures can be simulated on a PC using this technical tool. The efficiency of the measures suggested by simulations that were carried out are being tested in a study area within the pilot programme, «Game and Forest». Half way through this trial, after two years, we can say that there has been no significant increase of non-browsed areas. In 2004, after the collection of data for the entire study area, we will be able to tell whether applying this computer simulated strategy truly leads to an augmentation of non-browsed area and a decrease in bark-peeled forests in the pilot area.


2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.


2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.


2013 ◽  
Vol 631-632 ◽  
pp. 518-523 ◽  
Author(s):  
Xiang Li ◽  
Min You

Owing to the lack of a good theory method to obtain the accurate equivalent elastic constants of hexagon honeycomb sandwich structure’s core, the paper analyzed mechanics performance of honeycomb sandwich structure’s core and deduced equivalent elastic constants of hexagon honeycomb sandwich structure’s core considering the wall plate expansion deformation’s effect of hexagonal cell. And also a typical satellite sandwich structure was chose as an application to analyze. The commercial finite element program ANSYS was employed to evaluate the mechanics property of hexagon honeycomb core. Numerical simulation analysis and theoretical calculation results show the formulas of equivalent elastic constants is correct and also research results of the paper provide theory basis for satellite cellular sandwich structure optimization design.


2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.


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