Build Environment: of Hope House - Case Study Example

INTRODUCTION A twenty storey building (Hope House) is intended for construction in the city centre of Preston. In anticipation of a fire hazard protected building, the adoption of steel reinforced concrete during construction is a phenomena that will produce excellent structural fitness able to cope with fires. Use of dense concrete or the aerated concrete blocks coupled with the use of concrete made of siliceous aggregate leads to retarded spalling thus an increase fire resistance. Perfect masonry calculations during detailing will in doubt. The retaining walls of this building should ensure that lateral pressures of the retained soil do not cause overturning or sliding when the building is under attack by fire. When constructing walls, the English bond should be used since it is most appropriate to manage fires. Composite floors will be needed since they are good for complex loading that will involve this building than the precast hollow floors, though they are expensive. Care should be employed when producing arches which will lead to strong ones that can help in times of aggressive inferno. The inner leaf of the rear walls will carry all the loads from the roof and the suspended floors. The storey’s loads will thus be eccentric due to the use of joist hangers hence a firm building which is requisite since this “Hope House” will have 50% of it housing a hotel while the remaining 50% will be used as offices. It is targeted that an average of 500 persons will be in the building at any given time. To ensure safety, the building will be constructed as a ‘concrete high-rise’ with a strong foundation, strong and insulated walls, many exit channels with ‘flush-fire’ doors, and will be connected to the local fire brigade through an easy to remember hotline. LITERATURE REVIEW Design and materials The design for this building should be assigned to an experienced designer who will efficiently draw from the reliable knowledge of structural mechanics of bending movements, shearing forces of loadings and moments of resistance. Appropriate detailing of pile cap along with columns and beams should be embraced since reinforced concrete structure method of building is strongly called for in this construction. Columns will have at least four longitudinal bars and a series of transverse bars (links) which will compensate for the weakness the concrete and will bend at 90 degrees to help anchor the ends in the concrete. Although (Frisch 2001, p.14) claims that, ‘nothing can resist fire,’ and further adds that, ‘even concrete and steel can be cracked or melted by the heat of a very intense fire’, evacuation of persons in any building is depended on the duration that the building material can hold before collapsing due to fire heat. Steel will be used to reinforce the concrete because as (Macdonald 1994, p.29) puts, ‘steel will resist axial tension, axial compression and bending type load, and its low chemical instability which makes it susceptible to corrosion and fires is replaced by a great strength when used together with concrete’. The steel will act as the restraint to the concrete hence reducing the rate of degradation of the concrete when the building is under fire. The roof frames for this building should be made of steel members. (Chudley 1999, p.225) asserts that, ‘the roof should be done in accordance with building regulation B4 section 14 which requires the roof to offer adequate resistance to the spread of fire over the roof’. Each storey building should have four fire exit stair ways. Two of these stairways should also be the fire fighters shafts that have lifts and dry-rising mains. The emergency doors leading to these stairways must be those that open outwards or be sliding. These doors should be reachable from at most 50 meters from the furthest point. The exit doors should be of the flush-fire type which provide effective barrier to the passage of fire for a reasonable duration. They should be marked ‘Fire Exit’ or ‘Fire Door’ (FD) and the corresponding time in minutes they can resist fire and smoke. In the uppermost floors, fire exist stairways should be at least one meter wide since this is capable of facilitating the escape of 80 people per minute. This will ensure that there is enough space from everybody to escape. It is true, as (Phillips 1951, p. 64) puts, that, ‘panic and the ensuing rush for exits have caused more loss of lives than the fire itself’. Smoke control The design must be made in a way that smoke is adequately managed. The stairways should be pressured to ensure that they are smoke-proof. The exit doors to each stairway should be able to fasten completely after the people’s escape from each storey to keep the stairway free from smoke. It has been noted that 80% of all fatalities in fire situations are as a result of smoke. Smoke detectors that will activate smoke alarms should be installed in every floor to ensure that fire outbreak is noticed at its initial stage. These automatic detectors detect an increase in the smoke level of a building. These smoke alarms will also be designed to activate a sprinkler system that is able to manage the fire before it gets out of hand. The sobering point is that, all fires start small and the importance of this technology cannot be overstated. Smoke curtains should be installed. This are designed to activate upon receipt of a signal from the smoke alarms, thus preventing the lateral spread of smoke and superheated gases for a pre-determined period of time. Each storey must be well ventilated. This will be achieved by the provision of natural ventilation (like roof vents or wall openings) or the use mechanical ventilation like the extractor fans or a combination of both. The building will be such that it will be able to allow for both vertical and horizontal ventilations during fire fighting sessions. Ventilation will facilitate the escape of smoke and prevent the occupants from suffocation in times of a fire out-break. Lighting is also important; therefore, all stairways must have an emergency lighting arrangement and be constructed of fire retardant materials. Installation of extinguishing agents Portable fire extinguishers (PFEs) are handy in managing small fires. A 2002 survey in six European countries revealed that PFEs extinguished more than 80% of the fire reported to the survey team and that in 75% of those incidents, the fire was tackled without the need to call the fire brigade. The survey also found out that in the United Kingdom, the intervention of PFEs potentially helped prevent 24 fire-related deaths and 1,692 serious fire-related injuries saving business, in excess of 500 million pounds. The multi-purpose dry chemical fire extinguishers with stored pressure should be installed in the building. This being a multi-storey building, size 10lb or 20lb is recommended. These types of fire extinguishers are extremely versatile and will tackle a majority of fire risks found in most commercial, industrial and domestic environments. They are suitable for classes A, B and C fires and can mount on any surface with the wall hook supplied. They have chrome plated brass valves, stainless steel handle and hose band. Furthermore, they have color coded labels for instant type recognition and redesigned labels incorporating easy-to-follow instructions and larger fire pictograms. They have the ability to operate at both low and high temperatures and have epoxy coated steel cylinders that can resist corrosion, dents and punctures. However it is worth to appreciate that these types of fire extinguishers can not fight class D fires. They are also very expensive and heavier than all other types. Due to the combination of different chemicals that characterize this type of extinguishers, any mishandling during fire fighting sessions can lead to suffocations and poisoning. CONCLUSION All types of materials to be used in the construction of this building should be as fire retardant as possible. Steel has to be used where possible in the structures besides its usage with concrete in providing an insulating property. Smoke will be controlled to avoid corbon monoxide poisoning during fire out-breaks. Each storey will be installed with enough multi-purpose chemical extinguishers to fight class A, B and C fires. McCarthy and Gauche (2004) say that, ‘multidisciplinary planning and implementation of regular scheduled and sculpted fire drills are essential to prevent adverse fire outcomes’, therefore, the importance of educating occupants on the basic fire fighting skills can never be overemphasized. RECOMMENDATIONS Following recommendations have been put forward with a conviction that they will be implemented to ensure that this building is fire-safe and up to standard. I. Construction to should embrace use of fire retardant materials like steel, high quality concrete, use of clay tiles for the floor and ceiling finishing. Stairways should be availed, smoke be adequately controlled and flush-fire doors be used as fire exit doors. II. Multi-purpose dry chemical extinguishers should be installed on each floor at a height reachable even by the disabled. III. Structural engineers, detailers, brick layers and other building personnel employed should be those who have a great wealth of experience to ensure that a fire hazard free building is finally realized. REFERENCES Chudley, R 1999, Construction Technology, Longman, London. Frisch, A. 2001, Fire, Black Rabbit Books, Mankato. Macdonald, AJ 1994, Structure and Architecture, Reed Educational and Professional Publishers, United Kingdom McCarthy and Gauche, 2004 ’Developing a Fire Safety Plan’, Association of Registered Nurses Journal. March, Vol. 1 no.3 pp. 79 Naito, T. 1983, ‘Fire Prevention and Protection’, Encyclopedia of Occupational Health Safety, Vol.1 Pp.866, I.L.O Phillips, B.G, 1951, Escape from Fire, Spon Ltd, London Read More