Journal of Railway Engineering Society

Research methods: In combination with the features of engineering and man's action the numerical calculation is adopted for analyzing and determining anomaly of radioactivity based on comparison with the preventive standards for radioactivity.

Research results: The methods are offered for calculation and determination of radioactivity dosage in railway station, living area, normal railway section and tunnel construction, and the preventive threshold values and measures are presented for radioactive radiation anomaly.

Research Conclusions: For prevention of radioactive radiation in railway construction, the influence degree of radioactivity should be evaluated on the basis of learning the radiation degree and features of its distribution. The railway should bypass those areas in which anomaly of radioactivity exist in most locations when selecting railway route. For those locations with anomaly of radioactivity above the threshold value, the preventive measure should be taken according to the different conditions of each construction.

Research methods: According to the formula of railway curve and following strictly scientific calculation, this paper made the information of mileage and orientation of railway transformed into the railway orbit spatial information.

Research results: The paper realized the plane figure visualization of curve spatial information using the GIS module of Mapinfo and SuperMap of China and achieved the 3D visualization of curve data in VC using OpenGL.

Research Conclusions: It can save much time for track mapping of railway and has better technical and economic benefit.

Research methods: The analysis is made with the theory for structural design of flexible pavement and a new computing method for surface course thickness of flexible pavement is put forward with large deflection theory of slab. According to the real load distribution of wheel pressure, the wheel pressure is assumed as equivalent rectangle distribution instead of circular distribution used by traditional method. According to the deformation features of road slab, the simply supported boundary condition with long side is applied. The structural calculation is made with simplified model for infinite slab, from which the formula is derived for calculation of surface course thickness based on the large-deflection elastic theory. The calculator program is programmed and analysis is made for concrete calculation example.

Research results: About 18.3% surface course thickness can be saved by adopting this method compared with traditional method.

Research conclusions: This method provides an economic analysis mode for design of flexible pavement.

Research methods: Establish double layer continuous viscoelastic beam model of floating slab track structure, the vibration responses of the track structure are obtained with application of compiled programs by Fourier transform and making use of a software MATLAB, and we gained maximum forces transmitted to the ground-frequency curses. Besides influences of elastomeric bearing rigidity and damping below the floating slab, unit length mass of floating slab on the effectiveness of the floating slab track system are investigated.

Research results: We gained that the reasonable range of elastomeric bearing rigidity below the floating slab is in the range of 6~30 MN/m, choose the value of elastomeric bearing damping below the floating slab in the range of 40~80 kN/m, and choose the value of unit length mass of floating slab in the range of 2 000~4 000 kg/m.

Research Conclusions: Floating slab track system has a very good effect of vibration reduction on the high frequency vibration, and the less the value of elastomeric bearing rigidity below the floating slab is, the better the effect of vibration reduction is.

Research methods: This paper carries out a tension experiment with the U71Mn and U75V rail steels which are 60 kg/m at +20℃、0℃、-20℃ 、-40 ℃、-60℃ and gets the strength and plasticity index of the tow type of rail steels. The datum of the experiment is analyzed from the recent research results about steel.

Research results: The experiment of this paper gets the tensile strength, proof strength (non-proportional extension), percentage elongation after fracture and percentage reduction of area of U71 Mn and U75 V he echanical properties of rail steels at a series of low temperatures. Temperature sensitivity coefficients of the two types of rail steels are calculated and then the tensile strengths at low temperature can be forecasted. Which type of rail steel should be chosen at low temperature is proposed through the comparison of U71 Mn and U75 V.

Research conclusions: When the temperature drops, the strength of rail steels rises and the plasticity descends. The U71 Mn steel has a good plasticity at-60℃ while the U75 V steel get brittle seriously, so U71 Mn rail steel should be chosen when the temperature of the environment is low.

Research methods: Track random irregularity functions in time domain are established on the basis of H. Hamid's Power Spectrum Density (PSD) functions of track irregularities. The track irregularity sample functions are taken as exciting source to solve vibration differential equations of vehicle-bridge coupled vibration. This paper also studies the dynamic characteristics of railway bridges under moving vehicles.

Research results: The Hongshui River railway cable-stayed bridge in Guangxi is taken as example to calculate the dynamic response of the bridge under train passage, and the curves of time history of displacement at midpoint of bridge main span for different vehicle velocities and irregularity samples.

Research conclusions: The dynamic response of the bridge due to passing trains is related to the speed of train and the change of track irregularity samples, and it is of random characteristics. For the Hongshui River railway cable-stayed bridge, the speed at which the largest lateral displacements occur falls between 75 km/h and 95 km/h.

Research methods: The theoretical analysis is made for ameliorated high liquid limit clay with lime, and EDTA titration method for measuring lime dosage and construction technique for mixing high liquid limit clay with lime are adopted.

Research results: For ameliorated high liquid clay with lime as filling materials of subgrade, the construction quality and process can be guaranteed and the construction cost can be reduced, if the rational construction technique, qualified lime and correct measuring method are adopted.

Research Conclusions: In course of application of ameliorated high liquid limit clay with lime as filling materials of subgrade, the performance of soil for filling subgrade can be improved, the strength and stability of subgrade bed can be enhanced and construction quality of subgrade can be guaranteed only if the construction technique should be adjusted according to different conditions, lime quality is controlled well and EDTA titration method is adopted to measure lime dosage of compressed sample soil on time.

Research methods: We precede theory analysis and calculation regarding prestressed concrete as anisotropic complex material.

Research results: We deduce the formula of natural vibration frequency of Timoshenko beam.

Research conclusions: The calculation results indicate that the analytical method and formula of this paper can reflect the tendency that natural vibration frequency of beam increases with the increment of prestressing force well. Meanwhile, the results of calculation can agree with the results of experiment well. The natural vibration frequency and the second vibration frequency show relatively better accuracy. So, what we regard concrete material as anisotropic complex material is feasible and need further studies on it.

Research methods: For argument about this view point writer took three reinforced concrete bridges in her country as engineering background:(1) During construction, crack of one main span 40 m+65 m+40m prestressed concrete continuous beam bridge was found on main pier of the bridge. (2)During construction, some cracks of one large span reinforced concrete half-through highway arch bridge with both stringer and horizontal girder system were found on these horizontal girders.(3)The main beam anchor outline of one twin beams cable-stayed bridge in the south China area was changed. By 8-point isoperimetric element spatial analysis of Super SAP software, these local models were separately setup and we can carry on stress calculation as well as.

Research Conclusions: Both irrational components outline and reinforcement design lead to increase in tension of structural component and maximum stress seat just as the crack site of real component. Obviously, it can be explained production creak of concrete component from the angle of calculation stress. It is showed that it is important influence of both structural components outline and reinforced concrete design on their calculation stress besides loads.

Research methods: The absolute deformation of plasmodium is measured through measurement of relative deformation. First, the relative amount of deformation of the reference point surrounding the plasmodium is measured with nylon yarn base line and dialgauge measuring rod. At the same time of making relative measurement, the absolute position of reference point is measured with common measuring method and from which the absolute amount of deformation of plasmodium can be derived.

Research results: The computing model for amount of deformation is derived on the base of program selection and analysis principle.

Research conclusions: The application and analysis of measured accuracy show the result of measured deformation confirms to the deformation from theoretical analysis and the monitored accuracy reaches at submillimeter level, which can reflect the real deformation of plasmodium sensitively and meet the demands of monitoring deformation with high accuracy.

Research methods: A simulation analysis of the impact and collapse of the model structure with finite element software LS-DYNA was carried out. The analysis method was feasible after compared the results of the simulation analysis to the results of the test. Then, this paper analyzed 96 groups of the steel frame-RC tube structures using the same method, and formulated a simplified formula of the critical deflection for collapse using MATLAB. Finally, simulation analysis for the structure with protective measure against collapse was took with finite element software ABAQUS.

Research results: The results of the simulation analysis and the test were basically consistent. This paper returned the simplified formula of the critical deflection for collapse. The protective measure against collapse can significantly decrease the critical deflection for collapse of the structures.

Research conclusions: The method of the simulation analysis for the structure acted the impact load was feasible. The simplified formula was took which calculated accurately for the critical deflection for collapse. The results of the simulation analysis proved the measure against collapse to be valid.

Research methods: In view of the practical situation of Hangzhou Bay Over Sea Bridge, this paper researches movement and erection of 70 m box girder combining with research results Hangzhou Bay Over Sea Bridge at home and abroad and current regulation in China and foreign advanced construction technique.

Research results: Lateral movement of box girder can be realized by the traverse machine and slide beam. Longitudinal movement can be realized by hydraumatic pendant wheel-track machine which is 2 400 ton weights with full hydraulic pressure and electric control. Integrated equipment (2 500 ton and 3 000 ton) for beam-move-erection at sea are adopted for erection of box girder.

Research Conclusions: To adopt corrosion resistant plate and MGB plate can solve great consumption of transverse of box girder and to adopt hydraulic pressure and electric control technique can solve equalized stress and safety problem occurred in the course of lifting and movement of box girder. To adopt special developed integrated equipment (2 500 ton and 3 000 ton) for beam-move-erection at sea can solve stabilization and safety during transportation and erection of box girder in current on the sea. These mentioned above develop a brand-new construction method for development of construction technique for bridgework in China.

Research methods: The tests are carried out on mid-span and tip sections of box girder. With the principle of disclosing adequately the developmental rules of hydration of box girder, temperature probes covered in concrete are arranged at top tray, soleplate and web. Then the variation of hydration temperature would be measured after concrete placement.

Research results: With the results of temperature tests, time-temperature curves of hydration could be drawn. According to the test results of hydration temperature of Qinhuangdao-Shenyang Passenger Dedicated Railway Line concrete box girder, the general and developmental rules of concrete hydration temperature in earlier phase are discussed, including the commonly form of travel time curve, the basic rules of temperature rise and heat drop, the temperature gradient of concrete and the relations between pumping's temperature and thermal spike. Furthermore, the measures which are used to prevent concrete cracks caused by great temperature difference are given.

Research methods: The wide investigation is made on the tunnel design program and construction experience of foreign high-speed railway lines and the comparison and research are made for compressed conditions of tunnel structure, layout of drainage system and amount of construction work in some programs.

Research results: The lining section forms of tunnel are decided rationally for the passenger dedicated railway lines of 250 km/h and 350 km/h, and the structural design of tunnel lining has been further optimized.

Research conclusions: The defects in previous design made for passenger dedicated railway line have been overcome through making research and doing optimum design of lining section of tunnel for passenger dedicated railway line. After optimum design, the compressed situation of lining section of tunnel is more rational, it is more easy to use rescue passageway and the amount of construction work can be reduced.

Research methods: Take the double-track tunnel in the Lanzhou-Wunan for example，the relation graph of train speed and maximum pressure has been simulated and figured out with the formula.

Research results: The result of calculation indicates that transient pressure on the tunnel of Shanggulangxia cannot reach the standard of comfort while traveling speed is over 145 km/h.

Research conclusions: With the trains’ being-speed up, the transient pressure of double-track tunnel in the existing railway cannot reach the standard of comfort. In the future construction, we should take active or passive reduction methods according to the specific situation.

Research methods: This paper uses two levels fuzzy controllers to respectively control two parameters of air volume and air temperature. In order to appraise its implementation effect, simulation technology was used to compare the design control method and the traditional control method.

Research Conclusions: The result indicates that this fuzzy control system enhanced remarkably the ventilated control performance and automated level of tunnel construction and the energy conservation effect is very good.

Research methods: According to the real construction situation of Guantouling Tunnel underneath passing existing expressway tunnel on Wenzhou-Fuzhou Railway Line and in combination with the research achievements at home and abroad, and current state codes, the analysis and research have be made on construction scheme for newly building a tunnel around cross point and on measures for monitoring and measuring the existing expressway tunnel based on the analysis of integrity level of existing tunnel and construction countermeasures.

Research results: Several construction techniques and their relative parameters and control standard are presented.

Research conclusions: (1) more attention should be paid to the serious harm probably caused by blast vibration nearby. Therefore, it is necessary to evaluate the lining strength of existing tunnel cavity distribution behind lining and earthquake resistant behavior of lining, to work out the basic control standard for blast vibration and make research on rational blast parameters before construction of intersection of Guantouling Tunnel. (2)When the working face of newly-built tunnel approaches to whole diameter of 3~4 times from cross point, the monitoring and measurement in the existing tunnel should be done well. With the analysis result of monitoring, the adjustments should be made rationally of excavation way, blast parameters and method of ignition in order to ensure the safety of the tunnel. (3)After finishing the construction of intersection the safety should be re-evaluated to tunnel lining structure near the cross point of existing tunnel in order that the tunnel will not be damaged with time passing by.

Research methods: The analysis is made for the present situation of catenary of overhead contact wire system and main measures against wear of it.

Research results: The main technical measures against wear of catenary are proposed, that are to tie up continuously with single iron wire, match the surface hardness of hanging pulley with that of catenary and use auxiliary cable suspension catenary and preformed protection line for catenary.

Research conclusions: The structure of double cantilevers and special design should be adopted to turnout mast for the purpose of avoiding wear between catenaries, improving suspension structure of catenary and allowing usage of preformed protection line for catenary. Application of preformed protection line is an effective technical measure for solving the problem of wear.

Research methods: An introduction is given to the present situation of research on semi-active control technology of magnetorhelogical damper and summaries are made of the features of magnetorheological fluid, mechanics model of magnetorhelogical damper and tactics of semi-active control in this paper.

Research results: Since magnetorhelogical damper can offer adjustable damping force, it is an ideal semi-active control device and can be applied further in engineering.

Research methods: This paper analyzed the features and design principles of the comprehensive automation system for the traction substation. It expatiated the traction substation which was designed by the layered and distributed system framework, and analyzed respectively the functions of the equipment layer, alternation layer, station control layer and attempter layer.

Research results: This paper designed and realized a comprehensive automation system of traction substation for electrified railways. It can realize to watch automatically, measure, control, protect, and correspond to substation control, signal, measure, automechanism and so on.

Research Conclusions: The system can improve the whole functions and management level for the traction substation.

Research methods: According to “Design Code for Architecture Foundation”, the upper load can be directly transferred to the foundation stone by taking full advantage of the features of great horizontal resisting strength of rock subgrade and its seldom deformation caused by compression. In this way, the mast and rock stratum can be integrated through anchor rod and the anchor rod foundation of mast for overhead contact wire system can be formed.

Research results: The basic calculation method for foundation of rock anchor rod for overhead contact wire system, foundation structure and its construction method are put forward.

Research methods: Using the law of economic order batch, commodity purchase plan, “Three levels” maintenance system and so on to analyze its measures.

Research results: Through analyzing the existent problems of material management for construction enterprise, we can get that these existent problems resulted from faulty material management and management system. We need to carry on the standard to material management for construction enterprises by using thoughts and ideas of fine material management. At last, this paper proposed a series of measures to implement the fine management.

Research Conclusions: The fine management is one of ways to gain benefit maximization for construction enterprise. “Fine” is in advance; “thin” is in process and “quality” is to enhance in each link.

Research methods: The concrete analysis is made for how to get the information about international engineering how to distinguish between real and false information, how to inquire qualification, how to do market investigation and how to pay attention to the issues while studying the bidding documents, making site survey and submitting tender documents.

Research results: Some fresh and practical ideas are presented，which can provide reference to how to do business work well.

Research Conclusions: High quality business work is helpful for winning bid and enhancing the quality of tender.

Research methods: The posts should be sequenced according to their amounts of work their technical contents and their difficult levels and the standard for fixed number of employees on posts should be decided. On the base of post sequence, the wage system of deciding employees’ income by taking post work standard and his real work ability as base and the price in labour force market as guidance should be pursued.

Research results: Firstly, the post wage is more adaptive to the market change and by which the labour cost can be adjusted and controlled flexibly. Secondly the goal of changing wage with post changing can be achieved.

Research Conclusions: Implement of post wage system plays positive roles in invigorating inner distribution of enterprise, pursuing policy of distribution to each according to his work mobilizing the employees' activeness and stabling employees of enterprise.