It is now an accepted fact that the disruption and economic losses arising as a result of extreme storms are increasing at a significant rate. There is also tentative evidence to suggest that these storms are increasing in frequency and magnitude due primarily to climate change effects, although it is acknowledged that such evidence is far from conclusive. Any increases in magnitude and frequency of extreme storms are likely to result in serious damage to the urban infrastructure, the world economy and society as a whole. In European terms, it has been suggested that by 2080, there will be an increase in wind-related insured losses from extreme European storms by at least....25-30bn Euro. However, it is perhaps worth noting that these estimates do not take into account society's increasing exposure to extreme storms, due to growing populations, wealthier populations and increasing assets at risk. Over the last few years there has been renewed interest in the effects of extreme wind events, since in a number of cases these events are the most important with respect to wind loading (i.e., the design of buildings/infrastructure). One particular set of extreme wind events which has received little attention in the past are those associated with thunderstorm downbursts. During a downburst a column of air moves vertically downwards and impinges on the ground. This causes the resultant air to be displaced radially outwards from the point of impingement, with a ring vortex travelling away from the stagnation point. The effect of this is to alter the velocity field significantly. In other words, the velocity field which was assumed when the building was designed may no longer occur, and a new, very different field may exist. The effect that this new wind field has on typical structures has yet to be addressed. Hence, there is a need to undertake a comprehensive examination of the structure of thunderstorm downbursts and to investigate the corresponding wind induced forces which can arise. The scarcity of full-scale data and the difficulty of predicting such events ensure that at present, modelling is a sensible way forward. Furthermore, the uncertainties associated with both physical and numerical modelling strongly suggest that a combined physical/numerically modelling programme supplemented by (limited) full-scale data is the best way forward. Without such an examination of the wind field associated with thunderstorm downbursts, the suitability of existing design methods remains an open question. This is of importance since in many parts of the world wind speeds of this origin constitute the design wind speeds. Even in areas where these events are not dominant, the continued investment and development in society and its related infrastructure ensures that society as a whole is more vulnerable to the effects of such an event irrespective of how frequently they current occur.
The Earthquake Engineering Field Investigation Team (EEFIT) has appointed a group of 7 experts, of which 2 academics and a PhD. student eligible for funding from EPSRC, to conduct a reconnaissance mission to the regions of Chile struck by the Mw8.8 earthquake that occurred on the 27th February 2010, with epicentre 100 miles northwest from the City of Concepcion. The earthquake, the second strongest in the recorded history of Chile, was felt on land as far north as Santiago, where it caused severe damage and collapses, and Ica in Peru', and eastward as far as Sao Paolo, in Brazil. The shock also triggered a tsunami whose waves travelled westward past Hawaii, to Japan and New Zealand. The team will spend approximately 8 to 10 days in the region, surveying structural, infrastructural, geotechnical and seismological evidence and also comparing the Chile event with the recent earthquake in Haiti, which was considerably smaller (Mw7) but resulted in much more death and destruction. This earthquake has raised a number of specific issues which are discussed in greater depth in the following sections. The clearing operation is already underway and this has determined the very short notice with which this proposal is submitted with respect to the departing date. Post mission activities will include analysis of the collected data using high resolution imaging within the Virtual Disaster Viewer (VDV) and other tools specifically developed as part of the project. The findings will be disseminated to both researchers and professional engineers through seminars and publication on lines and in journals. This grant application seeks financial assistance for the three eligible members of the EEFIT group to participate in this mission.
Pedestrians represented roughly 24% of road fatalities and 22% of the seriously injured in the UK in 2015 (Department for Transport, Reported Road Casualties Great Britain: 2015, Annual Report). The most commonly recorded factors were: "in accidents where a pedestrian was killed or injured; pedestrian failed to look properly was reported in 59 per cent of accidents. Failed to judge other person's path or speed was the most typical secondary cause." (DfT, 2015) In this context, the increased use of Autonomous Vehicles (AVs) and new urban warning systems that can help monitor and assist pedestrians and their interactions with vehicles has the potential to dramatically reduce road deaths. A major concern, however, is that the AVs and warning systems must be designed to take into account the capabilities and limitations of pedestrians. This project will develop a new pedestrian laboratory to support safe experimental research in a repeatable fashion in which a variety of variables with respect to AV design, warning system design, and intersection configuration can be studied. The experiments can also look at the impacts of a wide range of human factors including age, vision and mobility. The pedestrian laboratory (PEDSIM) will consist of a Virtual Reality (VR) simulator that will allow a participant to experience a variety of urban configurations and interact with new vehicles and urban robots. The pedestrian laboratory will track the participant's performance in a variety of tasks to compare the effectiveness of various designs. What makes the PEDSIM unique in the world is its very high resolution displays combined with its large walkable environment (9 metres by 4 metres) and its integration with driving simulators to test interactions between pedestrians and drivers. As automated and autonomous vehicles get closer to deployment, research into their design and impact has rapidly increased. There are several studies currently funded by the EPSRC that can take immediate advantage of the new research capabilities of the PEDSIM. These include research to evaluate solutions for cooperative interaction of automated vehicles and urban robots with pedestrians and research that will test various lighting conditions and its impact on visibility, trip hazards, and understanding intentions of other pedestrians and vehicles.
This project will apply concepts from modern robust control theory to develop algorithms for determining the optimal policy that both achieves sustainable levels of emissions of CO2 (and other greenhouse gases) and minimises the impact on the economy, but also explicitly addresses the high levels of uncertainty associated with predictions of future emissions. The aim of the optimal policy is to adjust factors such as the mix of energy generation methods and policies for reducing emissions from housing, industry and transport, in order to achieve a rate of emissions that will allow the UK to achieve its emissions targets while maximising economic growth as measured by discounted GDP. A key difficulty in determining the optimal policy is handling the uncertainty associated with the effect that the policy changes will have on the rate at which is CO2 emitted. One of the main conclusions of the Stern Review is that policies for stabilisation of CO2 emissions have to be implemented immediately and it is not possible to delay decisions until models with less uncertainty become available. If this conclusion is accepted (and indeed even if it is not) model uncertainty has to be incorporated as an integral part of the design of these policies. Currently, economists are unable to find optimal policies in the presence of uncertainty and most existing economic models address model uncertainty by running repeated what if scenarios to predict the outcome for a range of parameter values. This project will use concepts from robust control theory to develop tools for incorporating uncertainty directly into the design of the optimal emissions policy; the tools can then be applied to other existing models. Including uncertainty within the design quantifies the risk associated with the emissions policy, which allows policy makers and emitters of CO2 to incorporate risk within their strategic plans. The tools will be implemented on the ECCO (Evolution of Capital Creation Options) model that describes the dynamic evolution of CO2 levels emitted by UK economy. Unlike many other economic models, this model is based on the physical principles of mass and energy balances, which are used to derive economic measures.
Human-structure dynamic interaction is defined not only as the influence of humans on the dynamic properties of structures they occupy, but also as forces which excite these structures. Both of these issues are becoming increasingly important for all slender civil engineering structures occupied and dynamically excited by humans, such as footbridges, long-span floors, grandstands and staircases. The problems are typically caused by excessive vibrations of such structures due to normal activities of their human occupants, such as walking, running and jumping. The excessive lateral vibrations of the infamous Millennium Bridge in London is the best known example of this problem. The human involvement in the problem the key source of considerable randomness in the following three key types of human-structure dynamic interaction: (1) human-induced dynamic actions on structures,(2) changes of structural dynamic properties due to the presence of humans, and (3) perceptions of structural vibration responses. Although the concept that we are all different is quite understandable, there has been almost no effort to articulate it within a common probability based theoretical, analysis and design framework of the kind which exists for other random excitations of civil engineering structures such as wind and earthquakes. The provision of this framework would enhance tremendously understanding of human-structure dynamic interaction and enable easier application of its various aspects in practice, including a development of more reliable design codes in civil structural engineering. The development of this novel framework is the key aim of this Fellowship.