CN110991824B - Method, device and storage medium for identifying coal rock impact tendency - Google Patents

Abstract

The invention discloses a method, device and storage medium for identifying the impact tendency of coal and rock, and relates to the fields of geotechnical engineering and mining engineering. It includes: determining the identification standard for identifying the impact tendency of the coal rock through the cohesive force of the coal rock; measuring the cohesive force of the coal rock to be identified; comparing the cohesive force with a preset threshold value, and identifying the impact tendency of the coal rock according to the identification standard. The method provided by the invention is suitable for the identification of impact tendency of coal rock, has the advantages of simple and efficient identification process, and improves the accuracy of identification of coal rock impact tendency.

Description

A method, device and storage medium for identifying coal rock impact tendency

technical field

The invention relates to the fields of geotechnical engineering and mining engineering, in particular to a method, device and storage medium for identifying the impact tendency of coal rocks.

Background technique

The problem of rock burst in deep coal is an important issue in the mechanics of rock mass in deep mines. Rock burst refers to the dynamic phenomenon of sudden and violent destruction of coal and rock around the shaft or working face due to the instantaneous release of elastic deformation energy. Strong destructiveness is one of the major disasters in coal mines.

Currently, rock burst can be described by shock propensity. In the current standards of the coal industry, the impact tendency of coal rock is determined by measuring the following indicators, including: uniaxial compressive strength R _C , impact energy index K _E , elastic energy index W _ET and dynamic failure time D _T , however, currently The method for identifying coal rock impact tendency has the following deficiencies:

First of all, the elastic energy index only considers the part of the coal sample before reaching the peak value during the uniaxial compression process, the dynamic failure time only considers the part after the coal sample reaches the peak value during the uniaxial compression process, and the uniaxial compressive strength only considers the peak value one point. These three indicators cannot fully consider the whole process of the stress-strain curve of coal; secondly, the above indicators only consider a single aspect of the impact tendency. As there is no impact, it is used for identification, and there may be large dispersion or conflicting results. When there are indicators that are particularly dangerous, they will be averaged by other indicators, making the evaluation underestimated, resulting in the identification of coal. The impact tendency is not accurate and objective enough.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method, device and storage medium for identifying the impact tendency of coal rocks in view of the deficiencies of the prior art.

The technical scheme that the present invention solves the problems of the technologies described above is as follows:

A method for identifying coal impact propensity, comprising:

Identify the cohesion of the coal rock to be identified;

The cohesive force is compared with a preset threshold, and the impact tendency of the coal rock is obtained according to the comparison result.

The beneficial effects of the present invention are: the method provided by the present invention, through identifying the cohesive force of coal rock, then determines the impact tendency of coal rock according to the identified cohesive force, compared with the traditional identification method of coal rock impact tendency, no need The determination of multiple indicators has the advantage of quick identification process, and there is a certain functional relationship between the cohesion force and the traditional indicators for measuring the coal-rock impact tendency. The cohesion force can fully reflect the multi-faceted influence of the existing indicators on the coal-rock impact tendency. Thereby improving the accuracy of identification of coal rock impact tendency.

Another kind of technical scheme that the present invention solves the problems of the technologies described above is as follows:

A storage medium, in which instructions are stored, and when a computer reads the instructions, the computer is made to execute the method for identifying coal rock impact tendency as described in the above technical solution.

Another kind of technical scheme that the present invention solves the problems of the technologies described above is as follows:

A device for identifying coal rock impact tendency, comprising:

memory for storing computer programs;

The processor is configured to execute the computer program to implement the method for identifying coal rock impact tendency as described in the above technical solution.

Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

Fig. 1 is the schematic flow chart that the present invention is used for the embodiment of the method for identifying the impact tendency of coal rock;

Fig. 2 is the schematic diagram of the pre-peak curve and the pressure relief curve of the coal sample provided by the embodiment of the method for identifying the impact tendency of coal rock in the present invention;

Fig. 3 is the full stress-strain curve schematic diagram of the coal sample that the present invention is used for the embodiment of the method for identifying the impact tendency of coal rock;

Fig. 4 is a schematic diagram of the curves of uniaxial compressive strength and cohesion provided by other embodiments of the method for identifying coal rock impact tendency of the present invention;

Fig. 5 is a schematic diagram of the impact energy index and cohesion curve provided by other embodiments of the method for identifying coal rock impact tendency of the present invention;

Fig. 6 is a schematic diagram of curves of elastic energy index and cohesion provided by other embodiments of the method for identifying coal rock impact tendency of the present invention;

Fig. 7 is a schematic diagram of curves of dynamic failure time and cohesive force provided by other embodiments of the method for identifying coal rock impact tendency of the present invention;

Fig. 8 is a schematic diagram of the structural framework provided by the embodiment of the device for identifying coal rock impact tendency of the present invention.

Detailed ways

The principles and features of the present invention will be described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

As shown in Figure 1, it is a schematic flow diagram provided for an embodiment of the method for identifying coal rock impact tendency of the present invention, the method includes:

S1, determine the identification standard for identifying the impact tendency of coal rock through the cohesive force.

S2, measure the cohesion of the coal rock to be identified.

S3, comparing the cohesion with a preset threshold, and identifying the impact tendency of the coal rock according to the identification standard.

It should be understood that the coal rock mentioned here may refer to a cylindrical coal or rock sample with a diameter of 50 mm and a height of 100 mm used in the impact propensity identification test.

Wherein, the preset threshold can be determined according to identification standards. For example, assuming that the preset threshold can include a first threshold and a second threshold, then when the cohesive force is less than the first threshold, the impact tendency of the coal rock is no impact; when the cohesive force is greater than or equal to the first threshold and less than the second threshold When , the impact tendency of the coal rock is weak impact; when the cohesion is greater than the second threshold, the impact tendency of the coal rock is strong impact.

It should be noted that the method for identifying the cohesive force of the coal rock to be identified can be selected from the existing cohesive force identification and measurement method according to actual needs. For example, the cohesive force of the coal rock to be identified can be measured through a triaxial compression test, which will not repeat.

It should be noted that in the current standards of China's coal industry, there are four indicators that characterize the impact tendency of coal rocks, namely, uniaxial compressive strength R _C , impact energy index K _E , elastic energy index W _ET and dynamic failure time D _T ; in the uniaxial compression test, the uniaxial compressive strength is the peak strength of the stress-strain curve; the dynamic failure time refers to the time from the ultimate strength to the complete failure of the coal specimen, and the elastic energy index refers to the Under the state of uniaxial compression, when the stress reaches 75%-85% of the strength, when the stress is completely unloaded, the ratio of the elastic deformation energy to the plastic deformation energy, the impact energy index refers to the total stress of the coal specimen under the uniaxial compression state In the strain curve, the ratio of the deformation energy accumulated before the peak to the deformation energy consumed after the peak.

The impact tendency of coal rock is comprehensively measured according to these four indicators, but the current evaluation method has the following deficiencies: First, the elastic energy index only considers the partial deformation of coal rock before reaching the peak value in the process of uniaxial compression; The time only considers the part after the peak of the coal rock in the process of uniaxial compression; the uniaxial compressive strength only considers a point of the peak of the stress-strain curve; although the impact energy index considers the mechanical properties before and after the peak of the stress-strain curve, it is obtained Full stress-strain curves are not easy. Therefore, the existing four indexes for judging the impact tendency have their limitations; secondly, each index only evaluates the strength of the coal-rock impact tendency unilaterally, resulting in large dispersion or conflicting results. Phenomenon. Although the fuzzy evaluation method can be used, when there are indicators showing that the impact tendency is particularly dangerous, it will be averaged by other indicators, making the evaluation underestimated and losing the objective accuracy of measuring the shock tendency.

Based on this, the inventor conducted a large number of experiments and found that there is a certain functional relationship between the cohesion force and these four indicators. Therefore, in order to measure the impact tendency of coal rock more accurately, the present invention proposes a new type of coal rock impact tendency The measurement method of the property is to use a single index cohesive force to evaluate the impact tendency of coal rock. By measuring the cohesive force of coal rock, the impact tendency of coal rock can be obtained conveniently and accurately.

In the following, with reference to Figure 2 and Figure 3, taking coal samples as an example, the principle that cohesion can be used to evaluate the impact tendency of coal rocks will be described.

As shown in Figure 2, it is a schematic diagram of the pre-peak curve and pressure relief curve of the coal sample, and as shown in Figure 3, it is a schematic diagram of the total stress-strain curve of the coal sample, which can be divided into two parts before the peak and after the peak. According to the image, the functional relationship between the pre-peak curve, pressure relief curve and post-peak curve of coal sample uniaxial compression and uniaxial compression strength can be set as follows:

y=E ₁ x

y=E ₂ xb ₂

y=-E ₃ x+b ₃

Among them, E ₁ , E ₂ , E ₃ are the slope of the curve, b ₂ and b ₃ are the constant coefficients of the equation;

The present invention establishes a coal sample parameter database by analyzing the physical and mechanical parameters and the impact tendency identification index of multiple coal samples, and the relationship between E ₁ , E ₂ , E ₃ and the uniaxial compressive strength R _C can be obtained as :

E ₁ =k ₁ R _c +e ₁

E ₂ =k ₂ R _c +e ₂

where k ₁ , k ₂ , k ₃ , e ₁ , e ₂ and e ₃ are constant coefficients of these three equations.

On this basis, the present invention establishes the relationship between the impact energy index K _E , the elastic energy index W _ET and the post-peak strain ε _post and the physical and mechanical parameter cohesion C, and the relational formula is as follows:

为摩擦角。in,

is the friction angle.

It should be understood that the post-peak strain ε _post and D _t both describe the span of the coal sample from the peak value to complete destruction, and there is a proportional relationship between the two parameters, so the relationship between D _t and cohesion C can be the relationship between ε _post and cohesion C To represent.

It is also known that the relationship between the uniaxial compressive strength R _C and the cohesion C is:

Therefore, based on the above contents, we can obtain the relationship between the four impact tendency identification indexes uniaxial compression strength R _C , impact energy index K _E , elastic energy index W _ET , dynamic failure time D _T and cohesion C, that is, to evaluate coal by cohesion Theoretical basis of rock impact tendency.

The method provided in this embodiment, by identifying the cohesive force of coal and rock, and then determining the impact tendency of coal and rock according to the identified cohesive force, compared with the traditional method for identifying the impact tendency of coal and rock, does not require multiple indicators to be measured. It has the advantage of fast identification process, and there is a certain functional relationship between the cohesion force and the traditional index for measuring the impact tendency of coal rock. accuracy of identification.

Optionally, in some embodiments, the cohesion of the coal rock to be identified is determined, specifically including:

The coal rock to be identified is measured through a triaxial compression test to obtain the cohesive force of the coal rock to be identified.

Optionally, in some embodiments, the cohesion is compared with a preset threshold, and the impact tendency of the coal rock is identified according to the identification criteria, specifically including:

respectively comparing the cohesion with a preset first threshold and a second threshold, wherein the first threshold and the second threshold are determined according to the identification criteria;

When C<T ₁ , the impact tendency of coal rock is no impact;

When T ₁ ≤ C < T ₂ , the impact tendency of coal rock is weak impact;

When C≥T ₂ , the impact tendency of coal rock is strong impact;

Wherein, T ₁ is the first threshold, T ₂ is the second threshold, and T ₁ <T ₂ , C is the cohesion.

For example, as shown in Table 1, an exemplary impact tendency judgment standard is given.

Table 1 Criteria for judging impact propensity

It can be seen from Table 1 that when the cohesive force is less than 1.5MPa, it indicates that the coal rock to be identified has no impact tendency; when the cohesive force is between 1.5MPa and 4.0MPa, it indicates that the coal rock to be identified at this time has a weak Impact tendency; when the cohesion is greater than 4.0MPa, it indicates that the coal rock to be identified at this time has a strong impact tendency.

It should be understood that the focus of the present invention is to identify the impact tendency of coal rocks through cohesive force, and the specific level of impact tendency corresponding to how much cohesive force can be set according to actual needs. For example, the impact tendency can also be divided into 4 levels , which are no impact, weak impact, strong impact and extremely strong impact, respectively, corresponding to different cohesion ranges, which can be set according to actual needs, and will not be repeated here.

In addition, in addition to the quantitative results of the impact tendency, the impact tendency can also be reflected by the value of the cohesive force. The larger the value of the cohesive force, the greater the impact tendency of the coal rock.

Optionally, in some embodiments, the preset threshold is determined according to the following steps:

Carry out uniaxial compression experiments on the target coal rocks to measure the preset indicators of the target coal rocks, among which the preset indicators are the existing national standards for evaluating the impact tendency of coal rocks; Correspondence of shock propensity;

The preset threshold is determined according to the corresponding relationship between cohesion and impact tendency.

For uniaxial compressive strength R _C , when R _C <7.0, the impact tendency is no impact; when _7.0≤RC <14.0, the impact tendency is weak impact; when R _C >14.0, the impact tendency is strong shock.

When R _C =7.0, the corresponding cohesive force C=1.9; when R _C =14.0, the corresponding cohesive force C=3.8.

For the impact energy index K _E , when K _E <1.5, the impact tendency is no impact; when 1.5≤K _E <5.0, the impact tendency is weak impact; when K _E >5.0, the impact tendency is strong impact .

When K _E =1.5, the corresponding cohesive force C=1.8; when K _E =5.0, the corresponding cohesive force C=4.1.

For elastic energy index W _ET , when W _ET <2.0, the impact tendency is no impact; when 2.0≤W _ET <5.0, the impact tendency is weak impact; when W _ET >5.0, the impact tendency is strong impact .

When W _ET =2.0, the corresponding cohesive force C=1.5; when W _ET =5.0, the corresponding cohesive force C=3.9.

For dynamic failure time D _T , when D _T <50, the impact tendency is no impact; when 50≤D _T <500, the impact tendency is weak impact; when D _T >500, the impact tendency is strong impact .

When _DT =50, the corresponding cohesive force C=1.8; when _DT =500, the corresponding cohesive force C=4.1. Then according to the relationship between the above four indicators and cohesion, after comprehensive analysis and processing, the identification standard of cohesion can be obtained: when C<1.5, the impact tendency is no impact; when 1.5≤C<4.0, the impact tendency It is a weak impact; when C>4.0, the impact tendency is a strong impact.

For example, the weights can be determined according to the degree of influence of the four indicators on the impact tendency, and the cohesion appraisal standard can be determined according to the weights, and more accurate cohesion appraisal standards can also be obtained through other data processing methods, which will not be repeated here.

It should be understood that the above are only illustrative descriptions and do not represent actual numerical values.

Optionally, in some embodiments, the preset index includes: uniaxial compressive strength, impact energy index, elastic energy index or dynamic failure time.

As shown in Fig. 4 to Fig. 7, the curves of uniaxial compressive strength R _C , impact energy index K _E , elastic energy index W _ET , dynamic failure time D _T and corresponding cohesion are given in sequence.

From Figure 4 to Figure 7, the horizontal axis is the cohesive force C in MPa, the vertical axis in Figure 4 is the uniaxial compressive strength R _C , the impact energy index K _E in Figure 5, and the vertical axis in Figure 6 is the elastic energy The index W _ET , the vertical axis in Fig. 7 is the dynamic destruction time D _T .

The discrete points in each figure are the measured values obtained through the uniaxial compression experiment, the solid line is the curve obtained through fitting, and the dotted line is the fitting curve of the theoretical value. According to the impact tendency evaluation criteria of each index, the corresponding values in the figure can be divided into three areas by dotted lines, from top to bottom are strong impact area, weak impact area and no impact area. Find the intersection point of the fitting curve and the regional boundary on the position of the horizontal axis, and then the corresponding relationship between the cohesion force and the impact tendency can be obtained through comprehensive analysis, so as to determine the threshold.

Optionally, in some embodiments, the corresponding relationship between cohesion and impact tendency is determined according to the correspondence between preset indicators and impact tendency, specifically including:

Establish the functional relationship between the preset indicators of the target coal and rock and the corresponding cohesion, and draw the relationship curve between the two;

Mark the evaluation range of preset indicators and impact propensity in the graph;

According to the scope of evaluation, determine the corresponding relationship between cohesion and impact tendency.

Optionally, in some embodiments, the preset threshold is determined according to the corresponding relationship between cohesion and impact tendency, which specifically includes:

The cohesion value at the endpoint of the evaluation range was used as the preset threshold.

It can be understood that, in some embodiments, some or all of the optional implementation manners in the foregoing embodiments may be included.

In other embodiments of the present invention, a storage medium is also provided. Instructions are stored in the storage medium. When the computer reads the instructions, the computer is made to execute the method for identifying coal rock impact tendency as described in any of the above-mentioned embodiments. method.

As shown in Fig. 8, in other embodiments of the present invention, a device for identifying the impact tendency of coal rocks is also provided, including:

Memory 1, used to store computer programs;

The processor 2 is configured to execute a computer program to implement the method for identifying coal rock impact tendency as described in any of the above embodiments.

Readers should understand that in the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the embodiments or examples are combined A particular feature, structure, material, or characteristic is described as included in at least one embodiment or example of the invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

In the several embodiments provided in this application, it should be understood that the disclosed devices and methods may be implemented in other ways. For example, the method embodiments described above are only illustrative. For example, the division of steps is only a logical function division. In actual implementation, there may be other division methods. For example, multiple steps can be combined or integrated into another A step, or some features, can be ignored, or not performed.

If the above method is realized in the form of software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of software products, and the computer software products are stored in a storage medium In, several instructions are included to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-OnlyMemory), random access memory (RAM, RandomAccessMemory), magnetic disk or optical disk and other media that can store program codes.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or modifications within the technical scope disclosed in the present invention. Replacement, these modifications or replacements shall all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (5)

1. A method for identifying coal rock impact tendency, characterized in that, comprising: Determining the identification standard for identifying the impact tendency of coal rock through its cohesive force; Determination of the cohesion of coal rocks to be identified; Comparing the cohesive force with a preset threshold value, and identifying the impact tendency of the coal rock according to the identification standard; Wherein, the preset threshold is determined by the following steps: A uniaxial compression experiment is carried out on the target coal rock, and the preset index of the target coal rock is determined, wherein the preset index is the existing national standard for evaluating the impact tendency of the coal rock, and the preset index includes the uniaxial resistance Compressive strength, impact energy index, elastic energy index or dynamic failure time; According to the corresponding relationship between the preset index and the cohesive force, determine the corresponding relationship between the cohesive force and the impact tendency; determining the preset threshold according to the corresponding relationship between cohesion and impact tendency; Wherein, according to the corresponding relationship between the preset index and the cohesive force, determining the corresponding relationship between the cohesive force and the impact tendency includes: Establishing the functional relationship between the preset index of the target coal rock and the corresponding cohesion force, and drawing the relationship curve between the two; Marking the evaluation range of the preset index and impact tendency in the graph; According to the evaluation range, determine the corresponding relationship between cohesion and impact tendency; Wherein, the determination of the preset threshold according to the corresponding relationship between cohesion and impact tendency includes: Taking the cohesion value at the endpoint of the evaluation range as the preset threshold; Wherein, the functional relationship between the preset index of the target coal rock and the corresponding cohesion is:

Wherein, _Rc represents the uniaxial compressive strength, C represents the cohesion,

represents the friction angle, K _E represents the impact energy index, k ₁ , k ₂ , k ₃ , e ₁ , e ₂ and e ₃ are all constant coefficients, W _ET represents the elastic energy index, ε _post represents the dynamic Failure time, E ₃ represents the curve slope of the post-peak curve of coal rock. 2. the method for identifying coal rock impact tendency according to claim 1, characterized in that, the cohesion of the coal rock to be identified is measured, specifically comprising: The unidentified coal rock is measured by a triaxial compression test to obtain the cohesive force of the unidentified coal rock. 3. The method for identifying the impact tendency of coal rocks according to claim 1, wherein the cohesive force is compared with a preset threshold value, and the impact tendency of the coal rocks is identified according to the identification standard, Specifically include: respectively comparing the cohesion with a preset first threshold and a second threshold, wherein the first threshold and the second threshold are determined according to the identification criteria; When C<T ₁ , the impact tendency of the coal rock is obtained as no impact; When T ₁ ≤ C < T ₂ , the impact tendency of the coal rock is weak impact; When C≥T ₂ , the impact tendency of the coal rock is strong impact; Wherein, T ₁ is the first threshold, T ₂ is the second threshold, and T ₁ <T ₂ , C is the cohesion. 4. A storage medium, characterized in that instructions are stored in the storage medium, and when the computer reads the instructions, the computer is made to execute the authentication method according to any one of claims 1 to 3. Method of coal rock impact propensity. 5. A device for identifying the impact tendency of coal rock, characterized in that it comprises: memory for storing computer programs; A processor, configured to execute the computer program to implement the method for identifying coal rock impact tendency according to any one of claims 1 to 3.

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