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Comparative analysis between single-train passing and double-train intersection in a tunnel

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Journal of Zhejiang university-Science A(Applied Physics & Engineering) 2024年第5期25卷 429-442页

作者： Jianming DU Qian FANG Xuan ZHANG Hualao WANG bridge and Tunnel Research Center Research Institute of Highway Ministry of TransportBeijing 100088China Tunnel and Underground Engineering Research Center of Ministry of Education Beijing Jiaotong UniversityBeijing 00044China

Aerodynamic pressure significantly impacts the scientific evaluation of tunnel service *** aerodynamic pressure of two trains running in a double-track tunnel is considerably more complicated than that of a single *** used the numerical method to investigate the difference in aerodynamic pressure between a single train and two trains running in a double-track ***,the numerical method was verified by comparing the results of numerical simulation and on-site ***,the characteristics of aerodynamic pressure were ***,the influence of various train-tunnel factors on the characteristics of aerodynamic pressure was *** results show that the aerodynamic pressure variation can be divided into stage I:irregular pressure fluctuations before the train tail leaves the tunnel exit,and stage II:periodic pressure declines after the train tail leaves the tunnel *** addition,the aerodynamic pressure simultaneously jumps positively or drops negatively for a single train or two trains running in double-track tunnel *** pressure amplitude in the two-train case is higher than that for a single *** maximum positive peak pressure difference(P_(STP))and maximum negative peak pressure difference(P_(STN))increase as train speed rises to the power from 2.256 to 2.930 in stage *** P_(STP) and P_(STN) first increase and then decrease with the increase of tunnel length in stage *** P_(STP) and P_(STN) increase as the blockage ratio rises to the power from 2.032 to 2.798 in stages I and II.

关键词： Railway tunnel Aerodynamic effect Pressure characteristic Train speed Tunnel length Blockage ratio

Utilization of recycled solid waste as ecological reclamation materials based on plant growth experiments and soil quality analysis

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Journal of Mountain Science 2024年第3期21卷 820-834页

作者： QIN Xiaochun NI Anchen YANG Dongxiao XING Wenhu LIU Shiliang College of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China Shanxi Road&bridge Construction Group Co. LtdShanxi 030006China School of Environment Beijing Normal UniversityBeijing 111875China

During the highway construction,a large number of spoil areas will be generated while a large amount of waste slag and soil could not be rationally ***,the vegetation recovery is slow in the spoil areas due to the soil *** at recycling the solid waste,the sieved engineering waste slag with local red clay and corn straw biochar was supplied to solve the problem of insufficient nutrients in engineering waste slag and *** addition,planting experiments of alfalfa(Medicago sativa L.)and Amorpha fruticosa *** with physical and chemical experiments were carried out to prove the feasibility of the novel improved substrate for the reclamation of spoil *** results show that the substrate's improvement effect is mainly affected by the soil to slag ratio and the biochar *** improvement effect of soil matrix in highway spoil area decreases with the increase of the waste slag content,especially when the soil-slag ratio is less than 3,and the promotion of plants is *** the contrary,the improvement effect is proportional to the biochar content(3%-8%).But it is noted that the Cu and Pb in the soil will exceed the clean limit corresponding to the Nemero soil pollution index level when the biochar content is 8%.Therefore,it is recommended that the soil-slag ratio should be≥3,and the biochar content should reach 3%-5%.This research provides experimental basis and technical support for utilizing solid waste resources in the reclamation of highway spoil areas.

关键词： Highway Spoil area Waste slag Modified soil Ecological reclamation

Influence of span-to-depth ratio on dynamic response of vehicle-turnoutbridge system in high-speed railway

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High-Speed Railway 2024年第1期2卷 30-41页

作者： Chuanqing Dai Tao Xin Shenlu Qiao Yanan Zhang Pengsong Wang Mahantesh M.Nadakatti School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China China Railway Engineering Design and Consulting Group Co. Ltd.Beijing 100070China Karnatak Law Society’s Gogte Institute of Technology Belagavi 590006India

For high-speed railways,the smoothness of the railway line significantly affects the operational speed of *** the train passes through the turnout on a long-span bridge,the wheel-rail impacts caused by the turnout structure irregularities,and the instability arising from the bridge's flexural deformation lead to a strong coupling effect in the vehicle-turnout-bridge *** significantly affects both ride comfort and operational *** addressing this issue,the present study considered a long-span continuous rigid-frame bridge as an example and established a train-turnout-bridge coupled dynamic model of high-speed *** a selfdeveloped dynamic simulation program,the study analysed the dynamic response characteristics when the train passes through the turnouts on the *** also investigated the influence of different span-to-depth ratios of the bridge on the vehicle dynamic response when the train passes through the main line and branch line of turnouts and then proposed a span-to-depth ratio limit value for a long-span continuous rigid-frame *** research findings suggest that the changes in the span-to-depth ratio have a relatively minor impact on the train’s operational performance but significantly affect the dynamic characteristics of the bridge *** on the findings and a comprehensive assessment of safety indicators,it is advisable to establish a span-to-depth ratio limit of 1/4500 for a long-span continuous rigid-frame bridge.

关键词： Turnout on bridge Span-to-depth ratio Dynamic response Vehicle-turnout-bridge system High-speed railway

Bird’s-eye view of recycled solid wastes in road engineering

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Journal of Road Engineering 2024年第2期4卷 93-150页

作者： Zhuangzhuang Liu Tengteng Feng Xingyi Zhu Jie Gao Kui Hu Meng Guo Fan Gu Feng Li School of Highway Chang'an UniversityXi'an 710064China Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang'an UniversityXi'an 710064China Key Laboratory of Road and Traffic Engineering of Ministry of Education Tongji UniversityShanghai 200092China School of Civil Engineering and Architecture East China Jiaotong UniversityNanchang 330013China College of Civil Engineering and Architecture Henan University of TechnologyZhengzhou 450001China State Key Laboratory of bridge Engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China School of Traffic&Transportation Engineering Changsha University of Science and TechnologyChangsha 410114China School of Transportation Science and Engineering Beihang UniversityBeijing 102206China

Recent trends in road engineering have explored the potential of incorporating recycled solid wastes into infrastructures that including pavements,bridges,tunnels,and accessory *** utilization of solid wastes is expected to offer sustainable solutions to waste recycling while enhancing the performance of *** review provides an extensive analysis of the recycling of three main types of solid wastes for road engineering purposes:industrial solid waste,infrastructure solid waste,and municipal life solid *** solid wastes suitable for road engineering generally include coal gangue,fly ash,blast furnace slag,silica fume,and steel slag,*** solid wastes recycled in road engineering primarily consist of construction&demolition waste,reclaimed asphalt pavements,and recycled cement ***,recent exploration has extended to the utilization of municipal life solid wastes,such as incinerated bottom ash,glass waste,electronics waste,plastic waste,and rubber waste in road engineering *** recycled solid wastes are categorized into solid waste aggregates,solid waste cements,and solid waste fillers,each playing distinct roles in road *** of solid waste acting aggregates,cements,and fillers in road infrastructures were fully investigated,including their pozzolanic properties,integration effects to virgin materials,modification or enhancement solutions,engineering *** of these materials not only addresses the challenge of waste management but also offers environmental benefits aiming carbon neutral and contributes to sustainable infrastructure ***,challenges such as variability in material properties,environmental impact mitigation,secondary pollution to environment by leaching,and concerns regarding long-term performance need to be further *** these challenges,the recycled solid wastes hold immense potential in revolutionizing road construction

关键词： Road engineering Industrial solid waste Infrastructure solid waste Municipal life waste Recycled materials

Reflection on methodology of the correlation between electromagnetic interference and safety in high-speed railway

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Railway Sciences 2024年第1期3卷 84-96页

作者： Chang Liu Shiwu Yang Yixuan Yang Hefei Cao Shanghe Liu Department of Electromagnetic Environmental Effects Technology Studio CRSC Research and Design Institute Group Co.Ltd.BeijingChina School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuangChina School of Automation and Intelligence Beijing Jiaotong UniversityBeijingChina Infrastructure Technology Research Institute CRSC Research and Design Institute Group Co.Ltd.BeijingChina Research Center for Electromagnetic Environmental Effects Shijiazhuang Tiedao UniversityShijiazhuangChina

Purpose – In the continuous development of high-speed railways, ensuring the safety of the operation controlsystem is crucial. Electromagnetic interference (EMI) faults in signaling equipment may cause transportationinterruptions, delays and even threaten the safety of train operations. Exploring the impact of disturbances onsignaling equipment and establishing evaluation methods for the correlation between EMI and safety isurgently ***/methodology/approach – This paper elaborates on the necessity and significance of studying theimpact of EMI as an unavoidable and widespread risk factor in the external environment of high-speed railwayoperations and continuous development. The current status of research methods and achievements from theperspectives of standard systems, reliability analysis and safety assessment are examined layer by ***, it provides prospects for innovative ideas for exploring the quantitative correlation between EMIand signaling *** – Despite certain innovative achievements in both domestic and international standard systems andrelated research for ensuring and evaluating railway signaling safety, there’s a lack of quantitative and strategic research on the degradation of safety performance in signaling equipment due to EMI. A quantitativecorrelation between EMI and safety has yet to be established. On this basis, this paper proposes considerationsfor research methods pertaining to the correlation between EMI and ***/value – This paper overviews a series of methods and outcomes derived from domestic andinternational studies regarding railway signaling safety, encompassing standard systems, reliability analysisand safety assessment. Recognizing the necessity for quantitatively describing and predicting the impact ofEMI on high-speed railway signaling safety, an innovative approach using risk assessment techniques as abridge to establish the correlation between EMI and signaling safety is proposed.

关键词： Electromagnetic interference Reliability Safety Risk assessment Signaling system High-speed railway

Analysis on running safety of train on the bridge considering sudden change of wind load caused by wind barriers

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Frontiers of Structural and Civil Engineering 2018年第4期12卷 558-567页

作者： Tian ZHANG HeXIA Weiwei GUO Institute of Road and bridge Engineering Dalian Maritime UniversityDalian 116026China beijing's Key Laboratory of Structural Wind Engineering and Urban Wind Environment (beijing jiaotong university) Beijing 100044China School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China

The calculation formulae for change of wind load acting on the car-body are derived when a train moves into or out of the wind barrier structure, the dynamic analysis model of wind-vehicle-bridge system with wind barrier is established, and the influence of sudden change of wind load on the running safety of the train is analyzed. For a 10-span simply-supported U-shaped girder bridge with 100 m long double-side 3.5 m barrier, the response and the running safety indices of the train are calculated. The results are compared with those of the case with wind barrier on the whole bridge. It is shown that the sudden change of wind load caused by wind barrier has significant influence on the lateral acceleration of the car-body, but no distinct on the vertical acceleration. The running safety indices of train vehicle with sectional wind barriers are worse than those with full wind barriers, and the difference increases rapidly with wind velocity.

关键词： wind barrier sudden change of wind load dynamic response running safety comfort bridges Wind Dynamic response Wind barriers COMFORT Wing loading TRAIN driving safety

STUDY OF CONSTITUTIVE RELATIONS FOR PSEUDO-ELASTICITY AND SHAPE MEMORY BEHAVIOR

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Acta Mechanica Sinica 1993年第1期9卷 44-52页

作者：王志刚黄克智 dept.of Engineering Mechanics Tsinghua UniversityBeijing China 100084

Constitutive relations are given for the description of the deformation behavior of shape memory materials. The deformation is the superposition of the elastic, the thermal and the phase transformation deformation caused by the transformation from one to the other among the high temperature phase, the low temperature phase and the stress induced phase. The phase transformation is controlled by the driving force, i.e., the Gibbs energy difference between the phases.

关键词： shape memory material pseudo-elastic deformation, shape memory deformation phase transformation constitutive relations

Application of New Concept Waterproofing in Xiang'an Undersea Tunnel,China

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China Ocean Engineering 2013年第1期27卷 121-130页

作者：陈铁林张顶力曾超应国刚 Tunnel and Underground Engineering Research Center of Ministry of Education Beijing Jiaotong University Xiamen Road and bridge Construction Group Co.Ltd.

As a kind of transportation mode for crossing channels, undersea tunnel has incomparable advantages for its directness, convenience, fastness, insusceptibility to weather conditions, and smaller influences on environments. In recent years, with the development of undersea tunnel construction, the design and construction technologies have been greatly enhanced. The first undersea tunnel in China has just been built. Waterproofing is the key technique of undersea tunneling. A new concept of waterproofing scheme of grouting, sealing, draining and divided sections was adopted in the construction of the tunnel based on the researches, the in-situ geological features, the astuteness of the current technology and the cost of construction. The structural details of the sealing and draining system are introduced to illustrate the salient features of the new waterproofing technique. It is hoped that experiences described in the paper can offer guidance for the construction of the extensive undersea tunnels in the coming years.

关键词： undersea tunnel waterproofing sealing-draining system

Discontinuous mechanical behaviors of existing shield tunnel with stiffness reduction at longitudinal joints

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Frontiers of Structural and Civil Engineering 2023年第1期17卷 37-52页

作者： Xiang LIU Qian FANG Annan JIANG Dingli ZHANG Jianye LI Liaoning Key Laboratory of Marine Environmental bridge and Tunnel Engineering Dalian Maritime UniversityDalian 116026China Key Laboratory for Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

An analytical model is proposed to estimate the discontinuous mechanical behavior of an existing shield tunnel above a new tunnel. The existing shield tunnel is regarded as a Timoshenko beam with longitudinal joints. The opening and relative dislocation of the longitudinal joints can be calculated using Dirac delta functions. Compared with other approaches, our method yields results that are consistent with centrifugation test data. The effects of the stiffness reduction at the longitudinal joints (α and β), the shearing stiffness of the Timoshenko beam GA, and different additional pressure profiles on the responses of the shield tunnel are investigated. The results indicate that our proposed method is suitable for simulating the discontinuous mechanical behaviors of existing shield tunnels with longitudinal joints. The deformation and internal forces decrease as α, β, and GA increase. The bending moment and shear force are discontinuous despite slight discontinuities in the deflection, opening, and dislocation. The deflection curve is consistent with the additional pressure profile. Extensive opening, dislocation, and internal forces are induced at the location of mutation pressures. In addition, the joints allow rigid structures to behave flexibly in general, as well as allow flexible structures to exhibit locally rigid characteristics. Owing to the discontinuous characteristics, the internal forces and their abrupt changes at vulnerable sections must be monitored to ensure the structural safety of existing shield tunnels.

关键词： tunnel–soil interaction discontinuous analysis longitudinal joints existing shield tunnel Timoshenko beam Dirac delta function