输电铁塔强震抗灾能力分析

为评价输电铁塔在强震作用下的抗灾能力，以实际地震记录作为地震输入，采用直接动力法分析了1基500 kV双回路典型铁塔在地震作用下的承载能力。分析结果表明：在基本设防烈度下，典型杆塔的地震作用荷载效应一般低于非地震作用的荷载效应，具有较好的抗震能力；在强震情况下，地震作用的荷载效应超出了杆塔的承载和变形能力。对于大跨越等抗灾能力要求很高的输电线路杆塔，建议设置更高的抗震设防目标，考虑强震作用下抗震性能设计；同时，对于横担悬臂较长的杆塔，抗震验算时应考虑竖向地震作用的影响。

Anti-Disaster Capability of Power Transmission Tower under Strong Earthquake

In order to evaluate the anti-disaster capability of power transmission tower under strong earthquake, the direct dynamic method was used to analyze the load bearing capacity under earthquake for a typical power transmission tower of 500 kV double-circuit lines by taking real earthquake record as the seismic input. The results show that the load impact on tower with the basic fortification intensity under earthquake is generally smaller than that of non-seismic actions, which means tower has good anti-seismic capability. However, the seismic impact of rare strong earthquake exceeds the load bearing and deformation capacity of typical towers. So, it is suggested that the power transmission towers, such as those for large-crossings, which demand highly for anti-disaster capability, should impose higher anti-seismic requirements and consider anti-seismic design under strong earthquake. Meanwhile, the impact of vertical earthquake should be considered in the seismic checking calculation of tower with long cross-arm cantilever.