Chengdu, China
Chengdu, China

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Wang J.,Shijiazhuang University | Xiao W.,China Railway Erju Co. | Zhang X.,Shijiazhuang University
Advanced Materials Research | Year: 2011

A numerical model is presented to analyze effect of wheel/rail friction on rolling contact fatigue. A three-dimension finite element model of rail is built up to investigate the rail stresses and strain around wheel/rail patch. Then, based on the critical plane concept, a new model was proposed to predict the rolling contact fatigue (RCF) crack initiation life under different wheel/rail frictions by using stress and strain on the critical plane as fatigue parameter. The numerical results obtained show that the wheel/rail friction coefficient has a great impact on the fatigue crack initiation life.and the curve of fatigue crack initiation life under different wheel/rail friction coefficient is roughly "S" type. The results are very useful in the wheel/rail friction management and determining grinding interval and grinding removal.

Zha J.,Southwest Jiaotong University | Ju X.,China Railway Erju Co.
ICLEM 2012: Logistics for Sustained Economic Development - Technology and Management for Efficiency - Proceedings of the 2012 International Conference of Logistics Engineering and Management | Year: 2012

The paper researches the decoupling relationship between transport economical growth, energy consumption and carbon emissions in China during 2000-2009 with the related theory and measurement model on " decoupling" and "coupling". The results show that the follow-up emphasis of decoupling work is to further improve the technology of transport energy efficiency, focus on optimizing traffic mode and energy structure as well as improving the energy production structure and energy consumption structure. © 2012 American Society of Civil Engineers.

Zhao Y.,Southwest Jiaotong University | Chen S.,Southwest Jiaotong University | Tan X.,Southwest Jiaotong University | Hui M.,China Railway Erju Co.
Journal of Modern Transportation | Year: 2013

Based on the construction of high risk tunnels in Guiguang-Guangzhou high-speed railway, several new technologies were developed for high-risk tunnel construction. First, an integrated advanced geological prediction was developed for tunneling in karst area. Then, a new system of ventilation by involving the dedusting technology was proposed and used in the field, which received a good air quality. Finally, a method to minimize the distance between the working face and the invert installation was proposed by optimizing the invert installation and adopting the micro bench method. Applying the method to the project obtained an excellent result. The achievement obtained for this study would be able to provide a valuable reference to similar projects in the future. © The Author(s) 2013.

Bin L.,Southwest Jiaotong University | Taiyue Q.,Southwest Jiaotong University | Wang Z.,Dalian University of Technology | Longwei Y.,China Railway Erju Co.
Tunnelling and Underground Space Technology | Year: 2012

This paper focuses on the grout cohesive strength and the grout friction angle of rock bolt, which have a significant influence on the pullout force and are difficult to estimate. Traditional method estimate the two parameters from the results of pull-out test conducted under different confining pressures. St. John and Van Dillen gave two approximate empirical formulas in 1984. In this text, a new method was proposed to back calculate the grout cohesive strength and the grout friction angle based on given field pullout force of rock bolt. In order to verify the method, a numerical model was built by FLAC 3D to approach the two parameters by the principle of dichotomy. The convergence result had been proved to be right by numerical pull-out tests. © 2011 Elsevier Ltd.

Liu C.-Y.,Fuzhou University | Xu D.-H.,China Railway Erju Co.
Journal of Railway Engineering Society | Year: 2013

Research purposes: As using the complete analysis method for beam on elastic foundation calculate the internal force as well as the displacement of the deep foundation ditch enclosure structure, the internal bracings was applied in advanced and the calculation condition was inconsistent with the actual of the construction, a method that considered the erection time of the inner bracings was proposed in this paper in order to improve the calculation accuracy. Research conclusions: (1) As the bar-system FEM complete analysis method for beam on elastic foundation was adopted to calculate the internal force and the displacement of the foundation ditch enclosure structure, the inner bracing was defined as compression-only bar unit with initial gap, and the width of the initial gap was equal to the lateral displacement of fender piles (or enclosure wall) on the point which the inner bracings were applied at the erection time. With that the erection time of the bracings were considered in the model, which makes the internal force and displacement calculations of the enclosure structure accord the actual better. (2) Without considering the erection time of the bracings while using the complete analysis method for beam on elastic foundation, the calculated values of the lateral displacements and moments of the fender piles (or enclosure wall) were smaller, that was not safety in practice. (3) Research findings of this paper can provide reference for the design and construction of foundation ditch enclosure structure.

Hu L.-S.,China Railway Erju Co. | Wang J.-X.,Tongji University | Lu Y.-R.,Tongji University
Yantu Lixue/Rock and Soil Mechanics | Year: 2012

The water pressure equilibrium system of deep tunnel is composed of groundwater, surrounding rock, grouting ring and lining, which can not be systematically investigated by the traditional methods for the stress and plastic zone of tunnel. The elastoplastic solution for deep tunnel is carried out. The surrounding rock, grouting ring and lining are assumed as isotropic continuous elastoplastic medium. Based on the elastoplastic mechanics, groundwater hydraulics theory and Mohr-Coulomb criterion, the calculation formulas for stress and plastic zone of axisymmetric deep tunnel under the combined action of four factors are deduced. To calculate a deep tunnel, Matlab is adopted to edit routine for the computation. Compared with the calculated results obtained from the traditional solutions, the correctness of deduced formulas is validated; and the defects of traditional methods are indicated. The influence of grouting parameters on plastic zone and the method for deciding optimum thickness of grouting ring are also discussed.

Qing S.-H.,China Railway Erju Co. | Yang Y.,China Railway Eryuan Engineering Group Co. | Zhang M.-H.,China Railway Eryuan Engineering Group Co.
Journal of Railway Engineering Society | Year: 2013

Research purposes: For the area of railway from Dali to Lijiang in Yunnan, combining the features of complex seismic geological conditions, highly required environmental protection and difficult route selection therein, the related study is carried out so as to establish, and then promote the technical system for the route selection combining geology and environmental geology for railway engineering in high-intensity earthquake zone. Research conclusions: This paper systemically summarizes the principle of the "route selection combining geology and environmental geology for railway engineering in high-intensity earthquake zone". By the means of remote sensing interpretation, geological mapping, geophysical prospecting (by electricity, seismic waves, or magnetotellurics etc.), drilling exploration, hole testing, in-situ testing, indoor tests and other comprehensive prospecting technique, as well as seismic safety evaluation (including active fault identification), environmental effect appraisal, this complete system is constituted, which has an important value to promote. An optimal route scheme is selected through overall comparison among three schemes from the aspects of seismic geological conditions and environmental sensitive area, and then verified by engineering construction and practical operation to be scientific and reasonable, which not only protects the ecological environment to a maximum extent, but also includes the route into a "safe island". With outstanding economic, social and environmental benefits, it is praised by experts from the Ministry of Environmental Protection as the "Example of Route Selection Combining Engineering Geology and Environmental Geology Organically", accumulating experience for railway route selection in similar region.

Liu Y.,China Railway Erju Co.
Modern Tunnelling Technology | Year: 2013

This paper introduces the application of curtain grouting with sulphoaluminate cement to F30 fault fracture zone of Gaogaishan tunnel, and it elaborates the effects of water blocking, application range, grouting parameters, selection of drilling tools and grouting machines, and construction technology of sulphoaluminate cement grouting in squeezing fault zone with high pressure, abundant water and large quantities of fault gouges. The test of grouting effect indicates that the grout filling is full, the effect of blocking fissure water under high pressure is obvious and the consolidation of fractured layer is sound, ensuring the safety of the tunnel excavation through the water-rich fault fracture zones with high pressure.

Hui M.,China Railway Erju Co.
Electronic Journal of Geotechnical Engineering | Year: 2015

A new calculation method of rock mass pressure in shallow muddy tunnel based on field measurement is presented. The new method is better than the traditional method on the deficiency of which relies on experience mechanical parameters of rock mass The structural mechanics model is established according to the relationship between the middle wall deformation and the horizontal rock mass pressure. The horizontal rock mass pressure of tunnel is calculated by the monitoring date of middle wall deformation. The vertical rock mass pressure of tunnel is calculated by the mechanical parameters which is inversed by horizontal rock mass pressure. Meanwhile, this calculation method is verified by the example of a soil shallow muddy tunnel. The results indicate that the horizontal pressure of the rock mass is 109.809kPa, and the vertical rock mass pressure is 294.881kPa if taking this new calculation method. The results are within the scope calculated by the traditional method and this new method is feasible. © 2015 ejge.

Hui M.,China Railway Erju Co.
Electronic Journal of Geotechnical Engineering | Year: 2015

The support scheme of inner supporting of piling support is adopted for the deep pit engineering of the access of an underground garage located in muddy stratum of Xiamen, under the circumstance of the excavation depth, area, soil layer and surrounding environment of the foundation pit. The monitoring result shows that the inner supporting of piling support better assures the excavation and construction of underground structure smoothly, which does not have adverse effect on the normal use of surrounding environment and achieves better economic and project benefit. Inner supporting of piling support technique is of certain reference value to the construction of foundation pit in soft layer. © 2015 ejge.

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