77 research outputs found
Querying a regulatory model for compliant building design audit
The ingredients for an effective automated audit of a building design include a BIM model containing the design information, an electronic regulatory knowledge model, and a practical method of processing these computerised representations. There have been numerous approaches to computer-aided compliance audit in the AEC/FM domain over the last four decades, but none has yet evolved into a practical solution. One reason is that they have all been isolated attempts that lack any form of standardisation. The current research project therefore focuses on using an open standard regulatory knowledge and BIM representations in conjunction with open standard executable compliant design workflows to automate the compliance audit process. This paper provides an overview of different approaches to access information from a regulatory model representation. The paper then describes the use of a purpose-built high-level domain specific query language to extract regulatory information as part of the effort to automate manual design procedures for compliance audit
Scoping study on the significance of mesh resolution vs. scenario uncertainty in the CFD modelling of residential smoke control systems
Computational fluid dynamics (CFD) modelling is a commonly applied tool adopted to support the specification and design of common corridor ventilation systems in UK residential buildings. Inputs for the CFD modelling of common corridor ventilation systems are typically premised on a ‘reasonable worst case’, i.e. no specific uncertainty quantification process is undertaken to evaluate the safety level. As such, where the performance of a specific design sits on a probability spectrum is not defined. Furthermore, mesh cell sizes adopted are typically c. 100 – 200 mm. For a large eddy simulation (LES) based CFD code, this is considered coarse for this application and creates a further uncertainty in respect of capturing key behaviours in the CFD model. Both co-existing practices summarised above create uncertainty, either due to parameter choice or the (computational fire and smoke) model. What is not clear is the relative importance of these uncertainties.
This paper summarises a scoping study that subjects the noted common corridor CFD application to a probabilistic risk assessment (PRA), using the MaxEnt method. The uncertainty associated with the performance of a reference design is considered at different grid scales (achieving different ‘a posteriori’ mesh quality indicators), with the aim of quantifying the relative importance of uncertainties associated with inputs and scenarios, vs. the fidelity of the CFD model. For the specific case considered herein, it is found that parameter uncertainty has a more significant impact on the confidence of a given design solution relative to that arising from grid resolution, for grid sizes of 100 mm or less. Above this grid resolution, it was found that uncertainty associated with the model dictates. Given the specific ventilation arrangement modelled in this work care should be undertaken in generalising such conclusions
Prediction of time to ignition in multiple vehicle fire spread experiments
This paper describes the application of the flux‐time product ignition criterion and the point source flame radiation model to predict the time to ignition in multiple vehicle spread scenarios. Ten experiments from the literature have been selected due to sufficiency of information required to apply the methods. The outcome of this work is to be applied to a risk‐based model for the design of car parking buildings to determine when and if a fire spreads between vehicles;
therefore, the analysis suggests properties of a representative material that can reasonably account for those external vehicle components that are most likely to ignite first. The application of both methods to the complex problem of multiple vehicle ignition requires several assumptions and simplifications which are discussed in the paper
Balancing stakeholder views for decision-making in steel structural fire design
Fire design stakeholders such as architects, regulators, fire service, etc., often have different opinions about which passive fire protection approach is the most appropriate one in meeting structural fire performance objectives. There are many options for protecting steel buildings in a fully developed fire, but there is the need to identify a strategy that could satisfy at best the different and sometimes conflictual stakeholder desires, thereby reducing design uncertainties. This paper proposes a three-stage approach to address this issue: (i) stakeholder engagement, to identify and extract stakeholder desires; (ii) decision analysis, and; (iii) risk-based parametric study. The paper focuses, in particular on the first two stages. The first stage describes the process of identification and extraction of stakeholder desires in steel structural fire design from literature and structured interviews through a stakeholder engagement plan. The second stage of the decision-making process is demonstrated using a simple stakeholder goal-rating and multi-criteria decision analysis (MCDA). In particular, the use of analytic hierarchy process (AHP) is proposed to manage the multiplicity of stakeholder desires towards common decision-criteria, manage possible inconsistent goal-rating, and to rank the different proposed passive fire protection options
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