The estimation of the disturbance input acting on a vehicle from its given responses is an inverse problem.To overcome some of the issues related to ill-posed inverse problems,this work proposes a method of reconstruc...The estimation of the disturbance input acting on a vehicle from its given responses is an inverse problem.To overcome some of the issues related to ill-posed inverse problems,this work proposes a method of reconstructing the road roughness based on the Kalman filter method.A half-car model that considers both the vehicle and equipment is established,and the joint input-state estimation method is used to identify the road profile.The capabilities of this methodology in the presence of noise are numerically demonstrated.Moreover,to reduce the influence of the driving speed on the estimation results,a method of choosing the calculation frequency is proposed.A road vibration test is conducted to benchmark the proposed method.展开更多
China's urban development is very fast,and the continuous improvement of the national economic level in recent years has also prompted most families to have their own scooters.In this situation,the increase and tr...China's urban development is very fast,and the continuous improvement of the national economic level in recent years has also prompted most families to have their own scooters.In this situation,the increase and transformation of road traffic has been a necessary work for the development of various regions.This paper starts with the basic reasons for the design of new and improved interchanges,and expounds the specific design type division and main influencing factors.Finally,the paper puts forward the design strategy of newly added and reconstructed interactive interchanges with high feasibility,hoping to provide reasonable reference for relevant road traffic engineering optimization.展开更多
The article presents Polish experience with cold recycling of asphalt pavements with the usage of bituminous emulsion and cement. In the 1990 s numerous roads in Poland required immediate reinforcement due to their si...The article presents Polish experience with cold recycling of asphalt pavements with the usage of bituminous emulsion and cement. In the 1990 s numerous roads in Poland required immediate reinforcement due to their significant degradation. Implementation of the cold recycling technology was one of the solutions to this problem. Cold recycled mixtures contain e beside the recycled asphalt pavement and aggregate e two different types of binding agents: bituminous emulsion and Portland cement. First Polish requirements were developed in the 1990 s and were based on the Marshall test. After several years of application of these requirements, numerous transverse cracks appeared on the pavements. Field investigation showed that the frequency of transverse cracking was not uniform on all evaluated sections and that the growth rate of the number of cracks was decreasing. The main reason of extensive cracking was the overly high amount of the Portland cement and insufficient amount of the bituminous emulsion. This led to production of very stiff mixtures, with dominance of hydraulic bonds, which behaved similarly to cement-treated mixtures. The idea of flexible cold recycled base course was not utilized. This experience motivated the Polish Road Administration to develop new requirements. Second part of the article presents the new requirements for cold recycling.New test methods as well as requirements concerning resistance to frost and water action were introduced in 2013. Implementing of the new requirements resulted in significant reduction in stiffness of the MCE mixtures. Values of stiffness modulus are even three times lower, which should significantly decrease the amount of potential reflective cracks on the pavement surface. Presently two types of technology of cold recycling are used in Poland, in-place and in-plant.展开更多
基金This work was supported by the Natural Science Foundation of Shaanxi Province(Grant No.2021KW-25)the Astronautics Supporting Technology Foundation of China(Grant No.2019-HT-XG)the Fundamental Research Funds for the Central Universities(Grant No.3102018ZY015).
文摘The estimation of the disturbance input acting on a vehicle from its given responses is an inverse problem.To overcome some of the issues related to ill-posed inverse problems,this work proposes a method of reconstructing the road roughness based on the Kalman filter method.A half-car model that considers both the vehicle and equipment is established,and the joint input-state estimation method is used to identify the road profile.The capabilities of this methodology in the presence of noise are numerically demonstrated.Moreover,to reduce the influence of the driving speed on the estimation results,a method of choosing the calculation frequency is proposed.A road vibration test is conducted to benchmark the proposed method.
文摘China's urban development is very fast,and the continuous improvement of the national economic level in recent years has also prompted most families to have their own scooters.In this situation,the increase and transformation of road traffic has been a necessary work for the development of various regions.This paper starts with the basic reasons for the design of new and improved interchanges,and expounds the specific design type division and main influencing factors.Finally,the paper puts forward the design strategy of newly added and reconstructed interactive interchanges with high feasibility,hoping to provide reasonable reference for relevant road traffic engineering optimization.
基金supported by the project RID-1A (DZP/ RID-I-06/1/NCBR/2016) financed by the National Center for Research and Development and the General Directorate for National Roads and Motorways under the program “Development of Road Innovations”
文摘The article presents Polish experience with cold recycling of asphalt pavements with the usage of bituminous emulsion and cement. In the 1990 s numerous roads in Poland required immediate reinforcement due to their significant degradation. Implementation of the cold recycling technology was one of the solutions to this problem. Cold recycled mixtures contain e beside the recycled asphalt pavement and aggregate e two different types of binding agents: bituminous emulsion and Portland cement. First Polish requirements were developed in the 1990 s and were based on the Marshall test. After several years of application of these requirements, numerous transverse cracks appeared on the pavements. Field investigation showed that the frequency of transverse cracking was not uniform on all evaluated sections and that the growth rate of the number of cracks was decreasing. The main reason of extensive cracking was the overly high amount of the Portland cement and insufficient amount of the bituminous emulsion. This led to production of very stiff mixtures, with dominance of hydraulic bonds, which behaved similarly to cement-treated mixtures. The idea of flexible cold recycled base course was not utilized. This experience motivated the Polish Road Administration to develop new requirements. Second part of the article presents the new requirements for cold recycling.New test methods as well as requirements concerning resistance to frost and water action were introduced in 2013. Implementing of the new requirements resulted in significant reduction in stiffness of the MCE mixtures. Values of stiffness modulus are even three times lower, which should significantly decrease the amount of potential reflective cracks on the pavement surface. Presently two types of technology of cold recycling are used in Poland, in-place and in-plant.
