Early warning decision support system for the management of underwater scour risk for road and railway bridges

合作伙伴-苏格兰交通局（TS）、英国铁路网（NR）、SEPA、奥雅纳。挑战-洪水引起的冲刷是迄今为止导致桥梁故障的主要原因，导致生命损失、交通中断和重大经济损失。TS负责1，567座桥梁，其中8%目前被列为需要冲刷保护措施，每年在例行检查中花费200万英镑。同样，NR Scotland Route包括1，750个易受冲刷的结构，需要每年40万英镑的检查费用。检查是昂贵的，耗时的，往往收集的信息是定性和subjective.Objective-开发一个原型的决策支持系统（DSS）的冲刷风险管理NR的和TS的桥梁，提高用户的安全，同时最大限度地减少交通中断和运输机构的运营成本。该系统将利用（i）冲刷深度监测的实时信息（ii）降雨预报和（iii）河流流量特性来估计并不断更新当前和未来的冲刷失效风险。创新-传感器和通信技术提供了真实的时间评估关键桥梁位置冲刷深度的可能性;然而，监测整个基础设施网络在经济上是不可持续的。克服这种限制的一种方法是在有限数量的关键位置安装监控系统，并使用概率方法将此信息扩展到整个资产。在洪水发生时，监测观测值被用来给出桥梁失效概率的实时最佳估计。所提出的传感技术是一种智能探头的原型，集成了电磁传感器，用于检测周围桥梁基础的介电常数变化，设计和校准用于检测各种土壤类型的冲刷和沉积物沉积。关键活动-收集NR和TS检查记录的过去冲刷检查数据;基于脆弱性曲线方法定义正式的脆弱性模型。基于SEPA降雨量和河流流量数据集定义洪水灾害模型，并考虑CCRA气候变化预测。-使用贝叶斯网络建立不同桥梁之间危险性和脆弱性的模型相关性。从TS试验冲刷监测系统收集数据。根据监测系统的实时信息，实施更新贝叶斯网络脆弱性曲线和状态变量的算法。开发一个原型DSS，利用试点监测系统和降雨预报的实时信息不断更新桥梁故障风险。可交付成果-桥梁易损性模型、洪水灾害模型和冲刷灾害模型将为NR和TS提供有关每座桥梁冲刷破坏概率的最新定量信息。在洪水发生前，这将允许根据风险优先进行检查，并在必要时采取预防性桥梁关闭或交通管理。该框架同样可以用于模拟潜在的极端天气事件对旅行社网络的影响，并提前计划适当的应急程序和对策。TS试验冲刷监测系统将为直接评估水下冲刷的新技术提供验证，这可以补充传统NR和TS的河岸视觉评估。决策支持系统将为未来冲刷风险的长期预测提供信息，以推动战略维护、维修和恢复行动。同样的决策支持系统也可用作预警系统，在估计的风险超过给定阈值时自动采取行动。开发计划署将制定一个路线图，将新的技术和知识转移到其他基础设施系统和地理区域。持续时间- 12 months成本- £ 94，763.02

PARTNERS- Transport Scotland (TS), Network Rail (NR), SEPA, Arup.CHALLENGE- Flood induced scour is by far the leading cause of bridge failures, resulting in loss of lives, traffic disruption and significant economic losses. TS is responsible for 1,567 bridges, 8% of these currently classified as needing scour protection measures and costing £2m per annum in routine inspections. Similarly, NR Scotland Route includes 1,750 structures susceptible to scour requiring an annual inspection spend of £0.4m. Inspections are expensive and time consuming, and often the information collected is qualitative and subjective.OBJECTIVE- To develop a prototype of a Decision Support System (DSS) for scour risk management for NR's and TS's bridges, which enhances users' safety, while minimizing traffic disruptions and transport agencies' operational cost. The system will estimate, and continuously update, the present and future scour failure risk using (i) real-time information from monitoring of scour depth (ii) rainfall forecast and (iii) river flow characteristics.INNOVATION- Sensor and communication technologies offer the possibility to assess in real time the scour depth at critical bridge locations; yet monitoring an entire infrastructure network is not economically sustainable. A way to overcome this limitation is to install monitoring systems on a limited number of critical locations and use a probabilistic approach to extend this information to the entire asset. In the occurrence of a flood, monitoring observations are used to give the real-time best estimate of bridge failure probability. The sensing technology proposed is a prototype of smart probe with integrated electromagnetic sensors designed to detect changes in the dielectric permittivity of the surrounding bridge foundation, designed and calibrated to detect scour and sediment deposition in various soil types.KEY ACTIVITIES- Collect data from past scour inspection on NR's and TS's inspection records; define formal vulnerability model based on the fragility curve method.- Define flood hazard models based on SEPA rainfall and river flow datasets, and accounting for CCRA climate change prediction.- Model correlation in hazard and vulnerability among different bridges, using Bayesian networks.- Collect data from TS pilot scour monitoring system.- Implement algorithms for updating fragility curves and state variables of the Bayesian network based on real-time information from monitoring system.- Develop a prototype DSS that continuously updates bridge failure risk using real-time information from pilot monitoring system and rainfall forecast.- Produce an exploitation plan.DELIVERABLES- The BRIDGE VULNERABILITY MODEL, the FLOOD HAZARD MODEL and the SCOUR HAZARD MODEL will provide NR and TS with quantitative up-to-date information on the probability of scour failure of each bridge. Before a flood event, this will allow prioritising inspections according to risk and, when necessary, to introduce precautionary bridge closures or traffic management. This framework can be equally used to simulate the impact of potential extreme weather events on travel agencies' network, and to plan in advance appropriate emergency procedures and countermeasures. The TS PILOT SCOUR MONITORING SYSTEM will provide validation to a new technology for direct assessment of underwater scour, which can complement traditional NR's and TS's river-bank visual assessments. The DECISION SUPPORT SYSTEM will provide information for long term prediction of future scour risk to drive strategic maintenance, repair and rehabilitation actions. The same DSS can be used as an early warning system that automatically takes action when the risk estimated exceeds a given threshold. The EXPLOITATION PLAN will set a roadmap to transfer the new technology and knowledge to other infrastructure systems and geographical areas.DURATION- 12 monthsCOST- £94,763.02