This study investigated the seismic responses, earthquake failure modes, and collapse fragility of a 1000 kV outgoing line frame (OLF1000, a supporting-equipment structure used in substations), by considering the interactions in the tower line system (ITLS). First, three analytical models of the OLF1000 were established, in which transmission lines were represented as massless springs based on their dynamic stiffness, and the lattice transmission tower was simplified to an elastic beam tower. Additionally, 40 real seismic records with similar spectral characteristics were used to analyze the seismic responses of the OLF1000 by considering the ITLS under minor, moderate, major and extremely major earthquakes. Moreover, a time history analysis was carried out to investigate the failure modes, and the collapse risk of the OLF1000 was considered from a probabilistic perspective. According to our results, the OLF1000 remains mostly elastic under minor and moderate earthquakes, as the energy consumption and elastic constraints of the transmission lines reduce the seismic response of the OLF1000. However, amplification of excitations by the transmission tower increases the previously reduced responses. Additionally, in the case of major and extremely major earthquakes, when considered in isolation, the OLF1000 remains intact or is only slightly damaged, but it becomes seriously damaged and can even collapse when the ITLS is considered. Furthermore, the failure mode of the OLF1000 is that of an in-plane global collapse, whereas the inclusion of the ITLS in the model suggests that an out-of-plane continuous collapse will be caused by a local failure. The ITLS significantly reduces the collapse load of the OLF1000. Finally, the ITLS substantially increases the probability of collapse of the OLF1000 under strong earthquakes.

这项研究通过考虑塔架线系统（ITLS）的相互作用，研究了1000 kV出线框架（OLF1000，变电站中使用的支撑设备结构）的地震响应，地震破坏模式和坍塌脆弱性。首先，建立了OLF1000的三种分析模型，其中基于其动态刚度将传输线表示为无质量弹簧，并将晶格传输塔简化为弹性梁塔。此外，考虑到ITLS在小地震，中地震，大地震和特大地震下的影响，使用了40个具有相似频谱特征的真实地震记录来分析OLF1000的地震响应。此外，还进行了时程分析以研究故障模式，从概率的角度考虑了OLF1000的崩溃风险。根据我们的结果，由于能量消耗和传输线的弹性约束降低了OLF1000的地震响应，OLF1000在小地震和中度地震下仍保持弹性。但是，输电塔对激励的放大会增加以前减小的响应。此外，在发生大地震和极大地震的情况下，如果将其单独考虑，OLF1000会保持完整或仅受到轻微破坏，但考虑到ITLS时，它将变得严重破坏甚至崩溃。此外，OLF1000的故障模式是面内全局崩溃，而在模型中包含ITLS则表明平面外连续崩溃将由局部故障引起。ITLS大大降低了OLF1000的崩溃负荷。最后，ILS大大增加了OLF1000在强地震下倒塌的可能性。