Evacuation Procedures in High-Rise Buildings

Abstract

High-rise buildings are characterized by high numbers of occupants hence the need to have enough evacuation procedures to evacuate these occupants during fire emergencies safely. Buildings should adhere to the safety standards and ensure enough emergency exits, fire-resistant doors and walls, fire suppression systems, and safety and emergency plans, among others. Despite high-rise buildings adhering to safety standards, there are other factors that affect evacuation procedures. This project analyzed different factors that affect evacuation procedures, including the building design, occupant use, and occupant characteristics. The research was helpful as it added information on the existing factors that affect evacuation procedures.

The research involved a qualitative research method that explored the topic of the research. Purpose sampling was used to identify research participants for responding to questionnaires that were issued by the researcher. The research revealed that most buildings have emergency doors and exit that are used for evacuation purposes. The size and number of means of egress affect the evacuation procedures because of the high number of occupants rushing to evacuate the building. Also, the physical abilities of the people with disabilities, knowledge of the premises and availability of the safety personnel affect the evacuation procedures. People with mobility issues require assistance during the evacuation process. The people trained in fire safety may decide to remain behind and fight the fire as others evacuate; this highlights how they portray a different behaviour. People with knowledge of the building also evacuate better compared to the rest. The use of a premise affects the evacuation procedures; people in a movie would evacuate differently compared to people at the hospital.

CHAPTER ONE: INTRODUCTION

1.1 Background of the Study

Urbanization has contributed to rapid development, which has created a high demand for high-rise buildings as seen in most modern skyscrapers stretching hundreds of meters. These buildings (exceeding 21 meters or 75 feet) present unique evacuation challenges due to the complex layouts, multiple floors, and stairs, use of elevators, longer wait for service, merging effects, chimney effects, dense occupant population, and safety procedures (Glauberman, 2020; Satir and Toprakli, 2020). This increases the likelihood of fatalities and injuries during the emergency evacuation from congestion and stampedes, especially for outdated building safety policies (Nguyen et al., 2019; Zhang, 2017). This means that building safety managers must consider how these aspects interact when developing safety policies to ensure occupant safety during emergencies. Ronchi and Nilsson (2013) note that high-rise building evacuation procedures should go beyond the basic requirements provided by safety regulations to enable efficient rescue operations during emergencies by handling all the safety issues presented by the structures and occupants.

The increased cases of fire accidents reported from high-rise buildings have caught the attention of the public as they question the safety of these apartments. As per the building codes, high-rise buildings are required to be made of fire-resistive construction and have reliable enclosed stairways, and this would confine fires and smoke to the individual rooms hence saving the lives of people in other rooms or offices. To enhance evacuation procedures, the Life Safety Code 101 section 4.7.2 and section 39.7.1 stipulates that relocation drills and emergency egress shall be conducted in all business occupancy buildings occupied by more than 500 persons. Conducting these drills improves the occupant’s capacity to respond swiftly during fire emergencies.

When there are fire emergencies in high-rise buildings, many people are required to move for great vertical distances down the stairs. It was reported that during the WTC bombings of 1993, some occupants took more than 6 to 8 hours to exit the building. These buildings have many stairs, and this demands physical fitness from the evacuees, and this may exceed the people’s capabilities. Most high-rise buildings are fitted with fire suppression systems like sprinklers which control fires hence lessening the urgency of evacuating all occupants. These examples show that the characteristics of building designs affect occupants’ ability to safely evacuate from a building.

1.2 Statement of the Problem

There are different building codes and fire safety rules like the NFPA standards that have been formulated to enhance safety in high-rise buildings. All proposed high-rise buildings are inspected and constructed as per the country’s regulations. Buildings should have stairs of standard dimensions to ensure the safe evacuation of people. During fires, the major duty of the firefighters is to save lives, and occupants are expected to exit the building using the nearest means of existence and collect at a safe area. Despite all these interventions, evacuation in high-rise buildings remains a challenge as some people cannot evacuate faster, resulting in more casualties. This research seeks to find out the different factors that determine evacuation procedures in high-rise buildings, including the building design, occupancy (use), and occupant characteristics as indicated in evacuation modelling software.

1.3 Research Objectives

The underlying aim of this paper is to look into the factors that influence evacuation procedures in high-rise buildings, as shown in evacuation software modelling simulations. The specific objectives tackled in the paper include:

1. Asses the evacuation procedures currently used in high-rise buildings
2. Determine how the building design requirements dictate evacuation procedures in high-rise buildings
3. Establish how occupant characteristics (physical abilities, safety awareness, environment familiarity, and availability of safety personnel) influence evacuation procedures in high-rise buildings
4. Determine how building occupancy, that is, its uses and activities influence evacuation procedures in high-rise buildings

1.4 Research Questions

1. What are the current evacuation procedures currently used in high-rise buildings?
2. How do building design requirements dictate evacuation procedures in high-rise buildings?
3. How do occupant characteristics (physical abilities, safety awareness, environment familiarity, and availability of safety personnel) influence evacuation procedures in high-rise buildings?
4. How does how building occupancy, that is, its uses and activities, influence evacuation procedures in high-rise buildings?

1.5 Significance of the Study

High-rise buildings present challenges to occupants during the evacuation, as some people cannot evacuate swiftly during emergencies. This research study will help in providing information on the existing evacuation procedures in these high-rise buildings. It will reveal how building designs influence evacuation procedures, thus enabling architects to design buildings that will have enough means of exit outside the building. The study will also reveal how an individual’s characteristics affect evacuation procedures in buildings. Additionally, the study will show how a building’s use influences evacuation procedures.

1.6 Limitations of the Study

This study is only limited to high-rise buildings, and therefore it cannot be used as a reference in short buildings or flats. The study is only limited to evacuation procedures only, and therefore it cannot be to study other factors of fire safety. The study also had limited time, and the researcher had to dedicate more time to conduct the research and collecting data.

CHAPTER 2: LITERATURE REVIEW

2.1 Evacuation Procedures in High-rise Buildings- Literature Review

2.1.1 Safety Procedures and Requirements in High Rise Buildings

High-rise buildings present crucial fire safety problems of complex designs, multiple floors, combined uses and activities, varying occupant awareness, and different safety policies. High-rise buildings, in this case, refer to buildings that are higher than 75 feet (22.86 meters) or extend between seven to ten stories (High-Rise, 2009). Sharma et al. (2014) note that evacuation procedures in high-rise buildings have to be conducted within the complex designs, high occupancy density, and high social and psychological stress. According to Ronchi and Nilsson (2013), the interaction between building infrastructure and the characteristics of the occupant population (physical abilities, safety knowledge, and familiarity) determine how evacuation procedures should be designed in order to accommodate them. This shows that designing effective safety evacuation procedures should be based on how these variables affect the safety of the occupants and rescue services during a fire emergency. Therefore, evacuation procedures are subject to constant change according to the architectural complexities of modern buildings and the current safety regulations. Galea et al.’s (2008) study on the World Trade Center (WTC) attack highlighted the need to base building evacuation procedures and strategies on the specific designs, occupant behaviour and profiles, and present exit routes. The Texas Department of Insurance (TDI) (2007) notes that the 1993 bombing of the WTC evacuation efforts took more than eight hours due to the high physical demands of using stairs and long vertical distances, which necessitated a conversation on the efficiency of high-rise evacuations.

There are various evacuation strategies employed in high-rise buildings, including phased, total, defend-in-place, and delayed evacuation strategies (Ronchi and Nilsson, 2013). The choice of the strategy used is based on the type of building occupancy, building accessibility, safety awareness, and design (Ronchi and Nilsson, 2013). For instance, the defend-in-place, phased, and delayed procedures should be accompanied by refuge areas, functional elevators, alarms and communication systems, and high-resistance building materials (Ronchi and Nilsson, 2013). The choice of the evacuation procedure should be based on the building height, building material, alarm systems, sprinklers, and the means of egress (Sharma, 2014, pp. 258-9). These provisions influence the evacuation process by determining the reaction-to-response times of the chosen strategy (Sudte and Patvichaichod, 2020). For instance, NFCC (2017) proposes that the stay-put strategy should be utilized for buildings that extend beyond 18 meters and should utilize communication mechanisms that support the different evacuation strategies

These discussions identify that current evacuation procedures are the result of gauging how the building features, safety provisions, and occupants interact during emergency situations to ensure the most efficient strategy through reduced time and congestion (Egodage et al., 2020). Software modelling and safety evacuation exercises are crucial elements that inform high-rise building safety procedures as they are based on the specific characteristics of the building and its occupants. Alalouf (2021) summarizes the modern requirements for evacuation procedures by noting that any changes in the building design, construction failures, occupant profiles, and safety code changes should result in a change in the evacuation strategy. Other factors that determine the evacuation procedures include the building’s evacuation policy, detection and reporting, communication coordination and safety inspections (Rameshan, n.d.). High-rise firefighting (n.d.) summarizes the factors affecting the choice of caution procedures or strategies by highlighting the interrelationships between occupancy, design and construction, safety maintenance and planning, type of occupancy, and human behaviour. These instances highlight the critical challenge of the adequacy of high-rise buildings to accommodate full-scale evacuations (Fenwick, 2006). This review looks into the various strategies that have been applied and proposed for high-rise evacuation as well as the factors that influence the chosen strategy and decisions during the evacuation procedures.

2.2 Defend in Place or Stay Put Evacuation Strategy

The defend-in-place evacuation strategy entails occupants shutting their doors, sealing any openings and remaining in their rooms and waiting for rescuer instructions (Ronchi and Nilsson, 2013). The strategy is highly suitable for occupants with disabilities, which may hinder their using other strategies and has been successfully utilized in the Rinkeby apartment fire (Ronchi and Nilsson, 2013). According to the San Diego Union Tribunal (2009), the fire occurred on 25^th July, 2009 in Stockholm, leading to six fatalities from stair smoke inhalation by the occupants who failed to use the defend-in-place strategy utilized in the building. The remaining apartments were successfully evacuated upon arrival of the rescue services without major damage to their buildings (San Diego Union Tribunal, 2009). According to Alalouf (2021) it is the most applied strategy in high-rise buildings, with different variations depending on the fire safety policy. The strategy is most suitable for extreme fires like explosions or biological and chemical accidents, which make it safer to shelter in place rather than evacuate the premises (Craighead, 2009). Ronchi and Nilsson (2013) the method is highly suited for residential buildings that have more than 6 floors, voice and alarm communication systems, and enclosed compartments. According to Rameshan (n.d.), occupants are required to retreat to an unaffected room that is equipped with a window, phone or signalling mechanism, and fire-resistant doors. The window ensures visibility by the fire services and provides a possible rescue entry or exit, while the phone ensures constant communication with the fire services (Rameshan, n.d.). Similar to the phased evacuation, the defend-in-place procedure requires a comprehensive analysis of the building’s fire safety protection measures to ensure that the structures can accommodate the occupants without exacerbating the fire risk (LGG, 2011).

Passive protection measures like compartmentation (fire-resistant walls and floors), structural fire resistance, and cavity barriers in high-rise buildings play the most crucial role in determining the suitability of the defence in place evacuation as they ensure that the fire and smoke do not reach the compartments or rooms used for the stay (LGG, 2011). As Rameshan (n.d.) identifies above, resistant doors, walls and sealed openings are vital in ensuring the safety of occupants from fire and smoke spread. The UK Local Government Group (LGG) (2011) described high-rise building structural resistance as the essence of the stay-put evacuation strategy. High Rise Firefighting (n.d.) notes that the strategy requires the active participation of the fire services to ensure that any developments render the building inhabitable due to unforeseen escalation.

The defend-in-place strategy’s application and shortcomings were seen in the Grenfell Tower tragedy as it contributed to more fatalities due to the cladding (Alalouf, 2021). Heath’s (2022) analysis of tragedy identified these shortcomings by citing evacuation delays as the London Fire Brigade waited for too long before revoking the stay-put strategy that blocked occupants in their apartments from the rapid-fire spread facilitated by the cladding system. Lack of clear communication also impedes the strategies’ applicability and may increase the fatalities, as indicated in the 25^th July 2009 Kuddbygrand12 fire in Stockholm, which led to 7 fatalities as occupants ignored the instructions (Ronchi and Nilsson, 2013). The challenges experienced in this tragedy underline the insistence on ensuring that the buildings have sufficient passive protection measures like structural resistance and compartmentation. This confirms the need to develop the evacuation procedure and strategy according to the building and occupant safety needs. Safety evacuation in high-rise buildings, therefore, depends on leveraging the available safety policy and mechanisms to choose the most effective and efficient procedure for emergency situations.

LGG (2011) notes that in buildings that are designed for the defend-in-place strategy, communal alarm systems are not necessary, as they might lead to false alarms and cause panic or overwhelm the provided means of egress. In cases where such alarms are provided, the safety manager of the firm services must have some control to ensure that it covers only the appropriate occupants (LCG, 2011).

2.3 Phased Evacuation Process

The application of the phased evacuation process is justified by the inadequate capacity of high-rise buildings to allow for a single staged evacuation due to the high occupancy rate, long travelling distance, and complex designs (Rameshan, n.d.). Also referred to as partial or zoned evacuation, this procedure aims to evacuate the occupants nearest to the fire (Craighead, 2009). The procedure targets the most impacted floors, that is, the fire floor and the two-neighbouring floor, for immediate evacuation, while the rest remain for subsequent follow-up if deemed necessary by the fire department (Nair, 2016). This means that the fire floor and the immediate floors are evacuated first to secure the occupants as well as reduce congestion in the egress routes (Ronchi and Nilsson, 2013). The Texas Department of Insurance (2007) supports the strategy’s effectiveness by noting that due to the high resistance of the high-rise building structures, not all occupants in high-rise buildings have immediate threat after a fire breaks. This is because the fire is usually restricted to a few compartments, which appropriates the occupants not impacted wait for evacuation instructions. Therefore, the provided fire-protecting features must assure the relocated and the rest of the occupants that they are sufficient to prevent the spread to the chosen safe area or floor. This shows that its effectiveness depends on the building’s level of compartmentation to secure the occupants waiting for fire service communication (Ronchi and Nilsson, 2013).

In instances where the lower floors are extensively damaged and untenable to facilitate downward evacuation, occupants are also advised to move upwards (Craighead, 2009). However, this may lead to congestion and accessibility challenges in case it is needed (Craighead, 2009). It also opens the building to using helicopters in instances where the building has provided a helipad. However, there are several safety considerations for the use of helicopters, like the fire conditions, affected floors, and limited capacity, as indicated in the 993 WTC response, which limited their use for evacuation (National Commission on Terrorist Attacks Upon the United States, 2004).

The approach is highly complex and requires highly coordinated communication systems and qualified personnel (Nair, 2016). This complexity requires buildings to have trained personnel and occupant awareness of the strategy’s application in the building to ensure effective application. High Rise Fire Fighting (n.d.) identifies that the strategy relies on a reprogrammed alarm system that classifies the occupants according to the perceived risk and gives warning, standby, or evacuation instructions. Rameshan (n.d.) also notes that the process is dependent on the availability of sprinkler systems, structural resistance and compartmentation to ensure effectiveness. According to Craighead (2009) one of the strategy’s advantages is its suitability to evacuate people with disabilities.

2.4 Total Evacuation Strategy

This strategy refers to the simultaneous and conventional evacuation of all the occupants to the ground level or fire assembly (Rameshan, n.d.). Ronchi and Nilsson (2013) identify the 9/11 WTC incident as the main large-scale application of the total evacuation, which illuminated its shortcomings like stair congestion. It is the simplest and least demanding evacuation procedure for high-rise buildings and entails self-evacuation (Rameshan, n.d.). The occupants are instructed to head to the lobby. Total building evacuation application in high-rises is usually initiated by the fire department and involves directing all occupants to a fire assembly point or refuge (Nair, 2016). The most utilized fire safety components for this strategy are the stairs, whose provisions, location, size, and design should be able to accommodate all the occupants simultaneously in cases of full-scale evacuations (Rameshan, n.d.).

The strategy introduces the danger of overcrowding the stairs as occupants scramble to exit at the same time, which overwhelms the egress routes’ capacity, further exacerbating the fire risk and blocking access to firefighting and rescue services (Craighead, 2009; Rameshan, n.d.). These shortcomings usually come from the required long distances for travel, especially if the building only relies on stairs evacuation (Ronchi and Nilsson, 2013). This makes it impractical for building with high occupancy, needs to incorporate phased evacuation (Craighead, 2009). Therefore, applying this strategy is more efficient in buildings whose egress mechanisms incorporate suitable elevators (Craighead, 2009). The use of elevators during total evacuations requires automated programming for the lifts to target evacuate the occupants on the highest floors first to the lobby or exit (Nair, 2016). When elevators are used for total evacuation, the procedure begins with the higher floors and accords all the occupants’ similar prioritization as it accommodates all the occupants (Nair, 2016).

2.5 Building Design Factors that Influence Evacuation Procedures

According to Sharma et al. (2014), the safety of evacuation procedures in a high-rise building is dependent on the cumulative influence of the building’s design. Several infrastructural design factors, including height, stairs, lifts, sky bridges, ramps, refuge floors, and halls, are very important in developing evacuation procedures (Akasha et al., 2020). All modern high-rise buildings like residential (hotels, apartments, shopping malls, offices, and government facilities should be provided with stairs cases that are sufficient to cater to the floor with the highest population and the merging floors as determined by their number, width, height, placement, and length (Ronchi and Nilsson, 2013). Each floor should be provided with egress routes that cater for its floor area, occupancy density and the likelihood of merging stairs from other levels (Gian et al., 2021). Alalouf (2021) notes that building safety managers should ensure a change in the evacuating strategy to correspond to any design, geometry, structural, or occupant profile changes.

This assertion requires high-rise buildings to conduct a fire safety assessment and evacuation drills to determine the need or type of evacuation procedures change. The designs, location and size of the building’s safety features should be able to factor in all occupants’ needs, including the capacity, the disabled and elderly, and assistance from safety personnel to reduce any delays that occur during emergency evacuation (Gian et al., 2021). According to Rameshan (n.d.), high-rise building elevators should have automated control, high fire resistance, accommodate people with disabilities, and trained operators. The building design, size, and occupancy also influence the type of required safety features like alarm systems, automatic sprinklers, and communication systems (Akasha et al., 2020, p. 5).

According to Zhang (2017) staircases form the most utilized evacuation provisions in high-rise buildings with increasing combination with other mechanized evacuation measures. High-rise stairs have to meet several structural and geometrical specifications, like number, size, location, and slope, of stairs to qualify for their use in fire emergency evacuation. Rameshan (n.d.) identifies that internal staircases should be separated from the fire escape entrance, always remain unobstructed, have a fire-resistant fire escape and have a direct connection to the lobby or ground level. Rameshan (n.d.) outlines the geometrical characteristics required for fire escape stairs, including a straight flight of at least 1.25 meters wide, 0.2 m treads, and not more than 0.19 risers. It also gives a minimum of 1 meter for the handrails, which must also be fire resistant (Rameshan, n.d.). The challenges of relying on stairs for evacuating high-rise buildings include crowding from merging streams, exhaustion, and its applicability to people with disabilities (Ronchi and Nilsson, 2013).

2.6 Alarms and Communication Systems

Sharma et al. (2014) note that it is mandatory for all high-rise buildings to provide fire-resistant construction, automatic sprinklers, and alarm systems. Alalouf (2021) underlines the importance of alarm systems by noting that high-rise buildings in Wales and the UK mandate the building to provide extra evacuation alert systems to inform both the occupants and rescue services. These include alarms or warning systems and voice communication systems for active communication between the occupants and rescue services (Alalouf, 2020). These indications show that the building’s safety features should be installed to complement the building’s design and characteristics to enable timely response and accessibility. These regulations are outlined under the BS 8629: 2019 to ensure that the buildings have a non-detection system solely used for communicating about evacuation and fire alerts (Alalouf, 2021). Although it might be economically viable to integrate the alert systems with the building’s conventional fire detection systems, BS 8629 proposes that it should endeavour to separate them (FIA, 2019). Each floor is supposed to have a separate control and indicator or combination system to ensure targeted notification instructions depending on the available risk (FIA, 2019). According to TDI (2007) high-rise building alarm systems should be fitted with emergency voice communication as the evacuation processes require instructional guidance for the needed measures due to varying fire conditions on different floors.

2.7 Elevators

Evacuation elevators, that is, lifts that are specifically designed with fire safety requirements like fire resistance, remote communication systems, shaft protection, lobby provision, and waterproofing, also provide evacuation options in high-rise buildings (Minegishi, 2021). This is despite earlier published safety documents warning against the use of elevators as they are prone to malfunction and smoke saturation, which increases the risk to the evacuees (TDI, 2007). The WTC bombing led to the reevaluation of their incorporation and use during fire emergencies (TDI, 2007). Rameshan (n.d.) notes that elevators provide tangible benefits for the evacuation process of any building with more than three storeys. This shows the need for its incorporation into high-rise building evacuation procedures. Although it is not a mandatory safety requirement, the Life Safety Code section 7.14 provides for the requirements of installing elevators as evacuation components in high-rise buildings (NFPA n.d.). However, its use shall not lead to its categorization as one of the building’s means of egress to satisfy the standard safety requirements. This means that despite using elevators, the other means of egress should still be sufficient according to the building’s occupancy and occupant load (NFPA, n.d.).

The use of elevators in evacuation procedures should be accompanied by suitable designs, clear marking and signage, two-way communication systems in the lifts, sprinkler systems, and activation by the building’s alarm (NFPA, n.d.). Rameshan (n.d.) also points out that elevators used for high-rise evacuations should be made from concrete and have adequate space for movement and acceptable comfort during emergencies. The required resistance for evacuation elevators should be at least 120 minutes, have sufficient ventilation, and have a minimum area of 0.5 m² for every occupant (Rameshan, n.d.). According to Ronchi and Nilsson (2013), evacuation elevators should also account for earthquakes and communication systems to ensure their suitability during extreme events.

During active evacuations, the elevator control should not allow any stops on the floors impacted by the fire and should always head to the lobby after picking up the occupants (Rameshan, n.d.). This requirement identifies the need for a qualified safety officer charged with manning elevators (Rameshan, n.d.). Other duties of the qualified safety personnel in manning the elevators include accounting for all the necessary delays incurred during charging and discharging, door closing delays from overcrowding, and acceleration/deceleration during emergencies (Rameshan, n.d.). When used to evacuate people with disabilities, they (the disabled) should be assisted to the waiting areas by safety managers or other occupants. The elevator stops should be designated to selected safety floors away from the origin or affected areas and should have fire-rated construction, adequate height, ventilation and signage (Rameshan, n.d.).

Elevator provision in high-rise buildings should combine evacuation and firefighting lifts to ensure their suitability during a fire. Evacuation lifts entail those that are fitted with additional functions that allow their utility in emergencies like automation (GLA, n.d.). These elevators are used for normal occupant-level access during non-emergency situations and are managed by rescue services or building management to aid during emergencies (GLA, n.d.). On the other hand, firefighting lifts are installed to ensure rescue services access to floors that are further from the main access point (IRM, 2020). The lifts can also be used to aid in the evacuation of disabled occupants and should be barred from moving goods to reduce the risk of obstructions during emergencies (IRM, 2020). Both types of elevators should be clearly marked and manned by trained personnel, have communication systems (visible and audible) and function independently from other elevators in the building to ensure their efficiency during evacuations (Varisco, 2019).

2.8 External Evacuation Mechanisms

There are various technological innovations that have been proposed to increase the efficiency of high-rise evacuations, including elevators, which were before prohibited from evacuation infrastructure. Rameshan’s (n.d.) characterization of the external evacuation systems was that although they increase evacuation efficiency when used in the right situation, they are also dangerous and may contribute to further injuries and fatalities in emergency situations. This explains their prohibitions under some safety standards, especially if they have not been tested in simulated or actual fire situations. According to Nair (2016) modern high-rise Buildings can also employ external devices like helicopters, rescue chutes, suspended rescue platform systems, not-structural dependent devices, and controlled descending apparatus.

The National Fire Protection Association (NFPA) (2022) recognizes and allows the use of external The Life Safety Code 101 allows the incorporation of the chute and controlled decent devices in high-rise buildings. These additions, have to be designed to suit a building’s architecture and available hazards (TDI, 2007). The evacuation and rescue chutes comprise a trough or cylindrical shaped device made from fire-resistant material and inclined at the side of the building to facilitate sliding own (Nair, 2016). The device’s descent is controlled by the inclination angle to ensure smooth sliding and a suitable speed (Nair, 2016). The main advantages of using chutes for high-rise evacuations are that they accommodate people with disabilities, are accessible from any floor, and have a high capacity, and speed (Nair, 2016). The devices can either be permanently installed or portable, which allows their use at various points in a given building (Rameshan, n.d.). The mechanism is capable of evacuating approximately 25 people a minute and depends on the gravitational pull to facilitate vertical descent (Rameshan, n.d.). This shows that the devices do not require power to aid the evacuation process, in addition to their portability and use on different floors. Despite these benefits, the TDI (2007) records that the US safety codes do not allow or recommend using external escape devices like chutes and descend devices their use in public and commercial buildings (TDI, 2007).

Figure 1. fire escape chutes. Source: Nair (2016)

Suspended rescue platform systems and controlled descent devices are external and permeant fixtures that may be manually operated or automated. According to Nair (2016), the suspended platforms include multiple cabins capable of gliding along the building’s exterior sides on guides and helping evacuate occupants and giving access to rescue services. Rameshan (n.d.) notes that the use of suspended platforms can be provided as a permanent safety component in a building, installed additional systems, or brought by fire services. The installations have the capacity of beginning with 30 people covering two floors (lite) or up to 160 occupants on five floors. The cabins are usually invisible from the ground and require occupant and firefighter awareness of their existence to ensure their use (Rameshan, n.d.). The system uses foldable cabins usually stored on the roof and requires an independent power source, a cabin array, a drive system, and a control and command system (Rameshan, n.d.). The building should also be configured, and windows stabilized to accommodate the systems (Rameshan, n.d.).

Figure 2: An illustration of a suspended rescue platform and controlled descend device. Source: Nair (2016).

On the other hand, the controlled descent devices are permanently installed evacuation systems that use a harness, braking device, and cable connections (Nair, 2016). These components interact to control occupant descent from higher floors and may be used by individuals or used by fire services to strap occupants or animals (Rameshan, n.d.). The system allows for either manual or powered decent mechanism and is limited in its capacity as it can only accommodate one or two occupants (Rameshan, n.d.). The devices are located at accessible points like balconies or windows (Nair, 2016). The TDI (2007) notes that although the use of external evacuation mechanisms is not widely utilized in the US and the Life Safety Code, they have been used in some manufacturing environments and towers, showing their increasing applicability during emergencies.

2.9 Human Characteristics Affecting Evacuation Procedures in High Rise Buildings

Alalouf (2021) notes that human behaviour is highly dynamic and unpredictable, which may result in unprecedented changes in evacuation procedures despite meeting the strategic and structural suitability thresholds outlined above. The level of training for the safety staff, safety awareness, familiarity with the building, physical conditions, age, and people with disabilities (wheelchairs) are key occupant characteristics that are considered in high-rise evacuation procedures and safety provisions. Akasha et al. (2020) note that the profiles of the occupants are crucial in modelling the evacuation procedures in high-rise buildings as they determine the speed and safety requirements of the building. The level of awareness of the safety policy, procedures, responsibilities, and plans is one of the most vital occupant elements that determine the evacuation (Akasha et al., 2020). Rameshan (n.d.) records that high-rise buildings safety managers can improve occupant safety awareness by conducting evacuation drills, training programs and visitor instructions in case of an emergency.

Egodage et al.’s (2020) research on high-rise considerations for the differently-abled found that buildings often overlook their needs during emergencies. This introduces the need for buildings to include facilities and procedures that accommodate their safety needs. This indicates that modern buildings should have communication systems, assistive facilities for wheelchairs, and accessibility (stairs, elevators) (Egodage et al., 2020). These provisions should factor all forms of disabilities, including mobility, hearing, and sight, within the evacuation procedures to meet the required safety arrangements. Despite the increasing awareness and code provisions for the disabled, most buildings, especially older structures, overlook their needs when designing evacuation procedures (Egodage et al., 2020). Nair (2016) notes that buildings should avail evacuation mechanisms for people with disabilities, temporarily injured, the elderly, and the pregnant, like wheelchair stair climbers and evacuation chairs. Craighead (2009) also includes extremely overweight people, occupants with mental challenges, as well those who have been injured during the emergency. High-rise buildings must register all these groups to ensure installing the required monitoring and assistance mechanisms (Craighead, 2009). Regardless of chosen evacuation procedure or strategy, a building housing people with disabilities should have a rescue assistance area for the disabled to wait for assistance services (Craighead, 2009).

Another key human factor influencing evacuation procedures, according to evacuation simulations, is group behaviour (Ronchi and Nilsson, 2013). These variations in group behaviour include decision-making like the direction, waiting for behaviour, panic, and choice of evacuation medium, which are critical in dictating the speed and effectiveness of the escape procedures (Ronchi and Nilsson, 2013; Satir and Toprakli, 2020, p. 556). Gian et al. (2021) note that a combination of the human characteristics among the occupants determines the walking speed of the group during evacuation. During an emergency, the building occupants interact with each other to inform their decisions, which influences the speed, direction, and exit routes (Niu et al., 2019). This shows that the chosen procedures and strategies must factor, through simulations, how these interactions influence evacuation efficiency and occupant safety (Niu et al., 2019). Some of the ways that safety personnel can influence positive group behaviour during an evacuation are through active communication and real-time reporting on the safety requirements and evacuation plans in the building (Niu et al., 2019). Fire disasters like the Grenfell tower indicate the role human behaviour and evacuation strategies can play in fire evacuation as the occupants rushed to the upper floors instead of staying put, which increased the fatalities (BBC, 2019). Ronchi and Nilsson (2013) also point to occupants ignoring fire rescue’s instructions to stay in place as the reason for the high fatality rate in the Kuddbygrand 12 fire in Stockholm.

CHAPTER 3: RESEARCH METHODOLOGY

3.1 Introduction

Research methodology outlines the methods and tools which will be used to collect data from the field of study. This chapter discusses the research design, target population, sampling design and sampling frame, sampling procedure, data collection procedure and instruments, data analysis and presentation.

3.2 Research design

Research design is a strategy used by a researcher to answer the research questions by the use of empirical data. Research can be either quantitative or qualitative, quantitative research methods are used in measuring and counting while qualitative research methods are for interviewing and observations.

The research will use qualitative methods since the major aim of the research is to analyze the factors that influence evacuation procedures in high-rise buildings. This method will provide in-depth insight allowing the researcher to explore the context of the research. The method will help the researcher bridge the gap as the study will add scientific information to the research topic. Qualitative methods are useful for exploratory purposes, and therefore the researcher will explore a lot.

3.3 Sampling Procedure

According to (Fred, 1983), a sample is a small portion of anything aimed at representing the whole. The research sampling design for this research was purposive sampling. According to Kassiani Nikolopoulu (2022), purposive sampling is a group of non-probability sampling methods where units are selected because they possess the characteristics needed in a sample. The researcher will select the occupants of high-rise buildings purposely, as the study is aimed at high-rise buildings.

3.4 Target Population

Target population refers to a broad group of people that are under examination by researchers. The target population for this research are building owners, high-rise building employees, business persons, or visitors to the premises. The researcher expects to collect information from these people as they are the direct users of that building.

3.5 Data Collection tools

Data collection is crucial in research because it provides information that helps the researcher to understand his/her objectives. Data collection involves collecting and measuring information on targeted variables in an already established system. This information is then used to answer research questions and evaluate the outcomes of the study. There are several methods of data collection, i.e. surveys and questionnaires, interviews, observations, records and documents, and focus groups.

This study will involve the use of questionnaires and interviews. The questionnaires will be distributed both physically and by survey monkey to a total of 50 participants.

3.6 Data Analysis and Presentation

After gathering data, the researcher has to obtain vital information from the data and present it in clear diagrams. To do this, data analysis has to be conducted on the collected data. The researcher will use Excel and manual analysis to analyze the data. The data will be presented in diagrams such as bar graphs, pie charts and tables.

3.7 Data Analysis

3.7.1 Introduction

Chapter four contains the data analysis and findings. The data was collected from a total of 50 participants by use of questionnaires and surveys. The questions in the questionnaire were based on the research questions and they helped the researcher to get more information on his research topic. The data were analyzed using manual analysis and excel and presented using diagrams, tables and figures formulated from the excel package.

3.7.2 Participant’s Gender

It is important to give equal representation to both genders as this will ensure gender balance which is important for research. For this research, there were 50% male and 50 % female, and the researcher used an equal number of both genders to understand the evacuation challenges of these genders.

3.7.3 Respondent’s Age

The age distribution is important for the research because mobility issues affect occupants’ ability to evacuate from high-rise buildings. These six people were aged fifteen years to twenty-five years, and nine respondents were aged between twenty-six years to thirty-five years, fourteen respondents were aged thirty-six years to forty-five years, ten respondents were aged forty-six years to fifty-five years, six respondents were aged fifty-six years to sixty-five years while five respondents were aged sixty-five years and above. Incorporating all age groups in the research was important as it helped the researcher to understand their experience in a fire evacuation.

3.7.3 Showing People with Disabilities

From the total respondents used for this study, 15% were people with disabilities, while 85% of the respondents were normal. Incorporating people living with disabilities in the research was important as they are part of the occupants, and they face challenges during evacuation in case of fires.

3.7.4 The Number of Occupants in the Buildings

Since it was impossible to count all the occupants of the high-rise building. The researcher did estimations and even questioned the building manager on the average number of people who occupy the building. It was reported that an average of 700 workers reside in the building and a 1000 visitors would visit the premise at a given time. These numbers varied depending on the season, days, and time of the day.

3.7.5 Showing Role of The Respondents in The Building

From the total respondents selected for the research, three were managers, and twenty were employees working in different businesses located in the building. Fifteen respondents were business people who invested in the building, eight people were visitors who had visited the building frequently, and four people were technicians and plumbers who visited the building to do repairs and maintenance work.

3.7.6 Showing If the Building Complies to Construction Regulations

The design of high-rise buildings can affect evacuation procedures during emergencies. 60% of the total respondents said that the design of the building affected the evacuation procedures while 40% said that it never affected evacuation. They cited the limited number of exits and many stairs, which increased the evacuation time.

3.7.7 Showing if the building has facilities for People Living with Disabilities

Building owners are mandated by law to put into consideration the safety of people living with disabilities. This includes wheelchairs, ramps, and emergency evacuation chairs, among others. 90% of the total respondents reported that the building has facilities for disabled persons. Only 10% of the respondents reported that they had not seen such facilities around the building. These were mostly the visitors who were not used to the building.

3.7.8 Showing Whether the Provided Means of Egress Were Enough for The Occupants

The number of egresses is calculated in the design phase based on the expected number of occupants. From observations and interviews, the building has enough means of egress for the occupants. However, sometimes the number of people in the building is high and this could be a challenge as the people would crowd in the available exits causing a stampede. The management reported that elevators are not used to evacuate people as the power supply is always cut in case of emergencies.

3.7.9 Showing the Length of Period Spend at The Building

Understanding the length of period the respondents had spent in the building was important as it informed the researcher on other aspects of the research topic. From the total respondents, 36% of respondents reported having stayed in the building for two years to five years, 24% reported having stayed in the building for six years to ten years, 18% of respondents reported having stayed in the building for six months to two years. Twelve per cent reported having more than ten years residing in the building, while 10% had less than six months in the building.

3.7.10 Showing Whether the People Knew the Building Fire Emergency Plan

The building owners and managers are required to sensitize their tenants and staff on the existing fire emergency plans. This is important as people have knowledge of how to evacuate in case of fire emergencies. From the total respondents, 80% of the respondents said that they were not aware of the building’s emergency plan, and only 20% of the total respondents understood the fire emergency plan. This implies that most people had not seen the emergency plan, and this would likely result in confusion in case of a fire emergency in the building.

3.7.11 Showing the Last Date of Fire Safety Training

This question sought to reveal fire safety training in the building. Eleven respondents reported having heard about training in a period of last year, nine respondents said they had heard about it two years ago, thirteen people said they had heard about it three years ago, and seventeen people said they had not heard about it. The management reported that they train the people on a yearly basis. The notification to conduct the pieces of training was not well circulated or maybe people ignored the trainings.

3.7.12 Showing Last Date for Fire Drill

Fire drills are supposed to be conducted annually to test the existing fire emergency plans. Of the total respondents, thirty-five reported that there was a fire drill last year, ten people reported participating in a drill in 2 years, while five people said that it had taken more than two years. These variations were caused by some factors like shift change or absenteeism from the building.

3.7.13 Showing Whether There Are Fire Safety Officers in The Building

The management reported that the security staff had been trained in basic fire safety courses, and therefore they had the knowledge to extinguish fires using fire extinguishers and hose reels. Also, the building has a safety officer who conducts inspections to ensure that there are no fire risks. The local authorities also conduct fire safety inspections as per the regulations.

3.7.14 Showing If There Are Special Safety Provisions Required During Evacuation Procedures

During fire emergencies, people should be carefully guided to evacuate the building. 75% of the total respondents agreed that there are special provisions in case of evacuation, and only 10% of the respondents claimed that there are no provisions given. Those who acknowledged the existence of these provisions cited the use of public address systems to warn the people, signages to show the exits, and security personnel also helping people exit the building. The disabled are also evacuated by their colleagues or security people using emergency evacuation chairs or wheelchairs.

3.7.15 Storage of Hazardous Goods

The management reported that it is prohibited to store any hazardous goods, and those doing show should report for further guidance. There is a safe storage facility near the building where some hazardous goods like petrol are safely stored.

CHAPTER FOUR: CONCLUSIONS AND RECOMMENDATIONS

4.1 Introduction

This chapter contains a conclusion that was based on the research findings. The researcher used questionnaires and analyzed data to understand the objectives. The conclusion made in this chapter is based on the research findings. Additionally, the chapter contains recommendations for improving the gaps noted in the research.

4.2 Conclusion

The researcher noted that most people who visit high-rise premises are employees and business persons. These categories of people spend more hours at the buildings, and therefore they are aware of their surroundings. Understanding the role of building occupants is key because it affects their behaviour during evacuation procedures. These people can delay evacuating to close their shops or take care of their property resulting in an increased number of casualties.

The construction process of buildings is regulated by well-formulated regulations like fire safety laws. The architects should ensure that their building designs adhere to safety laws. The premise was found to comply with most construction regulations; however, the number of emergency exits was not enough for a building of such occupancy. Some exit doors were obstructed and not clearly labelled.

Disabled people, including the elderly and children, play an important lot in planning evacuation procedures since they cannot move by themselves. Building owners are required to include wheelchairs, ramps, and emergency evacuation chairs, among others. The building had complied with most of these requirements.

Most of the building occupants were not aware of the building’s emergency plan. Occupants should be trained on evacuation procedures to ensure that they evacuate safely in case of emergencies. They should be made aware of the emergency exit doors, fire alarms, and fire assembly points, among other aspects.

The fire safety inspections were conducted in the building as required by the fire safety regulations of Oman, and this is commendable. Additionally, the building has a facility for the safe storage of hazardous goods.

4.3 Recommendations

The following recommendations are given based on the conclusions:

• The employees and business owners are an important lot during evacuation since they spend most of their time. They should be well trained on fire safety and evacuation plans to help the visitors and customers who frequent the buildings for different roles. The management should ensure that employees and business owners are aware of the safety plan, train them on the use of fire extinguishers, and they should also be aware of all emergency exits.
• The building owner should consider using new signages with self-illuminating features to direct evacuees during emergencies. Also, all building plans should be thoroughly inspected by fire safety engineers to ensure that they have enough emergency exits.
• The building should be fitted with more emergency evacuation chairs to help people with mobility issues. Security, employees, and business owners should be trained on how to use these chairs.
• The employees, business owners, and frequent visitors should be trained on the emergency plan. They should be involved in preparing and improving such plans as they are part of the building.
• The fire safety plan and emergency plans should be displayed on all floors near the lifts and stairs for building users to read and follow them in case fire or other emergencies like terrorism take place.

References

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APPENDICES

Appendix 1: Questionnaire

Evacuation Questionnaire

This questionnaire was developed as part of an academic research project titled ‘Evacuation Procedures in Highrise Buildings’ at the University of Central Lancashire- School of Engineering. The questionnaire seeks more information on the factors that influence evacuation in multi-storey buildings.

Part 1. Introduction

1. What is your gender?
   1. Male
   2. Female
2. What is your age bracket?
   1. 15-25
   2. 26-35
   3. 36-45
   4. 46-55
   5. 56-65
   6. Above 65
3. Do you have any disabilities?
   1. Yes
   2. No
4. How many employees or occupants use the building? _____________
5. What position or occupancy do you hold in the building?
   1. Manager/owner
   2. Employee
   3. Business person
   4. Visitor
   5. Other _________

Part 2. Building factors

6. Does the building design complicate evacuation procedures during emergencies?
   1. Yes
   2. No
7. Are there facilities for the disabled population, like wheel chairs and ramps?
   1. Yes
   2. No
8. Are the provided egress routes (stairs, corridors, doors) sufficient for the building occupancy?
   1. Yes
   2. No
9. Are the building’s elevators utilized during the evacuation procedures?
   1. Yes
   2. No

Part 3. Occupant characteristics

10. How long have you resided in the building?
    1. Less than 6 months
    2. 6 months – 2 years
    3. 2 to 5 years
    4. 5 to 10 years
    5. More than 10 years
11. Are you aware of the building fire emergency plan?
    1. Yes
    2. No
12. When was the last time the building had fire safety training?
    1. Less than 6 months ago
    2. Less than1 year
    3. 1 to 2 years
    4. 2 to 5 years
    5. More than 5 years (specify) ____________
13. When was the last time the building had a fire safety drill?
    1. Less than 6 months ago
    2. 1 year
    3. 2 years
    4. More than 2 years
14. Are there active fire safety officers in the building?
    1. Yes
    2. No

Part 4. Building occupancy

15. What is the building’s main use? ____________
16. Are there any special safety provisions required during evacuation procedures?
    1. Yes (Specify) _______________
    2. No
17. Are there any hazardous materials stored in the building?
    1. Yes
    2. No