Fire Risk Analysis and Emergency Evacuation Study on Large Comprehensive Building
Wang Qiquan, Wang Chen
Safety Engineering, China Institute of Industrial Relations, Beijing, China
To cite this article:
Wang Qiquan, Wang Chen.Fire Risk Analysis and Emergency Evacuation Study on Large Comprehensive Building. International Journal of
Science, Technology and Society. Vol. 4, No. 6, 2016, pp. 99-105.doi: 10.11648/j.ijsts.20160406.13
Received: October 13, 2016; Accepted: October 27, 2016; Published: November 11, 2016
Abstract: To prevent and control the fire risk of large comprehensive building, taking Jianye shopping plaza as an example, with the analytic hierarchy process (AHP) to establish large comprehensive building fire risk evaluation index system, the final evaluation index and fire risk level of Jianye shopping plaza is calculated by using the security check points and weight of the cumulative.Crowd evacuation time is simulated by using FDS, which can conclude that, in the ideal state, emergency evacuation time is 150 s and 3500 people are evacuated completely. In actual running state investigation, however, it is concluded that researchers were completely evacuated after the 450 s, while only 1500 people have been evacuated in 150 s.Finally, trajectory intersection theory is put forward in two aspects of the fire risk and emergency evacuation measures. Suggestions and measurements are proposed in order to prevent fire in reality and improve the possibilities timely as well as effectively in crowd evacuation after the fire, which are able to guarantee the safety of people.
Keywords: Fire Disaster, Emergency Evacuation, Large Comprehensive Building, Risk
With the deepening of China's openness and the increasing of economic level, all kinds of large-scale integrated construction emerge such as commercial buildings, supermarkets and so on , but, at the same time, large-scale integrated building fire has happened constantly.Only in terms of commercial building in large comprehensive building, its area in 2012 is already greater than 112.4 million m2 with approximately 13.1% average growing rate. And the single area of commercial buildings is growing with each passing year. In these buildings, cardinal numbers of personnel are large with big densities. Data displays that in some hot sell area, the densities often reach over 0.5 person per m2.
According to related data, only in 2014, the death toll in personnel intensive place reaches up to 307 people, accounting for 16.9% of the total number of deaths, which the accident caused incalculable economic losses .To analyze large comprehensive building fire risk, according to the results of analysis of the fire emergency evacuation study , it is an urgency that put forward the corresponding targeted improvement measures and Suggestions.
In recent years, domestic and foreign scholars focused more on the application of accident causation theory and fuzzy mathematics in fire risk analysis of buildings, in order to establish the evacuation model for fire protection and evacuation performance of buildings with evaluation and analysis through the simulation. The analytic hierarchy process is mainly used in this article to systematic analyze the main reasons and features of fire risk. Quantitative process is distinct and calculation results are simple, clear understandable and practical. Using simulation software to simulate evacuation, the comparison of each evacuation time is more focused, which can provide more intuitive simulation results and comparison of the evacuation effect in the real large comprehensive buildings. On the basis above, trajectory intersection theory is used to analyze and countermeasures put forward are also more practical.
2. Risk statistical analysis
2.1. Accident Statistics on large comprehensive building Fire Accidents
By collecting possible fire accidents in the large comprehensive buildings, according to the consequences of and the cause of fire accidents to do statistical analysis . During the past two years, statistics of fire accidents is shown intable 1, and the cause is shown intable 2.
|Item||amount||deaths||injuries||direct economic losses (millions)||Burned construction areas(m2)||Affected buildings|
|firing||electric||Production operation||Careless use of fire||smoke||Playing with fire||Spontaneous combustion||lightning stroke||static electricity||other|
2.2. Causes and Characteristics of Large Comprehensive Buildings Fire
From the perspective of the statistics causes of fire disasters of the large-scale integrated constructions in nearly two years, electric accounted for the highest percentage in the causes of the fire, followed by careless use of fire, production operation and smoke, and the least amount of the causes of the fire as a proportion is for firing, playing with fire, and spontaneous combustion .
From the perspective of the statistics of fire disasters of the large-scale integrated constructions in nearly two years, large-scale integrated buildings have huge number of fire accidents; more and more casualties and economic losses caused by fire accident are becoming more serious, and the burnedand affected building areas more also have a great number. It may be because of the inventory or goods and commodities with large quantities in and out in places such as shopping malls and supermarkets , and they are located in the downtown area with crowded and heavy traffic,once there happen fire, it will spreadquickly, prone to stampede, burns and other accidents of deaths and casualties with great number of persons .
3. Fire Risk Assessment
3.1. Fire Risk Assessment Index System and Its Weights
The author mainly uses the analytic hierarchy process (AHP) to establish largecomprehensive building fire risk evaluation index system. The main evaluation content are five parts including construction factor, fire using expert scoring methodtomark all levels of indicators factors according tothe impact of accidents’ consequences, calculating the various evaluation index for the relative weight value of evaluation content, and finally concluding that the lowest level indicators for cumulative weight value. For example, matrix of grades, in the first partin figure is table 3. 
|construction characteristic A1||1||-||-||-|
|fire-resistant rating A2||2/3||1||-||-|
Control facilities factor, product factor, safety evacuation factor and factor of safety management,five parts including construction factor, fire using expert scoring methodtomark all levels
Obtain the large-scale integrated building fire risk assessment index system and relative weight value and the accumulative weight value of indexes at all levels by calculation, and the results is shown in table 4.
|criterion layer||first level assessment indicator||relative weight||second level assessment indicator||relative weight||cumulative weight value|
|FactorA 0.150||construction characteristicA1||0.200||architectural scaleA11||0.200||0.006|
|Used service year A12||0.450||0.02025|
|fire-resistant rating A2||0.300||fire-resistant rating of building altitude A21||0.500||0.0375|
|fire-resistant rating of decorative materialA22||0.500||0.0375|
|Fireproofingzone A3||0.300||Horizontal Fireproofingzone A31||0.500||0.0375|
|vertical Fireproofingzone A32||0.500||0.0375|
|Characteristic of areaA4||0.200||fire lane A41||0.250||0.0075|
|The fire interval between buildingsA42||0.200||0.006|
|the distance from the fire brigade A43||0.250||0.0075|
3.2. Fire Risk Analysis ofJianye Shopping Plaza
Taikang county Jianye shopping plaza limited companyis located in intersection Construction Road and Zhinong road in Taikangcounty,zhoukou city in Henan province.Safety checks for Jianye shopping plazato markaccording to the security level is shown in the table 4, thento calculated the finalevaluation index fire risk level of Jianye shopping plaza by using the security check points and weight of the cumulative security evaluation level as shown in table 5.
|Evaluation rating||Good||preferably||general||Relatively bad||Bad|
The fire risk assessment of the Jianye shopping plaza is made and the final result is shown in table 6.
|serial number||Index||Assessment content||Points||The cumulative weight value||Index points|
|1||architectural scale A11||Is it a architectural scale||70||0.006||0.42|
|2||Used service year A12||Whether in service year||85||0.02025||1.72125|
|3||building altitude A13||Is it a high-rise buildings||50||0.0105||0.525|
|4||fire resistance rating of building structure A21||Whether to conform to the specifications or specific requirements||76||0.0375||2.85|
|5||fire-resistant rating of decorative materialA22||Whether accord with standards||70||0.0375||2.625|
|6||Horizontal Fireproofingzone A31||Whether over or accord with standards||70||0.0375||2.625|
|7||vertical Fireproofingzone A32||Whether over or accord with standards||70||0.0375||2.625|
|8||fire lane A41||Whether accord with standards or whether be blocked or occupied||50||0.0075||0.375|
|9||Whether accord with standards||Whether accord with standards||40||0.006||0.24|
|10||the distance from the fire brigade A43||arriving in five minutes as standards||70||0.0075||0.525|
|11||traffic condition A44||Average of free, crowd and blocked value||50||0.009||0.450|
Finally the score of Jianye shopping square is calculated: 56.73075. According to the levels of stipulations of index evaluation and scoring, the square level is less. So the possibility of a fire is higher.The main hidden trouble in the following areas:
(1) The mall fire channel had occupied and blocking phenomenon.During the holiday, fire channel wasoccupied because of the overmuch personnel cars unable to park.
(2) The unit paid little attention to the useof fire explosion protected electrical apparatus.Fire-resistant cable did not wear a buried pipe line processing, which is extremely easy to fire accident.
(3) Electrical ground handling situation was not ideal, and part of the appliance did not handle.
(4) Fire interval between buildings was short, not conforming to the relevant provisions of the state.
(5) Exit was shut down. There is no guarantee that the emergency evacuation channel unobstructed.
4. Emergency Evacuation
4.1. Evacuation Parameters ofJianye Shopping Plaza
According to statistics of marketing and security department of the Jianye shopping plaza, personnel composition situation as shown in table 7, the weekday traffic statistics as shown in figure 1, traffic statistics on weekend as shown in figure 2.
|staff composition||male||female||The aged||children|
4.2. FDSEvacuation Simulation
The author does the emergency evacuation study to Jianye shopping square model, setting up the fire for the shopping plaza happening during the evening peak at 19:00-18:00. Passenger flow volume is 3500 people, setting up by staff composition as women, men, children and the aged, respectively 1666, 1302, 256 and 276. To compared the analysis of running state of idealstate and the actual work of Jianye shopping plaza simulation. Purple part in figure 1 is store mobile shelves. Shopping malls have five exports, which have two store front and side and the remaining three exits for connecting the warehouse. In the field research and practice, locations of mobile shelves, corridors and public area displayed on the map; Store front and side were occupied by a vehicle jam or otherstaffs;Connection of warehouse three exit regularly closed and locked. Therefore, to do the emergency evacuation study ofJianyeshopping plazawithsimulation analysis in realistic operating conditions. There are two kinds of state simulation analysis below, figure 35,7, 8shown as the actual running state and 4, 6 as the ideal state.
According to simulation analysis of emergency evacuation in ideal state and the actual running state of Jianye shopping plaza, it is concluded that, in the ideal state, emergency evacuation time is 150 s and 3500 people are evacuated completely. In actual running state investigation, there are conditions including occupied the corridor on the public area with obstacles such as mobile shelves, closed exit, occupied fire engine access with other vehicles, and so on (details seen as the attachment). It is concluded that researchers were completely evacuated after the 450 s in actual running state.Only 1500 people have been evacuated in 150 s.For the above situation the following control measures are put forward:
(1) Fire channel exists conditions like blocked or occupied, etc., special warning label should be set up on fire channel. Once conditions like occupied or jam have been found, related personnel should be arranged immediately to take.
(2) Exits must keep unobstructed, and not be closed or occupied by the other goods jams.
(3) Because there are mobile shelves and other items on mall’s corridor between, causing fire prevention spacing decreases, so the mobile shelves on the corridor should be removed. Or the counter should be widened.
5. Risk Control Measures
By studying the fire risk and emergency evacuation of large-scale integrated buildings, according to the theory of trajectory cross as shown in figure 9, improvement measures of large-scale integrated building fire are put forward respectively from two aspects of fire risk and emergency evacuation. 
5.1. Fire Risk
By trajectory intersection theory,itcan be seen that they are human unsafe acts, unsafe state of objects and the lack of safety in fire manage to cause fire accidents. Therefore, measurements are put forward on the aspects of fire risk control.
(1) Electrical equipment must be bought or used observing the rules and regulations grimly, and fire-resistant wire must be embedded or poling or circuit grounding.
(2) Materials easy to spontaneous combustion need special handling, without placing together with combustible or inflammable ones.
(3) The firefighting equipment, such as fire extinguisher and fire hydrant facilities needs prophylactic repair as well as timely replacement, should be ensured the normal use of equipment, automatic alarm system, automatic sprinkler system design and construction in accordance with the relevant provisions of the state, regularly inspecting and replacing.
(4) When the production operation, staffs have to should be, after passing safety educations and trainings, in strict accordance with the rules and operation process before operations, finally mounting guard after qualified inspections.For special equipment operating personnel executing in strict rotation with employment with certificates institution, staffs should wear personal protective equipment by rules.
(5) Placing no smoking signs in each public place of a large comprehensive buildings, safety management personnel and workers should be discouraged while finding smoking.
(6) With enacting impeccable relative administrative rules and institutions, executing and practicing in strict rotation with safety production responsibility system, explicit ranges and contents of each post, building relative safety administrative department and institution needs related qualified personnel who pass the strict safety training to be in charge.
5.2. Emergency Evacuations
With orbit intersecting theory, it can be seen that unsafe behaviors and conditions and lacks of safety managements in emergency evacuations are able to enlarge fire accidents.
(1) Specifications and locations of emergency equipment like emergency indicator light and applied floodlight should be set up by relative rules of the state and prophylactic repairing in order to well function.
(2) Exits should be unobstructed, not being allowed to occupy or block.
(3) Public areas shouldn’t be occupied by commodities or campaign materials. Corridors shouldn’t be put with moving goods shelves or promotion items, in order to ensure that there are unblocked personnel paths.
(4) Exits graphs of this building should be put in the building entrance. Employees in mall should pass safety trainings to be familiar with emergency evacuation routes and master the fundamental firefighting knowledge.
(5) To provide advertise paper about evacuation and activities in aspect of evacuation to the customers.
Large comprehensive building’s fire could easily cause serious personal casualties and property losses. Because of the economic level continually rising and the high population density, it is vital to look for main causes and characteristics of large comprehensive buildings fire and to reduce and avoid the catastrophic accidents through prevention and emergency evacuation measurements. In this article, research is carried on large comprehensive building fire in three parts-- analysis of fire risk, emergency evacuation simulation and countermeasures and suggestions. The following is main conclusions:
1. From the perspective of the statistics causes of fire disasters of the large comprehensive buildings in nearly two years, electric accounted for the highest percentage in the causes of the fire, followed by careless use of fire, production operation and smoke . Targeted preventing buildings from those causes of the fire, especially the electrical fire, can effectively reduce fire accidents.
2. The severe accident consequences of large comprehensive buildings may be because of the inventory or goods and commodities with large quantities in and out in places, and the location in downtown area with crowded and heavy traffic. Once there are on fire, the fire will spread quickly, prone to stampede, burns and other crowded group death and injury accidents, which could have serious casualties. .
3. Taking Jianye plaza as an example, the main hidden troubles are: occupation and clogging phenomenon, lack of maintenances and managements for fire and explosion preventions, unsatisfactory electrical grounding, short fire interval, obstructed emergency evacuation channel.
4. By ideal and the actual situation of emergency evacuation simulation analysis on Jianye plaza, there are great differences of evacuation effect between ideal state and actual state. To rectify and improve the firefighting accesses, exits and shopping corridors can well improve this situation.
5. The occurrences of large comprehensive buildings fire are mainly owing to the improper management of safety evacuation passageways, items, placements and electrical equipment in buildings. Measurements on two aspects of equipment and management can effectively reduce the fire risk of large comprehensive buildings.
6. When large comprehensive buildings are on fire, reasonable emergency evacuation plans and good emergency equipment are the key to reducing losses and casualties. And based on the employee's safety trainings and safety knowledge in public for people can reduce or avoid the crowd panics caused by fire.
This paper is supported by general project of China Institute of Industrial Relations (16YY001).