The Patchway rail tunnels in Bristol were a major obstacle to the £3 billion electrification of the Great Western railway between London and south Wales, completed in December 2019. The tracks in the three nineteenth-century brick-arch tunnels needed to be lowered to provide the required clearances for new overhead line equipment. Extensive surveys, stability analyses and strengthening measures were undertaken to ensure structural integrity was maintained during the track lowering. An overhead conductor bar was developed specifically for the tunnels to reduce the lowering required. Further innovation included specially adapted drilling rigs to enable the efficient installation of tunnel fixings. This paper focuses on the civil engineering aspects of the project, with an overview of the electrification design to demonstrate how the overall integrated solution was achieved.

中文翻译：

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英国大西部铁路电气化：修补通道

布里斯托尔的Patchway铁路隧道是伦敦和南威尔士之间耗资30亿英镑的大西部铁路电气化的主要障碍，该铁路已于2019年12月完工。需要降低19世纪三个砖砌拱形隧道中的轨道，以提供新架空线设备所需的间隙。进行了广泛的调查，稳定性分析和加强措施，以确保在降低轨道的过程中保持结构完整性。专为隧道开发了架空导体条，以减少所需的降低。进一步的创新包括专门改装的钻机，可有效安装隧道固定装置。本文侧重于该项目的土木工程方面，