Research On Key Parameters Of Vehicle And Tunnel Under Heavy Load Train Action

Heavy rail transport is featured by high efficiency,strong transport capacity,energy saving and environmental protection,and low transport cost,which has attracted wide attention around the world.In today’s international transport market,heavy rail transport has become one of the main forms of freight transport.In recent years,China has made great progress in railway development.Some heavy goods vehicle railways have been built and the axle load of trains has increased.The train.However,when the train load increases,the mutual vibration between the train and the line will be more intense,which will lead to more significant elastic-plastic deformation of the tunnel structure,and the tunnel base is prone to cracking,damage and other diseases,which cannot guarantee the safety of the train operation.On the basis of the existing research results,according to the vibration response method,the basic structure of the heavy railway tunnel design,the foundation of the tunnel is not perfect,and often in cracks and damage in the process of operation.In view of the form of load,axle load train running speed and flow,density and other factors,the dynamic load on the heavy railway tunnel in different parts of the different,resulting in the distribution of internal forces is also very different.Therefore,it is crucial to explore the stress distribution of heavy railway construction infrastructure,analyze the dynamic response rules of the design parameters of the basic structure,and emphasize the reasonable design parameters of the basic structure of heavy transport tunnel and the basic structure of disease prevention measures.The research content of this thesis is as follows:(1)Three methods are usually used to obtain train dynamic load,namely,field measurement,artificial excitation force function simulation and train-track coupling simulation.In this thesis,artificial excitation force function is used to simulate moving load.The tunnel model is drawn by FLAC simulation software,and the vibration characteristics of the tunnel under the action of heavy load train are analyzed.(2)Aiming at heavy-haul railway tunnel,the vibration characteristics of surrounding rock structure are analyzed by the method of dynamic and static combination.In view of the most severely damaged basement structure,the displacement and dynamic stress distribution laws of different measuring points were compared,and more detailed basement vibration characteristics were obtained.(3)According to different vehicle parameters such as axle load,vehicle speed,base structure parameters such as vector span ratio,filling layer thickness,invert thickness and floor thickness,the vibration characteristics of heavy haul railway tunnel structure under the action of various parameters were obtained.(4)The sensitivity analysis was carried out on the factors of axle weight and train speed,and the four factors of pavement thickness,filling layer thickness,invert thickness and sagittal span ratio,so as to determine the maximum influencing factors and provide the basis for tunnel design and construction and disease prevention.