±800 kV悬索拉线塔静力稳定性研究

针对±800 k V悬索拉线塔立柱的静力稳定性问题,首先基于广义变分原理推导斜拉线的等效弹性模量公式,然后根据应变能相等得到了立柱的等效截面属性,再根据悬索拉线塔立柱的受力特点,将其简化为下端铰接、上端弹性支撑的等截面压杆,最后基于压杆稳定理论得到拉线塔立柱的计算长度系数μ与初始预拉力和风速的关系.研究结果表明:背风侧立柱在垂直线路方向以及迎风侧立柱的静力计算长度系数可取值为1;风荷载及初始预拉力对背风侧立柱沿线路方向的静力计算长度系数有较大的影响,当初始预拉力较小时,其静力计算长度系数随风速的增大而迅速地增大,但当初始预拉力超过某值之后,背风侧立柱的静力计算长度系数受风速的影响较小.

Research on Static Stability of ±800kV Suspension Cable Guyed Tower

To solve the problem of static stability of ±800 kV suspension cable guyed tower， equivalent elastic modulus formula of suspension cable is firstly derived based on the generalized variational principle. Then according to the strain energy， the equivalent column attributes of equivalent cross section are obtained. According to the force characteristics of suspension cable guyed tower column， it is simplified to the bar with uniform cross section which is hinged at the bottom and is supported elastically at the top. Finally， based on compressive bar stability theory， the relationship of calculation length coefficient of guyed tower column is got， the initial pretension and wind speed. The study results show that the static calculated length coefficient of column in windward side and column in leeward side along vertical transmission line direction is one， wind load and initial pretension have great impact on static calculated length coefficient of column in leeward side along transmission line， which rapidly increases with an increase in wind speed when initial pretension is lesser， but wind speed has a minor effect on it when initial pretension exceeds a certain value.