In this paper,the use of recycled tire-derived aggregates(TDA)mixed with ballast material is evaluated in order to reduce the train-induced ground-borne vibrations.For this purpose,a series of field vibration measurem...In this paper,the use of recycled tire-derived aggregates(TDA)mixed with ballast material is evaluated in order to reduce the train-induced ground-borne vibrations.For this purpose,a series of field vibration measurements has been carried out at an executed pilot track.The prepared ballast layer was mixed with different percentages of TDA in three sections.Moreover,another test section with pure ballast is considered as a reference.The vibrations generated by a motor-powered draisine at two different speeds are then recorded.Records of vibration data are provided using four seismometers placed once longitudinally and once transversely beside different sections.The outputs are then processed in both velocity–time and velocity–frequency domains.To verify the vibration mitigation performance of TDA in real operation conditions,field measurements under the passage of two planned passenger and freight trains are finally arranged.Results show that the best TDA mixture ratio,i.e.,10%by weight,can reduce the transmitted vibrations up to 12 dB for frequencies above 31.5 Hz.According to the obtained effi-ciency and the very low cost of the recycled materials,this solution can be considered as a competitive vibration countermeasure.展开更多
Driving safety is of significance in the automobile industry and transportation systems. Pavement skid resistance has long been recognized as the most important parameter in reducing traffic accidents especially in we...Driving safety is of significance in the automobile industry and transportation systems. Pavement skid resistance has long been recognized as the most important parameter in reducing traffic accidents especially in wet conditions. The knowledge of the friction coefficient and skid resistance is very valuable information for safety enhancement of roads. Thus, it is important to find proper methods for measuring skid resistance and frictional properties of the pavement surface. There is a wide range of measurement methods and devices for measuring skid resistance. This paper presents a review on the research studies that have been done on characterization of the frictional properties of the pavement surface and discussed methods used for measurement and evaluation of texture characteristics and the strengths and weaknesses of these methods. Finally, some ideas have been suggested to develop new methods for better and proper measurement of skid resistance.展开更多
文摘In this paper,the use of recycled tire-derived aggregates(TDA)mixed with ballast material is evaluated in order to reduce the train-induced ground-borne vibrations.For this purpose,a series of field vibration measurements has been carried out at an executed pilot track.The prepared ballast layer was mixed with different percentages of TDA in three sections.Moreover,another test section with pure ballast is considered as a reference.The vibrations generated by a motor-powered draisine at two different speeds are then recorded.Records of vibration data are provided using four seismometers placed once longitudinally and once transversely beside different sections.The outputs are then processed in both velocity–time and velocity–frequency domains.To verify the vibration mitigation performance of TDA in real operation conditions,field measurements under the passage of two planned passenger and freight trains are finally arranged.Results show that the best TDA mixture ratio,i.e.,10%by weight,can reduce the transmitted vibrations up to 12 dB for frequencies above 31.5 Hz.According to the obtained effi-ciency and the very low cost of the recycled materials,this solution can be considered as a competitive vibration countermeasure.
文摘Driving safety is of significance in the automobile industry and transportation systems. Pavement skid resistance has long been recognized as the most important parameter in reducing traffic accidents especially in wet conditions. The knowledge of the friction coefficient and skid resistance is very valuable information for safety enhancement of roads. Thus, it is important to find proper methods for measuring skid resistance and frictional properties of the pavement surface. There is a wide range of measurement methods and devices for measuring skid resistance. This paper presents a review on the research studies that have been done on characterization of the frictional properties of the pavement surface and discussed methods used for measurement and evaluation of texture characteristics and the strengths and weaknesses of these methods. Finally, some ideas have been suggested to develop new methods for better and proper measurement of skid resistance.
