The uneven distribution of the temperature field in the track structure,caused by various meteorological factors such as extremely low temperatures and snowfall,leads to significant temperature loads and is the primar...The uneven distribution of the temperature field in the track structure,caused by various meteorological factors such as extremely low temperatures and snowfall,leads to significant temperature loads and is the primary cause of damage to China Railway Track System(CRTS)Ⅲ ballastless tracks in cold regions during service.In this study,to predict the temperature of the track structure accurately,we analyzed meteorological data collected from Shenyang,China,and identified the factors that had the most effect on the track temperature field.We propose a temporal convolutional network(TCN)-based temperature field prediction model for ballastless tracks(TCN-Track model),which enhances the ability to extract and fuse local and global features from complex long-term meteorological data.The results indicate that the proposed TCN-Track model performs well in predicting track temperature fields from meteorological data,with a mean absolute error(MAE)ranging from 0.26 to 0.39,a root mean square error(RMSE)ranging from 0.32 to 0.50,and correlation coefficient(R)values ranging from 0.888 to 0.985.Compared with a long short-term memory(LSTM)model,the MAE of the TCN-Track model is reduced by 89.17%and the RMSE by 88.51%.This method offers a new solution for accurately predicting the temperature field of ballastless tracks in cold regions,aiding in predicting and preventing track damage caused by low temperatures.展开更多
In summer,unpredictable arching of the track slab frequently occurs in the CRTS II slab track system.This paper proposes a'weak longitudinal connection'method to release the internal temperature stress.A finit...In summer,unpredictable arching of the track slab frequently occurs in the CRTS II slab track system.This paper proposes a'weak longitudinal connection'method to release the internal temperature stress.A finite element model of the track structure,with unlocking and relocking connections on bridges was established.The mechanical properties of the track slab with weak longitudinal connections are analyzed in terms of strength,stiffness,and stability.Field tests were conducted,and the results indicate that when the temperature difference between locking and unlocking is within 5℃,the joints can be directly released.It is recommended to unlock the track slabs without loosening the rail fasteners.When the unlocking and relocking plate temperatures are 20 and 25℃,respectively,the compressive strength of the track slab and base plate meets safety requirements.After a weak longitudinal connection,the track will not experience vertical instability under high temperature conditions.The compressive failure of the track structure occurs earlier than the vertical instability failure of the track slab.Field construction tests show that the longitudinal displacement of the track slab during unlocking and relocking is almost unchanged,with a difference of about 0.1 mm.There will be no interlayer gaps between the track slabs due to construction.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52278461,52308467,and 52425213).
摘要The uneven distribution of the temperature field in the track structure,caused by various meteorological factors such as extremely low temperatures and snowfall,leads to significant temperature loads and is the primary cause of damage to China Railway Track System(CRTS)Ⅲ ballastless tracks in cold regions during service.In this study,to predict the temperature of the track structure accurately,we analyzed meteorological data collected from Shenyang,China,and identified the factors that had the most effect on the track temperature field.We propose a temporal convolutional network(TCN)-based temperature field prediction model for ballastless tracks(TCN-Track model),which enhances the ability to extract and fuse local and global features from complex long-term meteorological data.The results indicate that the proposed TCN-Track model performs well in predicting track temperature fields from meteorological data,with a mean absolute error(MAE)ranging from 0.26 to 0.39,a root mean square error(RMSE)ranging from 0.32 to 0.50,and correlation coefficient(R)values ranging from 0.888 to 0.985.Compared with a long short-term memory(LSTM)model,the MAE of the TCN-Track model is reduced by 89.17%and the RMSE by 88.51%.This method offers a new solution for accurately predicting the temperature field of ballastless tracks in cold regions,aiding in predicting and preventing track damage caused by low temperatures.
基金The National Natural Science Foundation of China(Nos 52378454,52508510,and 52408486)the Natural Science Foundation of Hebei Province,China(Nos E2024210065,E2022210086)+1 种基金The Research Project of National Railway Administration of China(No.KF2024-052)he Science and Technology Development Project of China Railway Design Group Co.,Ltd(No.2023A0203603).
摘要In summer,unpredictable arching of the track slab frequently occurs in the CRTS II slab track system.This paper proposes a'weak longitudinal connection'method to release the internal temperature stress.A finite element model of the track structure,with unlocking and relocking connections on bridges was established.The mechanical properties of the track slab with weak longitudinal connections are analyzed in terms of strength,stiffness,and stability.Field tests were conducted,and the results indicate that when the temperature difference between locking and unlocking is within 5℃,the joints can be directly released.It is recommended to unlock the track slabs without loosening the rail fasteners.When the unlocking and relocking plate temperatures are 20 and 25℃,respectively,the compressive strength of the track slab and base plate meets safety requirements.After a weak longitudinal connection,the track will not experience vertical instability under high temperature conditions.The compressive failure of the track structure occurs earlier than the vertical instability failure of the track slab.Field construction tests show that the longitudinal displacement of the track slab during unlocking and relocking is almost unchanged,with a difference of about 0.1 mm.There will be no interlayer gaps between the track slabs due to construction.