Investigation on Combined Wind Load Factors of Lattice Transmission Tower Body under the Action of Skewed Wind

In the current standards, wind loads on lattice transmission tower (LTT) bodies only account for the action of horizontal winds, which may not be suitable for an LTT under the action of extreme winds. The wind load coefficients of LTT bodies subjected the skewed wind with both horizontal and vertical components were measured via several well-designed wind tunnel tests. The test results and standard calculations of the skewed wind load factors (SWLF) at a wind attack angle of 0 degrees were compared and analyzed. A new parameter-combined wind load factor (CWLF) was introduced, and a suggested formula is proposed for it. The results showed that the standard-recommended formula was unable to accurately reflect the characteristics of SWLF, and its calculated results were significantly smaller than the test results, indicating that the actual wind loads were underestimated. The CWLF could correctly describe how wind load factors changed with the yaw angles or the attack angles. The CWLF effectively improved the calculation accuracy of the SWLF, and the absolute error between the calculations and test results under the critical yaw and attack angles was less than 7%.