Safety Assessment Of The Overall Structure Of Transmission Tower Under Damage

With the rapid development of social economy, energy is becoming the crux issue in the market. As a result, the electric power industry as the pillar industry of energy plays an important role in state economy development. The power transmission tower as the structure supporting the pillar industry shoulders an important mission as well. While due to its certain service environment, the power transmission tower could be damaged by strong breeze especially when it is long-crossing or high-rise. And the indirect and secondary disasters caused by its damage and collapse may lead to great losses of peoples'lives, economy and property. Therefore, it is important and urgent to do some instantaneous safety condition assessments for the global structure of active power transmission tower.Based on the integral structure model built up by predecessor, a new kind of finite element model of power transmission tower was set up in this paper considering the falling off of some bolts, instability and fracture of some members. As a result, the method of how to consider the structure damage of transmission tower by adjusting parameters was summed up. Owing to the uncertainty of damage locations and the inconsistency of damage, it is necessary to work out a complete set of finite element models regarding damages by changing rod parameters optionally.In this research, the wind load acting on transmission tower was divided into three kinds of common atmospheric boundary wind, do wnburst and typhoon. Among them, the first two kinds have been studied a lot before, while the last one just a little. Besides, the study status of typhoon at home and abroad was introduce, and a appropriate theoretical formula to describe the wind speed change approximately was found to make contribution to confirm wind load static effect of typhoon.As the safety problem of transmission tower has a significant influence on social development, a method of real-time safety evaluation was proposed in the paper, together with real-time security static analysis for the integral structure of existing transmission tower considering its damages. Some real-time safety analyses was done for several common damage conditions in this research, resulting in the conclusion that this safety assessment method is simple and practical for evaluating the safety of transmission.