ASSESSING THE UNDERWORLD - AN INTEGRATED PERFORMANCE MODEL OF CITY INFRASTRUCTURES

地面城市交通基础设施——我们的道路、自行车道、步行区、电车轨道和铁路——都是由地面支撑的，因此地面的性质必须在很大程度上控制其结构性能。公用事业服务基础设施——为我们的家庭提供公用事业服务和支持城市生活的管道和电缆——通常埋在我们的城市街道之下，也就是说，它位于地面交通基础设施（通常是道路和铺砌的步行区）之下。因此，使用传统的挖沟方式来安装、更换、修理或维护这些公用设施管道或电缆的街道工程将扰乱交通和人员流动，并经常严重破坏地面运输基础设施及其所承载的地面。因此，很明显，地面和物理基础设施（即公用事业服务和地面运输）是根据共生关系存在的：对其中一个进行物理干预，其他基础设施几乎不可避免地以某种方式受到影响，要么立即受到影响，要么将来受到影响。此外，管道和电缆、地面和上覆道路结构的物理状况在确定街道工程造成的影响的性质和严重程度方面至关重要。评估地下世界（ATU）旨在使用部署在地表和水管内部的地球物理传感器来远程（即无需挖掘）确定这些城市资产的状况。ATU建立在非常成功的地下世界测绘（MTU）项目的基础上，该项目由EPSRC的第一个IDEAS工厂（或沙坑）资助，并得到了许多行业合作伙伴的支持。MTU沙坑汇集了一个已经成长为该领域公认的国际领导者的团队。ATU将气候变化、基础设施政策、工程可持续性和管道系统方面的领导者引入MTU团队，将研究带入一个新的影响领域，作为其25年愿景的一部分，使街道工程更具可持续性。ATU建议开发MTU创建的地球物理传感器来寻找不同的目标：埋在地下的管道和电缆有退化或损坏的迹象，道路结构有退化的迹象（例如开裂、分层或湿化），以及地面与未改变的地面有不同的性质（例如因管道渗漏而被浸湿或侵蚀，因局部挖沟而松动，因裂缝的道路结构进水而被浸湿）。例如，与原始管道相比，变质（断裂、横向位移、腐蚀或有洞）的管道对地球物理传感器的响应不同，而邻近土壤的湿润或由含水管道泄漏引起的局部侵蚀产生的空隙将导致对未改变的自然土壤或填充物的不同地面响应。类似地，一条恶化的道路（有垂直裂缝，或有浸湿的基础），与排水良好的基础上的完整、连贯的约束层相比，会产生不同的反应。利用地球物理传感器提供的信息，将其与管道、电缆和道路的记录相结合，并为这些物理基础设施引入退化模型，了解它们的年龄和记录的状况（这些信息可用的地方），将允许一种预测方法，如果在特定道路上挖沟，它们将如何反应。在某些情况下，替代的建造技术可以避免严重的损坏（例如水管爆裂、道路结构损坏需要完全重建）或伤害（煤气管道爆裂）。将通过为街道工程工程师创建决策支持系统来提供这些信息。最后，街道工程对经济、社会和环境的全面影响将在可持续发展评估框架内进行模拟，以便清楚地了解工程的更广泛影响。

The surface urban transport infrastructures - our roads, cycle ways, pedestrian areas, tramways and railways - are supported by the ground, and hence the properties of the ground must control to a significant degree their structural performance. The utility services infrastructure - the pipes and cables that deliver utility services to our homes and which supports urban living - is usually buried beneath our urban streets, that is it lies below the surface transport infrastructure (usually roads and paved pedestrian areas). It follows that streetworks to install, replace, repair or maintain these utility service pipes or cables using traditional trench excavations will disrupt traffic and people movement, and will often significantly damage the surface transport infrastructure and the ground on which it bears.It is clear, therefore, that the ground and physical (i.e. utility service and surface transport) infrastructures exist according to a symbiotic relationship: intervene physically in one, and the others are almost inevitably affected in some way, either immediately or in the future. Moreover the physical condition of the pipes and cables, of the ground and of the overlying road structure, is consequently of crucial importance in determining the nature and severity of the impacts that streetworks cause. Assessing the Underworld (ATU) aims to use geophysical sensors deployed both on the surface and inside water pipes to determine remotely (that is, without excavation) the condition of these urban assets.ATU builds on the highly successful Mapping the Underworld (MTU) project funded by EPSRC's first IDEAS Factory (or sandpit) and supported by many industry partners. The MTU sandpit brought together a team that has grown to be acknowledged as international leaders in this field. ATU introduces leaders in climate change, infrastructure policy, engineering sustainability and pipeline systems to the MTU team to take the research into a new sphere of influence as part of a 25-year vision to make streetworks more sustainable.ATU proposes to develop the geophysical sensors created in MTU to look for different targets: indications that the buried pipes and cables are showing signs of degradation or failure, indications that the road structure is showing signs of degradation (e.g. cracking, delamination or wetting) and indications that the ground has properties different to unaltered ground (e.g. wetted or eroded by leaking pipes, loosened by local trench excavations, wetted by water ingress through cracked road structures). For example, a deteriorated (fractured, laterally displaced, corroded or holed) pipe will give a different response to the geophysical sensors than a pristine pipe, while wetting of the adjacent soil or voids created by local erosion due to leakage from a water-bearing pipe will result in a different ground response to unaltered natural soil or fill. Similarly a deteriorated road (with vertical cracks, or with a wetted foundation) will give a different response to intact, coherent bound layers sitting on a properly drained foundation.Taking the information provided by the geophysical sensors and combining it with records for the pipes, cables and roads, and introducing deterioration models for these physical infrastructures knowing their age and recorded condition (where this information is available), will allow a means of predicting how they will react if a trench is dug in a particular road. In some cases alternative construction techniques could avert serious damage (e.g. water pipe bursts, road structural failure requiring complete reconstruction) or injury (gas pipe busts). Making this information available will be achieved by creating a Decision Support System for streetworks engineers. Finally, the full impacts to the economy, society and environment of streetworks will be modelled in a sustainability assessment framework so that the wider impacts of the works are made clear.