The hotspot recognition algorithm is proposed based on a potential collision in order to study the aircraft taxi conflicts in large airports.The spatial and temporal distribution characteristics of hotspots are analyz...The hotspot recognition algorithm is proposed based on a potential collision in order to study the aircraft taxi conflicts in large airports.The spatial and temporal distribution characteristics of hotspots are analyzed based on the risk assessment model of hotspot constructed in this paper.Firstly,approaches for monitoring of the aerodrome movement were compared.The hotspot recognition algorithm taken into account of whether aircrafts'taxi track has spatial and temporal overlap based on the aerodrome surveillance radar(ASR)data was presented,by identifying the hotspots through analyzing whether the aircrafts'time of entering and exiting the same taxiway is overlap or not,and the heading difference and distance of the two aircrafts satisfy the specified threshold constraint condition.Then,the ASR data were divided into several parts,and then airport hotspots were recognized and the spatial and temporal distribution characteristics were analyzed.The risk assessment model of airport safety hotspots was constructed which is taken into account of the conflict probability and its severity consequence.Finally,based on the risk grade assessment criteria and hotspots'risk value,the risk grade ranking of hotspot in one airport of China was evaluated and designated.According to the result,the spatial and temporal distribution characteristics of airport hotspots were varied with the variation of airport traffic flow and operational mode of runway,which shows that the hotspots have the characteristics of dynamic periodicity and diurnal variation.And the risk assessment results were consistent with experts'opinions and actual operation condition,which verified the rationality of the hotspot recognition algorithm,risk assessment model as well as the risk grade ranking criteria.展开更多
Pavements of airport runway and apron are subjected to stern stresses imposed by landing and ground movements of aircraft. The stresses are primarily concentrated in touchdown zone and wheel path areas of the pavement...Pavements of airport runway and apron are subjected to stern stresses imposed by landing and ground movements of aircraft. The stresses are primarily concentrated in touchdown zone and wheel path areas of the pavement structure. This paper proposes that this area can be designed using geosynthetic layer reinforcement to minimise deflection and deterioration of the structure. The reinforcement can reduce the vertical stresses on the underground fuel pipes in the apron area, if used. The concept of ditch conduit reinforcement is suggested where a geosynthetic layer is used within a soil backfill to redistribute load over a conduit leading to stress redistribution. It is observed that the vertical load is significantly reduced by the arching action of the soil mass overlying the conduit. The load can be reduced further by placing a geosynthetic reinforcement layer within the soil backfill above the conduit. It is suggested that the inclusion of a geosynthetic layer in the granular backfill reduces the vertical load on a ditch conduit and the amount of reduction depends upon the tensile modulus, deflection of the geosynthetic and soil arching action. This leads to believe that a reinforced pavement structure for runway and aerodrome apron area improves the load carrying capacity of the pavement to sustain the operations of heavy transport aircraft, including occasional overloading of the pavement. Hence, this paper explores a possibility of using a geosynthetic layer under the runway pavement to provide reinforcement.展开更多
基金the Joint Funds of the National Science Foundation of China and the Civil Aviation Administration(Nos.U1733105 and U1733203)the Sichuan Science and Technology Program(No.2019YFG0308)
文摘The hotspot recognition algorithm is proposed based on a potential collision in order to study the aircraft taxi conflicts in large airports.The spatial and temporal distribution characteristics of hotspots are analyzed based on the risk assessment model of hotspot constructed in this paper.Firstly,approaches for monitoring of the aerodrome movement were compared.The hotspot recognition algorithm taken into account of whether aircrafts'taxi track has spatial and temporal overlap based on the aerodrome surveillance radar(ASR)data was presented,by identifying the hotspots through analyzing whether the aircrafts'time of entering and exiting the same taxiway is overlap or not,and the heading difference and distance of the two aircrafts satisfy the specified threshold constraint condition.Then,the ASR data were divided into several parts,and then airport hotspots were recognized and the spatial and temporal distribution characteristics were analyzed.The risk assessment model of airport safety hotspots was constructed which is taken into account of the conflict probability and its severity consequence.Finally,based on the risk grade assessment criteria and hotspots'risk value,the risk grade ranking of hotspot in one airport of China was evaluated and designated.According to the result,the spatial and temporal distribution characteristics of airport hotspots were varied with the variation of airport traffic flow and operational mode of runway,which shows that the hotspots have the characteristics of dynamic periodicity and diurnal variation.And the risk assessment results were consistent with experts'opinions and actual operation condition,which verified the rationality of the hotspot recognition algorithm,risk assessment model as well as the risk grade ranking criteria.
文摘Pavements of airport runway and apron are subjected to stern stresses imposed by landing and ground movements of aircraft. The stresses are primarily concentrated in touchdown zone and wheel path areas of the pavement structure. This paper proposes that this area can be designed using geosynthetic layer reinforcement to minimise deflection and deterioration of the structure. The reinforcement can reduce the vertical stresses on the underground fuel pipes in the apron area, if used. The concept of ditch conduit reinforcement is suggested where a geosynthetic layer is used within a soil backfill to redistribute load over a conduit leading to stress redistribution. It is observed that the vertical load is significantly reduced by the arching action of the soil mass overlying the conduit. The load can be reduced further by placing a geosynthetic reinforcement layer within the soil backfill above the conduit. It is suggested that the inclusion of a geosynthetic layer in the granular backfill reduces the vertical load on a ditch conduit and the amount of reduction depends upon the tensile modulus, deflection of the geosynthetic and soil arching action. This leads to believe that a reinforced pavement structure for runway and aerodrome apron area improves the load carrying capacity of the pavement to sustain the operations of heavy transport aircraft, including occasional overloading of the pavement. Hence, this paper explores a possibility of using a geosynthetic layer under the runway pavement to provide reinforcement.
