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Exeter, United States

Harvey W.J.,Bill Harvey Associates Ltd
Proceedings of the Institution of Civil Engineers: Engineering and Computational Mechanics | Year: 2010

When dealing with complex masonry structures, exploration of the potential flow of forces can sometimes be more useful than rigorous analysis. Exploration requires division of the structure into elements, computation of volumes and weights, summation of forces and then the tracing and visualisation of force flow. This briefing note describes how vector algebra and spreadsheets can be used to develop simple interactive spreadsheet models.

Harvey B.,Bill Harvey Associates Ltd
Life-Cycle and Sustainability of Civil Infrastructure Systems - Proceedings of the 3rd International Symposium on Life-Cycle Civil Engineering, IALCCE 2012 | Year: 2012

Masonry bridges, whether built of brick or stone, are complex structures. The arch is actually a vault which has considerable width. As well as fill, it supports spandrel walls at the edges and often within the width. The interaction of these elements is governed by stiffness but the stiffnesses are very difficult to define except in the most qualitative way. The paper presents some examples of observed and measured behaviour and how it relates to the development of damage. Some indications of potential analytical approaches are offered as are some proposed repair techniques.

Harvey B.,Bill Harvey Associates Ltd
Proceedings of the Institution of Civil Engineers: Bridge Engineering | Year: 2012

Load-related damage to masonry bridges is relatively uncommon. The author is aware of only a small number of cases and nearly all of them are in structures carrying high railway loads. Current assessment tools do not deliver any indication of the failure mechanisms that actually occur. Those mechanisms are characterised by the progressive development of cracks in various positions. Recent observations have made it clear that: bridges with internal spandrel walls create complex stiffness issues; so-called spandrel cracks and apparent ring separation are different manifestations of the same issue; the construction of some small bridges is not as assumed but often includes internal spandrel walls. This paper describes the damage observed, the construction to which it is related and the mechanisms creating damage. No calculations of any form are offered. This paper merely provides a first step in identifying the cause of a problem and a potential approach to analysis. The discussion begins with stone masonry viaducts, progresses to brick viaducts and concludes with problems in small span bridges.

Harvey B.,Bill Harvey Associates Ltd
Proceedings of the Institution of Civil Engineers: Bridge Engineering | Year: 2013

Owners need to be able to determine, with some certainty, which of their bridges are at risk of damage by loading and which are not. The underlying rules of distribution encapsulated in current assessment codes for arch bridges are not capable of yielding useful results. It is not, therefore, possible to distinguish effectively between those bridges which have an indefinite life and those which will fail in the near future if loads are increased. Experience suggests that short-span bridges with shallow fill are most at risk and increasing either span or fill depth reduces the risk dramatically. A useful model must be capable of following this trend. The paper presents evidence of failure under live load, a proposal for a new (still relatively simple) model for distribution and a link between that simple model and results from tests and analysis.

Harvey H.,Bill Harvey Associates Ltd | Hall J.,University of Oxford | Manning L.,Northumbria University
Proceedings of the Institution of Civil Engineers: Water Management | Year: 2014

Risk analysis of areas protected by flood defence systems involves probabilistic analysis of a large number of scenarios in which one or more of the defence sections that make up the system has failed. In systems with large numbers of defence sections, the computational expense of this calculation can be prohibitive. When the probability of failure of each defence section is not negligibly small, sampling approaches that are now in widespread use may not converge on a stable risk estimate in reasonable computational time. To overcome this worrying limitation, this paper reformulates the flood risk calculation in terms of the cumulative distribution function of the volume of floodwater entering a floodplain. An algorithm is presented whose computational expense scales linearly with the number of sections in the flood defence system. The approach is applied to flood risk analysis in areas protected by extensive systems of flood defences in the Thames estuary, revealing how flood risk varies depending on the characteristics of the flood defence system and floodplain topography. It opens up the possibility of more exhaustive risk-based appraisal and uncertainty analysis of flood risk management options than have hitherto been feasible.

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