Danny Hopkin

TL;DR: The safety foundation of fire safety solutions is investigated, indicating that PRA is necessary for demonstrating adequate safety when no appeal can be made to the collective experience of the profession.

TL;DR: This work presents a new approach to probabilistic material models for structural risk assessment against fire that takes into account the uncertainty in material behavior over a range of elevated temperatures.

TL;DR: In this article, the authors present a numerical study highlighting the consequences of adopting many of the differing property sets available in the literature, the sensitivity of temperature development resulting from deviations from the assumptions that underpin such properties, and the consequence of adopting plasterboard properties derived from standard fire tests, in natural fire situations.

Abstract: When conducting fire and smoke modelling it is important to adopt an appropriate design fire. Calculations may adopt a design fire that is represented in terms of a heat release rate per unit area (HRRPUA). This paper provides a historical review of recommended values that are predominantly used in the UK as well as values from other jurisdictions where appropriate. It has been determined that many of the HRRPUA values provided in UK guidance are derived from ten fire incidents for industrial fires in the 1960s and 1970s, and five wood crib experiments undertaken in the 1960s. The HRRPUA values originally calculated from these incidents and experiments ranged from 86 kW/m2 to 650 kW/m2. The data was gradually adapted in various forms to consider shops and retail buildings, offices, hotel rooms and residential buildings, where variations in recommended values have occurred over time due to adjustments and calculations from various authors. In light of the observations, this paper provides updated recommended values from literature which relate to specific occupancies and building types. These are summarised as a range of potential values, such as 270 kW/m2 to 1200 kW/m2 for shops and 150 kW/m2 to 650 kW/m2 for offices, where designers will need to take care in considering the relevant source material.

TL;DR: It is concluded that ambient safety targets cannot readily be scaled as a function of the fire occurrence rate for application to structural fire engineering problems, and the underlying cost-optimization model is applicable as a concept.