CN114357557A - Anti-overturning stable safety evaluation method for penetration explosion damage concrete gravity dam - Google Patents

Abstract

The invention discloses an anti-overturning stable safety evaluation method for a penetration explosion damage concrete gravity dam, which comprises the following steps: selecting a typical dam section of the concrete gravity dam; the type and the penetration condition of penetration weapons are known; determining the damage form of penetration explosion damage; determining the penetration explosion damage range; determining a damage path of the concrete gravity dam; determining the strength parameter of the residual section and checking the stress; calculating an anti-overturning stable safety coefficient according to an anti-overturning formula; and establishing a penetration explosion damage anti-overturning stable safety evaluation model. The method can evaluate the stability of the penetration explosion damage concrete gravity dam by only using a penetration explosion damage anti-overturning stability evaluation model which passes reliability verification without adopting a field explosion test. Under the condition that the gravity dam is attacked by different penetration weapons, different penetration conditions and different penetration parts, the method can quickly evaluate the anti-overturning stability of the concrete gravity dam damaged by explosion.

Description

A safety evaluation method for anti-overturning stability of concrete gravity dam damaged by penetration explosion

technical field

The invention belongs to the technical field of anti-overturning evaluation of gravity dams, and in particular relates to a safety evaluation method for anti-overturning stability of concrete gravity dams damaged by penetration explosions based on penetration weapons-penetration conditions-penetration parts.

Background technique

The penetrating strike of the guided weapon on the downstream surface of the concrete gravity dam may lead to the overturning of the upper part of the concrete gravity dam, resulting in the instability and damage of the dam, which poses a great threat to the safety of the dam. Therefore, it is very necessary to establish an anti-overturning stability safety evaluation model of concrete gravity dam based on penetrating weapon-penetration condition-penetration position, which can not only quickly know the safety performance of penetrating explosion damage concrete gravity dam, Moreover, this rapid evaluation method can provide a strong theoretical basis for decision makers to formulate relevant plans and avoid greater losses.

SUMMARY OF THE INVENTION

In view of the above-mentioned technical problems, the object of the present invention is to provide a method that can quickly evaluate the anti-overturning stability of a concrete gravity dam damaged by penetration explosion, by establishing a penetration method based on penetration weapons-penetration conditions-penetration part of the concrete gravity dam A complete safety assessment model for anti-overturning stability of explosion damage is used to quickly assess the safety performance of a dam after being attacked by a bomb, and to provide a theoretical basis for decision makers to formulate emergency rescue or other measures.

The technical scheme provided by the present invention is as follows:

An anti-overturning stability safety evaluation method used for penetrating explosion damage concrete gravity dam, comprising the following steps:

Step 1, select a typical dam section of a concrete gravity dam;

Step 2, understand the parameters and penetration conditions of penetrating weapons;

Step 3: First, use Young's empirical formula to calculate the penetration depth of the projectile based on the parameters of the penetration weapon and penetration conditions; then use Livingston's blasting funnel theory to determine the damage form of the projectile after it explodes inside the concrete gravity dam For internal action damage or blasting funnel damage;

Step 4: When a superficial explosion occurs to form a blasting funnel, the blasting crater depth and blasting crater radius are calculated according to the engineering blasting theory and its corresponding formula; when the internal effect of the penetrating explosion occurs, the corresponding internal blast effect is used to damage the partition. Calculate the damage range of concrete;

Step 5: According to the position of the penetration part, use the calculated depth and radius of the blasting hole to determine the rotation center, and further obtain the possible failure section of the concrete gravity dam, which is its failure path;

Step 6: Determine the strength parameters of the residual section at the section of the failure path, and then use the material mechanics method to check the stress at the upstream dam face of the section of the failure path to determine whether the upstream dam face at the section of the failure path will crack and form. through cracks;

Step 7, using the calculation formula of anti-overturning, find out the anti-overturning stability safety factor of the concrete gravity dam, and carry out safety assessment;

Step 8: Based on the above steps, the anti-overturning stability and safety performance of the concrete gravity dam can be quickly calculated by knowing the information of the penetration weapon, penetration condition and penetration position; Penetration weapon-penetration condition-penetration explosion damage anti-overturning stability safety evaluation database and model of concrete gravity dam in the penetration position.

Further, in the step 2, the parameters of the penetrating weapon include the mass of the projectile, the cross-sectional area of the projectile, the type of the warhead, the length of the projectile, the diameter of the projectile, the charge of the projectile and the radius of curvature of the surface of the projectile head; Conditions include penetration speed and hit angle.

Further, in the step 3, the calculation formula of the projectile penetration depth H _q is as follows:

In the formula: M is the mass of the projectile, kg; v ₀ is the target velocity of the projectile, m/s; A is the cross-sectional area of the projectile, m ² ; S is the penetrability index;

According to the different warheads, different calculation methods are used for N:

Where: L _n is the length of the projectile, m; d is the diameter of the projectile, m; CRH is the ratio of the surface curvature radius of the ground-penetrating projectile head to the cross-sectional radius of the ground-penetrating projectile.

Further, in the step 3, in the calculation formula of the projectile penetration depth H _q , the calculation formula of the penetrability index S is as follows:

S=2.7(f _c Q) ^-0.3 (4)

Where: f _c is the unconfined compressive strength, MPa; Q is the rock quality index.

Further, in the step 3, after the projectile exploded inside the concrete gravity dam, the method for determining whether its damage form is internal action damage or blasting funnel damage is:

In the case of known missile explosive equivalent and concrete deformation energy coefficient, using the blasting funnel theory proposed by Livingston, the buried depth of explosives in the critical funnel state of destruction on the concrete surface can be obtained, as follows:

W _C = E _b Q ^1/3 (5)

Where: Q is the amount of explosive, kg; E _b is the deformation energy coefficient of the rock; W _C is the critical burial depth, m.

When the penetration depth H _q of the projectile is less than the critical burial depth W _C of the explosive, a penetration explosion occurs inside the concrete gravity dam to form a blasting funnel; when the penetration depth H _q of the projectile is greater than the critical buried depth _WC of the explosive, the penetration The internal effect of the explosion is destroyed, and the blasting funnel will not be formed on the surface of the concrete gravity dam.

Further, in the described step 4, when a superficial explosion occurs to form a blasting funnel, an explosion occurs after the projectile penetrates to the maximum depth inside the target, and the blast core is at the center of the charge. According to the engineering blasting theory, the depth of the blast crater is determined by the following formula:

H=H _q -L·cos α (6)

In the formula: H _q is the penetration depth of the warhead in the medium, m; L is the height of the charge center; α is the hit angle.

After calculating the crater depth, use the relationship between the amount of explosives, the crater depth and the crater radius to determine the crater radius. The formula is as follows:

Q=f(H/r)q _standard ·H ³ (7)

Where: Q is the amount of explosives, kg; q is the consumption of explosives per unit volume of medium forming a _standard throwing funnel, kg/m ³ ; H is the penetration depth of the crater, m; f(H/r) is the blasting action index function.

Further, the calculation formula of f(H/r) is:

Substitute (8) into (7) to get:

Among them: r is the radius of the crater, m; η is the conversion coefficient of TNT to antimony, which is 1.1.

Further, in the step 4, when the internal action damage of the penetrating explosion occurs, the corresponding internal explosion action damage division calculation method is used to obtain the concrete damage range; the crushing zone radius R ₁ and the crack zone radius R ₂ can be determined by using The following theoretical formula:

In the formula: R ₁ is the radius of the crushing circle; ρ ₀ is the density of the explosive, D is the detonation velocity of the explosive; n is the pressure increase coefficient when the explosive product expands and collides with the blast hole wall, generally taking n=10; K is the charge diameter Directional uncoupling coefficient, K=d _b /d _c , d _b , d _c are the radius of the blast hole and the radius of the charge, respectively; γ is the expansion adiabatic index of the detonation product, generally taking γ=3; l _e is the charge axis α is the load propagation attenuation index (shock wave region); ρ _cd is the uniaxial dynamic compressive strength; r _b is the radius of the blast hole; σ _R is the radial stress on the interface between the crush ring and the crack ring; σ _td is the uniaxial dynamic tensile strength; β is the load propagation attenuation index (stress wave region).

where B is calculated as:

B=[(1+b) ² +(1+b ² )-2μ _d (1-μ _d )(1-b) ² ] ^0.5 (12)

In the formula, b is the lateral stress coefficient; μ _d is the dynamic Poisson’s ratio of the rock, μ _d = 0.8μ, and μ is the static Poisson’s ratio of the rock.

Further, in the step 6, because part of the concrete is damaged, the stress intensity of the damage path section will decrease, and the corresponding stress intensity reduction needs to be carried out; when the damage variable is defined according to the crack area, it is considered that the main mechanism of material deterioration is microscopic. The reduction of the effective bearing area caused by the defect, so the concrete strength after damage is σ=(1-D ₀ )σ ₀ , where D ₀ is the damage variable, and σ ₀ is the concrete stress strength without damage;

According to the material mechanics method, the stress check is carried out on the upstream dam surface of the failure path section obtained in step 5 to find out whether the maximum tensile stress it receives will exceed the tensile strength of concrete, and then judge whether there will be through cracks. : When the maximum tensile stress on the upstream dam face of the failure path section is less than the tensile strength of concrete, the upstream dam face of the failure path section will not crack; when the maximum tensile stress on the upstream dam face of the failure path section exceeds When the tensile strength of concrete is increased, the upstream dam face will crack, eventually forming through cracks.

Further, in the step 7, the anti-overturning calculation formula of the concrete gravity dam is used to obtain the anti-overturning stability safety factor of the concrete gravity dam, and the calculation formula of the anti-overturning concrete gravity dam is as follows:

In the formula: γ ₀ is the structural importance coefficient; ψ is the design condition coefficient; γ _d is the anti-overturning stability structural coefficient; ∑M ₀ is the sum of the overturning moments on the basic calculation surface; ∑M _s is the anti-overturning moment on the basic calculation surface The sum; among them, γ ₀ , ψ and γ _d are obtained by querying the "Hydraulic Design Manual".

After the failure path is known, the moment of the upper concrete gravity dam's self-weight to the rotation center is calculated, and then the self-weight of the upper concrete gravity dam, the concrete cohesion, the uplift pressure, and the horizontal water pressure's moment to the rotation center are calculated. The sum of the anti-overturning moment and the sum of the overturning moment, find out the relevant parameters, and substitute them into the above formula (24), then the stability of the concrete gravity dam damaged by the penetration explosion can be known;

The anti-overturning safety factor K _s is introduced to evaluate the anti-overturning stability of the gravity dam:

The formula for calculating the anti-overturning safety factor K _s is as follows:

The beneficial effects of the anti-overturning stability safety evaluation method for the explosion-damaged concrete gravity dam of the present invention are:

(1) The present invention can quickly evaluate the stability performance of the concrete gravity dam damaged by the penetration explosion. Compared with checking the damaged parts of the dam, it can save a lot of time and facilitate decision-making. Evacuate downstream residents quickly, and take emergency rescue measures more quickly when the dam may be repaired.

(2) when the concrete gravity dam is hit by any penetrating weapon, any penetrating condition and any penetrating part, the penetrating explosion damage anti-overturning stability safety assessment model of the concrete gravity dam established by the method of the present invention is still applicable, Its universality is also a great benefit.

Description of drawings

Figure 1 is a flow chart of the method of the present invention.

Figure 2 is a schematic diagram of the damage of the blasting funnel caused by the penetration explosion of the concrete gravity dam (the letters in the figure represent the length of each side, r is the radius of the blast crater, H is the depth of the blast crater, G is the gravity, U is the uplift pressure, and P is the horizontal water pressure , c'A is the cohesion between concrete).

Figure 3 is a schematic diagram of the internal action damage caused by the penetration explosion of the concrete gravity dam (the letters in the figure represent the length of each side, b ₀ is the radius of the damage damage zone, G is the gravity, U is the uplift pressure, P is the horizontal water pressure, c' A is the cohesion between concrete).

Detailed ways

The present invention will be further described below with reference to the accompanying drawings. The content of the present invention is not limited to this at all.

Example

As shown in Figure 1-3, the specific steps are as follows:

1. Select the typical dam section of the concrete gravity dam;

2. Know the type of penetrating weapon, know its projectile mass, projectile cross-sectional area, weapon charge and other parameters, and clarify the penetrating conditions, such as impact speed, etc.;

3. First, use the widely used and highly credible Young's experience formula, combined with the type of penetration weapon and penetration conditions, to calculate the penetration depth of the projectile. The Young's experience formula is as follows:

In the formula: M is the mass of the projectile, kg; v ₀ is the target velocity of the projectile, m/s; A is the cross-sectional area of the projectile, m ² .

Conical warhead: N=0.56+0.25L _n /d (3)

where L _n is the length of the projectile (m), d is the diameter of the projectile (m), CRH is the ratio of the surface curvature radius of the ground-penetrating projectile head to the cross-sectional radius of the ground-penetrating projectile, and S is the penetration index.

S=2.7(f _c Q) ^-0.3 (4)

Where: f _c is the unconfined compressive strength (MPa); Q is the rock quality index.

In the case of known missile explosive equivalent and concrete deformation energy coefficient, using the blasting funnel theory proposed by Livingston, the buried depth of explosives in the critical funnel state of destruction on the concrete surface can be obtained, as follows:

W _C = E _b Q ^1/3 (5)

Where: Q is the amount of explosive, kg; E _b is the deformation energy coefficient of the rock; W _C is the critical burial depth, m.

When the penetration depth H _q of the projectile is less than the critical burial depth W _C of the explosive, a penetration explosion occurs inside the concrete gravity dam to form a blasting funnel, as shown in Figure 2; when the penetration depth H _q of the projectile is greater than the critical buried depth of the explosive At W _C , the internal effect of the penetrating explosion is destroyed, and the blasting funnel will not be formed on the surface of the concrete gravity dam, as shown in Figure 3.

4. When a superficial explosion occurs to form a blasting funnel, the projectile will explode after it penetrates to the maximum depth inside the target, and the core of the blast is in the center of the charge. According to the engineering blasting theory, the depth of the crater is determined by the following formula:

H=H _q -L·cosα (6)

In the formula: H _q is the penetration depth of the warhead in the medium, m; L is the height of the charge center; α is the hit angle.

After calculating the crater depth, the crater radius is determined by using the relationship between the charge amount, the crater depth and the crater radius. The formula is as follows:

Q=f(H/r)q _standard ·H ³ (7)

Where: Q is the amount of explosives, kg; q is the consumption of explosives per unit volume of medium forming a _standard throwing funnel, kg/m ³ ; H is the penetration depth of the crater, m; f(H/r) is the blasting action index function.

Regarding the calculation method of f(H/r), the calculation formula proposed by the widely used Soviet scholar Boleskov is used, which is:

Substitute (8) into (7) to get:

Among them: r is the radius of the crater, m; η is the conversion coefficient of TNT to antimony, which is 1.1.

When the internal effect of penetrating explosion is damaged, the corresponding damage zone calculation method of internal explosion effect is used to obtain the damage range of concrete. The crushing zone radius R ₁ and the fracture zone radius R ₂ can be determined by the following theoretical formulas:

In the formula: R ₁ is the radius of the crushing circle; ρ ₀ is the density of the explosive, D is the detonation velocity of the explosive; n is the pressure increase coefficient when the explosive product expands and collides with the blast hole wall, generally taking n=10; K is the charge diameter Directional uncoupling coefficient, K=d _b /d _c , d _b , d _c are the radius of the blast hole and the radius of the charge, respectively; γ is the expansion adiabatic index of the detonation product, generally taking γ=3; l _e is the charge axis α is the load propagation attenuation index (shock wave region); σ _cd is the uniaxial dynamic compressive strength; r _b is the radius of the blast hole; σ _R is the radial stress on the interface between the crush ring and the crack ring; σ _td is the uniaxial dynamic tensile strength; β is the load propagation attenuation index (stress wave region).

where B is calculated as:

B=[(1+b) ² +(1+b ² )-2μ _d (1-μ _d )(1-b) ² ] ^0.5 (12)

In the formula, b is the lateral stress coefficient; μ _d is the dynamic Poisson’s ratio of the rock, μ _d = 0.8μ, and μ is the static Poisson’s ratio of the rock.

5. After the downstream surface of the concrete gravity dam is hit by penetration, the upper part of the dam may overturn. According to the penetration position, combined with the depth of the explosion crater and the radius of the crater calculated in the previous step, the rotation center can be determined. Due to the cohesion between concretes, it has a great influence on the anti-overturning stability of the concrete gravity dam, so the possible failure section of the concrete gravity dam can be judged, that is, its failure path.

6. The stress intensity of the section of the failure path will decrease due to the damage of part of the concrete, and the corresponding stress intensity reduction needs to be carried out. When the damage variable is defined by the crack area, it is considered that the main mechanism of material deterioration is the reduction of the effective bearing area caused by micro-defects, so the concrete stress intensity after damage is:

σ=(1-D ₀ )σ ₀ (13)

In the formula, σ is the concrete stress strength after damage, MPa; D ₀ is the damage variable, σ ₀ is the concrete stress strength without damage, MPa.

Since there are anti-seepage and drainage facilities such as drainage pipes and drainage corridors in the dam body, the uplift pressure inside the dam body is very small and can be ignored. Therefore, the uplift pressure is not considered when the stress check of the upstream dam surface of the failure path section is carried out by the material mechanics method. , the formula is as follows:

In the formula, ∑W is the sum of the vertical component forces acting on all loads above the calculated section; ∑M is the sum of the moments acting on all loads above the calculated section to the centroid axis of the vertical water flow of the section; x is the length of the calculated section; σ _yu and σ _yd are the upper and downstream edge stresses of the horizontal section, respectively.

Use equations (14) and (15) to calculate the normal stress σ _y on the horizontal section of the dam body, and τ, σ _x and σ ₁ , σ ₂ can be obtained according to the equilibrium conditions of the edge differential body, and the simplified formula is as follows :

τ _u =(p _u -σ _yu )n ₁ (16)

τ _d =(σ _yd -p _d )m ₁ (17)

σ _xu = p _u -τ _u n ₁ (18)

σ _xd = p _d +τ _d m ₁ (19)

σ _1u =(1+n ₁ ² )σ _yu -p _u n ₁ ² (20)

σ _1d =(1+m ₁ ² )σ _yd -p _d m ₁ ² (21)

σ _2u = p _u (22)

σ _2d = p _d (23)

In the formula, τ _u and τ _d are the shear stress of the upstream and downstream edges, respectively; n ₁ , m ₁ are the slope ratios of the upstream and downstream dams, respectively; σ _xu , σ _xd are the horizontal normal stresses of the upstream and downstream edges, respectively; σ _1u , σ _1d are the maximum principal stress at the edge of the upstream and downstream dam surfaces, respectively; σ _2u , σ _2d are the minimum principal stresses at the edge of the upstream and downstream dam surfaces, respectively; p _u , p _d are the water pressure strengths at the upstream and downstream dam surfaces ( If there is sediment pressure, it should be included).

Using the above formula, the maximum tensile stress on the upstream dam face of the failure path section can be obtained. When the tensile stress is less than the tensile strength of the concrete, the upstream dam face of the failure path section will not crack, and the upper gravity dam of the failure path section will not crack. When calculating the anti-overturning resistance, the cohesion between the concretes needs to be considered; when the tensile stress is greater than the tensile strength of the concrete, cracks will occur at the upstream dam face of the failure path section, and eventually through cracks will be formed. The cohesion between concretes cannot be considered when calculating the anti-overturning resistance of the upper gravity dam.

7. Using the calculation formula of anti-overturning, the anti-overturning stability safety factor of the concrete gravity dam is obtained. The calculation formula of the anti-overturning concrete gravity dam is as follows:

In the formula: γ ₀ is the structural importance coefficient; ψ is the design condition coefficient; γ _d is the anti-overturning stability structural coefficient; ∑M ₀ is the sum of the overturning moments on the basic calculation surface; ∑M _s is the anti-overturning moment on the basic calculation surface Sum. Among them, γ ₀ , ψ and γ _d are obtained by querying "Hydraulic Design Manual".

After knowing the failure path, calculate the moment of the self-weight of the upper concrete gravity dam to the center of rotation, and then calculate the moment of the horizontal water pressure, the pressure of sediment and the cohesion between the concrete, etc. to the center of rotation, and then calculate the resistance The sum of the overturning moment and the sum of the overturning moment can be used to find out the relevant parameters and substitute them into the above formula (24) to know the stability of the concrete gravity dam damaged by the penetration explosion. It is advisable to introduce the anti-overturning safety factor K _s to evaluate the anti-overturning stability of the gravity dam:

8. Based on the above ideas and steps, in the case of any penetrating weapon, penetrating condition and penetrating position, the parameters can be quickly changed to calculate the anti-overturning stability and safety performance of the concrete gravity dam, which is equivalent to establishing a A database, then as long as you know the type, conditions and action parts of the penetration weapon, you can know the safety of the concrete gravity dam by looking up the table, that is, the penetration of the concrete gravity dam based on the penetration weapon-penetration condition-penetration position Anti-overturning stability safety evaluation model for explosion damage.

The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited to this. Any modifications made by any person skilled in the art within the technical scope disclosed by the present invention are equivalent Substitutions and improvements, etc., should all be included within the protection scope of the invention.

Claims (10)

1. An anti-overturning stable safety evaluation method for penetration explosion damage concrete gravity dam is characterized by comprising the following steps:

step 1, selecting a typical dam section of a concrete gravity dam;

step 2, knowing the parameters and penetration conditions of penetration weapons;

step 3, firstly, calculating the penetration depth of the projectile body by using a Young empirical formula and combining penetration weapon parameters and penetration conditions; then, judging whether the damage form of the projectile is internal action damage or blasting funnel damage after the projectile explodes in the concrete gravity dam by adopting the blasting funnel theory of Livingston;

step 4, when the shallow surface explosion occurs to form the explosion funnel, calculating the depth and the radius of the explosion pit according to the engineering explosion theory and a corresponding formula; when the internal action damage of penetration explosion occurs, obtaining the damage range of the concrete by adopting a corresponding internal explosion action damage partition calculation method;

step 5, determining a rotation center by utilizing the calculated depth and radius of the explosion pit according to the position of the penetration part, and further obtaining a possible failure section of the concrete gravity dam, namely a failure path of the concrete gravity dam;

step 6, determining the strength parameter of the residual section at the section of the failure path, then performing stress check on the upstream dam facing at the section of the failure path by adopting a material mechanics method, and judging whether the upstream dam facing at the section of the failure path cracks or not and whether a through crack is formed or not;

step 7, solving the anti-overturning stability safety coefficient of the concrete gravity dam by using an anti-overturning calculation formula, and carrying out safety evaluation;

based on the steps, the anti-overturning stable safety performance of the concrete gravity dam can be rapidly calculated by acquiring information of penetration weapons, penetration conditions and penetration positions; collecting data of anti-overturning stable safety performance, and establishing an anti-overturning stable safety assessment database and a model based on penetration weapons, penetration conditions and penetration parts of concrete gravity dams.

2. The method of claim 1, wherein: in the step 2, parameters of the penetration weapon comprise the quality of the bullet, the cross section area of the bullet, the type of the bullet, the length of the bullet, the diameter of the bullet, the loading amount of the bullet and the curvature radius of the surface of the bullet; the penetration conditions include penetration speed and hit angle.

3. The method of claim 1, wherein: in the step 3, the penetration depth H of the projectile body_qThe calculation formula of (a) is as follows:

in the formula: m is the projectile mass, kg; v. of₀The target landing speed of the projectile body is m/s; a is the cross-sectional area of the elastomer, m²(ii) a S is an indicator of penetration ability;

n adopts different calculation methods according to different warheads:

an oval warhead:

a conical warhead:

in the formula: l is_nIs the warhead length, m; d is the diameter of the projectile, m; CRH is the ratio of the radius of curvature of the head surface of the earth-boring bullet to the radius of the cross-section of the earth-boring bullet.

4. The method of claim 3, wherein: in the step 3, the penetration depth H of the projectile body_qIn the calculation formula (2), the calculation formula of the penetrability index S is as follows:

S＝2.7(f_cQ)^-0.3 (4)

in the formula: f. of_cUnconfined compressive strength, MPa; q is the rock quality index.

5. The method of claim 1, wherein: in the step 3, the method for judging whether the damage form of the projectile body is internal action damage or blasting funnel damage after the projectile body is exploded in the concrete gravity dam comprises the following steps:

under the condition that the missile explosive equivalent and the deformation energy coefficient of concrete are known, the explosive burial depth of the concrete surface in a state of forming a damage critical funnel can be obtained by adopting a blasting funnel theory proposed by Livingston, and the following formula is shown:

W_C＝E_bQ^1/3 (5)

in the formula: q is the explosive amount, kg; e_bThe deformation energy coefficient of the rock; w_CIs the critical buried depth, m;

when the penetration depth H of the projectile body_qLess than the critical depth of burial W of the explosive_CIn the process, penetration explosion occurs inside the concrete gravity dam to form a blasting funnel; when the penetration depth H of the projectile body_qGreater than the critical buried depth W of the explosive_CIn time, the internal action of penetration explosion is damaged, and the surface of the concrete gravity dam cannot form an explosion funnel.

6. The method of claim 1, wherein: in the step 4, when the superficial explosion occurs to form a blasting funnel, the projectile body is penetrated to the maximum depth in the target and then explodes, the center of the detonation is at the center of the loading, and according to the engineering blasting theory, the depth of a crater is determined by the following formula:

H＝H_q-L·cosα (6)

in the formula: h_qThe penetration depth of the warhead in the medium is m; l is the height of the charge center; alpha is the hit angle;

after the depth of the crater is calculated, the crater radius is determined by using the relationship among the explosive quantity, the crater depth and the crater radius, and the formula is as follows:

Q＝f(H/r)q_{sign board}·H³ (7)

In the formula: q is the explosive amount, kg; q. q.s_{Sign board}Explosive consumption per volume of medium to form a standard throwing funnel, kg/m³(ii) a H is penetration craterDepth, m; f (H/r) is an exponential function of blasting effect.

7. The method of claim 6, wherein: the formula for f (H/r) is:

substituting the formula (8) into the formula (7) to obtain:

wherein: r is the radius of the crater, m; eta is TNT and is converted into conversion coefficient according to antimony, and the conversion coefficient is 1.1.

8. The method of claim 1, wherein: in the step 4, when the penetration explosion internal action is damaged, a concrete damage range is obtained by adopting a corresponding internal explosion action damage partition calculation method; radius of crush zone R₁Radius of fracture zone R₂The following theoretical formula can be used for determining:

in the formula: r₁Is the crush ring radius; rho₀D is the explosive density and the explosive detonation velocity; n is the pressure increase coefficient when the explosive explosion product expands and collides with the wall of the gun hole, and is generally 10; k is the radial decoupling coefficient of charge, K is d_b/d_c，d_b，d_cThe radius of the blast hole and the radius of the explosive package are respectively; gamma is the expansion adiabatic index of detonation products, and is generally taken as 3; l_eTo be provided withThe axial coefficient of the drug; α is the load propagation attenuation index (shock wave zone); sigma_cdUniaxial dynamic compressive strength; r is_bThe radius of the blast hole is; sigma_RThe radial stress on the interface of the crushing ring and the crack ring; sigma_tdUniaxial dynamic tensile strength; β is the load propagation attenuation index (stress wave zone);

wherein B is calculated using the formula:

B＝[(1+b)²+(1+b²)-2μ_d(1-μ_d)(1-b)²]^0.5 (12)

in the formula, b is a lateral stress coefficient; mu.s_dIs the dynamic Poisson's ratio of rock, mu_dμ is the static poisson ratio of the rock at 0.8 μ.

9. The method of claim 1, wherein: in the step 6, the stress intensity of the broken path section is reduced because part of the concrete is damaged, and corresponding stress intensity reduction is required; when the damage variable is defined in terms of the fracture area, it is considered that the main mechanism of material degradation is the reduction of the effective bearing area due to micro-defects, so the strength of the concrete after damage is σ ═ 1-D₀)σ₀，D₀As a damage variable, σ₀The concrete stress intensity is not damaged;

according to a material mechanics method, performing stress check on the upstream dam face of the section of the failure path obtained in the step 5, obtaining whether the maximum tensile stress applied to the dam face exceeds the tensile strength of concrete, and further judging whether a through crack is formed: when the maximum tensile stress borne by the upstream dam face of the broken path section is smaller than the tensile strength of the concrete, the upstream dam face of the broken path section cannot crack; when the maximum tensile stress on the upstream dam face of the broken path section exceeds the tensile strength of concrete, the upstream dam face cracks, and finally a through crack is formed.

10. The method of claim 1, wherein: in the step 7, the anti-overturning stable safety coefficient of the concrete gravity dam is obtained by using an anti-overturning calculation formula, and the anti-overturning calculation formula of the concrete gravity dam is as follows:

in the formula: gamma ray₀Is a structural importance coefficient; psi is the design condition coefficient; gamma ray_dIs the structural coefficient of anti-overturning stability; sigma M₀Calculating the sum of the face toppling moments on the basis; sigma M_sCalculating the sum of the anti-overturning moments on the surface on the basis;

after the damage path is obtained, calculating the moment of the dead weight of the upper concrete gravity dam to the rotation center, then calculating the dead weight of the upper concrete gravity dam, the concrete cohesion, the uplift pressure and the moment of the horizontal water pressure to the rotation center, then calculating the sum of the anti-overturning moments and the sum of the overturning moments, finding out relevant parameters, and substituting the parameters into the formula (24), namely knowing the stability of the concrete gravity dam damaged by the penetration explosion;

introduction of the safety factor K of anti-overturning_sTo evaluate the anti-overturning stability of gravity dams:

safety factor K against overturning_sThe calculation formula of (a) is as follows:

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