| With the rapid economic development in our country,electricity plays an increasingly important role in people’s life.As the most important medium of electric power transmission,transmission lines have been exposed to complex environments in the wild for a long time.They often suffer from the destruction of natural factors.Transmission lines are disconnected and down accidents occur from time to time.Therefore,it is of great practical significance to study and analyze the influence of wind load on the transmission tower-base system.In this paper,a transmission tower-the basic system for the study,the main research carried out the following:First of all,based on the actual project,the finite element software ABAQUS is used to establish the transmission pole model.Taking full account of the coupling effect between transmission pole and pole,this paper takes the "one pole two lines" model as an example to study the influence of pole-bar coupling system on the dynamic characteristics of power transmission pole.The results show that the bending stiffness of the steel bar is equivalent in both horizontal directions.The steel bar has more flexibility than the general transmission tower.In the process of structural static-dynamic performance analysis,the influence of conductor on the performance of the tower must be fully considered.Secondly,based on the related theory of soil excavation,a transmission tower-foundation model is established.The stress and deformation of transmission tower and foundation system under different excavation depths are analyzed.The influence of excavation depth and excavation distance on the structure system is also discussed.The results show that when the excavation depth is deeper,the greater the lateral displacement of the pile top,the greater the axial stress of the pile body.When the excavation distance is larger,the lateral displacement of pile top is smaller.Then,based on the theory of static wind load correlation,a finite element model of static wind loads acting on transmission towers and foundations is established.From the perspectives of excavation method,soil quality,excavation distance and direction of wind load,the changing trend of axial stress and lateral displacement of transmission tower-foundation system under different operating conditions are discussed respectively.The results show that the stability of the soil under both sides of transmission tower and the foundation system is the worst.When the elastic modulus of the soil is larger,the resistance of the transmission tower to the foundation system is worse.x)Excavation of foundation pit under direction wind load is more prone to damage.Finally,based on the theory of pulsating wind loads,a finite element model of the power-transmission tower-foundation system is established.The wind-induced response of the power transmission pole is studied and the results of static wind load and dynamic wind load time history are compared.The results show that under the action of pulsating wind loads,the buckling instability of the transmission tower-foundation system will not happen,and the strength yielding will occur first and then the structure will undergo plastic deformation failure.Under the action of pulsating wind load,the foundation of the transmission tower-base system Part of the more static wind load more easily destroyed. |
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