Concrete gravity dam explosion damage grading method
By quantitatively evaluating the explosion damage level of concrete gravity dams and combining it with specifications and judgment indicators, the problem of large evaluation errors in existing technologies is solved, and rapid and accurate damage level judgment and emergency protection are achieved.
Patent Information
- Application Number
- CN202510666362.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-22
- Publication Date
- 2025-09-19
AI Technical Summary
Existing technologies lack quantitative calculation indicators when evaluating explosion damage to concrete gravity dams, resulting in time-consuming and labor-intensive damage level judgment and large errors, making it difficult to apply to the assessment of dam structures under explosive loads.
A quantitative assessment method based on damage and cracks caused by high-pressure shock waves and fragment flames is provided. Combined with the "Concrete Gravity Dam Design Code" and the "Hydraulic Design Manual", the explosion damage level of the dam is determined through judgment indicators, including no damage, slight damage, moderate damage, severe damage and dam break levels.
It achieves fast and accurate grading of explosion damage levels, is applicable to concrete gravity dams of different structures and sizes, and supports timely emergency protection measures.
Smart Images
Figure CN120670697A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of hydraulic explosions, in particular to a rapid classification method for explosion damage to a concrete gravity dam under the action of an external explosion, and specifically to a classification method for explosion damage to a concrete gravity dam. Background Art
[0002] When a dam is subjected to underwater near-field explosions of conventional explosives such as local wars, terrorist attacks, and accidental explosions, after revealing the dynamic response laws and damage mechanisms of the dam structure, it is required to quickly determine the location of the action, the scope and extent of the damage, evaluate the health status of the dam structure, reveal the degradation laws of the overall performance of the dam structure, and promptly determine whether emergency rescue and reinforcement are needed.
[0003] The key to assessing the damage effects of dam explosions lies in determining indicators for determining dam penetration damage and criteria for classifying damage. Currently, research on these indicators and criteria focuses primarily on dam seismic resistance. However, the damage characteristics of dams under strong earthquakes differ fundamentally from those under blast loads. Concrete gravity dams respond primarily to earthquake loads, while blast loads primarily result in localized damage. Therefore, dam seismic damage assessment indicators and damage classification criteria are difficult to apply to blast damage assessment.
[0004] Therefore, the traditional dam explosion damage classification method is mainly based on existing field tests and engineering experience. It does not have quantitative calculation indicators and mostly describes the grade based on qualitative methods. It is time-consuming and labor-intensive, and the damage grade obtained has large errors, so its applicability is limited. Summary of the Invention
[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a method for grading explosion damage to concrete gravity dams. This method can be used to quickly determine the damage level of concrete gravity dams under explosion attacks, and can be used to determine the dangerous situation of the dam after the explosion attack, so as to facilitate timely emergency protection work for the dam. Moreover, this method has quantitative calculation standards, and the judgment of the level is time-saving and labor-saving, and is scientific and reasonable. It is applicable to concrete gravity dams of different structures and sizes.
[0006] In order to achieve the above-mentioned technical features, the purpose of the present invention is achieved as follows: a method for grading explosion damage to concrete gravity dams, based on the high-pressure shock wave and fragment flames generated by the explosion causing damage and cracks to the dam; according to the damage and cracking range of the dam under the explosion, the explosion damage grade of the dam is determined according to corresponding judgment indicators.
[0007] Preferably, the step of determining the explosion damage level of the dam based on corresponding judgment indicators specifically includes: S1: When a concrete gravity dam is struck by an external explosion, the surface of the struck area is observed for obvious damage or cracks. If there are no obvious damage or cracks on the surface, the dam can still operate safely and is classified as no damage. S2: When the dam is partially damaged and cracks appear on the dam body, but the dam is generally within the linear elastic working range σ≤σ e , belongs to the light damage level; among them, σ e is the elastic limit of dam concrete; S3: When the dam body is damaged and cracked to a large extent, the local area has exceeded the linear elastic working range σ>σ e , but meet the ultimate bearing capacity requirements ≥1, the damage can be repaired, which is a moderate damage level; S4: When the dam has large-scale damage or penetrating cracks, it exceeds the ultimate bearing capacity requirements <1, but the dam body meets the critical stability state 1. Instability damage without collapse, sliding or overturning is classified as severe damage level; S5: When the dam exceeds the critical stability state <1, when unstable damage such as collapse, sliding or overturning occurs, it is classified as a dam break level.
[0008] Preferably, if the dam is at a slightly damaged level in S2, the stress level of the concrete gravity dam is low, and the internal microcracks and plastic deformation have not developed significantly; at this time, local damage and cracks can be repaired and protected.
[0009] Preferably, the step S3 specifically includes: when the dam body is damaged and cracked to a large extent, and plastic deformation has developed significantly, the dam has exceeded the level of minor damage, and whether the dam body meets the ultimate bearing capacity requirements is determined, and the following calculation is performed: value: ; Where, R is the structural resistance of the dam, S The various effects of the dam, namely the effects of the explosion; is the standard value of material properties; is the material performance partial coefficient; is the standard value of geometric parameters; is the structural coefficient of the ultimate bearing capacity state; is the structural importance coefficient; is the design condition coefficient; is the permanent action partial coefficient; It is the standard value of permanent effect; is the variable action partial coefficient; It is the standard value of variable action.
[0010] Preferably, in S4 value: ; Where, F is the dam's sliding resistance, P is the sliding force of the dam, which is mainly the water thrust upstream of the dam; is the shear friction coefficient of the contact surface between the dam concrete and the dam foundation; is the normal component of the total load acting on the dam body to the sliding plane; It is the shear cohesion of the contact surface between the dam concrete and the dam foundation; is the cross-sectional area of the dam foundation contact surface; It is the tangential fraction of the total load acting on the dam body on the sliding plane.
[0011] The present invention has the following beneficial effects: 1. Traditional dam explosion damage classification methods are mainly based on existing field tests and engineering experience, without quantitative calculation indicators. Most of them describe the grade based on qualitative methods, which is time-consuming and labor-intensive. The resulting damage grades have large errors, thus limiting their applicability. The present invention provides a rapid classification method for dam damage grades under the action of explosions. The judgment of grades is time-saving and labor-saving, and has quantitative calculation standards. It is applicable to concrete gravity dams of different structures and sizes. 2. This invention combines the "Concrete Gravity Dam Design Code" and "Hydraulic Design Manual" and other specifications, taking into account the requirements of concrete gravity dam linear elastic work, ultimate bearing capacity, anti-sliding stability, etc., and uses explosion damage and cracking range as the main judgment indicators. Different from the existing earthquake damage judgment indicators, the classification method is scientific and feasible; 3. The method of the present invention can classify the damage to concrete gravity dams caused by explosions, and can be used to quickly determine the dangerousness of the dam after the explosion, so as to facilitate timely repair and protection of the dam. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention will be further described below with reference to the accompanying drawings and examples.
[0013] Figure 1 4 is a hierarchical flow chart of the method of the present invention.
[0014] Figure 2 This is a schematic diagram of the dam at the minor damage level according to this classification method.
[0015] Figure 3This is a schematic diagram of the dam at the medium damage level according to this classification method.
[0016] Figure 4 This is a schematic diagram of the dam at the severe damage level according to this classification method.
[0017] Figure 5 This is a schematic diagram of the dam at the dam break level according to this classification method. DETAILED DESCRIPTION
[0018] The embodiments of the present invention will be further described below with reference to the accompanying drawings.
[0019] Example 1: See also Figure 1-5 A method for grading explosion damage to concrete gravity dams is based on the fact that the high-pressure shock wave and fragment flames generated by the explosion cause damage and cracks to the dam. The explosion damage grade of the dam is determined based on the damage and cracking range of the dam under the impact of the explosion and the corresponding judgment indicators.
[0020] Preferably, the step of determining the explosion damage level of the dam based on corresponding judgment indicators specifically includes: S1: When a concrete gravity dam is struck by an external explosion, the surface of the struck area is observed for obvious damage or cracks. If there are no obvious damage or cracks on the surface, the dam can still operate safely and is classified as no damage. S2: When the dam is partially damaged and cracks appear on the dam body, but the dam is generally within the linear elastic working range σ≤σ e , belongs to the light damage level; among them, σ e is the elastic limit of dam concrete; S3: When the dam body is damaged and cracked to a large extent, the local area has exceeded the linear elastic working range σ>σ e , but meet the ultimate bearing capacity requirements ≥1, the damage can be repaired, which is a moderate damage level; S4: When the dam has large-scale damage or penetrating cracks, it exceeds the ultimate bearing capacity requirements <1, but the dam body meets the critical stability state 1. Instability damage without collapse, sliding or overturning is classified as severe damage level; S5: When the dam exceeds the critical stability state <1, when unstable damage such as collapse, sliding or overturning occurs, it is classified as a dam break level.
[0021] Preferably, if the dam is at a slightly damaged level in S2, the stress level of the concrete gravity dam is low, and the internal microcracks and plastic deformation have not developed significantly; at this time, local damage and cracks can be repaired and protected.
[0022] Preferably, the step S3 specifically includes: when the dam body is damaged and cracked to a large extent, and plastic deformation has developed significantly, the dam has exceeded the level of minor damage, and whether the dam body meets the ultimate bearing capacity requirements is determined, and the following calculation is performed: value: ; Where, R is the structural resistance of the dam, S The various effects of the dam, namely the effects of the explosion; is the standard value of material properties; is the material performance partial coefficient; is the standard value of geometric parameters; is the structural coefficient of the ultimate bearing capacity state; is the structural importance coefficient; is the design condition coefficient; is the permanent action partial coefficient; It is the standard value of permanent effect; is the variable action partial coefficient; It is the standard value of variable action.
[0023] Preferably, in S4 value: ; Where, F is the dam's sliding resistance, P is the sliding force of the dam, which is mainly the water thrust upstream of the dam; is the shear friction coefficient of the contact surface between the dam concrete and the dam foundation; is the normal component of the total load acting on the dam body to the sliding plane; It is the shear cohesion of the contact surface between the dam concrete and the dam foundation; is the cross-sectional area of the dam foundation contact surface; It is the tangential fraction of the total load acting on the dam body on the sliding plane.
[0024] Example 2: The present invention provides a method for grading explosion damage of a concrete gravity dam. In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.
[0025] The high-pressure shock wave, fragments, flames, etc. generated by the explosion will cause damage and cracks to the dam. The damage and cracking range of the dam under the explosion will be determined according to the following judgment indicators. Figure 1 As shown in the figure, the specific steps of the classification method for explosion damage of concrete gravity dams are as follows: 1. When a concrete gravity dam is struck by an external explosion, check whether there are obvious damages or cracks on the surface of the struck part. If there are no obvious damages or cracks on the surface, the dam can still operate safely and is classified as non-damage grade. 2. When the dam is partially damaged and cracks appear on the dam body, but the dam body is still within the linear elastic working range, that is, the stress level of the concrete gravity dam is low, and the internal microcracks and plastic deformation have not developed significantly, the overall dam meets the following formula: σ≤σ e Where σ e is the elastic limit of dam concrete.
[0026] At this point, local damage and cracks can be repaired and protected, and are classified as minor damage. 3. When the dam body is damaged and cracked to a large extent and plastic deformation develops significantly, the dam has exceeded the level of minor damage. To determine whether the dam body meets the ultimate bearing capacity requirements, calculate the following: η value: ; Where, R is the structural resistance of the dam, S The various effects of the dam, namely the effects of the explosion; is the standard value of material properties; is the material performance partial coefficient; is the standard value of geometric parameters; is the structural coefficient of the ultimate bearing capacity state; is the structural importance coefficient; is the design condition coefficient; is the permanent action partial coefficient; It is the standard value of permanent effect; is the variable action partial coefficient; It is the standard value of variable action.
[0027] When the structural resistance of the dam is greater than the various effects of the dam, that is, η At 1, the concrete gravity dam meets the ultimate bearing capacity requirements and the damage can be repaired. This is a medium damage level.
[0028] 4. When the dam is damaged on a large scale or has penetrating cracks, the dam body exceeds the ultimate bearing capacity requirement. η At 1, the dam has exceeded the medium damage level. To determine whether the dam meets the critical stability requirements, calculate the following value: ; Where, F is the dam's sliding resistance, P is the sliding force of the dam, which is mainly the water thrust upstream of the dam; is the shear friction coefficient of the contact surface between the dam concrete and the dam foundation; is the normal component of the total load acting on the dam body to the sliding plane; It is the shear cohesion of the contact surface between the dam concrete and the dam foundation; is the cross-sectional area of the dam foundation contact surface; It is the tangential fraction of the total load acting on the dam body on the sliding plane.
[0029] When the dam's anti-slip force is greater than the dam's sliding force, that is, At 1, the concrete gravity dam meets the critical stability state requirements and does not suffer from unstable damage such as collapse, sliding or overturning, but the damage is irreparable. This is the severe damage level.
[0030] 5. When the concrete gravity dam exceeds the critical stability state, the calculated At 1:00, the dam will suffer unstable damage such as collapse, sliding or overturning, and eventually burst. At this time, the damage is the most serious and belongs to the dam failure level.
Claims
1. A method for grading explosion damage of concrete gravity dams, characterized in that: The high-pressure shock wave, fragments and flames generated by the explosion cause damage and cracks to the dam; the degree of explosion damage to the dam is determined based on the damage and cracking range of the dam under the impact of the explosion and the corresponding judgment indicators.
2. A method for grading explosion damage to concrete gravity dams according to claim 1, characterized in that: The above-mentioned determination of the degree of dam explosion damage based on the corresponding judgment indicators specifically includes: S1: When a concrete gravity dam is struck by an external explosion, the surface of the struck area is observed for obvious damage or cracks. If there are no obvious damage or cracks on the surface, the dam can still operate safely and is classified as no damage. S2: When the dam is partially damaged and cracks appear on the dam body, but the dam is generally within the linear elastic working range σ≤σ e , belongs to the light damage level; among them, σ e is the elastic limit of dam concrete; S3: When the dam body is damaged and cracked to a large extent, the local area has exceeded the linear elastic working range σ>σ e , but meet the ultimate bearing capacity requirements ≥1, the damage can be repaired, which is a moderate damage level; S4: When the dam has large-scale damage or penetrating cracks, it exceeds the ultimate bearing capacity requirements <1, but the dam body meets the critical stability state 1. Instability damage without collapse, sliding or overturning is classified as severe damage level; S5: When the dam exceeds the critical stability state <1, when unstable damage such as collapse, sliding or overturning occurs, it is classified as a dam break level.
3. The method for grading explosion damage to concrete gravity dams according to claim 1, characterized in that: If the dam is classified as slightly damaged in S2, the stress level of the concrete gravity dam is low, and the internal microcracks and plastic deformation have not developed significantly; at this time, local damage and cracks can be repaired and protected.
4. The method for grading explosion damage to concrete gravity dams according to claim 1, characterized in that: The above S3 specifically includes: when the dam body is damaged and cracked to a large extent, and plastic deformation has developed significantly, the dam has exceeded the level of minor damage, and whether the dam body meets the ultimate bearing capacity requirements is determined by calculating the following: value: ； Where, R is the structural resistance of the dam, S The various effects of the dam, namely the effects of the explosion; is the standard value of material properties; is the material performance partial coefficient; is the standard value of geometric parameters; is the structural coefficient of the ultimate bearing capacity state; is the structural importance coefficient; is the design condition coefficient; is the permanent action partial coefficient; It is the standard value of permanent effect; is the variable action partial coefficient; It is the standard value of variable effect.
5. The method for grading explosion damage to concrete gravity dams according to claim 1, characterized in that: The S4 value: ； Where, F is the dam's sliding resistance, P is the sliding force of the dam, which is mainly the water thrust upstream of the dam; is the shear friction coefficient of the contact surface between the dam concrete and the dam foundation; is the normal component of the total load acting on the dam body to the sliding plane; It is the shear cohesion of the contact surface between the dam concrete and the dam foundation; is the cross-sectional area of the dam foundation contact surface; It is the tangential fraction of the total load acting on the dam body on the sliding plane.