Evaluation of a fire safety risk prediction model for an existing building

: Fire is one of the most critical risks devastating to human life and property. Therefore, humans make different efforts to deal with fire hazards. Many techniques have been developed to assess fire safety risks. One of these methods is to predict the outbreak of a fire in buildings, and although it is hard to predict when a fire will start, it is critical to do so to safeguard human life and property. This research deals with evaluating the safety risks of the existing building in the city of Samawah/Iraq and determining the appropriateness of these buildings in terms of safety from fire hazards. Twelve parameters are certified based on the National Fire Protection Association (NFPA2016) code. The concept of giving weight to each criterion was adopted to classify the criteria according to their importance and then conduct an on-site examination of these existing buildings to test the selected criteria. The result indicates a possible fire risk in these buildings due to the lack of compliance with fire safety instructions in the approved codes.


Introduction
According to the history of fire and fire codes, fire has been a fundamental aspect of humankind's existence and survival from its beginning.Years of experience, occurrences, tragedies, and education have all contributed to the evolution of how humans deal with, control, prevent, confine, and create safe circumstances in the face of fire.Many organizations, like the National Fire Protection Association (NFPA), the International Code Council (ICC), and Under-writers Laboratories (U.L.), have played a significant role in the creation of codes and laws that restrict the destructive effects of fire.Building codes have been existed throughout history to help prevent fires and limit their spread.These restrictions have evolved into the codes and standards produced by safety committees throughout the years [1].
The construction of buildings must enjoy sufficient safety to protect people, property, and the environment, even when it is required that the buildings become complex in their construction and be more demanding in the case of the implementation of less expensive buildings.It must be demonstrated that these buildings meet fire safety, and there must be a need to define and evaluate the fire safety design of the buildings [2].The systems for assessing fire danger have been researched over time.No matter how hard fire safety is researched, absolute safety can never be attained, but it may be decreased to an acceptable level [3].
Fire risk prediction, analysis, and appraisal are part of the fire risk assessment process.Fire hazard prediction and analysis may be expressed in qualitative, mixed, or quantitative approaches relying on the nature of the risk, the goal of risk analysis, and the availability of information resources [4].The method of determining the likelihood of fire incidents occurring under specific circumstances is known as fire risk prediction [5].The use of defined hazard standards to determine the amount of fire danger is what fire danger evaluation entails.The process of upgrading current risk-controlling measures and putting them in place to decrease fire risk is known as fire risk treatment.As the initial stage in fire danger management, fire hazard prediction is the basis for regulatory decision-making on danger reduction initiatives [6].
Buildings remain in need of research to improve the performance of fire forecasting techniques and methods, where models are applied to various buildings, and an attempt must be made to increase focus and accuracy in predicting fires by using new methods, as there are many methods for assessing fire risks, including making an index for all types of risks in buildings [7].
Many studies have been conducted around the world to assess and predict fire hazards.Where many different techniques and methods have been used for the purpose of achieving adequate safety and security in buildings.Watts [8] proposes a novel approach for estimating fire risk called fire risk indexing.According to his study, fire risk indexing is a heuristic methodology for fire safety based on the knowledge and understanding of fire professionals.While Nikolopoulos et al. [9], demonstrated the model's ability to forecast the presence of post-fire debris flows.They used a contingency table to compare the results of three different approaches: rainfall thresholds, logistic regression, and random forest.Also, Umar et al. [10], investigate a suggested fire protection administration assessment approach for Nigerian plastic industrial buildings.This research attempted to assess the factory's safety level established on the ten classes of fire security administration accepted by examining the performance of fire safety administration in the factory building through physical checking.According to the results of the theoretical study, expert opinion poll, and physical checking, it is apparent that fire protection administration in any structure should be evaluated using numeral performance.Whereas Garis and Clare [11] previously create a set of heuristics for calculating the frequency of commercial property blaze checks based on the buildings' attributes.They assigned a score to each property based on its degree of compliance during previous inspections, as well as a set of danger metric elements such as building type, age, and sprinkler presence.However, as they admit, the weights and selections of those elements were made by hand established on their fire code, not on historical details regarding aspects that were highly predictive of blazes.Also, Hassanain [12] present a study to assess the risks in hotels and identified the factors that make hotels high danger.The results recommended that contingency response plans should be implemented and developed, and the study also provided an approach for fire integrity inspectors to follow during fire integrity inspections.
Based on the findings of previous studies related to fire happening prediction.So, the analytical approaches that gave the best forecast performance differ depending on the specific prediction domain connected to the fire event [13].Our study differs from previous studies because it relies on fundamental standards within an internationally approved international code (NFPA code), and each standard is analyzed into three parts.Analyzing the standard into three parts is a new method, which gives high accuracy in predicting the possibility of a fire occurring in buildings, while Previous studies depend on historical fire incidents in buildings or on general surveys and opinions of building occupants in terms of fire risks.The scientific benefit of our research is to provide a new method for examining buildings and identifying weaknesses in fire safety proce-dures with high accuracy, thus reducing the outbreak of fires in buildings and reducing injuries, deaths and property losses.
The research challenge is the difficulty in determining the best strategy to determine the safety variables that influence the compatibility of existing structures and their compliance with international fire safety standards.As a result, the study's goal is to assess the fire prediction model for existing structures to determine how well they comply with the NFPA code in terms of fire safety risk.

Methodology
The study adopts twelve parameters from the NFPA code to create a model to predict safety from fire risks.The result of this predictive model is a set of scores from 0 to 100 (from the lowest to the highest degree of safety compliance from fire hazards); a percentage weight is given to each parameter according to its importance.Then, a site inspection is conducted for one of the existing commercial buildings, based on the list of approved parameters for safety from fire hazards in most international codes.The degrees of fire risk in the building is checked and compared with the list of parameters to produce the result of the degree of compliance of the building with the safety of fire risk.Table 1 shows the parameters adopted in this research.
The analysis focuses on each safety parameter's range or spread.The range of a safety parameter's value from the lowest to the highest is thought to measure its significance.The more significant spread, the greater the parameter's influence on the final fire safety score; consequently, the higher its implied relevance [14].Table 1 shows the parameters adopted in this research.

General requirements
The commercial building is selected to check the degree of compliance with fire safety, This type of building is chosen due to the crowding of people for shopping most of the time of the day.The NFPA code classifies these buildings as medium-risk, meaning that their risk is relatively high in terms of fire, so they need an assessment of the safety of fire risks to preserve the lives of residents and the building owner's property.

Case study description
The building consists of six identical floors, each floor area is 720 square meters, the height of each floor is 4.25 meters, and the floor is an open space with no fire barriers.These floors are connected by a 1.4-meter-wide concrete staircase, and the building has two exits on the ground floor, each 1.5 meter wide.The building also includes two rooms, one for administrative matters and the other used for other services.Figure 1 shows the ground floor plan, which is the same for all floors of the building.

Identifying fire hazards
Any process, condition, or material, based on the available information about the building, could cause a fire, or it could be a ready-made fuel source to increase the intensity of the fire or increase the speed of its spread and cause danger to human life and property [15].

Ignition sources
Electricity is the source of ignition in the building.There are no significant sources of ignition inside the workplace, and no one is allowed to smoke inside the building [16].

Fuel sources
The sources of flammable materials in the building are the materials that are sold in the commercial building such as home furniture and electrical appliances, and paper and plastic waste that results from the sale of these materials are collected and emptied every night outside the building in metal bins.

Fire safety evaluation prediction concepts and considerations
Eight variables are employed in the fire safety assessment technique for commercial occupancies to determine a building's fire control result, while 10 parameters are utilized to calculate its egress level.A score for overall fire safety is calculated by adding the values of all twelve criteria [14].
In this research, only the overall fire integrity scores are considered.Table 1 shows the parameters adopted in this research.The degree of compliance with fire safety has been divided into four categories.Each score has its safety compliance level and its predictive score as shown in Table 2.The final sum of the building evaluation during the on-site inspection indicates the level of compliance with the fire risk and predicting the occurrence of fire in the building.

Parameter weight analysis
The total parameter weight indicated in Table 1 is the ideal state for each parameter, and since there are no such cases in most of the buildings, this total weight of the parameter was divided into three classes (Low, Moderate, and High).Table 3 shows the partitioning of parameters.Each standard is of particular importance for fire safety, and these standards are a series that are interrelated with each other, the greater number of parameters comply with the instructions of the NFPA Code, the degree of fire safety of buildings will rise to a high degree of safety.Figure 2 shows the importance of each parameter according to the three fire hazard security classes.

Predictive score assessment
The parameters will be analyzed and the requirements of the NFPA code compared with the reality of the commercial building to form a predictive model of fire safety.

Construction
According to the requirements of the code (NFPA 5000), business buildings that contain a human gathering of fewer than 300 people must provide a fire resistance of at least one hour.
The building is built of reinforced concrete, meaning that its classification according to the code is (Type I), which means that it provides a fire resistance of more than 4 hours.So, this parameter checks the condition of the code.Therefore, this parameter is classified as Class III.

Segregation of hazards
Code requirements (NFPA101) for this parameter, there must be hazard insulation in business buildings that provides a fire resistance of at least one hour.When checking the building, it was found that the ground floor of the building is not isolated from the first floor, and this provides ease in the transmission of fire to the other floor.While the rest of the other four floors are isolated from each other and fulfill the condition of the code.Therefore, this parameter is classified as Class I.

Vertical openings
Vertical apertures and penetrations, such as ramps, exit stairways, other pipe shafts, vertical exits, duct penetrations, ventilation shafts, duct penetrations, incinerator chutes and laundry, are all affected by these values.Vertical apertures are charged according to the enclosure's fire resistance if one is available [17].The building contains vertical openings that meet the code's requirements, so this is classified as Class III.

Automatic sprinklers
The system must comply with the criteria of NFPA 13 when an automated sprinkler is installed for full or partial building coverage.To be eligible for credit for "whole building" sprinkler safeguarding, the entire building must be sprinkler-protected, and that coverage must cover all of the building's zones [17].When examining the building on-site, it was found that it does not have a sprinkler system for fire protection.So, it does not meet the code requirements and is classified as Class I.

Fire alarm
There is no fire alarm technique in place, or the system is insufficient and does not fulfill the criteria for a higherscoring class [17].The building contains a fire alarm system on four floors only.The other floors do not contain this system.So, this parameter is classified as Class II.

Smoke detection
All references to detectors refer to smoke detectors.Heat detectors in livable space receive no credit.Heat detec-tors can be used in uninhabited locations when ambient temperatures are likely to surpass 120 ∘ F (50 ∘ C) or dip below 0 ∘ F (−18 ∘ C), as long as there is at least a 30-minute fire-resistance-rated separation from occupied spaces.In this parameter, only those detectors whose activation will sound the alert within the origin zone are to be rewarded [17].This feature is also only available on four floors of the building.Therefore it is classified as Class II.

Interior finish
The flame spread index of interior finish materials on walls, columns, and partitions must not exceed 200.Interior ceiling finish materials must have a flame spread index of no more than 75.The smoke produced index is unrestricted.
The flame spread index of interior finish materials close to or surrounding a furnace or water heater, as well as the ceilings above them, must not exceed 25.The smoke produced index is unrestricted [17].
The floor of the building is made of porcelain, and the stairs are made of granite, and the diffusion index for both materials is less than 25, and this fulfills the condition of the code.As for the walls, they are impregnated with Pent light.The diffusion index of this material is less than 75, and it fulfills the condition of the code.As for the roof, it is a component of a plastic material (secondary roof), the diffusion index of this material exceeds 25, so it does not fulfill the condition of the code.Therefore, the classification of this parameter is Class II.

Smoke control
The building does not have any smoke control system so this section will be classified as Class I.

Exit access
The 50 ft (15 m) dead-end boundary applies to existing buildings.When applying this condition in the building, it was found that it did not achieve the required because the farthest distance found in the building is 36 meters.Therefore, the classification of this parameter is Class I.

Exit system
Exit System refers to all sorts and combinations of passageways that go from any place within a room to a public way [17].The building contains only two exit entries, and according to the requirements of the code, it should have had three exits.So, This section will be classified as Class II.

Corridor/room separation
If the corridor wall includes exposed apertures between the floor and ceiling (no door, or louvers, gaps, or transfer grilles), the separation is deemed "incomplete".If there are openings above the ceiling level, the separation is complete if the room's ceiling is a completed membrane [17].While the reality of the building's condition, there is no insulation in it, except for the administration and services room.Therefore, this parameter will be classified as Class I.

Occupant emergency program
The number of fire exit exercises done in the building each year determines the value of this attribute.The parameter is given a (−2) if no fire exit exercises are undertaken.If drills are only held once or twice a year (0), the value is zero.This parameter is set to 1 if drills are done more than twice a year.If the building's occupant load is less than 500 people and there are less than 100 people above or below street level, this parameter should be set to 1 [17].
No training was conducted to get out of the building in the event of a fire so that this parameter will be classified as Class I. Therefore, after analyzing the parameters, the final sum of the degree of fire safety prediction was (54.69), and this makes the classification of the building in terms of fire safety is (Moderate).Table 4 shows the analysis details for each parameter and the final predictive score for the building.

Conclusions
The study brings forth the following conclusions: • Fire safety prediction is an effective way to achieve high safety inside buildings.Continuous inspection of buildings to assess the safety of fire hazards is very important to preserve people's lives and property from fire hazards.• There are many violations of the approved international standards for safety from fire hazards by examining the building on site and comparing the results with these standards.• The building does not contain any firefighting system and this is the most dangerous part in assessing the safety of fire hazards.• Responsible government authorities must issue instructions to oblige real estate owners to provide the necessary conditions for fire safety in their buildings to provide adequate protection for residents.• There is little knowledge of real estate owners about fire safety procedures.Therefore, the civil defense authorities must train them on fire risk prevention measures and inform them of the conditions that must be met in buildings.• As a result of the moderate level of fire safety inside the building.There is a necessary need to complete the fire safety deficiencies such as firefighting sys-tems, fire detection devices, escape stair... etc. to raise the level of safety in the building to the level (High).

Figure 2 :
Figure 2: Weight each parameter according to the three classes

Table 2 :
Safety compliance level and its predictive score

Table 4 :
Predictive score assessment