Issue 20

For some time the ‘Fire Engineering Approach’ or the ‘Fire Safety Engineering Approach’ has been adopted in Hong Kong for the design of new buildings or for the alteration and addition works in existing buildings. Such approaches enable the fire safety objectives and performance requirements of the Buildings Ordinance and its allied regulations to be met. As an alternative to the prescriptive requirements set out in the three codes of practice, namely ‘Means of Escape in Case of Fire’, ‘Means of Access for Firefighting and Rescue Purposes’ and ‘Fire Resisting Construction’, the Building Authority also accepts a fire safety engineering approach that takes into account means of escape, means of access, fire services installation, fire resisting construction, size, height, use, location, and fire safety management of the building together with suitable applications of applied science and engineering principles. Fire engineering design offers a flexible alternative where it is impracticable to comply with prescriptive provisions in the three codes, especially when designing large and complex buildings or where significant alteration and addition works are required in existing buildings. The aim of fire safety design is to provide an overall level of safety equivalent to the one that was achieved by full compliance with the prescriptive provisions of the relevant codes of practice. It also provides a framework for engineers to demonstrate that the performance requirements of legislations are met, or in some cases bettered, to compensate for the deviation or shortfalls of the prescriptive codes. This paper aims to provide an overview on fire engineering design and construction, post fire assessment and the role of structural engineers in fire engineering. Paul T. C. Pang, BEng, CEng, PEng, FIStructE, MICE, FHKIE Chairman of Structural Discipline Advisory Panel, HKIE and Founding Member of the Fire Discipline Advisory Panel, HKIE

Many modern fire safety codes for building structures use either a prescriptive approach or a performance-based approach. It is widely recognised that performance-based approaches provide great advantages over prescriptive approaches as they allow designers to use rational fire engineering methods to assess structural fire safety. However, performance assessments of entire structures are not straightforward, so the majority of modern fire codes still adopt either a prescriptive approach or a combination of prescriptive and performance-based approaches. In Hong Kong, the prescriptive approach is still widely regarded as the fundamental method assuring fire resisting construction, and assuring building compartmentation. However, there is growing interest in the practical application of structural fire engineering, and with this technique, it is essential to recognise that the key feature for implementing performance-based structural fire engineering is the assessment of a structure’s fire resistance under specific fire exposures. This paper presents an overview of well established analysis methods for the assessment of building structure fire resistance. All the basic principles of these methods are presented and discussed through their application in assessing the performance of composite slabs under fire. Structural engineers are strongly recommended to recognise and acquire the skills of fire resistant design so that they can proactively contribute to fire resisting construction in practice. Prof K. F. Chung, BEng, PhD, DIC, CEng, FIStructE, MHKIE, FHKISC, RPF A. J. Wang, BEng Both with the Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, PR China

John Lyle was awarded the 2005 Rowen Travel Award by the IStructE Educational?Trust to research movable structures around the world. The award provided an opportunity to review overseas experience in developing and procuring movable structures. Structures that transform or retract are becoming increasingly common. The popularity of developing structures that move has partially been driven by the need to increase the flexibility of buildings or to enhance the appeal of structures. Computerised control systems also have greatly contributed to the development of this class of structure. In the past few years in the UK we have seen the completion of a number of significant movable structures such as the London Eye, the Falkirk Wheel and the Glasgow Science Tower, while ongoing projects include the retractable roofs for Wembley Stadium and Wimbledon’s centre court. Current evidence suggests the trend for movable structures is likely to be sustained by the economic pressures to provide greater flexibility of building usage. This research looks beyond the UK to review current design, procurement and installation practices found elsewhere in the world. While the principal centres for movable structures technology (outside of the UK) have been the US and Japan, there are many other parts of the world where the technology has created novel solutions for retractable grandstands (at the Telstra Stadium, Sydney) and retractable fabric roofs (Amsterdam Stadium). This paper is the result of seeing first hand a number of movable structures around the world and having discussions about their procurement with the designers, contractors and operators involved. John Lyle, BSc, CEng, MIMechE, ACIArb Ove Arup & Partners