Abstract:
In this study, methods for maintenance of transmission towers were determined based on the investigated results from surveying of the existing towers and by collecting maintenance data from the Electricity Generating Authority of Thailand (EGAT). The field areas were divided to industrial area, city area, rural I area and rural I1 area in order to determine the characteristics and causes of the tower damage. The data from fields surveying were used to determine the relationship between rust level and age of tower. Results of the study showed that rust of the tower tend to mostly occur in the industrial area. Severe corrosion was found at the stubs. Step-bolts, ladders and member joints were also found to be more corrosive than other members. Some tower foundations had high settlement. Furthermore, some members in the lower part of the tower were deformed or lost. The location, environment, topography, climate, constmction process, transportation method, unsuitable storage and human act for examples could cause the damages. This research offers the protective and maintained means of the transmission tower. It setups the method for maintenance by dividing to basic and elaborating investigation. This could extend the lifetime of the towers and can be used to develop the standard for tower design in the future.