Research on the Influence of Vertical Deformation of Bridge on the Track RegularityEI北大核心

Research purposes: The vertical deformation of high-speed railway (HSR) bridge will cause the track irregularity, which threatens the safe and efficient operation of the HSR. Taking the 32 m simple supported beam bridge as the research object, based on the existing mapping analytical model for bridge vertical deformation and rail geometry, the influence of the track regularity of the CRTS Ⅰ slab ballastless track structure caused by the key parameters such as the bridge vertical deformation amplitude, the hanging length of the beam end and the vertical stiffness of mortar layer were studied, and the corresponding measures to control the rail deformation were proposed, to provide theoretical reference for comprehensive treatment of rail deformation of HSR bridge. Research conclusions:(1) The pier settlement, the vertical rotation of the beam end and the beam fault will cause the rail to follow the beam deformation, and "up-warping" of the rail on the vertical deformation boundary will appear. (2) The rail deformation is directly proportional to the vertical deformation amplitude of the bridge and the key to control the rail deformation is to reduce the vertical deformation of the bridge. (3) The rail deformation can be controlled by reducing the hanging length of beam and vertical stiffness of mortar layer. (4) The research results can provide a theoretical reference for controlling the vertical rail deformation of high-speed railway bridges. © 2018, Editorial Department of Journal of Railway Engineering Society. All right reserved.     

Research on the Mechanical Properties of Transparent Sand Based on Triaxial TestEI北大核心

Research purposes: Transparent sand is a new type of geotechnical engineering material, which is made of fused silica sand and porous liquid with the same refractive index. In order to understand its mechanical properties, the CU and CD tests of fused silica sand with a particle size of 0.5~1.0 mm and 1.0~3.0 mm are carried out by triaxial apparatus, and the stress-strain curves, pore water pressure changes and effective stress ratio of the two are compared and analyzed. In addition, E-μ model parameters of coarse and fine sand are calculated respectively, which provide corresponding parameters for further numerical calculations. Research conclusions:(1) The loose sample's stress-strain curve shows hardening characteristics. (2) The coarse particle specimen with steeper stress-strain curve comes to the peak at faster velocity than fine particle specimen. (3)The pore pressure value of the coarse particle specimen is greater than the fine particle, the pore water pressure coefficient of the two shows a decreasing trend with the increase of the confining pressure. (4) Transparent sand can be used to simulate natural sand and the change of diameter can represent different soils. (5) The research results can provide reference for model tests based on transparent soil technique. © 2018, Editorial Department of Journal of Railway Engineering Society. All right reserved.     

Study on horizontal and vertical temperature gradient of ballastless track on curve lineEI北大核心

Research purposes: In order to get the time-varying rules of temperature field distribution in the track structure with superelevation and build the horizontal and vertical temperature gradient of ballastless track, a continuous observation of CRTS II; by using temperature sensors on curve segment of a passenger dedicated line was held. Research conclusions: (1) The temperature change of ballastless track between daytime and nighttime is big, the temperature changing value of surface was 24.7℃ in maximum, 19℃ in average. (2) The temperature changing value became small and the time of maximum temperature come late with the increase of distance to surface. (3) At the bottom of the track structure, the temperature changing value was 6.1℃ in maximum, 5.0℃ in average. (4) Fitting curve of vertical temperature gradient of longitudinally connected ballastless track on curve line can be exponential curve, and the curve sharp can match the distribution about the vertical temperature gradient of the code for design of bridge and culvert in China. (5) The horizontal temperature gradient of the CRTS II; longitudinally connected ballastless track included the track slab and support layer, temperature gradient of track slab could be fitted by using quadratic function, temperature gradient of support layer could be fitted by using piecewise linear function. (6) This study can provide guidance for the temperature load model in the design of high speed railway in central China.     

Thoughts on Transferring Traditional Operation to Full-process Logistic Service

Through expounding the methods of Guiyang South Station transferring to full-process logistic service such as exerting transport market by transferring mechanism, integrating station with dedicated line as to create special market, trying to create brand of full-process transportation, and convoying loading and transportation by jointless connection and ＂front-shop and back workshop＂, based on analyzing ＂three obvious items＂ and ＂three deficiencies＂ existing in practice, this paper puts forward the measures of transferring to the full-process logistic service in further step, such as organizing self-supporting train fleet and mastering market initiative; optimizing price mechanism and adapting for market demand; well building logistic port depending on changed center; and increasing hardware level and strengthening the capacity of freight yard.     

地铁迷流对钢筋混凝土中钢筋腐蚀的试验研究

By means of the mechanism of electrochemical corrosion of anodic oxidization of rebars in reinforced concrete main structure and metallic pipelines buried underground in metro，this paper deals with the simulation of two kinds of corrosive media，namely water and soil，in which reinforced concrete specimen is positioned，and executes the corrosion of rebars in concrete specimen under different external electric potential，simultaneously tests the electrochemical equivalent and corrosion rate of rebars in concrete specimen which is positioned in the two corrosive media.Through analyzing the measured data，it can be inferred that electrochemical equivalent and corrosion rate of metals are influenced by the corrosive environmental media，and the electrochemical equivalent of natural corrosion for metals can not be utilized to calculate the magnitude of metal corrosion induced by metro stray current flow.     

pared by Thermal OxidationZHEN

School, National University of Defense Technology,Changsha 410073,CHN;2. Department of Physics,Dalian University of Technology,Dalian 116023,CHN)ZnO thin films were fabricated on the P-Si,high resistivity Si,ceramic and N-Si substrates by thermal oxidation in air.The oxidation time was fixed to 1h at 300℃~800℃.The effects of different substrates such as the P-Si(111),the high resistivity Si,the ceramics substrates and the N-Si are investigated.To obtain high-quality ZnO films,some Zn films are also annealed in the oxygen.It is found that the ZnO films prepared on the high resistivity Si substrates exhibit the better excitonic ultraviolet (UV) emission,the ceramics substrates exhibit the better deep level visible emission.The ZnO fil     

Regularity analysis on transient over-voltage of grounding grid by lighting strokes in substationsEI北大核心

Research purposes: Lightning has been one of the important factors endangering safe and reliable operation of the railway. The grounding grid performance plays a particularly important role in lightning protection. In this paper, the author has established a grounding grid transient model by the electromagnetic transient analysis software and intended for quantitative analysis of typically grounding grid layout in engineering practice, to lay important theoretical basis for future lightning protection and grounding. Research conclusions: (1) The results show that the ground potential is significantly affected by the soil resistivity, lightning current amplitude and the mesh size. With increase of the soil resistivity and lightning current amplitude, the ground potential at the point of the lightning current injection will significantly improve, but due to the spark discharge of the soil. The ground potential does not increase exponentially with potential lightning current amplitude. The smaller the mesh size, the better the ground potential attenuation. For example of the lightning current 20 kA and the soil resistivity 100 Ω·m, the ground potential of the 5 m×5 m mesh decreases 22.3% compared with the 10 m×10 m mesh. (2) The study finds that the ground potential attenuation away from the lightning strike point at 15 m basically reaches the maximum, which is about 89%. And the degree of attenuation is independent of lightning current amplitude. (3) The results are mainly used for optimization program and design fields on substation lightning protection and grounding.     

重度脊柱畸形，我们应该关注什么？

What should we pay attention to in the management of severe spinal deformity? Huafeng Wang, Zhaomin Zheng, Hui Liu. Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510080, China 【Abstract】Severe spinal deformity is not an uncommon condition that often arises from untreated early onset scoliosis in developing countries. Patients most often present with severe clinical and radiographic deformity with poor pulmonary function. Previous literature has identified the challenges in the treatment of these patients and the higher risk for complications. An assessment of the preoperative, intraoperative, and postoperative factors leading to an optimal result was warranted. The early evaluation should include a multidisciplinary approach from the orthopaedic surgeon, pulmonologist, anesthesiologist, and perhaps the neurologist to provide a baseline assessment. Advanced imaging of the spine is useful and important. Current surgical strategies include aggressive anterior and posterior column release and osteotomies, either with a front–back or a posterior-only approach. With the extent of the surgical release and segmental instrumentation, the potential for curve correction is increased; however, so is the potential for neurologic compromise. Therefore, perioperative Halo traction was recommended. It was thought to improve both spinal deformity and pulmonary function and is a helpful adjuvant in the treatment of severe spinal deformity. Improvements in the clinical and radiographic appearance, pulmonary function, and self-image are often dramatic. Proper planning and execution of the correct surgical procedure for the surgeon provides an outstanding life-changing result in these patients.     

ABSTRACTS

Taking the logistic project of Bama mineral water inter-regional transportation by Liuzhou freigh transport center of Nanning Railway Administration, this paper analyzes the process of working out Iogisti planning program from aspects of logistic program, economic analysis and advantages ＆ disadvantage,, analysis. During the practice of railway freight transportation transferring to modern logistics, the thoughts or many aspects were put forward, including： railway enterprise should actively take door-to-door marketing anc expand service scope, should provide extended service chains of logistic value-added actions and organiz~ trans-administration logistic transportation as to increase service quality, all of these have reference meanin（ for other scattered ＂white goods＂ transportation.     

ABSTRACTS

Applying the Scientific Outlook on Development to Promote the Construction of Urban Rail Transit
-C Thinking on Current Construction Development of China Urban Rail Transit Jiao Tongshan 1
The construction of China Urban Rail Transit is now staying in the important time with rapid development. The achievements we obtained are objectively summarized. At the same time, the contradiction between the current construction speed and preliminary work, the construction procedure, the phenomena of despising operation, the unified planning of traffic integration, the control of construction standards, the difference of fare in domestic urban rail transit, as well as the enhancement of government management for urban rail transit are analyzed and investigated through some phenomena in the industry. Several suggestions are also presented.     

Technology Innovation Guards the High-speed Rail Electric Multiple Unit(EMU) Trains' Operation Safety

正Shanghai EMU Depot is located in the Yangtze River Delta that is the most developed economy area in China.It mainly undertakes maintenance and application tasks of high speed EMU trains from Grade One to Grade Five.By rule,high-speed EMU trains′maintenance mileages at all levels are respectively as follows:Grade One is 3 000km;Grade Two,100 000km;Grade     

ABSTRACTS

Innovation and Practice of Freight Transport Organization Mode in Suihua Car Depot
WU Zhong-kai（Suihua Car Depot, Harbin Railway Administration, Suihua 152000, Heilongjiang, China）
Abstract： Based on analyzing freight transport status of Suihua Car Depot in Harbin Railway Administration, targeting with status of the car depot and problems existing in traditional freight transport organization mode, the operation flow of freight transportation is re-established from 4 aspects of locomotive assembly, territorial transportation, inland organization and shipments arrangement. In the end, according to the freight transport innovation and practice of Suihua Car Depot, this paper puts forward suggestions on increasing innovation of railway freight transport organization mode, such as exerting advantages of resource, realizing win-win between railway freight transportation and clients and enhancing service aim. Key Words： Suihua Car Depot; Freight Transport Organization; Innovation; Operation Flow