A calculation method for ground impact load of ground explosion

Abstract

The present invention relates to a method for calculating the impact load of a ground-impact explosion, comprising: calculating the equivalent TNT charge mass, the distance from the explosion center and the elastic wave velocity of the soil according to the explosion situation; calculating the ground impact arrival time according to the distance from the explosion center and the elastic wave velocity of the soil; calculating the equivalent TNT charge mass, the distance from the explosion center and the elastic wave velocity of the soil according to the explosion situation; calculating the ground impact arrival time according to the distance from the explosion center and the elastic wave velocity of the soil 、 The elastic wave velocity of the soil and the density of the soil are used to calculate the peak pressure and impulse; the ground impact duration is calculated according to the peak pressure and impulse; and the ground impact load curve is obtained according to the calculation results. The beneficial effects of the present invention are as follows: the present invention comprehensively considers the influence of various factors on the ground impact load of the ground impact explosion, overcomes the limitations of the existing methods, and the derived calculation formula can more accurately calculate the ground impact pressure, load impulse and pressure rise time within the applicable range, thereby improving the accuracy of load calculation in the explosion-proof design of underground structures.

Description

Technical Field

[0001] The invention relates to the field of explosion-proof protection of underground engineering, and more specifically, to a method for calculating the impact load of ground explosion. Background Art

[0002] With the acceleration of urbanization and the increasing development and utilization of underground space, the safety issues of underground projects have become increasingly prominent. As an extreme load form, ground impact blast poses a serious threat to underground structures such as tunnels, subways, and civil air defense projects. The ground impact load generated by ground impact blast has the characteristics of high amplitude, fast attenuation, high frequency, and short duration, which poses a severe challenge to the dynamic response analysis and damage assessment of underground structures. At present, domestic and foreign scholars have conducted a lot of research on the calculation methods of ground impact loads caused by ground impact blast, mainly focusing on empirical formula method, numerical simulation method, and experimental research method. However, the existing methods still have certain limitations in accuracy and applicability. For example, although the empirical formula method is simple and easy to use, it is often difficult to accurately reflect the impact load characteristics under complex geological conditions; the numerical simulation method is limited by the accuracy of the calculation model and parameter settings; and the experimental research method is limited by its high cost, long cycle, and difficulty in simulating actual working conditions.

[0003] Although certain research results have been achieved, the calculation of ground blast impact loads still faces many challenges. First, due to the complexity and uncertainty of the explosion process, it is difficult to establish a universally applicable calculation model. Second, the mechanical properties of rock and soil media under different geological conditions vary greatly, which brings great uncertainty to the calculation. Finally, the existing calculation methods often ignore factors such as the energy attenuation and scattering of the explosion shock wave during propagation, resulting in deviations between the calculation results and the actual situation. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies of the prior art and to propose a method for calculating the impact load of a ground-impact explosion.

[0005] In a first aspect, a method for calculating ground impact load of a ground explosion is provided, comprising:

[0006] Step 1: Calculate the equivalent TNT charge mass based on the explosion situation W , explosion center distance R and soil elastic wave velocity c ;

[0007] Step 2: According to the distance from the explosion center R and the soil elastic wave velocity c , calculate the arrival time of the ground shock ;

[0008] Step 3: According to the equivalent TNT charge massW and center of blast distance R , calculate the boost time ;

[0009] Step 4: According to the equivalent TNT charge mass W , explosion center distance R、 Soil elastic wave velocity c and soil density , calculate the peak pressure P 0 and impulse I 0;

[0010] Step 5: According to the peak pressure P 0 and impulse I 0, calculate the duration of ground shock ;

[0011] Step 6. Establish a coordinate system and change (0, 0), ( , 0), ( + , P 0) and ( + , 0) The four coordinate points are connected by straight lines to obtain the ground impact load curve.

[0012] Preferably, in step 6, the ground impact load curve is a triangular pulse curve.

[0013] Preferably, in step 1, the explosion is a ground explosion, and the soil touching the ground is sandy clay or loess.

[0014] Preferably, in step 1, the distance from the explosion center is determined according to the positional relationship between the explosion point and the target point where the ground impact load needs to be considered. R .

[0015] As a preferred method, in step 1, the elastic modulus of the soil is obtained by measuring E and soil density , and according to the soil elastic modulus E and soil density Calculate the elastic wave velocity of soil c .

[0016] In a second aspect, a system for calculating ground impact load of a ground explosion is provided, which is used to execute any method described in the first aspect, including:

[0017] The first calculation module is used to calculate the equivalent TNT charge mass according to the explosion situation. W , explosion center distance R and soil elastic wave velocity c ;

[0018] The second calculation module is used to calculate the distance from the explosion center according to the R and the soil elastic wave velocity c , calculate the arrival time of the ground shock ;

[0019] The third calculation module is used to calculate the equivalent TNT charge mass according to the W and center of blast distance R , calculate the boost time ;

[0020] The fourth calculation module is used to calculate the equivalent TNT charge mass according to the W , explosion center distance R、 Soil elastic wave velocity c and soil density , calculate the peak pressure P 0 and impulse I 0;

[0021] A fifth calculation module is used to calculate the peak pressure according to the peak pressure P 0 and impulse I 0, calculate the duration of ground shock ;

[0022] Create a module to establish a coordinate system and convert (0, 0), ( , 0), ( + , P 0) and ( + , 0) The four coordinate points are connected by straight lines to obtain the ground impact load curve.

[0023] According to a third aspect, a computer storage medium is provided, wherein a computer program is stored in the computer storage medium; when the computer program is executed on a computer, the computer executes any method described in the first aspect.

[0024] In a fourth aspect, an electronic device is provided, including:

[0025] Memory, used to store computer programs;

[0026] A processor is used to execute the computer program to implement any method as described in the first aspect.

[0027] The beneficial effects of the present invention are:

[0028] 1. The present invention comprehensively considers the influence of various factors on the ground impact load of ground explosion by combining experimental research and numerical simulation, and overcomes the limitations of existing methods. The derived calculation formula can more accurately calculate the ground impact pressure, load impulse and pressure rise time within the applicable range, thereby improving the accuracy of load calculation in the explosion-proof design of underground structures.

[0029] 2. The calculation formula obtained by fitting the numerical simulation results in the present invention is specially optimized for the ground explosion situation of sandy clay and loess media, and the applicable proportional distance range is determined. It can more accurately calculate the ground impact pressure, load impulse and boost time, and provides an effective method for the analysis and calculation of ground impact loads caused by loess medium explosions, which is helpful for the development of related engineering practices and research. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A flow chart of a method for calculating the impact load of a ground-impact explosion provided by an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of applicable working conditions provided by an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of a ground impact load curve provided by an embodiment of the present invention;

[0033] Figure 4 A schematic diagram of the peak ground impact pressure provided by an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of specific impulse provided by an embodiment of the present invention;

[0035] Figure 6 A schematic diagram of the ratio of boost time to arrival time provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0037] Embodiment 1:

[0038] To solve the problems of the prior art, such as Figure 1 As shown, Embodiment 1 of the present application provides a method for calculating the ground impact load of a ground explosion, comprising:

[0039] Step 1: Calculate the equivalent TNT charge mass based on the explosion situation W , explosion center distance Rand soil elastic wave velocity c .

[0040] In step 1, if Figure 2 As shown, the explosion is a ground-touching explosion, the soil touching the ground is sandy clay or loess, and the distance from the explosion center is determined based on the positional relationship between the explosion point and the target point where the ground impact load needs to be considered. R .

[0041] In addition, it is necessary to measure the elastic modulus of the soil E and soil density, and according to the soil elastic modulus E and soil density Calculate the elastic wave velocity of soil c . Soil elastic wave velocity c The calculation formula is:

[0042]

[0043] Step 2: According to the distance from the explosion center R and the soil elastic wave velocity c , calculate the arrival time of the ground shock .

[0044] Earth impact arrival time The calculation formula is:

[0045]

[0046] Step 3: According to the equivalent TNT charge mass W and center of blast distance R , calculate the boost time .

[0047] In step 3, the present application provides a calculation formula for the ratio of the boost time to the arrival time, and the boost time can be calculated according to the formula .

[0048] The formula for calculating the ratio of the boost time to the arrival time is:

[0049]

[0050] In the formula, is the ratio of the boost time to the arrival time; is the distance from the explosion center, in m; W is the equivalent TNT charge mass, in kg, Represents proportional distance.

[0051] Step 4: According to the equivalent TNT charge mass W , explosion center distance R、 Soil elastic wave velocity cand soil density , calculate the peak pressure P 0 and impulse I 0.

[0052] Peak pressure P 0 and impulse I The calculation formula for 0 is:

[0053]

[0054] In the formula, P 0 is the free field impact peak pressure, unit: Pa; is the impulse, unit is kPa·ms; is the density of the soil, in kg / m3; c is the elastic wave velocity of soil, in m / s; R is the distance from the explosion center, in m; W It is the equivalent TNT charge mass, in kg.

[0055] Step 5: According to the peak pressure P 0 and impulse I 0, calculate the duration of ground shock .

[0056] Earth shock duration The calculation formula is:

[0057]

[0058] Where, the duration of ground impact is t d The unit is ms.

[0059] Step 6. Establish a coordinate system and change (0, 0), ( , 0), ( + , P 0) and ( + , 0) The four coordinate points are connected by straight lines to obtain the ground impact load curve.

[0060] In step 6, the ground impact load curve is a triangular pulse curve.

[0061] Embodiment 2:

[0062] Based on Example 1, Example 2 of the present application provides a more specific method for calculating the ground impact load of the ground explosion, including:

[0063] Step 1: Calculate the equivalent TNT charge mass based on the explosion situation W , explosion center distance Rand soil elastic wave velocity c .

[0064] For example, it is assumed that the equivalent TNT charge mass calculated based on the type and amount of explosives actually used is 1 kg; it is assumed that the distance from the explosion center is determined to be 0.5 m based on the positional relationship between the explosion point and the target point where the ground impact load needs to be considered.

[0065] Assume that the soil density is obtained through geotechnical testing is 1800 kg / m³, and the elastic modulus of the soil is 100 MPa. c The calculation formula is:

[0066]

[0067] Step 2: According to the distance from the explosion center R and the soil elastic wave velocity c , calculate the arrival time of the ground shock .

[0068] Earth impact arrival time The calculation formula is:

[0069]

[0070] Step 3: According to the equivalent TNT charge mass W and center of blast distance R , calculate the boost time .

[0071] For example, Figure 6 As shown, first calculate the ratio of the boost time to the arrival time:

[0072]

[0073] The boost time is calculated as:

[0074]

[0075] Step 4: Figure 4 and Figure 5 As shown, according to the equivalent TNT charge mass W , explosion center distance R、 Soil elastic wave velocity c and soil density , calculate the peak pressure P 0 and impulse I 0.

[0076] For example, the free-field impact peak pressure is calculated as:

[0077]

[0078] The calculation formula of impulse is:

[0079]

[0080] Step 5: According to the peak pressure P 0 and impulse I 0, calculate the duration of ground shock .

[0081] For example, the impact duration The calculation formula is:

[0082]

[0083] Step 6. Establish a coordinate system and change (0, 0), ( , 0), ( + , P 0) and ( + , 0) The four coordinate points are connected by straight lines to obtain the ground impact load curve.

[0084] For example, the calculation results of steps 2-5 are imported into MATLAB, such as Figure 3 As shown in the figure, the four coordinate points (0,0), (2.12,0), (3.30, 1.643) and (6.31,0) are connected by straight lines to draw the ground impact load curve.

[0085] Compared with the existing methods, the present invention has the following advantages: 1) Fewer key parameters are required for calculation. The existing method needs to determine the stress wave attenuation coefficient according to the soil quality. For the same soil quality, the value of this coefficient is a range, so it is completely based on experience. The method of the present invention is based on a large number of tests and is obtained by fitting test data. There is no need to consider this parameter in the formula; 2) The calculation accuracy is higher, such as Figure 4-Figure 6 It can be seen that the accuracy of calculating the ground shock peak pressure, specific impulse and the ratio of the pressure rise time to the arrival time using this method is higher than that of the existing methods, especially the specific impulse and the ratio of the pressure rise time to the arrival time.

[0086] It should be noted that the parts in this embodiment that are the same or similar to those in Embodiment 1 can be referenced to each other and will not be described in detail in this application.

[0087] Embodiment 3:

[0088] Based on the first and second embodiments, the third embodiment of the present application provides a system for calculating the ground impact load of a ground explosion, including:

[0089] The first calculation module is used to calculate the equivalent TNT charge mass according to the explosion situation.W , explosion center distance R and soil elastic wave velocity c ;

[0090] The second calculation module is used to calculate the distance from the explosion center according to the R and the soil elastic wave velocity c , calculate the arrival time of the ground shock ;

[0091] The third calculation module is used to calculate the equivalent TNT charge mass according to the W and center of blast distance R , calculate the boost time ;

[0092] The fourth calculation module is used for equivalent TNT charge mass W , explosion center distance R、 Soil elastic wave velocity c and soil density , calculate the peak pressure P 0 and impulse I 0;

[0093] A fifth calculation module is used to calculate the peak pressure according to the peak pressure P 0 and impulse I 0, calculate the duration of ground shock t d ;

[0094] Create a module to establish a coordinate system and convert (0, 0), ( , 0), ( + , P 0) and ( + , 0) The four coordinate points are connected by straight lines to obtain the ground impact load curve.

[0095] Specifically, the system provided in this embodiment is a system corresponding to the method provided in Embodiments 1 and 2. Therefore, the parts in this embodiment that are the same or similar to Embodiments 1 and 2 can be referenced to each other and will not be repeated in this application.

Claims

1. A method for calculating the impact load of a ground explosion, characterized in that: include: Step 1: Calculate the equivalent TNT charge mass based on the explosion situation W , explosion center distance R and soil elastic wave velocity c ; Step 2: According to the distance from the center of explosion R and the soil elastic wave velocity c , calculate the arrival time of the ground shock t a ; Step 3: According to the equivalent TNT charge mass W and center of blast distance R , calculate the boost time t r ; In step 3, the calculation formula for the ratio of the boost time to the arrival time is: In the formula, is the ratio of the boost time to the arrival time; R is the distance from the explosion center, in meters; W is the equivalent TNT charge mass, in kg, Indicates proportional distance; the boost time is obtained according to this formula t r ; Step 4: According to the equivalent TNT charge mass W , explosion center distance R、 Soil elastic wave velocity c and soil density , calculate the peak pressure P 0 and impulse I 0; Peak pressure P 0 and impulse I The calculation formula for 0 is: In the formula, P 0 is the free field impact peak pressure, unit: Pa; is the impulse, unit is kPa·ms; is the density of the soil, in kg / m3; c is the elastic wave velocity of soil, in m / s; R is the distance from the explosion center, in m; W is the equivalent TNT charge mass, in kg; Step 5: According to the peak pressure P 0 and impulse I 0, calculate the duration of ground shock t d ; Step 6. Establish a coordinate system and change (0, 0), ( t a , 0), ( t a + t r , P 0) and ( t a + t d , 0) The four coordinate points are connected by straight lines to obtain the ground impact load curve.

2. The method for calculating the ground impact load of a ground explosion according to claim 1, characterized in that: In step 6, the ground impact load curve is a triangular pulse curve.

3. The method for calculating the ground impact load of a ground explosion according to claim 2, characterized in that: In step 1, the explosion is a ground-touching explosion, and the soil touching the ground is sandy clay or loess.

4. The method for calculating the ground impact load of a ground explosion according to claim 3, characterized in that: In step 1, the distance from the explosion center is determined based on the positional relationship between the explosion point and the target point where the ground impact load needs to be considered. R .

5. The method for calculating the ground impact load of a ground explosion according to claim 4, characterized in that: In step 1, the elastic modulus of the soil is obtained by measuring E and soil density , and according to the soil elastic modulus E and soil density Calculate the elastic wave velocity of soil c .

6. A system for calculating ground impact load of a ground explosion, characterized in that: The method for executing any one of claims 1 to 5 comprises: The first calculation module is used to calculate the equivalent TNT charge mass according to the explosion situation. W , explosion center distance R and soil elastic wave velocity c ; The second calculation module is used to calculate the distance from the center of the explosion according to the R and the soil elastic wave velocity c , calculate the arrival time of the ground shock t a ; The third calculation module is used to calculate the equivalent TNT charge mass according to the W and center of blast distance R , calculate the boost time t r ; The fourth calculation module is used to calculate the equivalent TNT charge mass according to the W , explosion center distance R、 Soil elastic wave velocity c and soil density , calculate the peak pressure P 0 and impulse I 0; A fifth calculation module is used to calculate the peak pressure according to the peak pressure P 0 and impulse I 0, calculate the duration of ground shock t d ; Create a module to establish a coordinate system and convert (0, 0), ( t a , 0), ( t a + t r , P 0) and ( t a + t d , 0) The four coordinate points are connected by straight lines to obtain the ground impact load curve.

7. A computer storage medium, characterized in that: The computer storage medium stores a computer program; when the computer program is executed on a computer, the computer executes any one of the methods described in claims 1 to 5.

8. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the method according to any one of claims 1 to 5.

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