Effect of occluding hills on Wind-Induced Fatigue of Transmission Tower-Line Coupled System
Zhang Chuntao1 Li Zhengliang1, 2 Fan Wenliang1, 2 Wang Zhisong1, 2 Sun Yi1
1. School of Civil Engineering, Chongqing University, Chongqing 400045, China; 2. Key Laboratory of New Technology for Construction of Cities in Mountain Area (Chongqing University), Ministry of Education, Chongqing 400045, China
Abstract:In hilly terrain, the characteristics of wind field are distinct from the flat terrain wind field due to the interference of occluding hills, which make the wind-induced response of structures to be affected significantly. In this work, according to three kinds of different occluding hill terrains, the wind field of interfered hills is researched by the wind tunnel test. The effects of varies of different conditions are considered in the research, such as 5 different slopes of occluding hills, 3 different heights of occluding hills, and 5 kinds of occlusion distances between occluding hills and interfered hills. The rules of effects on the wind field of interfered hills by occluding hills are obtained. Furthermore, the joint statistical probability for both wind direction and wind speed is calculated by analyzed the record data. Meanwhile, the method for calculating the wind-induced fatigue of transmission tower-line coupled system is proposed by combined with the joint statistical probability and the time domain and frequency domain fatigue cumulative damage rules. At last, based on the proposed method and test data, the wind-induced fatigue of ultra-high voltage transmission tower-line coupled system is also studied. It can be found that the fatigue life of transmission tower is increased firstly and then decreased with the increasing slopes of occluding hills, and the fatigue life at hill base in lee side is shortest; the height of occluding hill has little effect on the fatigue life when the slope isn’t changed; the occlusion distance is shorter and the fatigue is also shorter, but the life is gradually becoming longer when the occlusion distance is increased.