KR200413246Y1 - Estimating System of Danger Rate for a Tunnel Fire - Google Patents

Abstract

The present invention relates to a tunnel risk prediction system, and more particularly, a step for estimating a tunnel fire occurrence scenario and an accident occurrence rate; Analyzing the congestion length and the number of vehicles in the tunnel during a fire; Measuring the evacuation time of the evacuator in the vehicle; Measuring temperature and harmful gas concentration in the tunnel; And a fractional effective dose (FED) measurement step. By using the tunnel fire risk prediction system of the present invention, the risk of various tunnels can be quantitatively evaluated, and thus can be used to supplement the construction or completed tunnels for safe tunnel construction.

Tunnel Risk, Tunnel Fire, FED

Description

Estimating System of Danger Rate for a Tunnel Fire

1 is a schematic diagram of a fire occurrence scenario;

Figure 2 shows a set point for classifying the evacuation time in tunnel fire,

3A and 3B are graphs showing probability distributions according to tunnel evacuation characteristics showing waiting time ( FIG. 3A ) and determination time distribution ( FIG. 3B ) in a vehicle .

4 is a graph comparing the evacuation time according to the number of lanes and the interval between the evacuation gang installation,

5 is a graph comparing the evacuation time according to the number of people,

6 shows a model tunnel for evacuation time review according to the vehicle arrangement,

7 is a hazardous substance risk assessment model,

8 is a traffic accident model,

9 is a tunnel basic specification input screen,

10 is a graph showing the relationship between visible speed and walking speed,

11 is a evacuation time graph comparing the present invention with simulex

12A and 12B are graphs comparing evacuation personnel by time in the case of an evacuation contact interval 250 m ( FIG. 12A ) and an evacuation contact interval 500 m ( FIG. 12B ),

13 is a graph showing evacuation time and FED evaluation by the risk assessment model,

14 is a schematic system configuration diagram according to an embodiment of the present invention.

The present invention relates to a tunnel risk prediction system, and more particularly, estimating an accident occurrence rate for a tunnel by estimating a tunnel fire occurrence scenario and an accident occurrence rate; Analyzing the congestion length and the number of vehicles in the tunnel during a fire; Measuring the evacuation time of the evacuator in the vehicle; Measuring temperature and harmful gas concentration in the tunnel; And a fractional effective dose (FED) measurement step.

Accidents in road tunnels can cause fatal consequences for human life as well as damage to property due to damage to facilities or the inability to use vehicles, so that the causes of accidents can be minimized and preventive measures can be taken promptly and systematically. It is necessary to prepare. Research on disaster prevention measures in domestic and foreign road tunnels has been actively promoted in recent years, and it has been recognized that the establishment of systematic countermeasures is essential in Korea due to the occurrence of a series of large-scale accidents such as the Mont Blanc tunnel and the Youngbul Submarine Tunnel. The fire accident at the Hongjimun Tunnel on June 6, following the Daegu subway fire disaster on February 18, 2015, has renewed the awareness of effective disaster prevention measures.

Disasters in tunnels are the most effective countermeasures against which the cause of occurrence is most effective, but unfortunately, when a disaster occurs, it is necessary to prompt evacuation of users by accurate judgment of the disaster situation, and to save lives, extinguish fire and prevent the spread of surrounding areas. . In addition, the construction of an efficient operating system is important along with the installation of response facilities, and the preparation of comprehensive disaster prevention manuals suitable for the characteristics of tunnels and the overall training are required by constructing detailed scenarios and developing systematic response systems for each situation. This series of measures will maintain a safer road tunnel environment and can be effectively used for road planning, design and maintenance work.

The risk assessment for road tunnels has recently been introduced to quantitatively evaluate the risks of tunnels. In Korea, the design of the backing tunnel and Geoje needle tunnel was carried out through foreign service. However, the evaluation of tunnel risks has not been specifically established until now, and it depends on a small number of statistical data. Representative evaluation models are the OECD (International Organization for Economic Cooperation and Development) and PIARC (permanent international association). There is a quantitative risk assessment model (QRAM) developed by road congress, but it is limited to vehicles carrying dangerous goods through tunnels.

Therefore, the inventors reviewed evacuation time and harmful gas concentrations of evacuated evacuators in tunnels based on the length of road tunnels, evacuation contact gang installation intervals, and fire size (fire intensity). The present invention was completed by developing a method to predict the risk of tunnels including casualties in tunnel fires by evaluating the risk according to various risk factors by quantifying the degree to FED.

The purpose of the present invention is to provide a safe tunnel construction and safe countermeasure by predicting the risk of tunnel by quantitatively evaluating and displaying the impact of evacuated by toxic gas and thermal environment in case of fire in tunnel.

In order to achieve the above object, the present invention comprises the steps of obtaining a data for estimating the tunnel fire occurrence scenario and the accident occurrence rate; Analyzing the congestion length and the number of vehicles in the tunnel during a fire; Measuring the evacuation time of the evacuator in the vehicle; Measuring temperature and harmful gas concentration in the tunnel; And it provides a tunnel fire risk prediction system comprising a step of measuring a fractional effective dose (FED).

Hereinafter, the present invention will be described in detail.

In the tunnel fire risk prediction system of the present invention, the scenario for the tunnel fire occurrence is composed of a fire occurrence scenario of a passenger car and a fire occurrence scenario of a bus and a cargo vehicle, and the fire occurrence scenario of the passenger car is performed on one passenger car. The maximum intensity of the fire is set to 5 MW, 40% of accidents are set to minor fires, the fire intensity spreading to two or more cars is set to 10 MW, and the probability of expanding the fire to adjacent vehicles is set to 2%. In the fire scenario of the bus and freight vehicle, 87% of freight and bus fires are set at 20 MW, 11% at 30 MW, and 2% at 50 MW or higher. It is desirable to set the fire growth rate and total heat generation amount to 0.1 ㎾ / s ² , 41 GJ and 54 GJ, and for fires of 50 MW or higher, the fire growth rate and total heat generation amount to 0.215 ㎾ / s ² and 65 GJ.

Further, in the tunnel fire risk prediction system of the present invention, it is preferable that the accident occurrence rate is set to 30-40 cases / 100 million Veh · km.

In addition, in the tunnel fire risk prediction system of the present invention, the analysis of the traffic jam length and the number of vehicles is set by dividing the traffic characteristics into congest traffic flow (normal traffic flow) and normal traffic flow (tunnel) Zones are divided into five zones based on the fire point (zone 1: zone where no vehicles exist behind the fire after the tunnel is closed, zone 2: zone where vehicles arriving before the tunnel are not aware of an accident and continue on, zone 3: Calculate the number of vehicles per time zone by dividing the vehicle into stagnant zones, zone 4: zones without fire downstream vehicles, zone 5: zones where vehicles downstream of fire continue, and

The speed of shock wave (U _w ) at the point of congestion

Where q ₁ : traffic flow rate at the point of congestion, q ₂ : time of arrival traffic (pc / h), D ₀ : traffic density at the point of congestion (150 pc / km), D ₁ : traffic of arrival traffic Density,

The car head spacing

Where N _i : the number of vehicles in I, PCU _total : Overall passenger car conversion factor, Φ _i : Mixing ratio of I model,

Average head spacing (Dv)

Where CL _i is the vehicle length of model i,

The walking speed according to the distance from the evacuator in front

W _spd = V _u , D _p > t _d

Where V _u is the walking speed in the absence of obstructions, V _u = 1.4 ㎧, D _p is the distance to the person in front of it, T _D : 1.6 m, b: body depth,

Walking speed by density

W _spd = 0.85k

Here, a = 0.266 m 2 / person, D _H : density, k is preferably constant in the case of ramps, corridors, doorways.

)이고 비율/확률분포식은 28 0.28+(1-0.28)GEV(-0.44, 13, 8.42)를 따르며, 나머지 사람중 51%는 80~130초 전에 차량을 버리는 사람으로 통계분포는 Norm(41.6, 17.1)을(Norm 함수:

), 49%는 80~130초 이후에 차량을 버리는 사람으로 통계분포는 Gumb(28.8, 155)(Gumb 함수 :

)이며, 이들의 비율/확률분포식은 8 0.08+(1-0.08)Norm(151, 8)를 따르는 것이 보다 바람직하다.In addition, in the tunnel fire risk prediction system of the present invention, the evacuation time of the evacuation of the evacuator in the vehicle is measured in the waiting time (car in the car or leave the car) after the fire and get off the evacuation It is desirable to set the hesitation time, the walking time to start evacuation and move to a safe place.The evacuation time of the evacuator in the vehicle is 81.6. % And the statistical distribution is GEV (-0.22, 19.81, 33.08) (GEV function:

), And the ratio / probability distribution follows 28 0.28+ (1-0.28) GEV (-0.44, 13, 8.42), with 51% of the people dropping cars before 80-130 seconds, with a statistical distribution of Norm (41.6, (Norm function: 17.1)

49% are those who dump their vehicles after 80 ~ 130 seconds, and the statistic distribution is Gumb (28.8, 155) (Gumb function:

It is more preferable that the ratio / probability distribution formula follows 8 0.08 + (1-0.08) Norms (151, 8).

In addition, in the tunnel fire risk prediction system of the present invention, the evacuation time of the evacuation of the in-vehicle evacuator is made of the number of lanes (one-way, two-way, three-way), respectively in the case of the 2, 3, 4 lanes It is desirable to set 1.14 s / m, 1.23 s / m, and 1.548 s / m, and additionally include children, and the walking speed of adults is 1 ~ 1.2 ㎧ and the walking speed of children is 0.7 ㎧. desirable.

In addition, in the tunnel fire risk prediction system of the present invention, the measurement of the temperature in the tunnel is the thermal equilibrium type at the time of tunnel fire

After t seconds, the temperature at the point x m downstream of the fire is

Where τ = t- (x / u) and h = 0.02 to 0.04 mW / m 2 · K

이고,

ego,

Radiation heat flux

here,

q '' = radiant heat flux (㎾ / ㎡)

F _s = fraction of the combustion heat radiated from the flame surface = 0.3

m = burning rate (kg / s) = 0.055 kg / (s.m 2)

ΔH _c = calorific value of gasoline = 43.7 MJ / kg

It is preferable to measure that x = distance (m) from fire.

Further, in the tunnel fire risk prediction system of the present invention, the harmful gas concentration is

으로,

to,

Oxygen reduction rate

로 측정하며,

Measured by

Additional visibility and visibility

Extinction coefficient (K)

Where OD: optical density (log ₁₀ (I _o / I), I _o : Intensity of light source, I: intensity of receiver light source)

를 대입하여In Equation 13

By substituting

이고,

ego,

In this case, the relationship between the visible distance V and the visibility (K)

로

in

Viewing distance (V, m)

Here, D _mass is preferably mass optical density.

In addition, in the tunnel fire risk prediction system of the present invention, the FED (fractional effective dose) is a Ct value that has a specific effect (incapacitation or death) of the cumulative amount of harmful gas (ppm · t) that the human breathed for t hours Divided by

At this time, the CO gas is

,

,

The effect of inhalation of CO gas on the human body is the risk index, F _I (FID: frctonal incapacitating dose).

Where F _ICO : risk index leading to unconsciousness, D: COHb concentration (%) leading to unconsciousness, 30%,

The reduction rate of oxygen

Where% O ₂ is the concentration of oxygen (%),

CO2

으로,

to,

CO2 risk index

로

in

Hydrogen cyanide (HCN)

80<ppmHCN<180 ppm이고,

80 <ppmHCN <180 ppm,

FED for temperature in thermal environment

으로

to

FED for radiant heat

FED evaluation of thermal and noxious gas environment

인 것이 바람직하다.

Is preferably.

Hereinafter, the present invention will be examined in more detail at each step.

Step 1: review the fire scenario

First, investigate the incidence of vehicle accidents in tunnels and roads in Korea (see Table 1). As a result, the number of accidents in road tunnels accounted for about 0.1 ~ 0.2% of the accidents on general roads, and the rate of fire accidents in tunnels since 2000 was 3.65 (2000), 2.74 (2001), 4.63. (2002), 2.43% (2003), up to 4.63%, with an average of 3.36%. Therefore, the present invention measures up to 4.63% by applying a fire accident rate of 5% to the general accident in the tunnel.

Generally, the accident rate is based on the driving distance (100 million Veh · km), and the accident rate in the tunnel is 30 ~ 40 cases / years based on the results of 2002 and 2003 when considering the factors of decrease. It is represented by 100 million Veh · km (see Table 2). In addition, the general accident rate in 2002 and 2003 is 74, 76 cases / 100 million Veh · km, respectively. As a result of estimating the incidence of fire accidents in tunnels, the reduction factor is 2.5 and 2.6 cases / 100 million Veh · km in 2002 and 2003, respectively.

In the scenario of tunnel fire occurrence, fire intensity is selected by dividing into a fire of a passenger car and a fire of a truck basically. In case of a fire of a car, two or more vehicles are considered. Lorry fires are generally classified into fires of 30 MW or less and fires of greater than or equal to that. In addition, since the traffic characteristics at the time of fire have a great influence on evacuation of evacuators, the operation of the ventilation fan is likely to result in contradictory life safety. Set the scenario considering the operation.

In the fire scenario of a passenger car, the fire intensity of a passenger car is generally about 2.5 ~ 5 MW, and the PIARC 95 report recommends 5 MW by quoting CETU (Large PC), EUREKA test results, etc. Is about 6 GJ, the fire duration is 20 to 40 minutes, and the fire growth rate is about 0.012 ㎾ / s ² . Therefore, in the present invention, the maximum material strength for one passenger car is set to 5 MW. In the case of a fire of a passenger car, the fire intensity is 10 MW when the fire spreads to two or more vehicles. From this, the rate of expansion of fire to adjacent vehicles is 1.5% and 1.6%, respectively, and the rate of expansion of fire to adjacent vehicles is estimated to be less than 2% of fires by passenger cars. Therefore, in the present invention, when a passenger car fire occurs in the tunnel, the probability of the fire spreading to the adjacent vehicle is set to 2%.

In the fire scenario of bus and freight vehicle (HGV), the fire intensity of the freight vehicle is greatly affected by the leakage of cargo or oil, but the present invention is based on the fire accident rate of the freight vehicle and the bus. 87% of the fires are considered to be 20 MW, 11% are 30 MW, and 2% are considered to be very serious fires. In addition, the fire growth rate of 0.215 ㎾ / s ² and the total heat generation amount of 65 GJ are applied to a fire of 50 MW or more, citing the results of a recent experiment conducted in the Runehammer tunnel (2003).

Second step: analyzing traffic jam

In a fire scenario, in a one-way or face-to-face tunnel, the operation of the ventilation fan during a fire increases the wind speed in the tunnel, increasing the likelihood that smoke will escape from the evacuation located downstream. There is a risk of increasing human life. Therefore, in a fire occurrence scenario, traffic characteristics are divided into congest traffic flow and normal traffic flow. Since the evaluation method or theory about the dead time is not known in particular, the present invention applies the method applied by the COWI company when designing the Geoje tunnel (see Fig. 1).

The model for analyzing the congestion length and the number of vehicles in a tunnel due to tunnel fire is based on the number of vehicles in the tunnel. Zone where there is no vehicle behind the fire after closing, zone 2: Vehicle which arrives before the tunnel block without recognizing the accident, zone 3: Vehicle congestion, zone 4: Vehicle without fire downstream Section, zone 5: a section in which the vehicle downstream of the fire continues to calculate the number of vehicles per time zone (see FIG. 6). The speed of shock wave is calculated by applying the dynamic incident control model (DICM) proposed by Yang, and the entrance of the vehicle in the tunnel is calculated under the condition that it is blocked after 3 minutes according to the Korea Highway Corporation standard.

The evacuation simulation model calculates the number of vehicles and the head spacing and arranges the vehicles in the congestion zone (zone 3) obtained from the Kyoto congestion model, taking into account the pre-fire speed in the tunnel and the mixing ratio by vehicle type. In addition, depending on the layout of the vehicle, the evacuation according to the number of passengers by vehicle type is arranged, and the delay time before evacuation is set in consideration of the vehicle disembarkation time and the decision time for each evacuator, and the evacuation speed of the evacuation is calculated when evacuation is started. Evacuate the simulation. The vehicle head spacing is obtained from the vehicle density (Do) at the time of congestion based on the current limit and considering the vehicle conversion factor for each vehicle and the mixing ratio for each vehicle.

Arrangement of vehicles in the congestion area is done randomly after finding the number of congestion vehicles by vehicle type for the congestion length. In order to calculate the maximum number of people, the maximum number of passengers by vehicle type is considered (see FIG. 8).

In the evacuation simulation model, evacuees are moved to the entrance and exit of the evacuation gang or tunnel over time, and the evacuation walking speed is calculated by the distance and density of the evacuator in front. The smaller of the walking speeds obtained by the above two methods is the walking speed of the evacuator, and when considering the smoke concentration in the tunnel, the smoke concentration is converted into the visible distance, and the distance shown in FIG. 9 shown in the PIARC 95 report is calculated. Apply the evacuation speed accordingly.

Comparing the evacuation time calculated in the present invention with the calculation result by simulex according to the evacuation contact interval (see Table 8 and Figure 10). As can be seen in Table 8 and FIG. 10, the error of the evacuation time is about 6.6% at maximum.

In addition, when the evacuation liaison interval is 250, 500 m, the cumulative evacuation personnel with time has a maximum error of about 160 people in the intermediate process, but shows a similar tendency (see FIG. 11).

Step 3: Measure Evacuation Time

In a tunnel, evacuation time in case of fire or emergency is generally divided into fire detection time, time to prepare for evacuation and evacuation time.In this design, the waiting time in a vehicle after a fire occurs (time in car or leave the car) and It is divided into a time for determining evacuation by getting off the vehicle, and a walking time for starting evacuation and moving to a safe place (see FIG. 2).

Evaluating evacuation time in tunnel fires requires a large number of personnel and no practical data is available. Therefore, when performing most risk assessment or evacuation simulation, the detection time and decision time after fire are generally assumed to be about 1 ~ 2 minutes. However, in this design, the time required for evacuation during tunnel fire is the waiting time in the vehicle. The evacuation time is divided into those who evacuate before the warning broadcast and evacuators who evacuate after the warning broadcast. The vehicle is divided into a group of people who let the vehicle go and a group that gets off later, and the ratio and probability distribution for each group are confirmed through a number of repeated experiments (see Table 5).

As a result, about 18.4% of the evacuees fail in the vehicle before the warning broadcast, 8% of them start evacuating without delay, and 81.6% escape the vehicle after the warning broadcast. Only evacuate without decision time. In addition, based on the probability distribution for each group, a probability distribution for each behavioral characteristic is obtained over time (see FIG. 2).

For evaluating evacuation characteristics, evacuation time according to lane number and evacuation contact gang installation interval is reviewed using Simulex program which is introduced in Korea and widely used as program for evaluating evacuation characteristics in construction and tunnel design field.

Specifically, evacuation time according to the lane number (one way 2, 3, 4 lanes) and the interval (200, 250, 300, 350, 500, 750 m) of the evacuation contact shaft is examined (see FIG. 3). Evacuation time tends to increase linearly with increasing evacuation liaison interval, and evacuation time per unit distance tends to increase slightly with increasing evacuation liaison distance, but average 1.14 s / m (2 Lanes), 1.23 s / m (three lanes), 1.548 s / m (four lanes), and the evacuation time increases dramatically in the fourth lane. In addition, when the number of lanes increases, evacuation time is almost the same as the second lane when the distance between the evacuation gang installation is less than 350 m.However, when the interval is more than 400 m, the evacuation time is significantly increased due to the tunnel width. see. Therefore, in the case of the fourth lane, it is not appropriate to apply the second lane standard.

In order to examine the effect of evacuation personnel in the tunnel on evacuation time, evacuation time is examined using the number of evacuators as a variable in a two-lane tunnel with an installation distance of 250 m. As a result, the evacuation time was shorter in the case of three lanes than in the second lane, and the change in evacuation time according to the number of people showed little difference (see Table 6). In other words, in case of the second lane, the evacuation time increased by about 6% from 276.2 seconds to 292.4 seconds even though the evacuation personnel in the tunnel increased from 704 to 1125 people. Increasing the number of people by 59% increases about 20%. Therefore, evacuation time in the tunnel is greatly influenced by the interval between the evacuation gang installation and it is judged that it is not affected by the evacuation population.

In order to examine the evacuation time according to the arrangement of vehicles and evacuation characteristics, the evacuation time for the case where the number of buses with the largest number of passengers differs for the tunnel model and the children considering the evacuation are considered (Fig. 5). As a result, the evacuation time was the shortest in the case of excluding children, and based on this, the evacuation time was increased by 40 to 53% in the simulation of evacuation time including young children (see Table 7). This is because the walking speed of adults is set at 1 ~ 1.2 ㎧ and the walking speed of children is applied at 0.7 ㎧. In addition, the effect of the stop position of the bus on the evacuation time is shown to be less than 10% (100 seconds), and the impact of the stop position of the vehicle on the evacuation time is not significant.

In the above review, evacuation time in the tunnel is not significantly affected by evacuation personnel when the distance of evacuation contact is the same, and the influence on the number of lanes is largely shown in tunnels of more than four lanes. The application of the 250 m spacing in the installation instructions is considered to be unreasonable. In addition, evacuation time is affected by the location of the vehicle, and it is determined that the presence of children has the greatest effect on the evacuation time.

4th step: measuring heat environment and harmful gas concentration in tunnel

The risk assessment model is to obtain the FED (fractional effective dose) value for the evacuator in order to quantitatively evaluate the effects of temperature and toxic gases on the evacuator in a tunnel fire. The risk assessment model is based on the event tree technique, which prepares fire scenarios, calculates fire incidence rates for each event, traffic queuing model for the placement of traffic jams and evacuation, Evacuation simulation model for calculating the evacuee's location, model for calculating the temperature and harmful gas concentration in the tunnel in the fire, and FED calculation model for calculating the exposure level of the evacuator's harmful gas in quantitative value (FED) Configured (see FIG. 6).

In the tunnel temperature and noxious gas concentration calculation module according to the fire, the module for calculating the temperature and noxious gas concentration according to the evacuator's location in the tunnel is configured to evaluate in two ways. The first method is a simple calculation method that calculates temperature, radiant heat and noxious gas concentrations (CO, CO ₂ , soot, visible distance) by Ingason's formula. The second method performs CFD simulation to calculate the MDB file. To generate and calculate.

The FED (fractional effective dose) is used to quantitatively evaluate the effects of the thermal environment and harmful gases.

FED is for quantifying and evaluating the effects of human exposure to thermal environment or harmful gas. The FED is the Ct value that affects the cumulative amount of harmful gas (ppm · t) that humans breathe in t hours as an incapacitation or death. Divided by In general, lethal effects are based on L (CT) ₅₀ . The FED method is applied to examine the effects of harmful gases and thermal environment on humans in tunnel fires.

The characteristics of the FED can automatically set or arbitrate evacuation areas for evacuees, automatically determine the initial vehicle position and evacuation location, and select the evacuation speed (walking speed) calculation (density of front evacuation, forward). Evacuation and distance consideration), and the calculation of different visibility of smoke concentration can be used to influence the smoke concentration. In addition, delay time until waiting time and evacuation decision time can be selectively applied in case of fire, and calculation by temperature and harmful gas concentration is possible, and DB and temperature DB for temperature and harmful gas concentration are available. Application is possible.

For the risk assessment of the tunnel, if a fire occurs in a traffic congestion situation in a 150 m tunnel in both directions, this design analyzes the evacuation time and the number of evacuation whose FED value is more than 0.3.

Calculation conditions are 1500 m in tunnel length, and the traffic is congested throughout the tunnel, the fire intensity is 20 and 50 MW, the evacuation personnel is about 2,369, and the time to decide when to evacuate and evacuate the vehicle at evacuation time. Consider, the warning broadcast is 120s after the fire.

If the fire intensity is 20 MW, the evacuation liaison interval is 250 m, but no evacuation of FED = 0.3 or more is known to affect the sensitive person, but the evacuation liaison interval is 300, 375, 500 m. As the number increases to 3.8, 31.8, 160 will increase rapidly. In addition, if the fire intensity is 50 MW, evacuation exceeding FED = 0.3 occurs even when the evacuation contact gang installation interval is 250 m.In this case, 53.2, 102.5, 141.8, 273.5 depending on the installation distance of the evacuation contact gang, respectively. Increasing in number.

In evaluating the evacuation time, if the evacuation contact interval is 250 m, evacuation time is 636 (20 MW) and 778 (50 MW), respectively, and as the fire intensity increases, the walking speed due to smoke decreases and the evacuation time increases. As a result, it appears to be about a 2.8-fold increase over the 276 s pure evacuation time described earlier.

In case of evacuation contact interval of 250 m, fire intensity is considered as 20 MW. In case of considering fire intensity as 20 MW, evacuation number exceeding 0.3 is 3.8 persons, which is only 0.16% of the total, but considering fire intensity as 50 MW In the case of the case, the increase was 53.2. The reason for the rapid increase in the number of evacuees whose FED value exceeds 0.3 is because the walking speed decreases due to the decrease in the visible distance as well as the increase in the concentration of harmful gases, which increases the time to stay in the tunnel.

At 20 MW fire intensity, the number of casualties expected to increase exponentially increases as the evacuation liaison interval increases, but increases proportionally with 50 MW. In addition, the evacuation time is affected by the fire intensity because it is affected by the visible distance, and considering the delay time, the evacuation time increases up to 1.8 times than the evacuation time by simulex without considering the visible distance and delay time. Therefore, it is necessary to consider the delay time and the effect of the decrease of walking speed due to the decrease of the visible distance for evaluating the evacuation time in the tunnel.

Hereinafter, the present invention will be described in detail by examples.

However, the following examples are merely to illustrate the present invention is not limited to the contents of the present invention.

Example 1 Analysis on Accident Frequency

<1-1> Incidents

The results of domestic investigations on the incidence of vehicle accidents in tunnels and roads are as follows (Table 1; Data from DB on Road Safety Management Authority, National Police Agency DB)

Incident rate of general accidents and tunnel accidents division year 2000 2001 2002 2003 2004 General road Number of occurrences (A) 290,481 260,579 230,953 240,832 220,755 Dead 10,236 8,097 7,224 7,212 6,563 injury 426,984 386,539 348,184 376,503 346,987 tunnel General accident Number of occurrences (B) 301 292 259 453 - Dead 13 9 8 25 - injury 593 578 545 949 - Fire accident Occurrence (C) 11 8 12 11 - Dead 4 One 2 - injury 2 48 - Occurrence B / A 0.10% 0.11% 0.11% 0.19% - C / B 3.65% 2.74% 4.63% 2.43% - Annual total driving distance (1 billion km) 290 300 310.8 317 324 In case of applying reduction factor for tunnel during general road accident The number of accidents in tunnel 137,252 123,124 125,357 96,780 104,307 Reduction rate 52.75% 52.75% 45.7% 59.8% 52.75% General accident rate (case / 100 million km) 47 41 40 30 32 Tunnel Fire Accident Rate 1.7 1.1 1.9 0.7 0.8 3.36% applied 1.6 1.4 1.4 1.0 1.1 When not considering reduction factors General accident rate (case / 100 million km) 100 87 74 76 68 Tunnel Fire Accident Rate 3.4 2.9 2.5 2.6 2.3

Note 1: Estimates considering growth rate from 2002 to 2003

Note 2: Result of average reduction rate of 2003 and 2002

Note 3: Estimates based on estimation results from Note 1 and Note 2.

According to the table above, the number of accidents in road tunnels accounted for about 0.1 ~ 0.2% of the number of accidents on general roads, and the rate of fire accidents in tunnels since 2000 was 3.65 (2000) and 2.74 (2001). , 4.63 (2002), 2.43% (2003), up to 4.63%, with an average of 3.36%. This trend is smaller than the 5% risk analysis based on the Norwegian statistical data on fire accidents (approximately 9%) out of 67 tunnel accidents, or based on Irish accident statistics on Hvalfjordur tunnels.

In this design, a maximum of 4.63% was applied and the rate of fire accidents related to general accidents in tunnels was 5%.

<1-2> Incidence Rate

In general, the occurrence rate of the accident is shown based on the driving distance (100 million Veh · km), and Table 1 shows the domestic and 2002 accident data and the estimated accident rate. The above table excludes accident types that cannot occur in tunnels, such as subordinates, or parking stops, when the reduction factors for tunnels are applied during general road accidents.

In the case of the reduction factor, the accident rate in the tunnel is 30-40 cases / 100 million Veh · km based on the 2002 and 2003 statistical results, which is 0-50 cases / 100 million Veh · km. It is considered to be a number within the range of the statistical data of PIARC 95 presented in Table 2).

Incident rate in French tunnels (1995, PIARC) (100 million km) division Only property damage occurred Casualty thinking Injured dead Urban Tunnel 40-150 10-50 10-50 0-3 One-way car tunnel 30-80 0-15 0-15 0 ~ 1 Two-way Regional Tunnel 20-100 0-20 0-20 0 ~ 2

In addition, the general accident rate in 2002 and 2003 is 74, 76 cases / 100 million Veh · km, respectively.

As a result of estimating the incidence of fire accidents in tunnels, the reduction factor is 2.5 and 2.6 cases / 100 million Veh · km in 2002 and 2003, respectively.

Considering the total driving distance ratio of domestic trucks and passenger cars and the accident rates of passenger cars and vans shown in Table 3 below, the accident rates of passenger cars and vans are calculated to be 1.29 and 4.5 billion / million Veh · km, respectively. . This is somewhat smaller than the accident rate in the French Tunnel presented in PIARC in 1995 (cars: 2/100 million Veh · km, and trucks: 9.2 / 100 million Veh · km). We think France's statistics are somewhat high.

Accident rate for vans and passenger cars (100 million Veh · km) source passenger car (PC) HGV HGV / PC Elb tunnel 6.3 24.6 3.90 France 2 9.2 4.60 ref 1 4.53 9.2 2.03 Average 3.51

Example 2 Tunnel Fire Scenario

In the scenario of tunnel fire occurrence, the fire intensity was selected by dividing it into a passenger car fire and a truck fire, and the case of two or more car fires was considered.

Lorry fires were classified into fires of 30 MW or less and more commonly known. In addition, since the traffic characteristics at the time of fire have a great influence on evacuation of evacuators, the operation of the ventilation fan is likely to result in contradictory life safety. The scenario was set considering the operation.

<2-1> Fire Scenarios for Passenger Cars

The fire intensity of passenger cars is generally about 2.5 ~ 5 MW, and the PIARC 95 report recommends 5 MW by citing CETU (Large PC) and EUREKA test results, and the total total calorific value is about 6 GJ. Is 20-40 minutes, and the growth rate is about 0.012 ㎾ / s ² . Therefore, in the present invention, the maximum material strength for one passenger car was 5 MW.

The rate of extinguishing a fire extinguisher as a fire extinguisher in a passenger car was set at 80 to 90% in the PIARC report and 53% according to the Japan Water Corporation. In this scenario, 40% is set to a minor fire accident. This is the same ratio that Gundni applied in the risk assessment for the Hvalfjordur tunnel.

In the case of a fire of a passenger car, when the fire spreads to two or more vehicles, the fire intensity was set at 10 MW. In Norway, only 67 cases (9%) of car collisions in tunnels are reported to occur continuously due to fire accidents.In the Elb tunnel in Germany, one of 63 fires in 16 years is adjacent. It is reported to have been expanded by vehicle. From this, the rate of expansion of fire to adjacent vehicles is 1.5% and 1.6%, respectively, and the rate of expansion of fire to adjacent vehicles can be estimated as less than 2% of fires by passenger cars. Therefore, in the present invention, when a passenger car fire occurs in the tunnel, the probability of the fire spreading to an adjacent vehicle is set to 2%.

<2-2> Fire Scenario of Bus and Freight Vehicle (HGV)

In the case of fire accidents caused by vans, the maximum strength of steel is 15 ~ 130 MW according to the PIARC 95 report, and the fire intensity of general buses is about 20 MW according to French and NFPA standards. Ingason also quotes a fire test in the EUREKA tunnel, and in 2001, published the fire intensity of the bus at 29-34 MW and in 2004 it was 30 MW.

Therefore, the fire intensity of the freight vehicle is greatly affected by whether the cargo or oil spills, but in this design, 87% of the fire of the freight vehicle and the bus is based on the fire accident rate of the freight vehicle shown in Table 4 below. 20 MW, 11% were considered 30 MW, and 2% were considered to be very serious fires.

Ingason's study suggests that the rate of fire growth in the event of a bus fire is ultra fast, according to NFPA's classification, and the fire growth rate is 0.1 ㎾ / s ² . The total calories generated is 41 GJ in the PIARC 99 report for public buses and 54 GJ for Ingason (2004). Therefore, the fire growth rate and total calorific value were set to 0.1 mW / s ² , 41 GJ and 54 GJ for 20 and 30 MW of fire.

Accident rate by vehicle type (1995 PIARC report) Classification of fire Number of fires per 100 × 10 ⁶ veh × km car Meaningful fire 1 ~ 2 Lorry free of dangerous goods Meaningful fire 8 Fire damaged in tunnel One Very serious fire 0.1 to 0.3 (evaluation) Lorry with dangerous goods Meaningful fire 2 (evaluation) A fire involving dangerous goods 0.3 (evaluation)

In addition, a fire growth rate of 0.215 ㎾ / s ² and total heat generation of 65 GJ were applied to fires of 50 MW or more, citing the results of a recent experiment conducted in the Runehammer tunnel (2003).

<2-3> Application of Stagnation Frequency

In the fire scenario of the present invention, the operation of the ventilation fan during a fire in a one-way tunnel or a face-to-face tunnel using the type ventilation system increases the wind speed in the tunnel, which increases the likelihood of the smoke being evacuated from the downstream fire. As a result, there is a risk of increasing the risk of human life. Therefore, in the fire occurrence scenario, traffic characteristics are divided into congest traffic flow and normal traffic flow.

Since the evaluation method or theory for the stagnation time is not known in particular, the present invention was applied to the method applied by the COWI company when designing Geoje tunnel (Fig. 1).

Example 3 Evacuation Characteristics

In a tunnel, evacuation time in case of fire or emergency is generally divided into fire detection time, time to prepare for evacuation and evacuation time.In this design, the waiting time in a vehicle after a fire occurs (time in car or leave the car) and Time to determine the evacuation to get off the vehicle (hesitation time), starting from the evacuation to the safety time (walking time) to move to a safe place (Fig. 2).

Evaluating evacuation time in tunnel fires requires a large number of personnel and no practical data is available. Therefore, when performing most risk assessments or evacuation simulations, it is generally assumed that the detection time and the determination time after the fire are about 1 to 2 minutes.

The most extensive study on evacuation time includes Modeling Crowd Evacuation from Road and Train Tunnels-Data and design For faster evacuation conducted by Anders Noren. A study on evacuation time including

<3-1> Examination of Evacuation Characteristics

In the present invention, the evacuation time was reviewed as follows (Table 5).

Evacuation Characteristics and Probability Distributions group Vehicle waiting time Decision time ratio(%) Behavior Statistical distribution Probability / Probability Distribution Formula One 18.4 51 Who dumps the vehicle 80-130 seconds ago Norm (41.6, 17.1) 8 0.08+ (1-0.08) Norm (151, 8) 2 49 Abandon the vehicle after 80 to 130 seconds Gumb (28.8, 155) 3 81.6 Person who throws away vehicle after warning broadcast GEV (-0.22, 19.81, 33.08) 28 0.28+ (1-0.28) GEV (-0.44, 13, 8.42)

Note) Norm function is cumulative normal distribution as follows.

Gumb means Gumbel distribution, and is as follows.

GeV means General Extreme Value distribution, and is as follows.

In this design, the time required for evacuation during tunnel fire is divided into waiting time, decision time and evacuation time in the vehicle.The behavioral characteristics of the evacuator are those who perform evacuation before warning broadcasting and evacuation after warning broadcasting. The evacuees, who are evacuated before the warning broadcast, are divided into those who let the vehicle go before 80 ~ 130 seconds and the group that gets off later.The ratio and probability distribution for each group through a number of repeated experiments. It was confirmed (Table 5).

In the table above, 18.4% of the evacuees fail in the vehicle before the warning broadcast, 8% of them start evacuating without delay, and 81.6% escape the vehicle after the warning broadcast. Only evacuation was made without decision time. In addition, the probability distribution for each group is as shown in the above table, and based on this, the probability distribution for each behavioral characteristic is as shown in FIG. 2.

<3-2> Review of Evacuation Contact Gang Installation Intervals and Evacuation Times by Lane Number

For evaluating evacuation characteristics, evacuation time according to lane number and evacuation liaison interval was reviewed using Simulex program, which was introduced in Korea and widely used as a program for evaluating evacuation characteristics in construction and tunnel design.

Evacuation time was examined according to the number of lanes (one way 2, 3, 4 lanes) and the intervals (200, 250, 300, 350, 500, 750 m) of the evacuation liaison (Fig. 3).

The evacuation time tends to increase linearly with increasing evacuation liaison intervals, and the evacuation time per unit distance tends to increase slightly as the evacuation liaison distance increases, but on average 1.14 s / m ( 2nd lane), 1.23 s / m (3rd lane) and 1.548 s / m (4th lane), indicating that evacuation time is rapidly increasing in the fourth lane.

In addition, when the number of lanes increases, evacuation time is almost the same as the second lane when the distance between the evacuation gang installation is less than 350 m.However, when the interval is more than 400 m, the evacuation time is significantly increased due to the tunnel width. It is showing. Therefore, in the case of the fourth lane, it is not appropriate to apply the second lane standard.

4 is a result of evaluating evacuation time using the number of evacuation in a two-lane tunnel with a 250 m interval between evacuation contact gang installation to examine the effect of evacuation personnel in the tunnel on the evacuation time.

In FIG. 4, the evacuation time is shorter than that of the second lane when the number of lanes is three, and the change in evacuation time according to the number of people is almost insignificant (Table 6). In other words, in the second lane, the evacuation time increased by about 6% from 276.2 seconds to 292.4 seconds even when the evacuation personnel in the tunnel were 704 to 1125.In the fourth lane, the number of people evacuated from 1414 to 2254. As a result, an increase of 59% is expected to increase by about 20%.

Comparison of Evacuation Time by Evacuation Personnel 2 lane Three lanes 4 lane Evacuation Evacuation Time Evacuation Evacuation Time Evacuation Evacuation Time 704 276.2 1062 273.0 1414 287.1 907 284.8 1347 281.0 1822 294.9 1125 292.4 1672 290.0 2254 344.2

Therefore, evacuation time in the tunnel is greatly influenced by the interval between the evacuation gang installation and it is judged that it is not affected by the evacuation population.

<3-3> Evacuation Time Review by Vehicle Arrangement and Evacuation Characteristics

Evaluate the evacuation time for the case where the bus occupies the largest number of passengers and the children among the evacuators are considered for the tunnel model shown in FIG. Was reviewed.

As a result of the simulation, evacuation time was the shortest in the case of excluding children, and based on this, the evacuation time was increased by 40 ~ 53% in the simulation of evacuation time including children (Table 7). This is because the walking speed of adults is set at 1 ~ 1.2 ㎧ and the walking speed of children is applied at 0.7 ㎧.

Evacuation Time Comparison According to Vehicle Arrangement Total evacuation staff composition Calculation Condition Evacuation Time Ratio of time to minimum adult child Total number of people 1288 336 1620 Evenly placed buses throughout the tunnel 16:52 (1012s) 45 1288 336 1620 When large buses are arranged at the fire site (evacuation contact B) 16:08 (968s) 38.3 1288 336 1620 When large buses are concentrated in the evacuation center A of the tunnel 17:55 (1075 s) 53.6 1288 336 1620 All vehicles in the tunnel are arranged from the fire point with a distance of 2 m between them. 16:55 (1015s) 45 8840 0 884 If the bus is arranged evenly throughout, excluding children 11:40 (700s) -

In addition, the effect of the stop position of the bus on the evacuation time is shown to be less than 10% (100 seconds), and the impact of the stop position of the vehicle on the evacuation time is not significant.

In the above review, evacuation time in the tunnel is not significantly affected by evacuation personnel when the distance of evacuation contact is the same, and the influence on the number of lanes is largely shown in tunnels of more than four lanes. The application of the 250 m spacing in the installation instructions is considered to be unreasonable. In addition, evacuation time is affected by the location of the vehicle, and it is determined that the presence of children has the greatest effect on the evacuation time.

Example 4 Risk Assessment

<4-1> Risk Assessment Model

The risk assessment model is to obtain the FED (fractional effective dose) value for the evacuator in order to quantitatively evaluate the effects of temperature and toxic gases on the evacuator in a tunnel fire. As shown in FIG. 6, the risk assessment model includes a fire scenario model for generating a fire scenario by an event tree technique, a fire scenario model for calculating a fire accident rate for each, a placement of a congested vehicle in a tunnel and an evacuation arrangement. Traffic que model for evacuation, evacuation simulation model for calculating the location of evacuation victims over time, model for calculating temperature and noxious gas concentration in the tunnel in case of fire, and quantitative value (FED) It is composed of FED calculation model to calculate

<4-2> Fire Scenario Model

A review of the fire occurrence scenario and the accident occurrence rate is as shown in Example 2.

<4-3> Traffic jam model

It is a model for analyzing traffic jam length and number of vehicles in tunnel due to tunnel fire. The number of vehicles in the tunnel calculation module is based on the traffic characteristics in the tunnel in case of fire. Zones that continue without recognizing this accident, zone 3: sections where the vehicle is congested, zone 4: sections where there are no cars downstream of the fire, and zone 5: sections where the cars downstream of the fire continue. The number is calculated (FIG. 6). The speed of shock wave was calculated by applying the dynamic incident control model (DICM) proposed by Yang, and the entry of vehicles in the tunnel was calculated under the condition that the vehicle was blocked after 3 minutes according to the Korea Highway Corporation standard. .

The speed of shock wave (U _w ) of the stagnation point is obtained by the following equation.

Where q ₁ : traffic flow rate at the point of congestion, q ₂ : time of arrival traffic (pc / h), D ₀ : traffic density at the point of congestion (150 pc / km), D ₁ : traffic of arrival traffic Density.

<4-4> Evacuation Simulation Model

The evacuation simulation model calculates the number of vehicles and the head spacing and arranges the vehicles in the congestion zone (zone 3) obtained from the Kyoto congestion model, taking into account the pre-fire speed in the tunnel and the mixing ratio by vehicle type. In addition, depending on the layout of the vehicle, the evacuation according to the number of passengers by vehicle type is arranged, and the delay time before evacuation is set in consideration of the vehicle disembarkation time and decision time for each evacuator, and when the evacuation is started, the evacuation speed Evacuation simulations were performed.

In the present design, the vehicle head spacing was calculated by Equation 2 from the vehicle density (Do) at the time of congestion in consideration of the conversion factor of each vehicle and the mixing ratio of each vehicle.

Where N _i : the number of vehicles in I, PCU _total : Overall passenger car conversion factor, Φ _i : I is the mixing ratio of I model.

The average head gap (Dv) is calculated by the following equation.

Here, CL _i is the vehicle length of model i.

Arrangement of vehicles in the congestion area is done randomly after finding the number of congestion vehicles by vehicle type for the congestion length.

The number of passengers by vehicle type is as shown in the input screen of FIG. 8, and in the present invention, the maximum number of passengers by vehicle type is considered to calculate the maximum number of persons.

In the evacuation simulation model, evacuees are moved to the entrance and exit of the evacuation gang or tunnel over time, and the evacuation walking speed is calculated by the distance and density of the evacuator in front. The walking speed according to the distance to the evacuator in front was calculated by Equation 4 below, and the walking speed by density was calculated by Equation 5 given in SPFE. In the present invention, the smaller of the walking speeds obtained by the above two methods is the walking speed of the evacuator, and when considering the smoke concentration in the tunnel, the smoke concentration is converted into a visible distance, which is shown in the PIARC 95 report of FIG. 9. Evacuation speed was applied according to the visible distance.

W _spd = V _u , D _p > t _d

Where V _u is the walking speed V _u = 1.4 ㎧ in the absence of obstructions, D _p is the distance to the person in front of it, T _D : 1.6 m, b: body depth.

W _spd = 0.85k

Where a = 0.266 m 2 / person, D _H : density, k is 1.4 kPa in the case of ramp, corridor, doorway as a constant.

The calculation results of the evacuation module were compared with the simulation results of simulex.

The results of evaluating the evacuation time calculated by the simulex according to the evacuation contact interval and the evacuation time calculated in the present invention were compared (Table 8 and FIG. 10). As can be seen in Table 8 and FIG. 10, the error of evacuation time is shown to be up to about 6.6%.

Evacuation time comparison by simulex and evacuation model Evacuation contact gap simulex This invention Persons / hour Time ratio Evacuation Evacuation Time Evacuation Evacuation Time This invention simulex (s-p) / s 200 880 241.0 881 225 3.916 3.651 6.6% 250 1125 292.7 1149 311 3.695 3.844 -6.3% 300 1335 344.8 1336 349 3.828 3.872 -1.2% 350 1561 396.7 1529 395 3.871 3.935 0.4% 400 1791 449.0 1783 474 3.762 3.989 -5.6% 500 2197 557.4 2169 577 3.759 3.942 -3.5% 750 3288 817.8 3286 855 3.843 4.021 -4.5%

In addition, FIG. 11 shows the cumulative evacuation personnel with time when the evacuation contact interval is 250, 500 m. The maximum error occurs in the middle process, but it can be seen that the trend is almost similar.

<4-5> Thermal Environment and Hazardous Gas Concentration Calculation Module in Tunnel

In the tunnel temperature and noxious gas concentration calculation module according to the fire, the module for calculating the temperature and noxious gas concentration according to the evacuator's location in the tunnel is designed to evaluate in two ways. The first method is a simple calculation method that calculates temperature, radiant heat and noxious gas concentrations (CO, CO ₂ , soot, visible distance) by Ingason's formula. The second method performs CFD simulation to calculate the MDB file. To generate and calculate.

Ingason's formula for evaluating heat and harmful gases in tunnels is as follows.

-Temperature

The thermal equilibrium type in tunnel fire is represented by the following equation.

In addition, after t seconds, the temperature at the fire downstream x m point is calculated by the following equation (7).

Where τ = t- (x / u) and h = 0.02 to 0.04 mW / m 2 · K

이다.

to be.

-Radiation heat flux

here,

q '' = radiant heat flux (㎾ / ㎡)

F _s = fraction of the combustion heat radiated from the flame surface = 0.3

m = burning rate (kg / s) = 0.055 kg / (s.m 2)

ΔH _c = calorific value of gasoline = 43.7 MJ / kg

x = distance from fire (m)

to be.

Hazardous Gas Concentration

The concentration of the noxious gas (i) is calculated by the following equation 10 and the oxygen reduction rate by the equation (11).

Visibility and visibility

The extinction coefficient (K) due to the fire in the tunnel is represented by the following equations (12) and (13).

Where OD: optical density (log ₁₀ (I _o / I), I _o : Intensity of light source, I: intensity of receiver light source).

를 대입하면 하기 식 14로 계산된다.In Equation 13

Substituting into is calculated by the following equation (14).

The relationship between the visible distance V and the visibility K is generally represented by the following equation (15), and 2 is a constant applied to a general fire.

In the above formula, the visible distance (V, m) is calculated by the following formula (16).

Here, D _mass is the mass optical density, and Ingoson is shown in Table 9.

Total optical density type of vehicle mass optical density, D _mass (㎡ / ㎏) road car (steel) 381 car (plastic) 330 bus 203 truck 76-102 subway (steel) 407 subway (aluminium) 331 rail IC-type 153 ICE-type 127-229 two joined half Veh 127-178

<4-6> FED calculation module

As a method for quantitatively evaluating the effects of the thermal environment and harmful gases, a method of evaluating the fractional effective dose (FED) was used.

FED is for quantifying and evaluating the effects of human exposure to thermal environment or harmful gas. The FED is the Ct value that affects the cumulative amount of harmful gas (ppm · t) that humans breathe in t hours as an incapacitation or death. Divided by In general, lethal effects are based on L (CT) ₅₀ .

In this design, FED method is applied to examine the effects of harmful gases and thermal environment on humans in tunnel fires.

Models for FED calculation include PURSER's model, N-GAS model, and US FAA model, and our inventors evaluate FED value higher than FAA model and also apply PURSER's model, which is generally applied to road tunnel risk assessment. The model for environment and visibility was further applied.

The characteristics of the PURSER's model and the contents applied to the present invention are described as follows.

-CO and HCN are the target materials. In this design, the research data on HCN were not applied due to the lack of tunnel fire.

-CO ₂ increases the volume of respiration, which increases the respiration of CO and HCN.

-The effects of oxygen reduction occur in combination with the effects of harmful gases.

-The effects of CO ₂ breathing are independent of the effects of hazardous gases.

-In this design, the FED value was calculated by weighting all the effects of harmful gas temperature and radiant heat as applied in the FAA risk assessment model.

The following is the description of the main equations among the FED equations for each hazardous gas:

(1) CO gas

CO reacts with hemoglobin in the blood by respiration to form COHb (carboxyhemoglobin), and the concentration of COHb in blood according to the CO concentration and exposure time is calculated by the following equation (17).

The effect of inhalation of CO gas on the human body is the risk index, and F _I (FID: frctonal incapacitating dose) is obtained by the following equation (18).

Here, F _ICO : risk index leading to unconsciousness, D: COHb concentration (%) from unconsciousness to 30% in the present invention.

(2) reduction rate of oxygen

Reduction of oxygen concentration is one of the risk factors leading to unconsciousness. When oxygen reduction rate reaches around 10%, it becomes unconscious, and 9.6% is known as the limit value. Another risk index for reducing oxygen is calculated by the following equation (19).

Here,% O ₂ : concentration of oxygen (%).

(3) carbon dioxide

Carbon dioxide is not a toxic gas, but as the concentration increases, it causes the respiratory volume to increase, thereby increasing the respiratory volume of the toxic gas.

In general, when the concentration of carbon dioxide is 3%, the respiratory volume is increased by 2 times, and when 5% is increased by about 3 times, the respiratory volume increase according to the CO ₂ concentration is calculated as follows.

In general, when the carbon dioxide concentration is 10% or more, it becomes unconscious within about 2 minutes, and the risk index due to carbon dioxide is represented by Equation 21 below.

(4) HCN (hydrogen cyanide)

The risk index for HCN is calculated by the following equation.

80<ppmHCN<180 ppm

80 <ppmHCN <180 ppm

(5) thermal environment

FED calculation for temperature

-FED calculation for radiant heat

The FED evaluation for the above-mentioned thermal environment and noxious gas environment is presented by Purser below.

However, the Federal Aeronautics and Space Administration is evaluating the FED in the FED evaluation model by evaluating the effects of thermal environment factors (temperature, radiant heat) and harmful gases on the FED evaluation model. Therefore, the present invention also evaluated the FED by adding up the effects of each factor on the human body. The FED evaluation formula was applied as follows.

<4-7> FED calculation example

The characteristics of the FED can automatically set or arbitrate evacuation areas for evacuees, automatically determine the initial vehicle position and evacuation location, and select the evacuation speed (walking speed) calculation (density of front evacuation, forward). Evacuation and distance consideration), and the calculation of different visibility of smoke concentration can be used to influence the smoke concentration. In addition, delay time until waiting time and evacuation determination time can be selectively applied in case of fire, calculation by temperature and harmful gas concentration is possible, calculation of DB and application of temperature and harmful gas concentration This is possible.

In order to evaluate the risk of the tunnel, when a fire occurs when the vehicle is congested in both directions of the 150 m tunnel, the evacuation time and the number of evacuation with the FED value of 0.3 or more were analyzed.

Calculation conditions are 1500 m in tunnel length, and the traffic is congested throughout the tunnel, the fire intensity is 20 and 50 MW, the evacuation personnel is about 2,369, and the time to decide when to evacuate and evacuate the vehicle at evacuation time. Consider, the warning broadcast is 120s after the fire.

If the fire intensity is 20 MW, the evacuation liaison interval is 250 m, but no evacuation of FED = 0.3 or more is known to affect the sensitive person, but the evacuation liaison interval is 300, 375, 500 m. As the number increases to 3.8, 31.8, 160 will increase rapidly. In addition, if the fire intensity is 50 MW, evacuation exceeding FED = 0.3 occurs even when the evacuation contact gang installation interval is 250 m.In this case, 53.2, 102.5, 141.8, 273.5 depending on the installation distance of the evacuation contact gang, respectively. Increasing in number.

In evaluating the evacuation time, if the evacuation contact interval is 250 m, evacuation time is 636 (20 MW) and 778 (50 MW), respectively, and as the fire intensity increases, the walking speed due to smoke decreases and the evacuation time increases. As a result, it has been shown to be about 2.8 times greater than the 276 s pure evacuation time described earlier.

In case of evacuation contact interval of 250 m, fire intensity is considered to be 20 MW. In case of considering fire intensity as 20 MW, evacuation number exceeding 0.3 is 3.8 persons, which is only 0.16% of the total, but fire intensity is considered as 50 MW. In the case of the case, the increase was 53.2. The reason for the rapid increase in the number of evacuees whose FED value exceeds 0.3 is because the walking speed decreases due to the decrease in the visible distance as well as the increase in the concentration of harmful gases, which increases the time to stay in the tunnel.

At 20 MW fire intensity, the number of casualties expected to increase exponentially increases as the evacuation liaison interval increases, but increases proportionally with 50 MW. In addition, the evacuation time is affected by the fire intensity because it is affected by the visible distance, and considering the delay time, the evacuation time increases up to 1.8 times than the evacuation time by simulex without considering the visible distance and delay time. Therefore, it is necessary to consider the delay time and the effect of the decrease of walking speed due to the decrease of the visible distance for evaluating the evacuation time in the tunnel.

On the other hand, Figure 14 shows the configuration of a schematic system according to an embodiment of the present invention. As shown, the central control unit of the present invention is a data acquisition module; Traffic jam length and vehicle number analysis module; and evacuation time measurement module; and temperature and harmful gas measurement module; And an FED measurement module, and may further include a sensing unit and an input / output unit as necessary. In addition, the central control unit may store and recall data measured in conjunction with the illustrated DB.

The data acquisition module obtains data for estimating a tunnel fire occurrence scenario and an accident occurrence rate as described above, and the congestion length and vehicle number analyzing module analyzes the traffic jam length and the number of vehicles in the tunnel when a fire occurs. The evacuation time measuring module measures the evacuation time of the evacuator in the vehicle, the temperature and noxious gas measuring module measures the temperature and noxious gas concentration in the tunnel, and the FED measuring module measures the fractional effective dose (FED). do.

As described above, the tunnel fire risk prediction system of the present invention is an automatic determination of evacuation area, initial vehicle position and evacuee position, calculation of evacuation speed, reflection of smoke concentration on evacuation speed, fire It is possible to apply the delay time to the waiting time and evacuation decision time in the vehicle, to calculate the temperature and harmful gas concentration, to create the DB and apply the temperature and harmful gas concentration, It can be used to evaluate and secure tunnel construction or to supplement a completed tunnel.

Claims (11)

In the tunnel fire prediction system consisting of a central control unit, a sensing unit, an input-output unit and a DB linked thereto, The central control unit includes a data acquisition module for acquiring data for estimating a tunnel fire occurrence scenario and an accident occurrence rate; Congestion length and vehicle number analysis module for analyzing the congestion length and the number of vehicles in the tunnel in the event of a fire; And Evacuation time measuring module for measuring the evacuation time of the evacuator in the vehicle; And Temperature and harmful gas measurement module for measuring the temperature and harmful gas concentration in the tunnel; And Tunnel fire risk prediction system, characterized in that it comprises a FED measurement module for measuring the fractional effective dose (FED). The method of claim 1, The scenario for the tunnel fire occurrence is composed of a fire occurrence scenarios of passenger cars and fire occurrence scenarios of buses and freight vehicles, In the fire scenario of the passenger car, the maximum ash strength for one passenger car is set at 5 MW, and 40% of accidents are set at a minor fire, and the fire intensity spreading to two or more cars is set at 10 MW. The probability of fire escalation is set to 2%. The fire scenarios of the buses and freight vehicles are set to 87 MW, 20 MW, 11% to 30 MW, 2% to 50 MW, and 20, 30 MW of fire. Tunnel fire characterized by setting the growth rate and total calorific value to 0.1 ㎾ / s ² , 41 GJ and 54 GJ, and for fires of 50 MW or higher, the fire growth rate and total calorific value to 0.215 ㎾ / s ² , 65 GJ Risk Prediction System. The system of claim 1, wherein the accident occurrence rate is 30 to 40 cases / 100 million Veh · km. The method of claim 1, wherein the traffic length and the number of vehicles are analyzed by setting traffic characteristics into congestion traffic and normal traffic flow. Zones (zone 1: section where no vehicle exists behind the fire after the tunnel is closed, zone 2: section where the vehicle arriving before the tunnel is not aware of the accident and continues to progress, zone 3: section where the vehicle is stalled, zone 4 : The number of vehicles per time zone is calculated by dividing into zones without vehicles downstream of fire, zone 5: zones where vehicles downstream of fire continue. The speed of shock wave (U _w ) at the point of congestion

Where q ₁ : traffic flow rate at the point of congestion, q ₂ : time of arrival traffic (pc / h), D ₀ : traffic density at the point of congestion (150 pc / km), D ₁ : traffic of arrival traffic Density, The car head spacing

Where N _i : the number of vehicles in I, PCU _total : Overall passenger car conversion factor, Φ _i : Mixing ratio of I model, Average head spacing (Dv)

Where CL _i is the vehicle length of model i, The walking speed according to the distance from the evacuator in front

W _spd = V _u , D _p > t _d Where V _u is the walking speed in the absence of obstructions, V _u = 1.4 ㎧, D _p is the distance to the person in front of it, T _D : 1.6 m, b: body depth, Walking speed by density

W _spd = 0.85k Where a = 0.266 m 2 / person, D _H : Density, k is a constant constant fire hazard prediction system, characterized in that 1.4 에는 in the case of ramps, corridors, doorways. The method of claim 1, wherein the evacuation time of the evacuation of the in-vehicle evacuation is a time in car or leave the car waiting for the fire after the fire (hesitation time to determine the evacuation by getting off the vehicle, Prediction system of tunnel fire risk, characterized in that set to the walking time (starting evacuation and moving to a safe place). The method of claim 5, wherein the evacuation time of the evacuation of the in-vehicle evacuation is 81.6% of the people who discard the vehicle after the warning broadcast and the statistical distribution is GEV (-0.22, 19.81, 33.08) (GEV function:

), And the ratio / probability distribution follows 28 0.28+ (1-0.28) GEV (-0.44, 13, 8.42), with 51% of the people dropping cars before 80-130 seconds, with a statistical distribution of Norm (41.6, (Norm function: 17.1)

49% are those who dump their vehicles after 80 ~ 130 seconds, and the statistic distribution is Gumb (28.8, 155) (Gumb function:

And their ratio / probability distribution follows 8 0.08 + (1-0.08) Norms (151, 8). The method of claim 1, wherein the evacuation time of the evacuation of the in-vehicle evacuation is made by the number of lanes (one way 2, 3, 4 lanes), 1.14 s / m, 1.23 s / for each of the 2, 3, 4 lanes m, 1.548 s / m tunnel fire risk prediction system, characterized in that. The tunnel of claim 7, wherein the evacuation time of the evacuation of the in-vehicle is additionally included including a child, the walking speed of the adult is 1 ~ 1.2 ㎧, the child walking speed is applied to the tunnel of 0.7 ㎧ Fire hazard prediction system. The method of claim 1, wherein the measurement of the temperature in the tunnel The thermal equilibrium type in tunnel fires

to, After t seconds, the temperature at the point downstream of fire x m

Where τ = t- (x / u) and h = 0.02 to 0.04 mW / m 2 · K

ego, Radiation heat flux

here, q '' = radiant heat flux (㎾ / ㎡) F _s = fraction of the combustion heat radiated from the flame surface = 0.3 m = burning rate (kg / s) = 0.055 kg / (s.m 2) ΔH _c = calorific value of gasoline = 43.7 MJ / kg x = tunnel fire risk prediction system, characterized in that it measures the distance from the fire (m). The method of claim 1, wherein the harmful gas concentration is

to, Oxygen reduction rate

Measured by Additional visibility and visibility Extinction coefficient (K)

Where OD is optical density (log ₁₀ (I _o / I), I _o : intensity of light source, I: intensity of receiver light source) In Equation 13

By substituting

ego, In this case, the relationship between the visible distance V and the visibility (K)

in Viewing distance (V, m)

Here, D _mass is a tunnel fire risk prediction system, characterized in that the mass optical density (mass optical density). The method of claim 1, wherein the fractional effective dose (FED) is a cumulative amount (ppm · t) of the harmful gas breathed by a human for t hours, divided by the Ct value having a specific effect (incapacitation or death), At this time, the CO gas is

, The effect of inhalation of CO gas on the human body is the risk index, F _I (FID: frctonal incapacitating dose).

Where F _ICO : risk index leading to unconsciousness, D: COHb concentration (%) leading to unconsciousness, 30%, The reduction rate of oxygen

Where% O ₂ is the concentration of oxygen (%), CO2

to, CO2 risk index

in Hydrogen cyanide (HCN)

80 <ppmHCN <180 ppm, FED for temperature in thermal environment

to FED for radiant heat

FED evaluation of thermal and noxious gas environment

Tunnel fire risk prediction system, characterized in that.

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