Railroad operating experience in permafrost conditions has shown that deformations of embankments on thawing foun- dations last for a long time. After an initial period of heat settlement due to permafrost degradation...Railroad operating experience in permafrost conditions has shown that deformations of embankments on thawing foun- dations last for a long time. After an initial period of heat settlement due to permafrost degradation, the determining factor is the plastic flow of seasonal thawed soils of the foundation upper layer under the embankment. This paper provides a method to evaluate these deformations, and calculation examples using data from line sections of the Chum-Labytnangi Railway in northwestern Russia. It also discusses several methods of embankment stabilization, including the use of ver- tical thermosiphons.展开更多
Earthquake-induced strong near-fault ground motion is typically accompanied by largevelocity pulse-like component,which causes serious damage to slopes and buildings.Although not all near-fault ground motions contain ...Earthquake-induced strong near-fault ground motion is typically accompanied by largevelocity pulse-like component,which causes serious damage to slopes and buildings.Although not all near-fault ground motions contain a pulse-like component,it is important to consider this factor in regional earthquake-induced landslide susceptibility assessment.In the present study,we considered the probability of the observed pulse-like ground motion at each site(PP)in the region of an earthquake as one of the conditioning factors for landslide susceptibility assessment.A subset of the area affected by the 1994Mw6.7 Northridge earthquake in California was examined.To explore and verify the effects of PP on landslide susceptibility assessment,seven models were established,consisting of six identical influencing factors(elevation,slope gradient,aspect,distance to drainage,distance to roads,and geology)and one or two factors characterizing the intensity of the earthquake(distance to fault,peak ground acceleration,peak ground velocity,and PP)in logistic regression analysis.The results showed that the model considering PP performed better in susceptibility assessment,with an area under the receiver operating characteristic curve value of 0.956.Based on the results of relative importance analysis,the contribution of the PP value to earthquakeinduced landslide susceptibility was ranked fourth after the slope gradient,elevation,and lithology.The prediction performance of the model considering the pulse-like effect was better than that reported previously.A logistic regression model that considers the pulse-like effect can be applied in disaster prevention,mitigation,and construction planning in near-fault areas.展开更多
This paper presents the main findings of the environmental and social impact assessment (ESIA) for the Egyptian national railways restructuring. This paper consists of the two parts: 1) modernizing the signaling syste...This paper presents the main findings of the environmental and social impact assessment (ESIA) for the Egyptian national railways restructuring. This paper consists of the two parts: 1) modernizing the signaling system on the Arab El Raml-Alexandria Line and creating a Central Traffic Management Center in Tanta;and 2) renewing 200 km of track in Lower and Upper Egypt. The purpose of this evaluation is to identify and examine the potential socio-cultural, economic, and physical impacts of the railway restructuring, and propose measures to mitigate its adverse impacts, and develop plans for managing and monitoring the environmental aspects of the railway restructuring. This paper describes outlines of the environmental and social sensitivities of the railway restructuring area, potentially significant impacts of the proposed project and plans for their mitigation. Detailed information on the environmental and socio economic settings of the railway restructuring, components and activities of the proposed project and the results of the environmental and social impact assessment studies are presented in the body of the paper.展开更多
As the railway sector intensifies its efforts in the technology research,system R&D and technology application of 5G-R,the paper conducts a preliminary study on its application frequency in terms of its frequency ...As the railway sector intensifies its efforts in the technology research,system R&D and technology application of 5G-R,the paper conducts a preliminary study on its application frequency in terms of its frequency propagation,network carrying capacity,its ability to work as industrial pillar,system applicability,and the compatibility of 5G-R with other systems.In line with China's GSM-R application practice and the application needs,the paper focuses on the study of key technologies such as model alignment of base station equipment,and optimization of 5G-R terminal and core network,identifying the priorities for the China's efforts to develop 5G-R and providing references for the research and application of related technologies.展开更多
In view of the practical application of centralized traffic control(CTC)system of the Beijing-Shanghai HSR and in combination with the line conditions and user requirements,the system is optimized in terms of route se...In view of the practical application of centralized traffic control(CTC)system of the Beijing-Shanghai HSR and in combination with the line conditions and user requirements,the system is optimized in terms of route self-triggering polling frequency,train receiving route self-triggering timing,train departure route section processing,route self-triggering between yards,wireless route forecasting and automatic train number conversion,which improves the efficiency of automatic route setting of CTC system and the adaptability of high-density and long-major lines.At the same time,according to the intelligent development requirements of railways,the paper proposes the expectation for the centralized traffic control system of the Beijing-Shanghai HSR in terms of intelligent adjustment of TWD,information sharing with traction power supply supervisory control and data acquisition(SCADA)system/disaster monitoring system,intelligent linkage of posts,etc.展开更多
This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ent...This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ential settlement. Based on the study of ballastless track additional load and of vehicle, track, and bridge dynamic responses under different differential settlements, a control standard of differential settlement during operation is proposed preliminarily.展开更多
This scoping review aims(1)to map the literature dealing with neurophysiological and biomechanical aspects of back problems in athletes in order to identify valid risk-factors for their prevention,plus(2)to identify g...This scoping review aims(1)to map the literature dealing with neurophysiological and biomechanical aspects of back problems in athletes in order to identify valid risk-factors for their prevention,plus(2)to identify gaps in the existing research and propose suggestions for future studies.A literature search conducted with Scopus,Web of Science,MEDLINE and Cochrane Library was completed by Elsevier,SpringerLink and Google Scholar.The main neurophysiological risk factors identified leading to back problems in athletes are neuromuscular imbalance,increased muscle fatigability,muscle dysfunction and impaired motor control,whilst biomechanical risk factors include maladaptive spinal,spinopelvic and lower limb kinematics,side-to-side imbalances in axial strength and hip rotation range of motion,spinal overloading and deficits in movement pattern.However,most studies focused on back pain in the lumbar region,whereas less attention has been paid to thoracic and cervical spine problems.The range of sports where this topic has been studied is relatively small.There is a lack of research in sports in which the core muscles are highly involved in specific movements such as lifting weights or trunk rotations.A limited number of studies include female athletes and master athletes of both genders.In addition to chronic back pain patients,it is equally important to conduct research on healthy athletes with a predisposition to spine problems.Investigators should focus their empirical work on identifying modifiable risk factors,predict which athletes are at risk for back problems,and develop personalized sport-specific assessment tools and targeted prevention strategies for them.展开更多
文摘Railroad operating experience in permafrost conditions has shown that deformations of embankments on thawing foun- dations last for a long time. After an initial period of heat settlement due to permafrost degradation, the determining factor is the plastic flow of seasonal thawed soils of the foundation upper layer under the embankment. This paper provides a method to evaluate these deformations, and calculation examples using data from line sections of the Chum-Labytnangi Railway in northwestern Russia. It also discusses several methods of embankment stabilization, including the use of ver- tical thermosiphons.
基金the National Natural Science Foundation of China(41977213,41977233)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0906)+2 种基金CREC Sichuan Eco-City Investment Co,Ltd.(R110121H01092)Fundamental Research Funds for the Central Universities(XJ2021KJZK039)SichuanProvincial Transportation Science and Technology Project(2021-A-03)。
文摘Earthquake-induced strong near-fault ground motion is typically accompanied by largevelocity pulse-like component,which causes serious damage to slopes and buildings.Although not all near-fault ground motions contain a pulse-like component,it is important to consider this factor in regional earthquake-induced landslide susceptibility assessment.In the present study,we considered the probability of the observed pulse-like ground motion at each site(PP)in the region of an earthquake as one of the conditioning factors for landslide susceptibility assessment.A subset of the area affected by the 1994Mw6.7 Northridge earthquake in California was examined.To explore and verify the effects of PP on landslide susceptibility assessment,seven models were established,consisting of six identical influencing factors(elevation,slope gradient,aspect,distance to drainage,distance to roads,and geology)and one or two factors characterizing the intensity of the earthquake(distance to fault,peak ground acceleration,peak ground velocity,and PP)in logistic regression analysis.The results showed that the model considering PP performed better in susceptibility assessment,with an area under the receiver operating characteristic curve value of 0.956.Based on the results of relative importance analysis,the contribution of the PP value to earthquakeinduced landslide susceptibility was ranked fourth after the slope gradient,elevation,and lithology.The prediction performance of the model considering the pulse-like effect was better than that reported previously.A logistic regression model that considers the pulse-like effect can be applied in disaster prevention,mitigation,and construction planning in near-fault areas.
文摘This paper presents the main findings of the environmental and social impact assessment (ESIA) for the Egyptian national railways restructuring. This paper consists of the two parts: 1) modernizing the signaling system on the Arab El Raml-Alexandria Line and creating a Central Traffic Management Center in Tanta;and 2) renewing 200 km of track in Lower and Upper Egypt. The purpose of this evaluation is to identify and examine the potential socio-cultural, economic, and physical impacts of the railway restructuring, and propose measures to mitigate its adverse impacts, and develop plans for managing and monitoring the environmental aspects of the railway restructuring. This paper describes outlines of the environmental and social sensitivities of the railway restructuring area, potentially significant impacts of the proposed project and plans for their mitigation. Detailed information on the environmental and socio economic settings of the railway restructuring, components and activities of the proposed project and the results of the environmental and social impact assessment studies are presented in the body of the paper.
文摘As the railway sector intensifies its efforts in the technology research,system R&D and technology application of 5G-R,the paper conducts a preliminary study on its application frequency in terms of its frequency propagation,network carrying capacity,its ability to work as industrial pillar,system applicability,and the compatibility of 5G-R with other systems.In line with China's GSM-R application practice and the application needs,the paper focuses on the study of key technologies such as model alignment of base station equipment,and optimization of 5G-R terminal and core network,identifying the priorities for the China's efforts to develop 5G-R and providing references for the research and application of related technologies.
文摘In view of the practical application of centralized traffic control(CTC)system of the Beijing-Shanghai HSR and in combination with the line conditions and user requirements,the system is optimized in terms of route self-triggering polling frequency,train receiving route self-triggering timing,train departure route section processing,route self-triggering between yards,wireless route forecasting and automatic train number conversion,which improves the efficiency of automatic route setting of CTC system and the adaptability of high-density and long-major lines.At the same time,according to the intelligent development requirements of railways,the paper proposes the expectation for the centralized traffic control system of the Beijing-Shanghai HSR in terms of intelligent adjustment of TWD,information sharing with traction power supply supervisory control and data acquisition(SCADA)system/disaster monitoring system,intelligent linkage of posts,etc.
基金supported by the National Nature Science Foundation of China (U1234206 and 61503311)+4 种基金support under the Railways Technology Development Plan of China Railway Corporation (2016X008-J)the Fundamental Research Funds for the Central Universities (2682015CX039)supported by the National United Engineering Laboratory of Integrated and Intelligent Transportation
文摘This paper discusses the main impact factors of the local settlement and differential settlement of high- speed railway lines. The analysis results show that groundwater exploitation is the direct cause of differ- ential settlement. Based on the study of ballastless track additional load and of vehicle, track, and bridge dynamic responses under different differential settlements, a control standard of differential settlement during operation is proposed preliminarily.
基金supported by the Scientific Grant Agency of the Ministry of Education,Science,Research and Sport of the Slovak Republic and the Slovak Academy of Sciences (No.1/0089/20 and 1/0725/23)the Slovak Research and Development Agency (No.APVV-15-0704)+1 种基金the Cross-border Co-operation Programme INTERREG V-A SK-CZ/2018/06 (No.NFP 304011P714)INTERREG V-A SK-CZ/2020/12 (No.NFP304010AYX7)co-financed by the European Regional Development Fund.
文摘This scoping review aims(1)to map the literature dealing with neurophysiological and biomechanical aspects of back problems in athletes in order to identify valid risk-factors for their prevention,plus(2)to identify gaps in the existing research and propose suggestions for future studies.A literature search conducted with Scopus,Web of Science,MEDLINE and Cochrane Library was completed by Elsevier,SpringerLink and Google Scholar.The main neurophysiological risk factors identified leading to back problems in athletes are neuromuscular imbalance,increased muscle fatigability,muscle dysfunction and impaired motor control,whilst biomechanical risk factors include maladaptive spinal,spinopelvic and lower limb kinematics,side-to-side imbalances in axial strength and hip rotation range of motion,spinal overloading and deficits in movement pattern.However,most studies focused on back pain in the lumbar region,whereas less attention has been paid to thoracic and cervical spine problems.The range of sports where this topic has been studied is relatively small.There is a lack of research in sports in which the core muscles are highly involved in specific movements such as lifting weights or trunk rotations.A limited number of studies include female athletes and master athletes of both genders.In addition to chronic back pain patients,it is equally important to conduct research on healthy athletes with a predisposition to spine problems.Investigators should focus their empirical work on identifying modifiable risk factors,predict which athletes are at risk for back problems,and develop personalized sport-specific assessment tools and targeted prevention strategies for them.
