A method for assessing the risk of building collapse during fire

Abstract

The present invention discloses a method for evaluating the risk of building collapse during a fire, which relates to the field of construction. The method for evaluating the risk of building collapse during a fire comprises the following steps: step S10, establishing a proportional three-dimensional model according to data of an actual building, establishing a fire database, and annotating the three-dimensional model; step S20, performing fire simulation analysis, assigning different values ​​to basic data such as the ignition point and the degree of ignition of the building, continuously performing repeated tests, and establishing a test database; step S30, analyzing the fire test data, obtaining the weak positions of the building, and sorting them according to the degree of weakness; step S40, evaluating the fire risk of the building and outputting an evaluation. By evaluating and sorting the collapse risk of the building under different fire scenarios, it can provide important references for relevant units, and corresponding protective measures can be gradually taken according to the degree of risk.

Description

Technical Field

[0001] The invention relates to the field of buildings, and in particular to a method for assessing the risk of building collapse during fire. Background Art

[0002] With the substantial improvement of my country's urbanization level, the construction industry has also developed rapidly. The complexity of building structures and functions and the emergence of various new technologies and processes have significantly increased the factors causing building fires. At the same time, a fire may also cause the collapse of a building, thus bringing huge risks to trapped people and rescuers. Therefore, it is necessary to conduct a fire collapse risk assessment of buildings.

[0003] However, the existing building fire collapse risk assessment rarely pays attention to the weak parts of the building, which are the most vulnerable parts of the building when a fire occurs. The collapse is likely to start from the weak parts. Therefore, it is urgent to focus on the building collapse caused by the weak parts. To this end, we propose a method to assess the risk of building collapse during fire. Summary of the invention

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A method for assessing the risk of building collapse during fire, comprising the following steps:

[0006] Step S10, based on the data of the actual building, a proportional three-dimensional model is established, a historical fire situation database is established, and the three-dimensional model is annotated;

[0007] Step S20, conduct fire simulation analysis, set analysis scenarios considering important factors such as the fire location and fire scale of the building, conduct repeated tests continuously, and establish a simulation test database;

[0008] Step S30, analyzing the fire simulation test data, obtaining the weak locations of the building, and sorting them according to the degree of weakness;

[0009] Step S40, assessing the risk of collapse of the building due to fire and outputting the assessment.

[0010] Further, step S10 specifically includes the following steps:

[0011] Step S11, collecting statistics on publicly available building fire information and establishing a fire situation database;

[0012] Step S12, classifying and summarizing the fire points of buildings in previous fires based on the fire situation database;

[0013] Step S13, based on the established three-dimensional model, the ignition point is marked on the three-dimensional model according to the classification and summary results.

[0014] Further, step S12 includes the following steps:

[0015] Step S121: Based on the fire situation database, the fire points that have occurred in the building are screened out and marked at the corresponding positions in the established three-dimensional model;

[0016] Step S122: Based on the fire situation database, count the number of occurrences of each fire point and sort them to determine the probability of fire at each location in the building;

[0017] Step S123: Based on the fire database, for buildings where fires have occurred, the severity of the fires at each fire point is counted, and the economic losses caused are quantified to form a ratio of economic losses to building costs;

[0018] Step S124, based on step S122 and step S123, the number of fires generated at the ignition point and the sum of the ratio of the corresponding economic losses caused to the building cost are marked in the three-dimensional model.

[0019] Further, step S20 includes the following steps:

[0020] Step S21, based on the marking result of step S124, forming several times of the test number according to the number of times the fire point appears; designing corresponding fire scenes to form different test intensities;

[0021] Step S22, based on the test intensity and test number obtained in step S21, under different time parameters, the location where the building collapses in the test is obtained, which is the weak location, and the ratio of the economic loss caused by the collapse to the building cost is obtained, and the degree of loss is output;

[0022] Step S23, establishing a test database based on the test results of the building damage after the fire obtained in step S22;

[0023] Step S24, based on the test results obtained in S22, the strength of the building structure at the weak position is strengthened.

[0024] Furthermore, the step S30 includes the following steps:

[0025] Step S31, based on the test database obtained in step S23, determine the weak position of the building that causes collapse after being damaged, compare the building structure strength of the weak position with the maximum structural strength of the corresponding position in the three-dimensional model, output the strength ratio, confirm the degree of weakness according to the strength ratio, and assign a value;

[0026] Step S32, based on step S31, count the number of times each weak position appears, and use the degree of weakness, the number of occurrences, and the degree of loss to confirm the expected value of weakness.

[0027] Step S33, based on step S32, calculate the standard deviation of the weakness degree.

[0028] Furthermore, the number of occurrences of the weak position is assigned as A1, A2, A3, etc., the weak degree is assigned as B1, B2, B3, etc., the loss degree is assigned as C1, C2, C3, etc., and the weak expected value is assigned as E, where:

[0029] Furthermore, the step S30 further includes a step S33, based on the step S32, the standard deviation of the weakness is assigned as σ, where:

[0030] Furthermore, the step S40 further includes a step S41, based on the steps S33 and S32, the risk value of the building F(X)=σ / E, and the risk assessment of the building is formed by using F(X), and the risk of loss caused by fire in different buildings is assessed by comparing the values ​​of E and F(X). Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) In the present invention, when used, by collecting the fire point conditions of the building, a fire simulation analysis is performed on the building, and by using different parameters such as time and fire intensity, the weak position of the building and the degree of loss caused by the collapse of the building at the weak position are determined, and the expected weakness value of the building is obtained. The risk value is formed in combination with the standard deviation of the weakness degree, and an assessment result of the fire risk of the building is formed.

[0032] (2) In the present invention, by evaluating and ranking the collapse risk of buildings under different fire scenarios, a good reference can be provided for relevant units, and corresponding protective measures can be gradually taken according to the degree of risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the evaluation method of the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and embodiments. The embodiments of the present invention include but are not limited to the following embodiments.

[0035] Example

[0036] A method for assessing the risk of building collapse during a fire described in this embodiment includes the following steps:

[0037] Step S10, based on the data of the actual building, a proportional three-dimensional model is established, a historical fire situation database is established, and the three-dimensional model is annotated. Specifically, the three-dimensional model can be completed by some common three-dimensional mapping software or on-site three-dimensional scanning.

[0038] Step S10 specifically includes the following steps:

[0039] Step S11, collecting statistics on publicly available building fire information and establishing a fire situation database;

[0040] Step S12, classifying and summarizing the fire points of buildings in previous fires based on the fire situation database;

[0041] Step S13, based on the established three-dimensional model, the ignition point is marked on the three-dimensional model according to the classification and summary results.

[0042] When in use, a proportional three-dimensional model is constructed based on the actual building, and the fire point is marked on the three-dimensional model to facilitate the development of fire simulation tests.

[0043] Specifically, step S12 includes the following steps:

[0044] Step S121: Based on the fire situation database, the fire points that have occurred in the building are screened out and marked at the corresponding positions in the established three-dimensional model;

[0045] When in use, by screening fire points from buildings where fires have already occurred, it is possible to avoid selecting locations where fires will never occur or where the probability of fire occurring is extremely low during fire simulation analysis, thereby wasting analysis time and resources, or even obtaining completely incorrect results. In actual situations, a large amount of historical fire data is collected, and the samples are rich enough to cover all locations where fires may occur.

[0046] Step S122: Based on the fire situation database, count the number of occurrences of each fire point and sort them to determine the probability of fire at each location in the building;

[0047] When in use, by sorting the number of times a fire occurs at each fire point in each building, the probability of a fire point at each location can be determined, which facilitates the reasonable allocation of energy during simulation analysis.

[0048] Step S123: Based on the fire database, for buildings where fires have occurred, the severity of the fires at various ignition points is counted, and the economic losses caused are quantified to form a ratio of economic losses to building costs; specifically, the quantification standard is consistent with the economic losses directly caused by the fire.

[0049] When in use, by ranking the impact of fire on the entire building after a fire occurs at each fire point in each building, it is possible to determine which fire point at each location has caused the greatest damage and requires the most attention, thereby facilitating the rational allocation of energy when simulating a fire.

[0050] Step S124, based on step S122 and step S123, the number of fires generated at the ignition point and the sum of the ratio of the corresponding economic losses caused to the building cost are marked in the three-dimensional model.

[0051] When in use, the ignition point is marked to make the simulation analysis results more reasonable.

[0052] Step S20, conduct fire simulation analysis, set analysis scenarios considering important factors such as the fire location and fire load of the building, conduct repeated tests continuously, and establish a simulation test database; specifically, the simulation analysis can be completed by simulation software.

[0053] Specifically, step S20 includes the following steps:

[0054] Step S21, for buildings that have experienced historical fires, based on the marking results of step S124, several times the number of tests are formed according to the number of times the fire point appears; for buildings that have not experienced historical fires, a certain number of tests are formed according to the fire load characteristics and distribution patterns inside the building, and with reference to similar buildings that have experienced historical fires in the marking results of step S124; a variety of fire scenes are designed to form different test intensities; for example, in the fire database, the scale of the fire at the fire point is increased by 20%, so that the building is subjected to an excessive fire to confirm whether the building can withstand it, but the maximum increase ratio does not exceed 25%.

[0055] Step S22, based on the test intensity and test number obtained in step S21, under different time parameters, the location where the building collapses in the test is obtained, which is the weak location, and the ratio of the economic loss caused by the collapse to the building cost is obtained, and the degree of loss is output;

[0056] Step S23, establishing a test database based on the test results of the building damage after the fire obtained in step S22;

[0057] Step S24, based on the test results obtained in S22, the strength of the building structure at the weak position is strengthened.

[0058] When in use, based on an actual fire, by testing a three-dimensional model built based on a real building, it is possible to find out the damage that the building has suffered after the fire, and if a collapse occurs, where in the building the collapse will occur.

[0059] Step S30, analyzing the fire simulation test data, obtaining the weak locations of the building, and sorting them according to the degree of weakness; specifically, the steps include:

[0060] Step S31, based on the test database obtained in step S23, determine the weak position of the building that causes collapse after being damaged, compare the building structure strength of the weak position with the maximum structural strength existing in the three-dimensional model, output the strength ratio, confirm the degree of weakness according to the strength ratio, and assign a value;

[0061] Step S32, based on step S31, count the number of times each weak position appears, and use the degree of weakness, the number of occurrences, and the degree of loss to confirm the expected value of weakness.

[0062] Specifically, there are the following assignments, so that the number of occurrences of weak positions is assigned as A1, A2, A3..., the degree of weakness is assigned as B1, B2, B3..., the degree of loss is assigned as C1, C2, C3..., and the expected value of weakness is assigned as E, among which E=(A1*B1*C1+A2*B2*C2+A3*B3*C3...) / (A1+A2+A3...).

[0063] Step S33: Based on step S32, the weak position is marked in the three-dimensional model, and then the standard deviation of the weak degree is determined, where σ = {[A1*(B1*C1-E) 2 +A2*(B2*C2-E) 2 +A3*(B3*C3-E) 2 +…] / (A1+A2+A3…)} 0.5 .

[0064] Step S40, assessing the fire risk of the building and outputting the evaluation;

[0065] Specifically, the step S40 further includes a step S41, based on steps S33 and S32, making the risk value F of the building (X) =σ / E, using F (X) A risk assessment of the building is formed, and the risk of loss incurred by different buildings in the event of a fire is evaluated through the size of the E and F(X) values.

[0066] When in use, by collecting the fire point conditions of the building, a fire simulation analysis is performed on the building. By adopting different parameters such as time and fire intensity, the weak position of the building and the degree of loss caused by the collapse of the building at the weak position are determined, and the expected weakness value of the building is obtained. The risk value is formed in combination with the standard deviation of the weakness degree, and an assessment result of the fire risk of the building is formed. By evaluating and ranking the collapse risk of the building under different fire scenarios, a good reference can be provided for relevant units, and corresponding protective measures can be gradually taken according to the degree of risk.

[0067] The above embodiment is only one of the preferred implementation modes of the present invention. Any changes or modifications that are made to the main design concept and spirit of the present invention and have no substantial significance, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention.

Claims

1. A method for assessing the risk of building collapse during a fire, characterized in that: The following steps are involved: Step S10, based on the data of the actual building, a proportional three-dimensional model is established, a fire situation database is established, and the three-dimensional model is annotated; Step S20, conduct fire simulation analysis, set analysis scenarios considering important factors such as the fire location and fire scale of the building, conduct repeated tests continuously, and establish a simulation test database; Step S30, analyzing the fire simulation test data, obtaining the weak locations of the building, and sorting them according to the degree of weakness; This step includes the following steps: Step S31, based on the test database, determine the weak position that causes the collapse after the building is damaged, compare the building structure strength of the weak position with the maximum structural strength of the corresponding position in the three-dimensional model, output the strength ratio, confirm the degree of weakness according to the strength ratio, and assign a value; the number of occurrences of the weak position is assigned as A1, A2, A3..., the degree of weakness is assigned as B1, B2, B3..., the degree of loss is assigned as C1, C2, C3..., and the expected value of weakness is assigned as E ,in, ; Step S32, based on step S31, counting the number of occurrences of each weak position, and confirming the weak expected value using the degree of weakness, the number of occurrences, and the degree of loss caused; Step S33, based on step S32, calculate the standard deviation of the degree of weakness; the value of the standard deviation of the degree of weakness is σ, where ; Step S40, assess the risk of collapse of the building due to fire and output an evaluation; in this step, based on steps S33 and S32, the risk value F of the building is （X） =σ / E, using F （X） Form a risk assessment of the building, through E and F （X） The value is used to assess the risk of loss of different buildings in the event of a fire.

2. The method for assessing the risk of building collapse during fire according to claim 1, characterized in that: Step S10 specifically includes the following steps: Step S11, collecting statistics on publicly available building fire information and establishing a fire situation database; Step S12, classifying and summarizing the fire points of buildings in previous fires based on the fire situation database; Step S13, based on the established three-dimensional model, the ignition point is marked on the three-dimensional model according to the classification and summary results.

3. The method for assessing the risk of building collapse during fire according to claim 2, characterized in that: Step S12 includes the following steps: Step S121: Based on the fire situation database, the fire points that have occurred in the building are screened out and marked at the corresponding positions in the established three-dimensional model; Step S122: Based on the fire situation database, count the number of occurrences of each fire point and sort them to determine the probability of fire at each location in the building; Step S123: Based on the fire database, for buildings where fires have occurred, the severity of the fires at each fire point is counted, and the economic losses caused are quantified to form a ratio of economic losses to building costs; Step S124, based on step S122 and step S123, the number of fires generated at the ignition point and the sum of the ratio of the corresponding economic losses caused to the building cost are marked in the three-dimensional model.

4. The method for assessing the risk of building collapse during fire according to claim 1, characterized in that: Step S20 The following steps are included: Step S21, based on the marking result of step S124, forming several times of the test number according to the number of times the fire point appears; designing corresponding fire scenes to form different test intensities; Step S22, based on the test intensity and test number obtained in step S21, under different time parameters, the location where the building collapses in the test is obtained, which is the weak location, and the ratio of the economic loss caused by the collapse to the building cost is obtained, and the degree of loss is output; Step S23, establishing a test database based on the test results of the building damage after the fire obtained in step S22; Step S24, based on the test results obtained in S22, the strength of the building structure at the weak position is strengthened.

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