针对成昆铁路峨攀段K279发生的崩塌落石灾害，首先，采用Rockfall软件进行落石轨迹及冲击动能分析，评定落石对铁路的危害程度。然后，根据冲击动能计算结果确定坡面帘式防护网的设置范围及被动网和其他防护措施的设置，根据落石影响范围确定明洞接长范围。对于接长明洞，结合现场地形，提出在铁路运营期间增设明洞时采用明洞内外边墙现浇、明洞拱圈预制拼装的方案。最后，介绍明洞内外边墙现浇、明洞拱圈预制拼装方案的设计及施工情况。根据最终的整治效果可知，采用预制拼装式明洞结构方案可安全快速地在既有线增设明洞结构。

In view of the collapse and rockfall disaster occurred in the K279 section of the EmeiPanzhihua section of the ChengduKunming railway, the Rockfall software is employed to analyze the rockfall trajectory and impact kinetic energy and assess the damage degree of rockfall to the railway. Furthermore, based on the calculation results of impact kinetic energy, the setting range of the slope curtain protection net and the setting of the passive net and other protective measures are determined, and the extension range of the opencut tunnel is determined based on the impact range of falling rocks. For the extension of the opencut tunnel, an innovative proposal that use the castinplace inner and outer walls of the opencut tunnel and the prefabricated assembly of the opencut tunnel arch ring when adding an opencut tunnel during railway operation is proposed based on the onsite terrain. Finally, the design and construction of the castinplace inner and outer walls of the opencut tunnel and the prefabricated assembly plan of the opencut tunnel arch ring are introduced. According to the final rectification effect, the use of prefabricated and assembled opencut tunnel structures can safely and quickly add opencut tunnel structures to existing lines.