A comprehensive lithology determination method based on arch structure development and its application

Abstract

The present invention discloses a comprehensive lithology determination method based on the development of an arch structure and its application. The determination method includes: dividing according to whether the working face mining is sufficient, calculating the trajectory equation of the arch structure corresponding to different coal mining stages, and calculating the area formed by the closure of the arch structure; arranging observation lines on the main section of the working face and observing regularly, based on the measured data, drawing the subsidence curve of the main section of the ground surface strike, dividing the ground surface subsidence curve into multiple sections, and calculating the area formed by the closure of the ground surface subsidence curve based on the differential idea; calculating the damage volume ratio; giving the critical value of the damage volume ratio to determine the comprehensive lithology of the overlying strata; and applying this method to the prediction of the ground surface movement duration. The present invention effectively solves the problems in the prior art that determining lithology through physical experiments cannot represent the entire mining area and does not consider the comprehensive effect after the combination of rock strata, accurately determines the comprehensive lithology, and significantly improves the accuracy of predicting the ground surface movement duration.

Description

Technical Field

[0001] The present invention relates to the technical field of lithology determination. Specifically, it is a comprehensive lithology determination method based on the development of arch structures and its application. Background Art

[0002] With the rapid development of China's national economy, the demand for coal resources has gradually increased. By the end of 2021, the national coal output reached 4.13 billion tons, accounting for 56.0% of the total energy consumption. In the foreseeable future, coal will still remain the main energy source for consumption in China. While coal mining brings huge economic and social benefits, it also brings a series of problems such as surface subsidence and environmental damage. The surface movement and deformation caused by coal mining is a complex spatio-temporal problem, and the duration of surface movement is an important indicator for judging whether the surface movement and deformation are stable. The prerequisite for the government and relevant departments to reuse land is that the surface has stabilized. Therefore, monitoring the surface movement and deformation caused by mining and accurately predicting the duration of surface movement is of great significance for the utilization of mining area land resources, building reconstruction, foundation engineering treatment, etc.

[0003] Traditionally, the empirical formula given in the "Three-Under" coal mining regulations is mainly used to predict the duration of surface movement. However, this formula does not consider the lithology of overlying strata. In application, it is found that the calculation results are often too large, resulting in the inability to carry out construction projects on time. Therefore, when predicting the duration of surface movement, the relationship between it and the lithology of overlying strata should be considered. Research has confirmed that the process and results of surface movement are greatly affected by the lithology of overlying strata. Therefore, it is particularly important to determine the comprehensive lithology of overlying strata in mining areas.

[0004] Research shows that the harder the properties of overlying strata, the longer the duration of surface movement, and the softer the properties of overlying strata, the shorter the duration of surface movement. Therefore, it is particularly important to accurately judge the properties of overlying strata. The properties of overlying strata (firmness coefficient) are generally obtained through physical experiments after drilling and sampling. However, the drilling cost is too high, and the obtained coefficient cannot represent the entire mining area and lacks universality.

[0005] Meanwhile, the strata are composed of many rock layers with different lithologies, some soft and some hard. Instead of only considering the effect of a single rock layer, the comprehensive effect after the combination of rock layers should be considered, which thus has a certain restrictive effect on the goaf engineering project. Patent document CN111577268B discloses a method for judging the lithology of rocks by using the vibration parameters of drilling tools. This method analyzes the lithology of rocks based on the extracted vibration data of drilling tools, according to the root mean square of acceleration, stress-strain relationship and mechanical specific energy. However, due to the presence of multiple rock layers in the strata, using the vibration data of drilling tools to determine the lithology of rocks can only target one or several layers, and it is impossible to determine the comprehensive lithology of the strata in the mining area (expected area), and it is time-consuming and laborious. Patent document CN102720489B discloses a method for analyzing the lithology of strata while drilling in gas drilling, which can quickly and accurately analyze the cuttings returned in gas drilling. By determining the cuttings arrival time, obtaining the cuttings, and performing on-site X-ray diffraction analysis to judge the lithology. This method of analyzing the lithology of strata while drilling in gas drilling can accurately determine the lithology at the drilling site, but it is impossible to determine the comprehensive lithology of the entire mining area (expected area). In order to determine the comprehensive lithology of the mining area, accurately predict the duration of surface movement, and provide guidance for land resource utilization, it is necessary to design a comprehensive lithology determination method. Summary of the Invention

[0006] For this reason, the technical problem to be solved by the present invention is to provide a comprehensive lithology determination method and its application based on the development of arch structures, so as to solve the problems in the prior art that the determination of the overlying rock properties does not consider the comprehensive effect after the combination of rock layers, cannot represent the entire mining area, lacks universality, and affects the accuracy of predicting the duration of surface movement.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] A comprehensive lithology determination method based on the development of arch structures, comprising the following steps:

[0009] Step (1): Divide according to whether the working face mining is sufficient, calculate the arch structure trajectory equation corresponding to different coal mining stages, and calculate the area S formed by the closure of the arch structure g ;

[0010] Step (2): Arrange an observation line on the main section of the working face and observe regularly. Based on the measured data, draw the subsidence curve of the main section of the ground surface strike, divide the ground surface subsidence curve into multiple sections, and calculate the area S formed by the closure of the ground surface subsidence curve based on the differential idea d ;

[0011] Step (3): Calculate the damage volume ratio α;

[0012] Step (4): Give the critical value of the damage volume ratio and determine the comprehensive lithology of the overlying rock.

[0013] In the above comprehensive lithology determination method based on the development of the arch structure, in step (1), when the working face is not fully mined, i.e., L < L c , the trajectory equation of the arch structure is:

[0014]

[0015] When the working face is fully mined, i.e., L ≥ L c , the trajectory equation of the arch structure is divided into the following two cases:

[0016] ① When , the trajectory equation of the arch structure is:

[0017]

[0018] ② When , the trajectory equation of the arch structure is:

[0019] y = h c (4);

[0020] In formulas (1), (2) and (3): L c = (1.2 - 1.4)H, where H is the average mining depth, m; L is the advancing distance of the working face, m; S L is the distance from the inner side of the arch structure to the coal wall, m; h is the height of the arch structure, m; h c is the height of the bedrock, m.

[0021] In the above comprehensive lithology determination method based on the development of the arch structure, in step (1), the calculation formula for the distance S L from the inner side of the arch structure to the coal wall is:

[0022]

[0023] The height h of the arch structure is obtained through the following formula:

[0024]

[0025] In formulas (5) and (6): M is the coal seam thickness, m; K is an empirical coefficient with a value of 0.05 - 1.

[0026] In the above comprehensive lithology determination method based on the development of the arch structure, in step (1), when calculating the area S g formed by the closure of the arch structure:

[0027] ① When the working face is not fully mined, i.e., L < L c , the area formed by the closure of the arch structure is:

[0028]

[0029] ②When the working face is fully mined, i.e., L≥L c , the area formed by the closure of the arch structure is:

[0030]

[0031] In Formulas (7) and (8): L c =(1.2 - 1.4)H, where H is the average mining depth, m; L is the advancing distance of the working face, m; h c is the bedrock height, m; M is the coal seam thickness, m; K is an empirical coefficient with a value of 0.05 - 1.

[0032] In the above method for determining the comprehensive lithology based on the development of the arch structure, in step (2), according to the measured data, draw the subsidence curve of the main section along the strike of the ground surface, and the fitted subsidence curve function is:

[0033] y = f(x) (9);

[0034] Based on the differential idea, the area S formed by the closure of the ground surface subsidence curve is obtained d as:

[0035]

[0036] In Formulas (9) and (10), y is the ground surface subsidence value, mm; x is the horizontal distance of the ground surface observation line, m; △x is the length of the flat bottom part of the ground surface subsidence curve, m; W max is the maximum ground surface subsidence value, mm; L c =(1.2 - 1.4)H, where H is the average mining depth, m; L is the advancing distance of the working face, m.

[0037] In the above method for determining the comprehensive lithology based on the development of the arch structure, in step (3), the calculation formula for the damage volume ratio α is:

[0038]

[0039] S c = LM (12);

[0040] In Formulas (11) and (12): S c is the goaf area; S d is the area formed by the closure of the ground surface subsidence curve; S g is the area formed by the closure of the arch structure; L is the advancing distance of the working face, m; M is the coal seam thickness, m.

[0041] In the above comprehensive lithology determination method based on the development of the arch structure, in step (4), when the value of the damage volume ratio α is less than or equal to 0.30, the comprehensive lithology of the overlying strata is soft lithology; when the value of the damage volume ratio α is greater than 0.30 and less than or equal to 0.65, the comprehensive lithology of the overlying strata is medium-hard lithology; when the value of the damage volume ratio α is greater than 0.65 and less than or equal to 1.00, the comprehensive lithology of the overlying strata is hard lithology.

[0042] In the above comprehensive lithology determination method based on the development of the arch structure, in step (1), when the working face is in non-full mining, that is, L < L c , the trajectory equation of the arch structure is:

[0043]

[0044] When the working face is in full mining, that is, L ≥ L c , the trajectory equation of the arch structure is divided into the following two cases:

[0045] ① When , the trajectory equation of the arch structure is:

[0046]

[0047] ② When , the trajectory equation of the arch structure is:

[0048] y = h c (4);

[0049] The distance S from the inner side of the arch structure to the coal wall L is calculated by the formula:

[0050]

[0051] The height h of the arch structure is obtained by the following formula:

[0052]

[0053] When calculating the area S formed by the closure of the arch structure g :

[0054] ① When the working face is in non-full mining, that is, L < L c , the area formed by the closure of the arch structure is:

[0055]

[0056] ② When the working face is in full mining, that is, L ≥ L c , the area formed by the closure of the arch structure is:

[0057]

[0058] In the formula: L c =(1.2 - 1.4)H, where H is the average mining depth, in m; L is the advancing distance of the working face, in m; S L is the distance from the inner side of the arch structure to the coal wall, in m; h is the height of the arch structure, in m; h c is the bedrock height, in m; M is the coal seam thickness, in m; K is an empirical coefficient, with a value range of 0.05 - 1.

[0059] In the above method for determining the comprehensive lithology based on the development of the arch structure, in step (2), according to the measured data, draw the subsidence curve of the main section along the strike of the ground surface, and the fitted subsidence curve function is:

[0060] y = f(x) (9);

[0061] Based on the differential idea, obtain the area S formed by the closure of the ground surface subsidence curve d as:

[0062]

[0063] In formulas (9) and (10), y is the ground surface subsidence value, in mm; x is the horizontal distance of the ground surface observation line, in m; △x is the length of the flat bottom part of the ground surface subsidence curve, in m; W max is the maximum ground surface subsidence value, in mm;

[0064] In step (3), the calculation formula for the damage volume ratio α is:

[0065]

[0066] Sc = LM (12);

[0067] In formulas (11) and (12): S c is the goaf area;

[0068] In step (4), when the value of the damage volume ratio α is less than or equal to 0.30, the comprehensive lithology of the overlying strata is soft lithology; when the value of the damage volume ratio α is greater than 0.30 and less than or equal to 0.65, the comprehensive lithology of the overlying strata is medium-hard lithology; when the value of the damage volume ratio α is greater than 0.65 and less than or equal to 1.00, the comprehensive lithology of the overlying strata is hard lithology.

[0069] An application of the method for determining the comprehensive lithology based on the development of the arch structure, using the above method for determining the comprehensive lithology based on the development of the arch structure to predict the duration of ground surface movement; the calculation formula for the duration of ground surface movement T is as follows:

[0070]

[0071] In formula (13), H is the average mining depth, in m; α is the damage volume ratio.

[0072] The technical solution of the present invention has achieved the following beneficial technical effects:

[0073] 1. The comprehensive lithology determination method based on the development of the arch structure in the present invention calculates the damage volume ratio by obtaining the area of the arch structure and the area of the surface subsidence curve (strike) during coal mining, and gives a critical value to achieve the goal of determining the comprehensive lithology of the rock stratum, which is beneficial to improving the accuracy of predicting the duration of surface movement and effectively solves the problems in the prior art that determining the lithology through physical experiments cannot represent the entire mining area and does not consider the comprehensive effect after the combination of rock strata.

[0074] 2. The present invention correlates the damage volume ratio with the comprehensive lithology and the duration of surface movement, can accurately and efficiently determine the comprehensive lithology of the entire mining area, and is beneficial to improving the accuracy of predicting the duration of surface movement. Existing methods often take a part to represent the whole or only consider the role of a certain rock stratum. Based on the development process of the arch structure, the present invention determines the comprehensive lithology through the damage volume ratio, which has better universality. Compared with determining the lithology by drilling and sampling, the method of the present invention greatly reduces the cost, can accurately determine the comprehensive lithology while obtaining the maximum economic benefit, and significantly improves the accuracy of predicting the duration of surface movement. Description of the Drawings

[0075] Figure 1 Schematic diagram of the arch structure trajectory in the embodiment of the present invention (L < L c );

[0076] Figure 2 Schematic diagram of the arch structure trajectory in the embodiment of the present invention (L ≥ L c );

[0077] Figure 3 Schematic diagram of the arch structure evolution analysis in the embodiment of the present invention (L < L c );

[0078] Figure 4 Schematic diagram of the arch structure evolution analysis in the embodiment of the present invention (L ≥ L c );

[0079] Figure 5 Schematic diagram of the surface subsidence curve in the embodiment of the present invention. Detailed Embodiment

[0080] The comprehensive lithology determination method based on the development of the arch structure in this embodiment is divided into the following 4 steps.

[0081] Step 1: Divide according to whether the working face is fully mined, calculate the arch structure trajectory equation corresponding to different coal mining stages, and calculate the area S formed by the closure of the arch structure g ;

[0082] As the working face advances continuously, the overlying strata in the stope will collapse under their own control to form an "arch" structure, which plays a macroscopic supporting role for the overall overlying strata. When the working face advances to L c (1.2 - 1.4H, where H is the average mining depth), the working face is fully mined, and the surface subsidence value reaches the maximum. At this time, the height of the arch structure develops to the top of the bedrock, reaching the maximum value under this geological mining condition. As the working face continues to advance, the arch structure becomes unstable and no longer develops, and its shape is a flat arch.

[0083] In this embodiment, after the underground coal seam is mined, an arch structure will be formed inside the overlying strata, as shown in Figure 1 and Figure 2 . The X-axis is the advancing direction of the working face, the Y-axis is vertically upward, and the coordinate origin is the center of the goaf. When the working face advances by △L, the coordinate origin advances by △L / 2 along the positive direction of the X-axis. When L < L c , the shape of the arch structure is as shown in Figure 1 . When L < L c , the height of the arch structure develops to the top of the bedrock, reaching the maximum value under this geological mining condition. As the working face continues to advance, the arch structure becomes unstable and the height no longer changes, as shown in Figure 3 .

[0084] (1) When the working face is in non-fully mined state, that is, L < L c , determine the arch structure equation:

[0085]

[0086] As can be seen from the above formula, as long as the values of coefficients a and b are determined, the arch structure equation can be determined. From the figure, b = h, substituting it in, the arch structure equation can be obtained as:

[0087]

[0088] where: L is the advancing distance of the working face, m; S L is the distance from the inner side of the arch structure to the coal wall, m; h is the height of the arch structure.

[0089] From formula (2), it can be known that during the process of the working face advancing from the starting cut to a distance of L c , the arch structure continuously expands outwards, and its shape is an arch, as shown in Figure 3 . As the working face advances continuously, the arch height and span gradually increase. When the working face advances to L c , the evolution height of the arch structure develops to the top of the bedrock, reaching the critical value h c (bedrock height).

[0090] (2) When the working face is in fully mined state, that is, L ≥ L c , determine the arch structure equation:

[0091] The arch structure is a flat arch, and the equation can and be analyzed in two intervals.

[0092] ① When , the equation of the arch structure is:

[0093]

[0094] ② When , the equation of the arch structure is:

[0095] y = h c (4)

[0096] Where: h c is the bedrock height, that is, the maximum value of the arch structure height under this geological mining condition. The meanings of the other parameters are the same as before. As the working face advances continuously, the arch structure becomes unstable, and the height h c no longer changes, is stretched along the strike, and its shape evolves from an arch to a flat arch. The flat part c (L c -L) increases with the increase of the advancing distance of the working face, and a stable periodic weighting phenomenon occurs. The flat arch no longer has a load-bearing effect, as Figure 4 shown.

[0097] (3) Calculate the volume of the arch structure

[0098] Since during the advancement of the working face, the arch base will gradually move deep into the coal wall, that is, S L will increase with the increase of the advancing distance L of the working face. According to the two-zone constraint theory of A.H. Wilson, the distance from the inner side of the arch base to the coal wall can be expressed as:

[0099]

[0100] The height h of the arch structure is obtained by the following formula:

[0101]

[0102] Where: M is the coal seam thickness, m; H is the mining depth, m; K is an empirical coefficient, with a value of 0.05 - 1. The meanings of the other parameters are the same as before.

[0103] ① When L < L c , the arch structure is similar to a semi-ellipse. According to the ellipse area formula S = πab, by combining equations (1)-(6), the area of the arch structure at this stage can be obtained as:

[0104]

[0105] ② When L ≥ L cWhen the time is [specific time], the arch structure form is a flat semi-ellipse. At this stage, the area of the arch structure is:

[0106]

[0107] Step 2: Layout the observation line on the main section of the working face and conduct regular observations. Based on the measured data, draw the subsidence curve of the main section of the ground surface strike. Divide the ground surface subsidence curve into multiple sections. Based on the differential idea, calculate the area S formed by the closure of the ground surface subsidence curve d ;

[0108] When the working face is in non-full mining, that is, L < L c , the ground surface subsidence curve is in a "V" shape; when the working face is in full mining, that is, L ≥ L c , the ground surface subsidence curve is in a "U" shape, with a flat ground at the bottom, as shown in Figure 5 . According to the measured data, the subsidence curve function is fitted as:

[0109] y = f(x) (9)

[0110] Where: y is the ground surface subsidence value, in mm; x is the horizontal distance of the ground surface observation line.

[0111] Based on the differential idea, the area of the ground surface subsidence curve can be obtained as:

[0112]

[0113] Where: △x is the length of the flat bottom part of the ground surface subsidence curve, in m; W max is the maximum ground surface subsidence value, in mm, and the meanings of the other parameters are the same as before.

[0114] Step 3: Calculate the damage volume ratio α;

[0115]

[0116] S c = LM (12)

[0117] Where: S c is the goaf area, and the meanings of the other parameters are the same as before.

[0118] Step 4: Give the critical value of the damage volume ratio and determine the comprehensive lithology of the overlying strata.

[0119] The smaller the damage volume ratio, the softer the comprehensive lithology, and the shorter the duration of ground surface movement; the larger the damage volume ratio, the harder the comprehensive lithology, and the longer the duration of ground surface movement. Give the critical value of the damage volume ratio and determine the nature of the comprehensive lithology and the duration of ground surface movement, as shown in Table 1.

[0120] Table 1 Judgment of the comprehensive lithology of the overlying strata

[0121]

[0122] The accuracy of the surface movement duration calculated by the method of this embodiment is significantly improved compared with that calculated by the prior art.

[0123] Based on the development process of the arch structure, this embodiment determines the comprehensive lithology of the rock strata in the mining area (predicted area) by calculating the damage volume ratio. When determining the comprehensive lithology of the rock strata, multiple boreholes can also be arranged in the entire mining area (predicted area) for sampling and comparison to determine the comprehensive lithology, but in this way, the construction cost and construction time will increase significantly. This embodiment can better judge the comprehensive lithology by calculating the damage volume ratio, so as to achieve the purpose of accurately predicting the surface movement duration.

[0124] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the claims of this patent application.

Claims

1. A comprehensive lithology determination method based on the development of arch structures, characterized in that, It includes the following steps: Step (1): Divide according to whether the working face mining is sufficient, calculate the arch structure trajectory equation corresponding to different coal mining stages, and use the arch structure trajectory equation to calculate the area formed by the closure of the arch structure S g ; Step (2): Layout an observation line on the main section of the working face and conduct regular observations. Based on the measured data, draw the subsidence curve of the main section of the ground surface along the strike. Divide the ground surface subsidence curve into multiple cross-sections, and calculate the area formed by the closure of the ground surface subsidence curve based on the differential idea. S d ; Step (3): Calculate the damage volume ratio α; The calculation formula for the damage volume ratio α is: (11)； (12)； In Formulas (11) and (12): S c is the gob area; S d is the area formed by the closure of the surface subsidence curve; S g is the area formed by the closure of the arch structure; L is the advancing distance of the working face, m; M is the coal seam thickness, m; Step (4): Give the critical value of the damage volume ratio and determine the comprehensive lithology of the overlying strata, where the comprehensive lithology of the overlying strata includes soft lithology, medium-hard lithology, and hard lithology.

2. The comprehensive lithology determination method based on arch structure development according to claim 1, wherein In step (1), when the working face is under non-full mining, that is , the trajectory equation of the arch structure is: (2)； When the working face is in full mining, that is , the trajectory equations of the arch structure are divided into the following two cases: When the trajectory equation of the arch structure is as follows: (3)； When the trajectory equation of the arch structure is as follows: (4)； In Formulas (1), (2), and (3): L c = (1.2 to 1.4) H , H is the average mining depth, m; L is the advancing distance of the working face, m; S L is the distance from the inner side of the arch structure to the coal wall, m; h is the height of the arch structure, m; h c is the height of the bedrock, m.

3. The comprehensive lithology determination method based on arch structure development according to claim 2, characterized in that In step (1), the distance between the inner side of the arch structure and the coal wall S L is calculated by the following formula: (5)； Arch structure height h Obtained by the following formula: (6)； In Formulas (5) and (6): M is the coal seam thickness, in m; K is the empirical coefficient, with a value range of 0.05 to 1.

4. The comprehensive lithology determination method based on arch structure development according to claim 1, characterized in that In step (1), calculate the area formed by the closure of the arch structure S g When: ①When the working face is in non-full mining, that is , the area formed by the closure of the arch structure is: (7)； ②When the working face is fully mined, that is , the area formed by the closure of the arch structure is: (8)； In Formulas (7) and (8): L c = (1.2 to 1.4) H , H is the average mining depth, m; L is the advancing distance of the working face, m; h c is the height of the bedrock, m; M is the coal seam thickness, m; K is the empirical coefficient, with a value range of 0.05 - 1.

5. The comprehensive lithology determination method based on arch structure development according to claim 1, characterized in that In Step (2), based on the measured data, draw the subsidence curve of the main surface strike section, and the fitted subsidence curve function is: (9)； Based on the differential idea, the area formed by the closure of the ground subsidence curve is obtained S d It is as follows: (10)； In formulas (9) and (10), y is the surface subsidence value, in mm; x is the horizontal distance of the surface observation line, in m; △ x is the length of the flat part of the ground settlement curve, m; W max is the maximum surface subsidence value, in mm; L c = (1.2 - 1.4) H , H is the average mining depth, in m; L is the advancing distance of the working face, in m.

6. The comprehensive lithology determination method based on arch structure development according to claim 1, characterized in that In Step (4), when the value of the damage volume ratio α is less than or equal to 0.30, the comprehensive lithology of the overlying strata is soft lithology; when the value of the damage volume ratio α is greater than 0.30 and less than or equal to 0.65, the comprehensive lithology of the overlying strata is medium-hard lithology; when the value of the damage volume ratio α is greater than 0.65 and less than or equal to 1.00, the comprehensive lithology of the overlying strata is hard lithology.

7. The integrated lithology determination method based on arch structure development according to claim 1, characterized in that In step (1), when the working face is not fully mined, that is , the trajectory equation of the arch structure is: (2)； When the working face is in full mining, that is , the trajectory equations of the arch structure are divided into the following two cases: When the trajectory equation of the arch structure is as follows: (3)； When the trajectory equation of the arch structure is as follows: (4)； Distance between the inner side of the arch structure and the coal wall S L The calculation formula is as follows: (5)； Arch structure height h Obtained by the following formula: (6)； Calculate the area formed by the closure of the arch structure S g When: When the working face is in non-full mining, that is , the area formed by the closure of the arch structure is: (7)； When the working face is fully mined, that is , the area formed by the closure of the arch structure is: (8)； In the formula: L c = (1.2 to 1.4) H , H is the average mining depth, m; L is the advancing distance of the working face, m; S L is the distance from the inner side of the arch structure to the coal wall, m; h is the height of the arch structure, m; h c is the height of the bedrock, m; M is the coal seam thickness, m; K is the empirical coefficient, with a value range of 0.05 - 1.

8. The comprehensive lithology determination method based on arch structure development according to claim 7, characterized in that In Step (2), based on the measured data, draw the subsidence curve of the main surface strike section, and the fitted subsidence curve function is: (9)； Based on the differential idea, the area formed by the closure of the surface subsidence curve is obtained S d It is as follows: (10)； In Formulas (9) and (10), y is the surface subsidence value, in mm; x is the horizontal distance of the surface observation line, in m; △ x is the length of the flat part of the ground settlement curve, in m; W max is the maximum surface subsidence value, in mm; In Step (4), when the value of the damage volume ratio α is less than or equal to 0.30, the comprehensive lithology of the overlying strata is soft lithology; when the value of the damage volume ratio α is greater than 0.30 and less than or equal to 0.65, the comprehensive lithology of the overlying strata is medium-hard lithology; when the value of the damage volume ratio α is greater than 0.65 and less than or equal to 1.00, the comprehensive lithology of the overlying strata is hard lithology.

9. Application of a comprehensive lithology determination method based on arch structure development, characterized in that, Use the comprehensive lithology determination method based on the development of the arch structure as described in Claim 1 to predict the duration of surface movement; the calculation formula for the duration of surface movement T is as follows: (13)； In Equation (13), H is the average mining depth, in m; α is the damage volume ratio.

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