Stress Analysis of the Foundation of Transmission Tower-Line System under Wind Load

To study the force of foundation of the transmission tower-line system under wind load, refined finite element models of the transmission tower-line system and the foundation were established. First, the wind load time history of the transmission tower-line system was simulated. The response of the structure was calculated by the dynamic analysis method and a comprehensive assessment of the ultimate wind-resistant bearing capacity of the transmission line was conducted. The force of the foundation of the transmission tower line system under the action of wind load was obtained. The force was applied to the foundation and the dynamic analysis of the pile foundation was conducted based on the reaction time history of the dangerous foundation, then the crack form of the foundation was predicted through the index of main tensile stress of the concrete foundation. The results show that the first 228 modes of the three-tower and two-line system are all vibrations of the ground line, and then the tower body will vibrate in the vertical direction; under wind loads, the tower legs on the windward side of the transmission tower are weaker; under the wind speed of 40m/s, the maximum main tensile stress of the pile foundation concrete is at the edge of the anchor bolt, which is close to the cracking strength of the concrete; when the pile foundation is tensioned, the stress distribution of the local concrete around a single anchor bolt forms a cone shape. After the stress is superimposed, a large stress ring area is formed on the surface of the foundation. When the concrete is tensioned and cracked, it will be damaged in the form of a cone. The force analysis results of the transmission tower foundation under wind load show the more dangerous parts of the foundation and provide theoretical guidance for the design and reinforcement of the foundation in the project.