Groundwater and Flood Risk in the London Rail Infrastructure Network: Building Resilience into Existing Masonry Infrastructure Assets

降水增加带来的环境危害给铁路运输基础设施所有者和运营商带来了更大的风险，因为更频繁的恶劣天气事件增加了洪水和相关地面条件问题造成的服务中断的范围和复发性。这是一个在事件发生期间和事件发生后立即出现的问题，因为服务会中断，在某些极端情况下，线路需要恢复，这对运营商来说是一个巨大的成本，比如2014年德力士线路崩溃后，网络铁路公司投资了350亿英镑用于恢复和改善工程（BBC新闻）。地下水波动和地下水位过高所造成的危害也使负责基础设施网络和资产的持续维护和复原力规划的人员不断感到关切。观察到的变化和潜在的润湿机制的进一步改变给基础设施运营商带来了未知的风险，同样，那些在基础设施开发中提供咨询服务的人已经确定需要增加他们对这些危害和风险的了解，以便继续向客户提供相关建议。然而，就历史结构而言，这些破坏性事件所涉及的物理过程尚未完全了解，此外，这些事件对网络弹性的长期影响尚未确定。虽然历史建筑就其持续存在的性质而言，显示出对极端气候事件的适应能力，但我们没有办法确定它们对特定严重条件的反应。实现这一目标，就可以通过分析此类事件发生频率变化对长期复原力的影响，准确预测未来的风险。考虑到行业确定需要在网络中建立弹性，这一点尤为重要；只有我们首先了解所需的额外缓解投资工作的程度，才能成功实现这一目标。该项目将利用UCL CEGE提供的技能和知识，分析历史基础设施组件隧道、堤防和高架桥在结构稳定性和运动方面对不断变化的地下水条件的响应，并适用于基础设施运行形成边界条件的公差。从与气候变化相关的湿度状况波动有关的历史基础设施资产的脆弱性将被量化。最后，利用网络维持其容量函数的能力得出的关键指标来评估这种响应对网络弹性的影响。伦敦交通局——伦敦地铁作为资产所有者，将列出资产中最受关注的危险和脆弱性的性质，因此应该首先作为初步调查的一部分进行研究。奥雅纳作为基础设施发展经济部门的主要贡献者，将确保所使用的方法和产生的产出是量身定制的，以适应更广泛的专业服务部门，从而使该方法的行业适用性最大化。该项目旨在通过制定有关未来基础设施管理战略的指导方针来解决这一问题，这些战略涉及制定维护铁路网络内遗产资产的长期方法。该指南将确定与这些结构易受腐蚀和破坏有关的关键机制。此外，它还将提出修复现有资产的方法，作为对这些脆弱性的回应，而且还将提出改造这些资产的方法，作为永久减轻未来风险的一种手段。通过这种方式，可以将增强的弹性构建到网络中，确保为未来的风险做好准备，减少其潜在影响。

The environmental hazard posed by increased precipitation presents an ever more significant risk for rail transport infrastructure owners and operators, as more frequent severe weather events increase the extent and recurrence of disruption to services through flooding and associated ground condition problems. This is an issue during and in the immediate aftermath of an event, as services are disrupted and in some extreme cases lines require reinstatement at significant cost to the operator, such as that required following the Dawlish line collapse in 2014 where Network Rail are investing upwards of £35 billion in re-instatement and improvement works (BBC News).The hazards posed by groundwater fluctuations and excessive groundwater levels also pose a continual concern for those responsible for the ongoing maintenance and resilience planning for infrastructure networks and assets. Observed changes and potential further alterations to wetting regimes present an unknown risk for infrastructure operators, and similarly those providing consultancy services within infrastructure development have identified a need to increase their knowledge of these hazards and risks in order to continue to provide relevant advice to their clients.The physical processes involved in these disruptive events are however not fully understood with respect to historic structures, and furthermore the long-term impact of these events on resilience of the network is yet to be determined. Whilst historic structures, by nature of their continued presence, show resilience to extreme climate events, we do not have a means of determining their response to conditions of specified severity. Achieving this would allow for accurate prediction of future risks, through analysis of the impact of changing frequency of such events on long-term resilience. This is especially important in light of the need identified by the industry to build resilience into the network; this can only be successfully achieved if we first understand the extent of additional mitigation investment work required.The project will analyse using the skills and knowledge available at UCL CEGE the response of the historic infrastructure components tunnels, embankments and viaducts to changing groundwater conditions in terms of stability and movement within the structure, with tolerance's applicable to infrastructure operation forming the boundary conditions. From this vulnerability of historic infrastructure assets linked to moisture regime fluctuations associated with climate change will be quantified. Finally assessment of the impact of this response on the network resilience is measured using key indicators derived from ability of network to maintain its capacity function. Transport for London-London Underground as the asset owner will set out the nature of the hazard and vulnerabilities within the asset that are of most concern, and hence should be studied first as part of this initial investigation. Arup, as a key contributor to the economic sector of infrastructure development will ensure the methods used and outputs generated are tailored to suit the wider professional services sector, and hence that industry applicability of the method is maximised.The project seeks to address this through production of guidelines on future infrastructure management strategies concerned with developing a longer-term approach to maintenance of heritage assets within the rail network. The guidelines will identify the key mechanisms associated with vulnerability to decay and failure in these structures. Further, it will propose methods for not only repairing existing assets as a response to these vulnerabilities, but also for retrofitting them as a means of permanently mitigating against future risks. Through this increased resilience can be built into the network, ensuring risks of the future are prepared for now, reducing their potential impact.