## 1 Introduction
[22] analyzed the wind-induced vibration response of the transmission tower-line system, identifying locations of potential collapse and assessing the safety of the transmission tower under wind loads. [PERSON] et al. [23] conducted a four-year field observation on a transmission tower in southern England, analyzing a large amount of measured data to study the effects of wind loads on the forces at the base of the transmission tower foundation. Fire is one of the most frequent and devastating natural hazards, often causing significant direct economic losses that can exceed those from earthquakes, and is one of the more common natural disasters [24]. The mechanical properties of steel are significantly influenced by temperature, with its strength and elastic modulus varying at different temperatures. When the temperature reaches the melting point, the material's strength and elastic modulus approach zero. Many scholars have studied the mechanical properties of different steel structures and steel components under fire conditions. [PERSON] et al. [25]conducted fire tests on a 36 m \(\times\) 12 m portal steel frame and found that asymmetric fires caused the frame to collapse out of the plane. [PERSON] et al. [PERSON] et al. (2018) proposed a calculation method for the internal forces and deflections of steel frame beams under fire conditions, using this method to analyze the impact of different initial restraint conditions on the results. [PERSON] et al. [PERSON] et al. (2018) carried out fire tests on steel frame structures and observed that the structure experienced a reverse arching effect, which was highly detrimental to the integrity of the frame. [PERSON] et al. [PERSON] et al. (2018) performed a spread fire test on a two-story steel frame structure, revealing that steel components affected by the spread fire exhibited a different temperature increase pattern compared to previous studies, requiring three distinct stages: heat-up due to diffusing hot gases, direct fire heating, and cooling. [PERSON] et al. [PERSON] et al. (2018) studied the fire resistance of Q460 steel beams using the equivalent stiffness method, proposing a simplified method to predict the critical temperature of Q460 steel beams under non-uniform temperature distribution. [PERSON] et al. [PERSON] et al. (2018) investigated the effects of longitudinally non-uniform fires on steel columns, finding that the critical temperature of columns with longitudinally non-uniform heating was higher than that of uniformly heated columns. [PERSON] et al. [PERSON] et al. (2018), based on existing creep models and combined with steel column fire test data, proposed a time-dependent reinforced creep model for Q345 steel and the Norton creep model. [PERSON] et al. [PERSON] et al. (2018) suggested that the mechanical properties of steel columns at high temperatures are influenced by fire temperature, cooling methods, and fatigue strain amplitudes, and fitted fatigue life and cyclic stress-strain curves for Q690 high-strength steel based on experimental data. [PERSON] et al. [PERSON] et al. (2018) investigated the mechanical properties of steel columns under different ventilation conditions and fire locations, finding that localized fires caused uneven heating of the steel columns, with more pronounced temperature gradients on the cross-section as the distance from the fire source decreased. [PERSON] et al. [PERSON] et al. (2018), based on cross-sectional geometry and temperature gradients, proposed a new method to estimate the buckling load capacity of I-beams under fire conditions. [PERSON] et al. [PERSON] et al. (2018), considering the effects of fire temperature, load ratio, axial restraint stiffness ratio, slenderness ratio, and material strength, proposed a simplified method for calculating the residual load capacity of restrained steel columns after a fire. Although the performance of steel structures and steel components in fire has been extensively studied, research on transmission towers under fire conditions remains relatively scarce.