CN115014982B - Method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics - Google Patents
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- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
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Abstract
The invention discloses a method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics, which comprises the following steps of: drawing a stress-time curve and a gas pressure-time curve; calculating to obtain a first evaluation value k and drawing a first evaluation value-time curve; when t is>t 2 Calculating an air pressure fluctuation evaluation value f, a fracture energy evaluation value g when cracks are generated and a damage inferiority evaluation value r by using an air pressure-time curve; and evaluating the damage stage of the coal rock according to k, r and g, and evaluating the damage inferiority of the coal rock according to r. A characterization method and regularity recognition are formed for evaluating the evolution condition and damage degree of the pore fracture by using the gas migration rule, the problems that the compressed gas migration characteristics and the pore fracture evolution of different coal bodies have differences and the pore fracture evolution cannot be evaluated regularly by using the gas migration rule in the prior art are solved, the prediction and guidance of actual engineering are realized, and a foundation is laid for preventing and controlling coal mine safety accidents.
Description
Technical Field
The invention relates to the technical field of coal rock drilling safety engineering, in particular to a method for evaluating damage quality of coal rock based on gas migration pressure fluctuation characteristics.
Background
With the continuous increase of the mining depth and strength of coal, coal rock gas outburst geological disasters become safety problems generally concerned by coal mines, and the engineering disasters are the effect results of stress deformation and fracture of coal rocks.
At present, in a closed space, the degradation action characteristics of the coal rock mass in the loading process are generally obtained and analyzed through a detection technology and a digital image processing technology, and the coal fracture evolution process in the loading process is monitored in real time. Nuclear magnetic resonance, CT scanning, ultrasonic waves and the like are commonly used methods for assisting in identifying and determining structural characteristics of pores and cracks of coal bodies. However, these testing techniques are complex in operation, high in cost, and large in workload, and external factors in the sampling and sample preparation process affect the internal structure of the coal body, affect the accuracy of the experiment and the reliability of the result, and are difficult to meet the real-time monitoring and analysis requirements in the field construction process.
Researches find that the gas migration in the uniaxial coal loading process has certain regularity, and the evolution condition and damage degree of the pore fracture of the coal body can be well shown. Therefore, the gas migration state of the coal body can be used as a means for researching the evolution condition and damage degree of the pore fractures of the coal body. However, due to the fact that the pore structure and mineral composition of coal bodies are complex, compressed gas migration characteristics and pore fracture evolution of different coal bodies have differences, a characterization method and regularity recognition are not formed at present, and a method for evaluating the pore fracture evolution condition and damage degree based on the gas migration rule in the compression process is not established.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides the following technical scheme.
The invention provides a method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics, which comprises the following steps:
acquiring stress data in the coal rock radial loading experiment process and pressure data of gas escaping from the coal rock, and drawing a stress-time curve and a gas pressure-time curve;
calculating to obtain a first evaluation value k according to the stress-time curve and drawing a first evaluation value-time curve, wherein the first evaluation value is a function of the slope of the stress-time curve;
in the first evaluation value-time curve, the time corresponding to the maximum first evaluation value is t 2 When t is>t 2 Using a pressure-time curve, according toThe following formula calculates an air pressure fluctuation evaluation value f, a fracture energy evaluation value g when a crack is generated, and a damage inferiority evaluation value r:
calculating f using the gas negative pressure region data, wherein: n is the total number of vertices of the air pressure jitter, n 1 Is the number of the peaks of the pressure fluctuation falling in the regular fluctuation region, n 2 Is the number of the air pressure shaking peaks falling in the general shaking area, n 3 The number of the peaks of the air pressure vibration falling in the strong vibration area, m 1 、m 2 、m 3 Y is the air pressure vibration amplitude, y is the importance coefficient i Amplitude of the air pressure vibration, n, denoted by i y For the number of pressure jitter vertices for which y is within a specified range,
is the air pressure average dither amplitude, y max Is the maximum jitter amplitude of the air pressure, p 1 The amplitude of the air pressure vibration is smaller than
The probability of (d);
wherein, the first and the second end of the pipe are connected with each other,
the duration of the shaking with the largest amplitude of the air pressure shaking, if it is strongShaking, namely taking strong shaking duration; if it is general jitter, take general jitter duration, m 0 In order to adjust the coefficients of the coefficients,
is composed of
The absolute value of the difference between the maximum and minimum values of the internal stress,
max is composed of
Maximum value of internal stress, P max Is the maximum positive air pressure during loading, P min Is the minimum negative air pressure during the loading process;
wherein the content of the first and second substances,
is a distribution coefficient;
and evaluating the damage stage of the coal rock according to k, r and g, and evaluating the damage inferiority of the coal rock according to r.
Preferably, the method further comprises:
when t is less than or equal to t 2 And when the first evaluation value is 0.57 times of the maximum value, t = t 1 Or, when t is less than or equal to t 2 And when the first evaluation value is 2.15, t = t 1 ；
When t is less than or equal to t 1 When the coal rock is in the primary pore compaction closing stage;
when t is 1 <t≤t 2 The coal body is in the elastic homogeneous deformation stage.
Preferably, the calculating a first evaluation value according to the stress-time curve includes:
according to the stress numberDrawing an ideal curve and a fitting curve of stress-time, and calculating to obtain the slope k of the ideal curve 1 And the slope k of the fitted curve 2 ；
The first evaluation value k is calculated by the following formula:
k=k 1 -k 2 。
preferably, the ideal curve slope k 1 The calculation is performed according to the following formula:
wherein, the first and the second end of the pipe are connected with each other,
is the stress, t is the loading time,
a time variable is loaded.
Preferably, when the air pressure shake is a strong shake or a general shake, if
Then m is 0 Taking 0.7; if the jitter amplitude is larger than 500Pa, m is 0 Taking 0.6; otherwise m 0 Taking 1.0; when there is no strong jitter and general jitter, m 0 0 is taken.
Preferably, the conventional fluctuation region corresponds to gas pressure intervals of (0, 40) and (0, -40), the general jitter region corresponds to gas pressure intervals of (40, 100) and (-40, -100), and the robust jitter region corresponds to gas pressure intervals of (100, + ∞) and (-100, - ∞).
Preferably, the evaluation of the damage stage of the coal rock according to k, r and g and the evaluation of the damage inferiority of the coal rock according to r comprise:
when k is less than or equal to 2.15, the coal rock is in a primary pore compaction closing stage;
when k is less than or equal to 6.5 after 2.15 yards are formed, the coal rock is in an elastic homogeneous deformation stage;
when k is greater than 6.5 and g is greater than 3.65 or r is greater than 0.32, the coal rock is in a post-peak destruction stage;
k is greater than 6.5, g is less than or equal to 3.65, and r is less than or equal to 0.15, the coal rock is in a fracture stable extension stage;
k is more than 6.5, g is less than or equal to 3.65, and r is less than or equal to 0.15 but less than or equal to 0.32, and the coal rock is in a fracture accelerated extension stage;
the larger the r value, the more serious the deterioration damage of the coal rock.
Preferably, the method further comprises: pretreating the coal rock, and putting the coal rock into a device for a loading experiment; connecting the coal rock with a guide channel, guiding out gas and monitoring pressure; the stress during the experiment was monitored.
The second aspect of the present invention also provides a memory storing a plurality of instructions for implementing the method according to the first aspect.
The third aspect of the present invention also provides an electronic device, comprising a processor and a memory connected to the processor, wherein the memory stores a plurality of instructions, and the instructions can be loaded and executed by the processor to enable the processor to execute the method according to the first aspect.
The invention has the beneficial effects that: according to the method for evaluating the damage inferiority of the coal rock, the gas migration state of the coal body is taken as a means for researching the evolution condition and the damage degree of the pore fracture of the coal body, a method for evaluating the evolution condition and the damage degree of the pore fracture based on the gas migration rule in the compression process is established, a characterization method and regularity recognition are formed, the problems that the compressed gas migration characteristics and the pore fracture evolution of different coal bodies have differences due to the fact that the pore structure and mineral composition of the coal body are complex, and the gas migration rule cannot be regularly utilized to evaluate the evolution condition and the damage degree of the pore fracture in the prior art are solved, and prediction and guidance significance is provided for actual engineering.
Drawings
FIG. 1 is a schematic flow diagram of a method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics.
FIG. 2 is a graph of a first evaluation value versus time according to the present invention;
FIG. 3 is a graph of air pressure versus time in accordance with the present invention;
fig. 4 is a schematic diagram of damage inferiority evaluation parameters and results according to an embodiment of the present invention.
Detailed Description
In order to better understand the technical solution, the technical solution will be described in detail with reference to the drawings and the specific embodiments.
The method provided by the invention can be implemented in the following terminal environment, and the terminal can comprise one or more of the following components: a processor, a memory, and a display screen. Wherein the memory has stored therein at least one instruction that is loaded and executed by the processor to implement the methods described in the embodiments described below.
A processor may include one or more processing cores. The processor connects various parts within the overall terminal using various interfaces and lines, performs various functions of the terminal and processes data by executing or executing instructions, programs, code sets, or instruction sets stored in the memory, and calling data stored in the memory.
The Memory may include a Random Access Memory (RAM) or a Read-Only Memory (ROM). The memory may be used to store instructions, programs, code, sets of codes, or instructions.
The display screen is used for displaying user interfaces of all the application programs.
In addition, those skilled in the art will appreciate that the above-described terminal configurations are not intended to be limiting, and that the terminal may include more or fewer components, or some components may be combined, or a different arrangement of components. For example, the terminal further includes a radio frequency circuit, an input unit, a sensor, an audio circuit, a power supply, and other components, which are not described herein again.
Researches find that the coal body fracture and the coal rock gas migration dynamic evolution have a corresponding relationship in the coal rock deformation fracture process, and the research on the relationship between the gas migration characteristic and the damage and degradation degree of the coal rock is a basis and a necessary condition for preventing and controlling coal mine safety accidents, and has very important engineering application value and social significance. In addition, the coal bed is a discontinuous medium structure and has anisotropic and anisotropic properties. The gas-containing coal body has a large amount of random natural defects, the destructive mechanical property is very complex, the difference change is obvious, and the gas-containing coal body has the characteristics of nonlinearity, discontinuity and anisotropy, so the research on the existing coal bed gas migration property and the coal body damage inferiority is not only the technical difficulty of the existing mining safety engineering, but also one of the problems to be solved urgently. The deformation and damage characteristics of the coal body need to be analyzed, and the research of inverting the damage inferiority of the coal body through the characteristics of gas migration has prediction and guiding significance for actual engineering.
As shown in fig. 1, an embodiment of the present invention provides a method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics, including:
s101, acquiring stress data in the coal rock radial loading experiment process and pressure data of gas escaping from the coal rock, and drawing a stress-time curve and a gas pressure-time curve;
s102, calculating to obtain a first evaluation value k according to the stress-time curve and drawing a first evaluation value-time curve, wherein the first evaluation value is a function of the slope of the stress-time curve;
s103, in the first evaluation value-time curve, the time corresponding to the maximum first evaluation value is t 2 When t is>t 2 Then, an air pressure fluctuation evaluation value f, a fracture energy evaluation value g when a crack is generated, and a damage inferiority evaluation value r are calculated by using an air pressure-time curve according to the following formulas:
calculating f using the gas negative pressure region data, wherein: n is the total number of pressure flutter peaks, n 1 Is the number of the peaks of the pressure fluctuation falling in the regular fluctuation region, n 2 Is the number of the peaks of the air pressure vibration falling in the general vibration area, n 3 The number of the peaks of the air pressure vibration falling in the strong vibration area, m 1 、m 2 、m 3 Is the importance coefficient, y is the air pressure vibration amplitude, y i Amplitude of the air pressure vibration, n, denoted by i y For the number of pressure jitter vertices for which y is within a specified range,
is the air pressure average dither amplitude, y max Is the maximum jitter amplitude of the air pressure, p 1 The amplitude of the air pressure vibration is smaller than
The probability of (d);
wherein the content of the first and second substances,
the duration time of the shaking with the maximum air pressure shaking amplitude is taken if the shaking is the powerful shaking; if general jitter, take general jitter duration, m 0 In order to adjust the coefficients of the coefficients,
is composed of
The absolute value of the difference between the maximum and minimum values of the internal stress,
is composed of
Maximum value of internal stress, P max Is the maximum positive air pressure during loading, P min Is the minimum negative air pressure during the loading process;
wherein the content of the first and second substances,
is a distribution coefficient;
and S104, evaluating the damage stage of the coal rock according to k, r and g, and evaluating the damage inferiority of the coal rock according to r.
The first evaluation value-time curve may be as shown in fig. 2. In FIG. 2, k max Is the maximum value of the first evaluation value, and corresponds to a time t 2 . In the embodiment of the invention, t is 2 And (4) judging the damage condition and the damage stage of the coal rock by adopting different methods as a boundary point. When t is>t 2 And then, inputting the stress data and the air pressure data into formulas for calculating an air pressure fluctuation evaluation value f, a fracture energy evaluation value g when cracks are generated and a damage inferiority evaluation value r, calculating f, r and g, and evaluating the damage stage of the coal rock in the period according to the r and the g. When t is less than or equal to t 2 When the first evaluation value is 0.57 times of the maximum value, the corresponding time t is t 1 (see also FIG. 2), or, when t ≦ t 2 And when the first evaluation value is 2.15, the corresponding time t is t 1 (ii) a When t is less than or equal to t 1 When the coal rock is in the primary pore compaction closing stage; when t is 1 <t≤t 2 The coal body is in the elastic homogeneous deformation stage.
And r is a damage inferiority evaluation value, the damage inferiority of the coal rock can be comprehensively evaluated, and the larger the r value is, the larger the damage inferiority of the coal rock is.
In a preferred embodiment of the present invention, the calculating the first evaluation value according to the stress-time curve includes:
according to the stress numberDrawing an ideal curve and a fitting curve of stress-time, and calculating to obtain the slope k of the ideal curve 1 And the slope k of the fitted curve 2 ；
The first evaluation value k is calculated by the following formula:
k=k 1 -k 2 。
wherein the ideal curve slope k 1 The calculation is performed according to the following formula:
wherein the content of the first and second substances,
for stress, t is the loading time,
is a load time variable.
In the air pressure-time (p-t) curve, when the air pressure is in a negative pressure area, the air pressure is negatively deviated from a certain pressure and the air pressure difference exceeds 20Pa, then the negative deviation is recovered to exceed 20Pa, and the phenomenon of forming a V-shaped curve is defined as primary negative jitter of the air pressure. Similarly, when the air pressure is in the positive pressure region, one positive vibration of the air pressure is defined. One air pressure negative shake and one air pressure positive shake may be referred to as one air pressure shake or one shake. And the point corresponding to the peak air pressure of the primary shaking is the shaking vertex. The amplitude of the jitter vertex deviating from 0 pressure is the jitter amplitude, and the jitter amplitude is taken as an absolute value.
As shown in fig. 3, the p-t image is divided into a regular fluctuation area, a general jitter area, and a strong jitter area according to the magnitude of the air pressure jitter. The jitter pressure intervals correspond to (0, 40) and (0, -40), (40, 100) and (-40, -100), (100, + ∞) and (-100, - ∞), respectively.
The jitter is defined as a normal fluctuation when the jitter vertex falls in a normal fluctuation area in the p-t image, as a normal jitter when the jitter vertex falls in a normal jitter area in the p-t image, and as a strong jitter when the jitter vertex falls in a strong jitter area in the p-t image. In a normal shake, the duration of the air pressure value in the normal shake area is defined as the normal shake duration. In one power jitter, the duration of the air pressure value in the power jitter region is defined as the power jitter duration.
In the embodiment of the present invention, when the air pressure vibration is a strong vibration or a general vibration, if
Then m is 0 Taking 0.7; if the jitter amplitude is greater than 500Pa, m is 0 Taking 0.6; otherwise m 0 Taking 1.0; when there is no strong jitter and general jitter, m 0 Take 0.
In the calculation formula of the damage inferiority evaluation value r,
for the partition coefficient, 0.63 may be taken.
In the embodiment of the present invention, the coal rock damage stage may include: the method comprises a primary pore compacting and closing stage, an elastic homogeneous deformation stage, a crack expansion stable extension stage, a crack accelerated extension stage and a post-peak damage stage. In a preferred embodiment of the present invention, the evaluating the damage inferiority and the damage stage of the coal rock according to k, r and g includes:
when k is less than or equal to 2.15, the coal rock is in the stage of primary pore compaction and closure. At this stage, the pore volume is smaller and the number of fractures is also smaller. The primary microcracks and microporosities close when force is applied. The pattern damage inferiority was undamaged.
When k is less than or equal to 6.5 after 2.15 yards are formed, the coal rock is in an elastic homogeneous deformation stage. At this stage, the coal rock is elastically deformed, producing microcracks. The number of pore fractures will begin to increase and the original fractures will be further developed when the pressure in the fractures is greater than the fracture critical pressure of the surrounding coal-rock group.
k >6.5, and g >3.65 or r >0.32, the coal rock is in a post-peak destruction stage. At this stage, the fissures are open and macroscopic fissures are formed.
k is more than 6.5, g is less than or equal to 3.65, and r is less than or equal to 0.15, the coal rock is in the fracture stable extension stage. At this stage, the coal begins to plastically deform, initially damaging. The micro-fissures are increased suddenly, and a plurality of micro-fissures are in a net shape or a wild goose shape. All the new microcracks are developed along the bedding direction, and the microcracks are developed along the bedding direction. Some microcracks are closed and opened, some microcracks are in lap joint communication with the initial cracks, and the pore crack connectivity is low on the whole.
k is more than 6.5, g is less than or equal to 3.65, and r is less than or equal to 0.15 but less than or equal to 0.32, and the coal rock is in the fracture accelerated extension stage. At this stage, the coal rock generates local brittle failure, the crack propagation speed is accelerated, the crack pores are mainly communicated with each other, and the cracks are in lap joint communication with peripheral cracks to gradually form a crack network.
The damage deterioration degree evaluation value r is a comprehensive evaluation index, and the larger the r value is, the more serious the deterioration damage of the coal rock is. Specific evaluation parameters and results are shown in fig. 4.
The method for evaluating the coal rock damage inferiority based on the gas migration pressure fluctuation characteristics, provided by the embodiment of the invention, further comprises the following steps: pretreating the coal rock, and putting the coal rock into a device for a loading experiment; connecting the coal rock with a guide channel, guiding out gas and monitoring pressure; the stress during the experiment was monitored.
Specifically, the following method can be adopted: the coal sample is firstly processed, and then the prepared cylindrical coal sample is sleeved by an isolation layer which is sealed by a fluororubber sleeve. The two ends of the coal sample are tightly attached to the fluororubber sleeves and are connected with the surfaces of the pressure heads in a sealing mode through silica gel, and therefore the surfaces of the coal sample are not in contact with external hydraulic oil. The heater was sheathed over the coal sample. And finally sealing the sealed chamber. The hydraulic oil is injected into the sealing chamber through the oil pump to fill the whole sealing chamber. The coal sample is kept in a vertical state in the sealed chamber. In the embodiment of the invention, the loading experiment system is in a closed constant-temperature state, and the temperature of the closed system is controlled to be constant by the temperature controller. The axial deformation rate is set to be 0.002mm/s in the loading process, and the coal body sample is unstably damaged after compaction, elastic deformation and plastic deformation. In the process, the stress change condition of the sensor is monitored in real time, the escaping gas is led out through the gas guide tube, and the pressure of the escaping gas is detected. And outputting the current air pressure curve and stress curve after the monitored data are transmitted to the information processing equipment.
The present invention also provides a memory storing a plurality of instructions for implementing the method as described in the above embodiments.
The present invention also provides an electronic device, which includes a processor and a memory connected to the processor, wherein the memory stores a plurality of instructions, and the instructions can be loaded and executed by the processor, so that the processor can execute the method according to the above embodiment.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the invention. It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (8)
1. A method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics is characterized by comprising the following steps:
acquiring stress data in the coal rock radial loading experiment process and pressure data of gas escaping from the coal rock, and drawing a stress-time curve and a gas pressure-time curve;
calculating to obtain a first evaluation value k according to the stress-time curve and drawing a first evaluation value-time curve, wherein the first evaluation value is a function of the slope of the stress-time curve;
the calculating of the first evaluation value according to the stress-time curve includes:
drawing an ideal curve and a fitting curve of stress-time according to the stress data, and calculating to obtain the slope k of the ideal curve 1 And the slope k of the fitted curve 2 ；
The first evaluation value k is calculated by the following formula:
k=k 1 -k 2 ；
the slope k of the ideal curve 1 The calculation is performed according to the following formula:
wherein the content of the first and second substances,
is the stress, t is the loading time,
is a loading time variable;
in the first evaluation value-time curve, a time corresponding to a maximum value of the first evaluation value is t 2 When t is>t 2 Then, an air pressure fluctuation evaluation value f, a fracture energy evaluation value g when a crack is generated, and a damage inferiority evaluation value r are calculated by using an air pressure-time curve according to the following formulas:
calculating f using the gas negative pressure region data, wherein: n is the total number of vertices of the air pressure jitter, n 1 Is the number of the peaks of the air pressure jitter falling in the regular fluctuation zone, n 2 The number of the peak of the air pressure vibration falling in the general vibration areaAmount, n 3 The number of the peaks of the air pressure vibration falling in the strong vibration area, m 1 、m 2 、m 3 Is the importance coefficient, y is the air pressure vibration amplitude, y i Amplitude of the air pressure vibration, n, denoted by i y For the number of pressure jitter vertices for which y is within a specified range,
is the air pressure average dither amplitude, y max Is the maximum jitter amplitude of the air pressure, p 1 The amplitude of the air pressure vibration is smaller than
The probability of (d);
wherein the content of the first and second substances,
the duration time of the shaking with the maximum air pressure shaking amplitude is taken if the shaking is the powerful shaking; if general jitter, take general jitter duration, m 0 In order to adjust the coefficients of the coefficients,
is composed of
The absolute value of the difference between the maximum and minimum values of the internal stress,
is composed of
Maximum value of internal stress, P max Is the maximum positive air pressure during loading, P min For in the process of loadingA minimum negative air pressure of;
wherein the content of the first and second substances,
is a distribution coefficient;
and evaluating the damage stage of the coal rock according to k, r and g, and evaluating the damage inferiority of the coal rock according to r.
2. The method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics according to claim 1, further comprising:
when t is less than or equal to t 2 And when the first evaluation value is 0.57 times of the maximum value, t = t 1 Or, when t ≦ t 2 And when the first evaluation value is 2.15, t = t 1 ；
When t is less than or equal to t 1 When the coal rock is in the primary pore compaction closing stage;
when t is 1 <t≤t 2 The coal body is in the elastic homogeneous deformation stage.
3. The method for evaluating the coal rock damage inferiority based on gas migration pressure fluctuation characteristics according to claim 1,
when the air pressure is shaking strongly or shaking normally, if
Then m is 0 Taking 0.7; if the jitter amplitude is larger than 500Pa, m is 0 Taking 0.6; otherwise m 0 Taking 1.0;
when there is no strong jitter and general jitter, m 0 0 is taken.
4. The method for evaluating coal petrography damage inferiority based on gas migration pressure fluctuation characteristics as claimed in claim 1, wherein the conventional fluctuation region corresponds to gas pressure intervals of (0, 40] and (0, -40), the general jitter region corresponds to gas pressure intervals of (40, 100] and (-40, -100), and the robust jitter region corresponds to gas pressure intervals of (100, + ∞) and (-100, - ∞).
5. The method for evaluating the damage inferiority of the coal rock based on the gas migration pressure fluctuation characteristics as claimed in claim 1, wherein the evaluating the damage stage of the coal rock according to k, r and g and the evaluating the damage inferiority of the coal rock according to r comprise:
when k is less than or equal to 2.15, the coal rock is in a primary pore compaction closed stage;
when k is less than or equal to 6.5 after 2.15 yards are formed, the coal rock is in an elastic homogeneous deformation stage;
when k is greater than 6.5 and g is greater than 3.65 or r is greater than 0.32, the coal rock is in a post-peak destruction stage;
k is greater than 6.5, g is less than or equal to 3.65, and r is less than or equal to 0.15, the coal rock is in a fracture stable extension stage;
k is more than 6.5, g is less than or equal to 3.65, 0.15< -r is less than or equal to 0.32, and the coal rock is in a fracture accelerated extension stage;
the larger the r value, the more serious the deterioration damage of the coal rock.
6. The method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics according to claim 1, further comprising:
pretreating the coal rock, and putting the coal rock into a device for a loading experiment;
connecting the coal rock with a guide channel, guiding out gas and monitoring pressure;
the stress during the experiment was monitored.
7. A memory storing a plurality of instructions for implementing the method of any one of claims 1-5.
8. An electronic device comprising a processor and a memory coupled to the processor, the memory storing a plurality of instructions that are loadable and executable by the processor to enable the processor to perform the method according to any of claims 1-5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210947483.0A CN115014982B (en) | 2022-08-09 | 2022-08-09 | Method for evaluating coal rock damage inferiority based on gas migration pressure fluctuation characteristics |
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