特高压单柱拉线塔的静力稳定性分析

拉线塔在地广人稀的地区具有性价比优势，对于特高压拉线塔，受到的载荷变大，结构尺寸也变大，需要进行稳定性的分析。针对特高压单柱拉线塔的静力稳定性问题，建立拉线的分析模型，定义并推导出拉线的等效弹性模量以及拉线临界初应力的公式，将拉线塔的主柱简化成顶端为弹簧铰支座、底端为固定铰支座的压杆，推导出弹簧的弹性刚度与主柱的计算长度系数的公式；研究了不同风荷载以及不同拉线初始预应力的情况下计算长度系数的变化规律。研究结果表明：在拉线预应力保持不变的条件下，风速越大，计算长度系数越大；在风速保持一定的条件下，拉线的初始预应力越大，计算长度系数越小；预应力超过临界初应力时，主柱的计算长度系数不再减小且恒为1。可见将拉线的初始预应力设置为大于等于临界初应力可提高拉线塔的稳定性，拉线的临界初应力可以作为实际施工的参考。

Static Stability Analysis of UHP Single Column Cable Tower

Guyed tower have a cost-effective advantage in sparsely populated areas. The ultra-high voltage (UHV) guyed towers are subjected to larger loads and larger structural dimensions, so stability analysis is required. For stay static stability problem of the UHV single column tower, established analysis model of stay wire. The equivalent elastic modulus of stay wire and the formula of critical initial stress of stay wire were defined and deduced. Main column was simplified into a compression bar with spring hinge support at the top and fixed hinge support at the bottom. Formulas of the elastic stiffness of the spring and the effective length coefficient of the main column were derived. The variation law of calculated length coefficient under different wind loads and initial prestress of stay wire was studied. The result shows that when the prestress of stay wire remains constant, the greater the wind speed, the greater the calculated length factor; When the wind speed remains constant, the greater the initial prestress, the smaller the calculated length coefficient; When the prestress of stay wire exceeds the critical initial stress, calculated length coefficient does not decrease and is always 1. Setting the initial prestress to be greater than or equal to the critical initial stress can improve the stability of guyed tower. The critical initial stress of stay wire can be used as a reference for actual construction.