Study on Calculation Method of Stresses under Embankment

2011 ◽  
Vol 90-93 ◽  
pp. 656-661
Author(s):  
Hong Bin Xiao ◽  
Yue Wang
Keyword(s):  
Calculation Method ◽  
High Speed ◽  
Influence Factors ◽  
Engineering Practice ◽  
Correction Coefficient ◽  
Calculation Methods ◽  
Uniform Load ◽  
High Speed Railway ◽  
Railway Engineering ◽  
The Relationship

In China high-speed railway engineering practice, embankment settlements calculated values were often greatly different to the measured values, which may result from the stresses distribution under the embankment usually simplified. According to this issue, the elastic embankment method was introduced, the stresses under various embankment were calculated, the influence factors of the stresses values and distribution were analyzed. The stresses calculated by elastic embankment method, proportional load form and uniform load form were compared with the measured stresses. The relationship among the four kinds of stresses was analyzed. The applicable conditions of the various calculation methods were put forward. If the ratio of embankment half surface width and height was less than 4.5, when the stresses calculated by uniform load form were multiplied by correction coefficient 1.15, they were tallied well with the measured stresses.

Study on Influences of Thickness of Flange of U Rib on Mechanical Behaviors of Orthotropic Monolithic Steel Bridge Deck System

2010 ◽  
Vol 163-167 ◽  
pp. 122-126 ◽  
Author(s):  
Ru Deng Luo ◽  
Mei Xin Ye ◽  
Ye Zhi Zhang
Keyword(s):  
Finite Element Analysis ◽  
Yangtze River ◽  
High Speed ◽  
Bridge Deck ◽  
Steel Bridges ◽  
Engineering Practice ◽  
Steel Bridge ◽  
Mechanical Behaviors ◽  
Element Analysis ◽  
High Speed Railway

Orthotropic monolithic steel bridge deck system stiffened by U rib is very fit for high-speed railway steel bridges because of its excellent mechanical behaviors. Thickness of flange is a very important parameter of U rib and has influence on mechanical behaviors of orthotropic monolithic steel bridge deck system. Based on the engineering practice of Anqing Yangtze River Railway Grand Bridge, the kind and the extents of influences of thickness of flange of U rib on mechanical behaviors of orthotropic monolithic steel bridge deck system are studied with finite element analysis. The results show that thickness of flange of U rib has relative large positive influences on rigidity, strength and stability of orthotropic monolithic steel bridge deck system. 14~18mm is the appropriate range of thickness of flange of U rib for high-speed railway steel bridges.

The Calculation Method and Experimental Research on Throttling Pressure Drop during Kill a Well

2012 ◽  
Vol 229-231 ◽  
pp. 495-498
Author(s):  
Hui Xin Liu ◽  
Xian Min Yang ◽  
Cheng Tao Li ◽  
Xiang Cheng
Keyword(s):  
Pressure Drop ◽  
Calculation Method ◽  
Engineering Practice ◽  
Exploration Process ◽  
Throttle Valve ◽  
Long Time ◽  
Valve Opening ◽  
Casing Pressure ◽  
The Relationship ◽  
Control Accuracy

There is a common problem during kill a well, which is how to quickly and accurately control the surface casing pressure according to the requirements for killing a well. A step-by-step exploration process is employed on operation sites. Continuously adjusting throttle valve to acquire surface casing pressure may lead to failure of kill operation because of its long time and low control accuracy. Obviously, if the calculation problems of throttling drawdown can be resolved,the relationship between drawdown and throttle valve opening can be found and the course of explorating can be converted into a straight course.Then the success rate of killing well can be improved. More importantly, this can make automatic controll of surface casing pressure possible. The paper built the calculation method of throttling pressure drop by theoretical analysis and verified the calculation method by adopting it into field test. The result has showed that the calculation method of throttling pressure drop coincides with experimental results and it can be used in engineering practice.

Quick assessment of high-speed railway bridges based on a non-dimensional parameter representation

2017 ◽  
Vol 20 (11) ◽  
pp. 1623-1631 ◽  
Author(s):  
Patrick Salcher ◽  
Christoph Adam
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Response Assessment ◽  
Engineering Practice ◽  
Characteristic Parameters ◽  
Dimensional Parameter ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Parameter Representation ◽  
Bridge Model

The objective of this study is to provide the engineering practice with a tool for simplified dynamic response assessment of high-speed railway bridges in the pre-design phase. To serve this purpose, a non-dimensional representation of the characteristic parameters of the train–bridge interaction problem is described and extended based on a beam bridge model subjected to the static axle loads of the crossing high-speed train. The non-dimensional parameter representation is used to discuss several code-related design issues. It is revealed that in an admitted parameter domain, a code-regulated static assessment of high-speed railway bridges may under-predict the actual dynamic response. Furthermore, the minimum mass of a bridge as a function of the characteristic parameters is presented to comply with the maximum bridge acceleration specified in standards.

Study on Prediction Model of Shrinkage and Creep of Prestressed Concrete Beam in Passenger Dedicated Line

2011 ◽  
Vol 255-260 ◽  
pp. 3998-4002
Author(s):  
Jun Li Luo ◽  
Zhi Sheng Xu ◽  
Jun Li ◽  
Ji Hao Yang
Keyword(s):  
Prestressed Concrete ◽  
High Speed ◽  
Concrete Beam ◽  
Influence Factors ◽  
Creep Model ◽  
High Speed Railway ◽  
Modified Model ◽  
Shrinkage And Creep ◽  
Prestressed Concrete Bridge ◽  
Passenger Dedicated Line

To improve the calculation precision of deformation in prestressed concrete bridge in passenger dedicated line and accurately predict the development of shrinkage and creep in bridge, a universal applicable modified model was put forward in this paper based on ACI 209R(1992) shrinkage and creep model. In the modified model, three influence factors-slump, strength and reinforcement - are corrected. And the modified model results were compared with the experimental results. It shows that the modified model can more accurately predict the development of shrinkage and creep of high-speed railway bridge and better accord with the law of it.

Mapping relationship between dynamic responses of high-speed trains and additional bridge deformations

2020 ◽  
pp. 107754632093689
Author(s):  
Hongye Gou ◽  
Chang Liu ◽  
Hui Hua ◽  
Yi Bao ◽  
Qianhui Pu
Keyword(s):  
High Speed ◽  
Coupled Model ◽  
Dynamic Responses ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Running Safety ◽  
High Speed Trains ◽  
Track Bridge ◽  
The Relationship ◽  
Track Deformation

Deformations of high-speed railways accumulate over time and affect the geometry of the track, thus affecting the running safety of trains. This article proposes a new method to map the relationship between dynamic responses of high-speed trains and additional bridge deformations. A train–track–bridge coupled model is established to determine relationship between the dynamic responses (e.g. accelerations and wheel–rail forces) of the high-speed trains and the track deformations caused by bridge pier settlement, girder end rotation, and girder camber. The dynamic responses are correlated with the track deformation. The mapping relationship between bridge deformations and running safety of trains is determined. To satisfy the requirements of safety and riding comfort, the suggested upper thresholds of pier settlement, girder end rotation, and girder camber are 22.6 mm, 0.92‰ rad, and 17.2 mm, respectively. This study provides a method that is convenient for engineers in evaluation and maintenance of high-speed railway bridges.

Micro-Simulation System on Passengers of the PDL Station Design

2011 ◽  
Vol 467-469 ◽  
pp. 493-496 ◽  
Author(s):  
Chun Xia Gao ◽  
Bao Tian Dong ◽  
Qian Li ◽  
Ai Li Wang
Keyword(s):  
High Speed ◽  
Simulation System ◽  
Railway Station ◽  
High Speed Railway ◽  
Micro Simulation ◽  
Output Module ◽  
The Relationship

The paper presents the context of the micro-simulation on passengers of high-speed railway station, designs the micro-simulation system, meanwhile, divides the system into four modules, they are: passengers setting module, station design module, passengers simulation module and results output module. The functions and detailed contents of the modules are described, at the same time, the models of each module involved are introduced, and the relationship between modules are represented.

Nighttime Monitoring and Assessment Technology of Subgrade Settlement for Chengdu-Guanxian Line during Operation Period

2013 ◽  
Vol 742 ◽  
pp. 13-18
Author(s):  
Qian Su ◽  
Wei Jiang ◽  
Kai Jiang ◽  
Yu Jie Li ◽  
Ling Ling Yang
Keyword(s):  
High Speed ◽  
Influence Factors ◽  
Residual Deformation ◽  
High Speed Train ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Operation Period ◽  
Assessment Technology ◽  
Railway Passenger ◽  
Maintenance Plan

The criterion for residual deformation of Substructure of ballasteless track on railway passenger dedicated line is extremely strict in order to satisfy the safety and comfort requirements of the high-speed train during operation period, urgent need to strengthen the ballastless track lines settlement deformation observation, prediction and assessment technology. Based on Chengdu-Guanxian line, this paper puts forward observation programs of subgrade settlement combined with the characteristics of Subgrade Settlement through the analysis of the influence factors of subgrade settlement deformation and key consideration about the factors of nighttime observation precision. It shows that the monitoring and assessment technology could meet the requirements through the analysis of field data, it can be guidance of railway management departments to make maintenance plan. Some advices provide reference for the monitoring and assessment of high-speed railway subgrade settlement during operation period.

A General Steel Hardenability Calculation Method

2013 ◽  
Vol 816-817 ◽  
pp. 140-143
Author(s):  
Zhi Gang Yu ◽  
Li Na Wang ◽  
Jia Liu
Keyword(s):  
Experimental Data ◽  
Calculation Method ◽  
Prediction Accuracy ◽  
General Relationship ◽  
Alloying Elements ◽  
Calculation Methods ◽  
Linear Fitting ◽  
Fitting Method ◽  
Limited Applicability ◽  
The Relationship

This paper presents a general calculation method of steel hardenability. First use non-linear fitting method to establish a general relationship between hardenability coefficient and end-quench distance, and then use SVM method to establish the relationship between alloying elements and hardenability coefficients. It solves the limited applicability and poor precisions problems of the currently applied calculation methods for hardenability. It gives an enhancement scheme to make sure the accuracy of the model when the data are not complete enough. Experimental data show that using this method can effectively improve the hardenability prediction accuracy and can be widely used.

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