Proceedings of the 1st International Workshop on High-Speed and Intercity Railways

Lateral wind is one of the most important influencing factors on train running performance. In process of high speed train running along the flexible bridge under lateral wind, there is the interaction among wind, vehicle, and bridge, which represents the coupling vibration of wind-vehicle-bridge system. There was some existing research was reviewed, the latest advance in the field of wind-vehicle-bridge system is presented. Firstly, aerodynamic characteristics, A new test rig with moving vehicle model is developed in a large wind tunnel to respectively measure the aerodynamic force on bridge deck and vehicles while vehicles are running along the bridge deck under cross wind. The effects of vehicle speed, rail position of vehicle on the aerodynamic characteristics of vehicle and bridge are studied. The sudden change of vehicle aerodynamic forces are measured by wind tunnel test when vehicle is passing through the bridge tower and two vehicles are passing each other. Aerodynamic coefficients of CRH2 are also measured in wind tunnel. In addition, train induced wind is simulated by CFD. Second, coupling and failure mechanism, with engineering examples, many parameter studies are carried out to explore coupling mechanism of wind-vehicle-bridge system, including wind field, stiffness of bridge, vibration of bridge, the effect of sudden change of wind load and so on. The control factors in wind-vehicle-bridge system are analyzed for different bridge types. Meanwhile, the above-mentioned research findings and conclusions have been applied in Anqing Yangtze River Bridge, Hanjiatuo Yangtze River Bridge, Tongling Yangtze River Bridge, Shanghai Yangtze River Bridge, etc.

A 7-DOF nonlinear dynamic model is established for a semi-active suspension bogie installed with MR damper. The active control law of the system is designed based on the LQR control theory. Then, a semi-active control law of the system is proposed using the clipped LQR control law. The dynamical responses of the controlled suspension system with both active and semi-active control are worked out to compare with that of the uncontrolled system. The results show that both the active and semi-active control can enhance the critical speed of the system. Considering the uncertainty in actual suspension system, the robust stability of the bogie model with uncertain parameters is also analyzed. The lateral stability criteria for both the controlled and uncontrolled systems with uncertain parameters are derived using the Lyapunov stability theory.

In China, the construction of passenger dedicated line is in progress on a large scale. As the important infrastructure of passenger dedicated line, the fastener damping of ballastless turnout influences the vibration and noise of the track. In order to study the mutative fastener damping’s impact on the vibration and noise of ballastless turnout, The method for determining the fastener damping was established by using the vehicle-turnout coupling dynamic analysis, and the noise prediction method for ballastless turnout was stated from three parts of the excitation of wheel-rail roughness, the sound radiation efficiency and the calculation of wheel-rail radiated noise. From both aspects of vibration decrease and noise reduce, the reasonable fastener damping of ballastless turnout was determined by using the above method. The research results showed that the damping of 0.15~0.225 to the fastener of ballastless turnout was reasonable for vibration decrease and noise reduction.

Currently, the world’s major EMU manufacturers and railway operators are eager to carry out a lot of railway testing of the high-speed train bogie and optimize bogie performance according to the test data. Therefore, developing a vibration simulation system to simulate the excitation between the rail and the bogie wheel is quite necessary. In response to this situation, a novel bogie test bench of 6-DOF vibration simulation was developed, the rail spectrum reproduction technologies of wheel-rail relative vibration were studied, and many indicators of the system were optimized according to the CRH3 and CRH5 EMU wheel-rail vibration state. The results show that this technology can be used to simulate the operation of vehicles in a variety of railway state and evaluate the dynamic performance of the bogie objectively, which does not only lays a sound foundation for steady development of Chinese high-speed railway vehicles, but also plays a technological supporting role for the security and stability of high-speed train.

Enabled by the world’s largest and fastest high-speed rail network, the railway passenger transportation in China will change from a resource-oriented model to a passenger-oriented model. As one of the six mainframe parts for high-speed rail, the passenger dedicated service system is the main interfaces between rail systems and passengers. Based on business model and system requirement analyses, this paper presents the system architecture design, main challengers and core technologies for a passenger dedicated service system. In addition, it also reviews the current development status and describes future research plan.

This paper mainly studies architecture, main functions, application software structure and key equipments technical requirements of the ticketing system for Chinese intercity railway to satisfy the demands of the special operation management mode and ticketing management mode which are different from that of the national railway, the urban subway and the intercity railways of other countries. This paper presents a new ticketing transaction processing model of intercity railway, which can satisfy the demands of accurate seat transaction processing and passengers’ alighting and boarding for high-speed trains as well as the demands of free-seat management and passengers’ alighting and boarding for ordinary-speed trains. Combining with practical applications of intercity railway in the Yangtze River region and Zhujiang river region, this paper has studied the applicable promotion value of visual autotype technology in the ticketing system for intercity railway.

The massive construction of high-speed railway in China greatly promoted the development of passenger service systems at railway stations. However, passenger service systems on trains are lagged far behind. In this paper, an intelligent onboard passenger service system for high-speed railway is introduced. It provides travelling information, entertainment and online shopping services and so on to passengers who will have a delightful experience during the trip. Besides, it allows train attendants to better serve customers. The features of the system we developed include: a). Comprehensive context-aware environment based on Internet of Things; b). Distributed cooperate system architecture based on event or complex event processing; c). an intelligent service mechanism; c). Easy and flexible configuration for service adjustments and updating. In the paper, the architecture and functions are described briefly first, and then the key technology of the system is discussed. Finally, implementation details are presented.

The new high-speed railway will shift the focus from the capacity management system to the customer-centric passenger services system for the entire rail travelling experience. The Transit Operation Platform (TOP) is the key element to support passenger service mainframe. It monitors and controls the operation of all devices and subsystems in the stations, regions and lines. Based on the analysis of business requirements, in combination of survey of the proven technical approaches of the industry, this paper presents the research and development work on the TOP architecture design, core technologies and real implementation.

Revenue Management (Abbr. RM) method was introduced after the deregulation of the U.S. airline industry in 1970s. The application experience shows that RM is a valuable management method for transportation efficiency enhancement. However, there are few literatures reported to exploit RM advantages in passenger high-speed railway. After a brief review of research development of RM in railway, we propose a dynamic optimization model for a single line high speed passenger railway with multiple fares and time periods. Some practical factors such as two way travelling direction, coupling and decoupling of train units, flexible stopping pattern are combined into our model. It is an integrated model that optimizes seat inventory allocation and train departure schedule in order to maximize the overall revenue. With a set of real operational data of a high speed railway, numerical results show that this approach can be applied in practice and may significantly improve the operation performance.

Since the initiation of 200 km·h

− 1

High Speed Railway (HSR) in the Japanese Shinkansen, the lateral stability solutions of High Speed Rolling Stocks (HSRS) have been developed and improved through the theoretical and practical courses, especially the novel theory of anti-hunting wide-band absorption is presented and put into Chinese 300 km·h

− 1

HRS practices. The lateral vibrations of some motor-vehicle coaches are experienced during the test running of 16-vehicle train with CRH380B bogies in Jinghu HSR line. Based on the contrastive data from anti-hunting damper testrig, the determining criterion was formulated definitely for the in-series stiffness. After the comparison with the acceptance tests, it is further pointed out that the radical reason for the above coaches’ lateral vibrations is that the in-series stiffness of anti-hunting dampers is too hard so that the stability margin of rear bogie is reduced much, and the direct factors are due to the wind load interactions and longitudinal eccentric loads which cause their wheel sideslips. The anti-hunting soft-constraint technique strategy is therefore proved to be the successful and effective solution, in which there exists a theoretical optimal value of the in-series stiffness to trade off the stability of trailer bogies and the handling performance of motor bogies.

In the test-measured contrast foundation of the ride comfort evaluations, the contrastive study was carried out on the influences of the airspring suspension features to the ride comfort and floor vibration of High-Speed Rolling Stock (HSRS) carbodies. Because of the different design styles on the orifice’s damping effective between the German and Japanese airsprings, the German airspring suspension remains therefore the ‘soft suspension’ under the high-speed operation, but the dynamical stiffness of the Japanese airspring suspension becomes harder remarkably, by which the vertical ride comfort of carbody is affected badly. When the vehicle velocity is raised above 300 km·h

− 1

, the vibration of 1st vertical floor bending mode begins to be appeared on the end parts of carbody, and increased gradually to the extent that the mode vibration of the local floor above bogie is brought into. For the German airspring suspension, when the secondary vertical damper is introduced, the unfavorable influence is produced on the carbody end floor vibration. And for the mid floor vibration, there is less relevance to the airspring suspensions.

The sub-rail stiffness of bolted alloy steel frog has a great influence on impact load of rail head and rail internal tensile stress. So it is very essential to optimize the sub-rail stiffness and carry on a fatigue calculation on weak frog components to guide frog design. Taking No.12, bolted alloy steel frog, single-way turnout as an example, the rules of frog stresses and deformations influenced by different sub-rail stiffness under the train dynamic load were analyzed and compared based on the finite element method, and carried on a fatigue calculation on the weak zone of the frog centre. It turned out that as the sub-rail stiffness increases, the rail impact load by train increase, and rail tensile stress and vertical deformation both decrease. A proposal sub-rail stiffness is 50kN/mm; The maximum fatigue stress appears in the zone where the frog centre sections change greatly, so the nose rail structure in this zone should be optimized.

In recent years, high-speed trains are rapidly developed in China, and the maximum speed was over 480 km/h in a test ride. With the increasing speed of trains, we can take less time from one place to another; but the safety and comfortableness are concerned not only by the designers but also by the train passengers. In comparison with trains with a running speed less than 200 km/h, the wind effect on high-speed trains is significant, and the aerodynamics of high-speed trains such as the aerodynamic force during normal running, meeting with another train, running in the tunnel, is widely investigated by researchers. Apron boards are located at the lower side of a car body to reduce the air resistance. But the aerodynamic force applied on the apron board is unknown and researchers can only use an assumed value in their simulation. The Fibre Bragg grating (FBG) is a new kind of sensors and has been used in many areas such as bridges, buildings, planes, and dams. FBG sensors with the advantages of immunity to electromagnetic interference, non-corrosion, light weight, and small size are suitable to be used in high-speed trains to measure temperature, strain, acceleration, and inclination. In this study, an FBG wind pressure sensor is specifically designed and tested by installing on the inside and outside of the apron board of high-speed trains. The results show that the FBG pressure sensor can measure the wind pressure of high-speed trains with high resolution.

With the construction of passenger dedicated lines, the demand of high-speed turnouts has been stared in the face. Base on Kinematic Gauge Optimization (KGO), a switch designed by Germany, this paper designs a gauge-widen switch of NO.18 turnout. In order to study the impact of gauge-widen switch on the stability and security of train, the author constitutes the spatial coupling model and analysis the impact of two factors (value of gauge widening and the maximum widening position). The research results show the following two conclusions: 1) Increasing the value of gauge widening can significantly improve the stability when train passes through the turnout, the increasing value should not exceed 15mm; 2) Where the tongue rail’s width is 30mm is the optimal position to set maximum value of gauge widening.

Large-span steel truss cable-stayed bridge largely appears in railway bridge construction in China, so it is very essential to find a method to help engineers and designers carry on calculation of continuous welded rail (CWR) on this kind of bridge easily. Two simplified models and algorithms were proposed, and a software BCWR was built up based on the algorithms. To validate algorithms above are feasible, take the truss steel cable-stayed bridge of “5×32m simple beam +(36+96+228+96+36)m steel truss beam+5×32m simple beam” for example, a bridge-rail interaction plane model was established, which could embody all structural characteristics, such as steel truss, stay cable, main tower. Rail additional longitudinal forces and the bridge-rail displacements obtained based on finite element method (FEM), and those obtained based on two algorithms above were compared mathematically. Results show that distribution regularities of the additional forces and the bridge-rail displacements obtained by FEM are the same as those obtained by the algorithms. So these two simplified algorithms can both satisfy the CWR design on this kind of bridge, and are very efficient and effective.

In the operation of the high-speed railway, strong wind is one of the important disasters to cause the overturning of the high-speed train. In this article, based on the wind direction and wind speed data in past 50 years (1951~2010) of 738 meteorological stations along the national high-speed railway, combining more than the gradient wind monitoring data of 100 iron towers along the high-speed railway, 6-elements (wind direction, wind speed, temperature, humidity, rainfall, air pressure) and 5-layer (0.15m, 0.5m, 1.0m, 2.0m, 4.0m) gradient wind strong wind monitoring data in the thirty miles of wind area and one hundred miles of wind area of Lanzhou-Xinjiang No.2 Line, and wind speed and direction monitoring data of 2,000 automatic meteorological stations and 100 strong wind monitoring stations in the past 10 years (2001~2010), the authors conduct standardized information integration, and combine the integrated data with the topography, roadbed height, bridge height, roughness and other parameters in each mileage along the high-speed railway, and revise the time-distance, height, terrain, high embankment and hug bridge strong wind growth rate, and use the methods in combination with meteorology, wind monitoring technology, railway engineering technology, mathematical statistics and probability theory to conduct systematic analysis and study of spatial distribution, vertical distribution, horizontal distribution of maximum wind speed along the high-speed railway, system analysis and research, and propose specific methods and measures to prevent and control the strong wind disasters on the high-speed railway (traffic warning surveillance and control measures, wind fences and artificial tunnel protective measures), having provided technical support for the safe operation of high-speed railway in China.

According to the structural mechanical characteristics of unit ballastless track and the spatial demand of the bridge with criss-cross beams, geometric optimizations were carried out on the slab track.4 T-type bosses are installed around the slab track instead of circular convex in the middle, which lead the slab to adopt to the bridge with criss-cross beams better. The research indicates that the 4 T-type bosses around the slab can reduce the warping stress and warping distortion effectively and the stress is distributed better. Under the train load, the deformation of the track slab tends to decrease, which lead it to more reasonable stress and deformation state.

In some developed countries, vehicle for both railways and highways is maturing in technology and function after 70 years of exploration and development, which makes the dream of no transfer “from highway to railway” or “from railway to highway” being true. However, the research and development of vehicle for both railways and highways in China are still in its infancy. At the present time, the chief problems of Chinese vehicle for both railways and highways are backward technology, simplex function, the lack of humanization in design and the lack of variability in use. Due to the above shortcomings, Chinese vehicle for both railways and highways is always at a disadvantage in the international competition. In this paper, human-based design, body structure and modularization of function and form were imported in the design cases as new design strategies.

The paper briefly introduces the development plan of high speed railways in China in the near future. A few serious derailment accidents in the world are listed and the corresponding causes are briefly described. In this paper these causes are defined as the extremely severe environments in which the trains operate. The paper reviews the important published papers regarding the discussions on the mechanisms and the modelling of trains running in such severe environments. The traditional derailment criteria are briefly discussed. A traditional geometry criterion for estimating train safety operation is further improved and discussed. The strategy of the study on the safety operation boundaries of the high speed trains running in severe environments is put forward. In the strategy, the safety operation boundaries are strictly defined. They are found through the numerical simulation by using the theoretical models for vehicle/track and the derailment criteria. The paper introduces the theoretical models for the high speed vehicle and the two kinds of the high speed tracks. The two kinds of the tracks are, respectively, the ballasted track and the slab bed track. Only the model for the high speed vehicle coupled with the ballasted track is employed in the calculating the safety operational boundaries for the high speed train passing over the bulked tangent track as a numerical example in order to fully understand the present strategy. The results include the dynamical behaviours of the wheelsets, the transient derailments and the safety operation boundaries.

The high maintenance cost of high-speed wheels due to wear and rolling contact fatigue becomes a main problem in the commercial operation of high-speed trains in China. In order to understand the wear behaviour of high-speed wheels and its influence on the motion stability of high-speed trains, the worn profiles and the work-hardening of the wheels of the CRH3 high-speed trains operating on Wuhan-Guangzhou line were monitored in different periods during service, and the influence of the wheel hollow wear on the lateral acceleration of the bearing-box was investigated in detail. A new wheel profile design method was suggested to reduce the hollow wear by seeking an optimization match of the wheel profiles, the vehicle suspension systems, and the wear behaviour of the wheels in service. The feasibility of the method was verified by numerical simulation using the operation conditions of CRH3 high-speed trains on Wuhan-Guangzhou line. A new wheel profile was designed using this method. The wheel/rail contact performance and the vehicle dynamic behaviour of the designed new wheel were investigated in detail and compared with those of the original wheel. The wear behaviour of the designed new wheel profile was predicted based on the measured wear data of the original wheel. The results show that, compared with the original wheel profile, the designed new wheel profile can improve the wheel/rail contact state, reduce the contact stress level, and lower the friction power of wheel and rail. The hollow wear on the new wheel decreases greatly and the vehicle has improved dynamic behaviour when wheelsets with the designed new profile are used. Thus, the period of re-profiling can be effectively extended.

Through the pulse hammer excitation test, the influence of rail vibration characteristics for fastener loose was researched, for five different buckle pressure conditions the vibration modes of rail were tested. Experimental analysis shows that: in less than 2000Hz frequency, rail vibration response is decreasing with the increase of tighten twist torque of fastener. In 2000-3000Hz frequency, rail vibration response is increasing with the increase of tighten twist torque of fastener. When fastener tighten torque less than 80N ∙ m, vibration of the rail head and base slope under the rail increase suddenly. So from the perspective of rail vibration, we suggested that the fastener tighten twist torque should be more than 80N ∙ m in construction and maintenance. With the increases of fastener tighten twist torque, the order frequency of rail increase.

Extensive research has shown that steel fiber reinforced concrete (SFRC) has excellent plastic deformation and dynamic performance. Material damping (MD) is one of the most crucial aspects of structure damping which reflects energy dissipation characteristics of structural system during vibration. This paper presents a new approach to analysis MD of SFRC. Based on the study of the relation between MD and stress amplitude (SA) by Lazan, the area of hysteresis loop of SFRC components under axial cycle loads is calculated with Karsan-Jirsa loading-unloading law by OpenSEES system. The value of energy dissipation is then obtained. It is indicated that energy dissipation per unit of SFRC increases with the increase of maximum SA and decreases with the increase of concrete strength. The relation formula of energy dissipation of SFRC with maximum SA, concrete strength and steel fiber ratio is established by nonlinear regression with SPSS and will be helpful in material character study of SFRC and dynamic response computation of SFRC structures.

Vibration and acoustic radiation characteristics of rails are the keys for wheel-rail noises. In order to find out it, build a CHN60 rail three-dimensional finite element model and boundary element model in this paper and then do modal、harmonic response and sound radiation analysis for it. The results show that there are lateral、vertical and tensional three vibration forms in rail; the main vibration parts of the rail is the rail web and the both sides of the rail bottom ; there are multiple peaks in rails sound radiation curve in 0-4000Hz band, respectively, the sound pressure level is 82.1 dB (A) when the rail vibration frequency is at 625 Hz, 85.7 dB (A) at 2350Hz, 84.6 dB (A) at 4000Hz.

Envisioning the rapid development of high-speed railway network worldwide but envisaging potential threats to the safe operation of the network due to continuous ageing of train structures, a fatigue damage detection technique for train structures was developed. For metal structures used in high-seeped trains, fatigue crack may take place under cyclic loads, causing unexpected accident. However inspection of fatigue damage can be a difficult task during the normal operation of the train using tradition nondestructive evaluation techniques. In this study, nonlinear Lamb waves were used to interrogate train structures. Higher-order harmonic wave fields were generated, to observe that under certain conditions the second harmonic was cumulative. The fatigue damage modulated the nonlinearity of the structure due to the plastic deformation or micro-cracks, influencing the cumulative character of the second harmonic Lamb wave. To quantify the degree of such cumulative second harmonic, a nonlinearity parameter was used. A short-time Fourier transformation-based signal processing was applied to the collected signals to extract the amplitudes of the first and second harmonics. Experiments on an aluminum plate containing fatigue damage validated the proposed method. The results indicated that the fatigue crack can break the cumulative character of the nonlinearity parameter whereby the fatigue damage can be detected. It is noteworthy that this method can be carried out without any baseline data or a benchmark structure, increasing the flexibility of the application.

Chengdu-Dujiangyan express railway is an intercity line equipped for speed of 200 km/h. In this paper a systematic introduction was made of structural design on ballastless track in different section of subgrade, bridge and tunnel, etc. as well as drainage system, transition section and integrated grounding system. A summary is made of technical innovations on structural design, engineering material, construction survey and control technology and maintenance technology, etc.

High and steep side-slope in mountainous area is susceptible to geological disasters such as landslide and collapse in the rainy season, which threatens seriously the construction and operation safety of railway. Since the disasters are sudden and catastrophic, this paper puts forward the study approach of monitoring technology for high and steep side-slope and discusses the monitoring technology proposal that is to ensure the operation safety of railway as centre and take “The rockfall can not fall on the railway” and “For train traveling, the rockfall on the railway cannot be obstacle”as basic requirements for high and steep side-slope in the mountainous area. “The rockfall can not fall on the railway”to be solved is mainly to monitor rockfall source, while “For train traveling, the rockfall on the railway cannot be obstacle” to be served is mainly monitor the rockfall invasion to protected main body (railway operation facilities). This paper describes the treatment of the high and steep side-slope problem of railway in mountain area and necessity of use of monitoring technology, puts forward the monitoring technology proposal that carries out the rockfall source monitoring, rockfall invasion monitoring and protected main body video monitoring based on FBG sensor technology and the data acquisition and transmission with optical cable, moreover, describes the key technical problem in the monitoring technology proposal and study approach to be used. The comprehensive monitoring technology concept for high and steep side-slope in this paper can be used as an important reference for disaster prevention monitoring design of railway and highway.

The interaction of wheel & rail, pantograph & overhead lines (OHL) and the aerodynamics are three key-technologies in high-speed railway. This paper is imposed to research the interaction between pantographs and overhead lines in 300~350km/h railways with the CATMOS ® simulation program.

The overhead line-pantograph system is supposed to supply energy to the traction vehicle via continuous electrical and mechanical contact, whilst keeping the wear on the contact wire and the collector strips as low as possible. The materials, cross-sectional areas of the contact line & the catenary wire and the tensile force can have significant effect on the behavior of an overhead line for high speed railway. In the high speed railway, the interaction between the flexible overhead wire and the rigid pantograph is much more complicated and difficult to maintain stable. With the simulation program, the interaction is convenient for research and optimization without a large amount of time and cost. Through the optimization, we get high tensile forces on the contact line and catenary for low and uniform elasticity of overhead lines in the simulation.

In this paper, dynamical response of pantograph-catenary coupled system considering contact wire stagger design and local singularities of contact wire with critical wavelengths is studied. First, the finite element model of the catenary using Euler-Bernoulli beam elements is established. The pantograph model considering the stagger design of contact wire is proposed as a multi-body system with mass, stiffness, damping and friction. The contact forces between contact strips and the contact wire are calculated by using Newmark numerical method. The reference pantograph-catenary system in EN50318 is worked out to verify the correctness of the proposed dynamical models and numerical method. The PSD of contact wire vertical irregularity in real line of Chinese high speed railway will be formulated, from which the critical wavelengths of contact wire irregularity are obtained. Then, the contact wire irregularity due to local singularities with critical wavelengths is introduced into the dynamical model of pantograph-catenary system as the excitation. The influence law of the local singularities of contact wire on the dynamics of pantograph-catenary system is studied, and the maximum allowable levels of local singularities for each critical wavelength are determined.

Heavy haul and fast speed are the main development direction of railway wagon all over the world, in recent years, railway wagon technologies are flourished developed of which are consisted with low tare weight, high reliability of wagon body technology, heavy axle load and low wheel/track effect, fast speed bogie technology, low impulse coupler and draft gear technology, high reliability of braking technology and advanced fabrication technology. Through research to above key technologies, some typical wagons such as 20000t of C80 and C80B heavy haul wagons running on Daqin railway and 160km/h fast speed container flat wagon are developed and excellent achievements are got. The heavy haul and fast railway wagon is systemic engineering that need cooperation of different technologies, among them, many deep research should be made on the following topics such as the relation of axle load and load density with bridge, dynamic performance and low wheel/track effect, brake distance and thermal load of wheel, outline and its auxiliaries, reliability studies and checking criteria.

In order to satisfy the requirements of the networking development of high speed railway in China, the train control system shall be suitable for train cross-line-operation, which is interoperability. In this paper, the requirements of the interoperability of CTCS-3 on-board equipment was firstly analyzed in depth, to determine the basic principles and basic methodology for the interoperability test; secondly the testing system and methodology of the interoperability test of CTCS-3 were studied, and the structure and main functions of the test bench for interoperability testing of CTCS-3 on-board equipment was analyzed. Then the development of the interoperability test for operational onboard equipment was researched, the method of test sequences generation and the test schedule was introduced. At last, the test result of the interoperability test for onboard equipment was summarized and analyzed in depth, and the method to manage the test result was given. The research results of this paper can provide guidance for the laboratory interoperability test for the onboard equipment.

During the design of high-speed railway bridges in China, the dynamic responses of bridges under high-speed trains and the running properties of train vehicles were systematically studied by the Academy of Railway Sciences and some universities under the organization of the Ministry of Railways of China. In this paper, some practical applications of train-bridge interaction study in the high-speed railway bridge design in China are introduced, through the research work by the Beijing Jiaotong University. The analytical model of train-bridge interaction system is established, by which the dynamic responses of the bridge under the actions of high-speed trains, wind and earthquake excitations, as well as the running safety and stability indices of train vehicles are analyzed. Many useful results have been applied, through providing important parameters and references, to the practical bridge designs in the special passenger railways and high-speed railways in China.

This paper presents an experimental study of a new assessment of track irregularity based on a new inverse analysis method. Two tri-axial accelerometers are mounted on the axel box of a track recording vehicle to measure the dynamic response. And according to the acceleration responses at axel box, the spatial path of the moving wheel on the track will be found by an inverse analysis method. The rotation gradients in three moving coordinate direction along the tracks scanned over by the accelerometers can be clearly identified. These rotation gradients can be used to identify the locations of the geometrical irregularities of the tracks due to settlement, deformation, lose of fastener, crack, and welding point of the inspected track. Some examples are demonstrated to verify the feasibility and accuracy of this innovative theory.

The proposed Chengdu-Lanzhou railway is located in terrain gradient sharply changing belt with highly complicated and dangerous geological conditions, and it crosses the core of severely afflicted areas of 5.12 Wenchuan Earthquake. Many factors such as existed complicated geological conditions and earthquake secondary disasters, sensitive points of environmental protection control the route schemes, among which, geological conditions is the key point. Based on the route selection principal and practical countermeasures in relation to main controlling factors, This paper mainly works on the railway location in complicated and dangerous mountainous areas, and this could be used for reference for linear structures such as railway, road, irrigation works and oil-gas pipeline in similar condition of areas.

The safety of high-speed railway over areas with serious regional land settlement is further concerned by more and more engineers. However, there is few research concerned about the influence on bearing behaviour of pile foundations by regional land settlement in high-speed railway bridge construction at present. This paper presents a new method using the numerical method to simulate underground water level’s annual variations in the situation of continuous pumping based on the limited site measurement data and studying the influence on bridge pile foundations by regional land settlement on that basis, finally obtaining the relationship between regional land settlement and bridge pile foundation settlement. The result shows that increase of land settlement lags behind pumping due to soil creep effect, in early phase the land settlement is mainly affected by the consolidation of soil mass and in late phase affected by creep. The associative relationship of regional land settlement and bridge pile foundation settlement is very obvious which generally expresses as a logarithmic form.

The fatigue problem is significant for the vehicle safety, especially the fatigue failure of weld joint can result in a serious safety problem along with a fast speed promotion. For the purpose of fatigue life predicting in the early design stage, a middle trailer car of CRH3 EMU (Electric multiple unit) made of Aluminum Alloy Extrusions was researched as an example, its finite element model of mid trailer EMU carbody was built, the strength was performed by use of the finite element method, and the computed results were compared with the test ones, therefore the validity of finite element model was verified. Then, by use of the improved modal synthesis method called the Craig-Bampton, the motion equations of the flexible carbody was built, this motion equations was integrated into the ADASM/Rail software, then a rigid-flexible coupling dynamic model with the rigid bogie and the flexible carbody was set up, the stress and deformation of carbody were computed by use of the modal synthesis method based on this model. The structure stress and equivalent structural stress of key weld joints of carbody such as the window corner, car body coupler and side wall et al were extracted, applying the main S-N curve method, the fatigue life was predicted; and according to ASME standard, the fatigue strength was evaluated. The results show that the carbody fatigue life and strength all meet the design requirement. In this research, it makes the technology route integrated from rigid-flexible coupling dynamic simulation to fatigue life predict of weld line according to the master S-N procedure, and provides theoretical support for the design.

Extensive research has shown that the Cement-soil Mixing Method (CSMM) is an effective method of dealing with soft soil ground (SSG) and the cement-soil is relatively cheap and low energy consumption. By stating reinforcement mechanics and analysing statistics, this paper presents a new approach to analyse the parameters of cement-soil and put forward a new method to determine the target properties and the mixture ratio by solving the coefficient matrix. Based on the experiments, the relation formulas of cohesion, internal friction angle and modulus of deformation of the mixture with the cement mixture ratio, the lime mixture ratio and curing period are built and they will be helpful in the study of dealing with SSG.

Simulation computation of vehicle-bridge coupling vibration and field experiment are carried out in a long-span continuous beam bridge of an intercity railway. And the effect of soil-structure interaction on the coupled vibration of continuous beam bridges and vehicles under high speed vehicle load was discussed in this paper. With BDAP V2.0(Bridge Dynamic Analysis Program), which is certificated by National Copyright Administration, the natural frequencies and dynamic responses of the bridge under vehicle load are calculated by using a more complex bridge FEM model(whole-pile model), which can take account of the interaction of lateral displacement and bending angle on group-piles. In order to assess the influence of soil-structure interaction on bridge dynamic response and evaluate the actual dynamic response of a long-span continuous beam high speed railway bridge, dynamic loading tests were made at the speed varying from 200km/h to 380km/h to get the vertical dynamic displacements in the mid-span and the lateral and vertical amplitude and acceleration of some typical points in the beam and pier. With a comparison of simulation computation results of different bridge FEM models and field experiment results, we can draw some conclusions, which is beneficial to research and design of long-span continuous beam bridges in high speed railway: Compared with commonly used consolidation model and equivalent-stiffness model, the dynamic response of the bridge with whole-pile model, especially the lateral dynamic response, varies a lot by considering soil-structure interaction. While the maximum dynamic accelerations get lower, the maximum lateral amplitudes become higher. And the results of field experiment show that with whole-pile model, a precise and reasonable simulation computation result can be gained because soil-structural interaction is also taken into account. For a high speed railway bridge located in soft ground with group-piles foundation, whole-pile model is proposed to analysis the coupled vibration of vehicle and bridge.

There is a trade-off in scheduling between a punctual and reliable “system railway” with lots of running time supplements on the one hand and preferably short running times in addition to a high availability of additional train slots on the other hand. In this paper the effects of different allocations of time supplements on railway infrastructure providers, railway operating companies, goods and passengers will be shown.

At first, scenarios with different allocations of time supplement will be developed. According to each scenario, parts of the running time supplement will be shifted from each line respectively line section to the subsequent stop. Afterwards, these scenarios will be analysed in their effectiveness of achieving operational and commercial targets. Parameters for different lines will be determined by a multitool- analysis. The parameters are either extracted from the timetable construction or the simulation of the railway operation. These parameters vary due to the different allocation of the time supplement in the scenarios. Later, monetary values will be assigned to the parameters for comparing the scenarios with each other. The calculations will be made using different monetary values due to the different possibilities of evaluating the delay respectively the running time.

The profit and the loss of each scenario compared to the current status will be demonstrated separately for the above-named groups that participate in the system railway.

High Speed railway passenger transport of china developed rapidly in recent years. System integration is even more important. For this reason, a CAD software for Traction Drive System of High Speed Train is being developed based on researching on Traction curve, regenerative braking curve, the match of electrical and mechanical characteristics, calculation of electrical parameters, control method of motor and converter, arithmetic of running simulation etc. This paper provides a whole develop project of this CAD software, and presents the design ideas, the framework, the function and the modules. The application of this simulator aims at designing a traction drive system of High Speed train can be suitable for a certain line. This traction drive system must meet the technical requirements led by the top-level technology goals for the line. This CAD software has three main functions. First, design traction curve, regenerative braking curve and some electrical parameters of traction drive system according to the technical requirements. Second, run the High Speed train on the certain line. Speed curve, current and voltage curves of motor, temperature rise of motor and converter, running time, energy consumption can be got by the simulation. Third, decide whether the train’s performance meet the technical requirements according to the simulation results, and improve the design.

Interior Permanent Magnet Synchronous Motor (IPMSM) has the advantages of high efficiency, good performance of speed regulation and so on. So the IPMSM is suited to high-speed train traction system. This paper introduces the operation principle of IPMSM which used in high-speed train traction and the process of flux-weakening control under the limit of the current limit trajectory and the voltage limit trajectory. When the IPMSM’s speed is higher than the rated speed, the q-axes current and d-axes current couple deeply, the traditional flux-weakening control strategy can’t achieve ideal control effect. The paper introduces a flux-weakening control strategy which is easy to achieve and has good robustness—a single current regulator flux-weakening control strategy. The single current regulator flux-weakening control strategy broadens the motor speed range and makes the IPM used in high-speed train operate steady with high speed. The simulation of the traditional flux-weakening control strategy and the single current regulator flux-weakening control strategy in MATLAB/SIMULINK proves that the single current regulator flux-weakening control strategy can easy to achieve and has wide speed range, rapid response speed and good robustness.

Permanent magnet synchronous motors (PMSMs) have been more and more interesting for railway vehicle traction system because of their high efficiency and light weight. For the existing of permanent magnet material, the back EMF can be generated during coasting. The inverter components may be destroyed without proper control, when the peak value of back EMF is higher than its withstand voltage. Presently, there are two ways to solve the problem: reducing synthesized air-gap flux linkage by adding negative d-axis current during coasting which can reduce the efficiency, or adding some contactors between inverter and PMSM which is commonly used. But when close the contactors, the phase and frequency of the output voltage of inverter should agree with that of the back EMF to ensure system security. In this paper, an integrated control method of PMSMs during coasting when applied to high speed train is proposed. Based on the mathematical model of PMSM in the synchronous rotating reference frame, the relationship between stator currents, stator voltage and back EMF is analyzed. Then a closed-loop restarting control method after coasting is designed: add an gradual voltage to ensure the smooth switching from coasting to traction or brake. As it has turned out by the simulation results, the method is correct and effective.

Load torque of the high-speed train traction motor is discussed in this paper, including constituent elements of the load torque (Hyung-Min Ryu

et al

. 2002) and how to simulate the torques. This paper establish the mathematical model of the traction motor from the energy point of view, the equivalent damping torque and the equivalent inertia loads has been obtained under continuous load conditions(Akpolat

et al

. 1999). In order to emulate the actual operation, algorithms were tested and verified with the use of Matlab/Simulink first, and then a emulation platform was built under laboratory conditions, the platform is consisted by two induction machines and a small flywheel. Experiments of emulating a high-speed train traveling on certain given line is executed with the use of the DASPACE system.

The subsidence assessment of construction projects under track is very important for laying ballastless track for high-speed railway. The method how to obtain the measurement of the subsidence is introduced in details. And then, the discussion on the usability and scientificity of the relevant subsidence assessment method is carried on. The problem and weakness about the assessment is analyzed and demonstrated. According to the analysis and demonstration, the improved assessment is put forward here. Also, the effective and simple method to obtain the subsidence measurement is suggested. The reliability and accuracy of the measurement and the assessment is emphasised. At last, the assessment results are demonstrated in order to explain the improvement, basing on the examples of subsidence assessment about Chinese high-speed railway in ballastless track.

Stable operation of the high speed train requires reliable contact between pantograph and catenary in order to offer stable electricity. But as the train speed increases, the vibration between pantograph and catenary intensifies, so the current collection between pantograph and catenary of high speed train gets more attention. A simulation model of the dynamic current collection between pantograph and catenary is established by MSC. Marc simulation software based on FEM. According to elastic catenary suspension system, the simulation is carried out under different working conditions. In this paper, with the standard deviation of contact pressure and the rate of current collection bad points as the evaluation standard of the current collection, the effect of the design parameters (contact wire tension) of catenary to the current collection quality is discussed. By analyzing the results of simulation data, this paper obtains the general law of the effect of the contact wire tension to the current collection quality.