Analysis method of strain-structure plane sliding rockburst failure mechanism in tunnels using drilling and blasting method

Abstract

The present invention provides a method for analyzing the failure mechanism of strain-structural surface sliding rockbursts in tunnels using the drilling and blasting method, and relates to the technical field of tunnel rockburst microseismic monitoring. The present invention collects microseismic data of strain-structural surface sliding rockbursts during tunnel construction, combines it with engineering geological survey data, and performs microseismic monitoring and data analysis on strain-structural surface sliding rockbursts that have already occurred in the tunnel. The method divides strain-structural surface sliding rockburst risk zones and determines rockburst microseismic early warning areas. Through these data, the microseismic activity patterns of strain-structural surface sliding rockbursts in deep-buried drilling and blasting tunnels are deeply understood, the respective roles of tension and shear in the rock failure process are distinguished, and the failure mechanism of strain-structural surface sliding rockbursts in deep-buried drilling and blasting tunnels is comprehensively analyzed. The method further derives the failure mechanism of strain-structural surface sliding rockbursts in deep-buried drilling and blasting tunnels, providing an important theoretical basis for predicting and preventing rockburst disasters.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel rockburst microseismic monitoring, and in particular to a method for analyzing the damage mechanism of a tunnel strain-structural surface sliding type rockburst using a drilling and blasting method. Background Art

[0002] Rockbursts are a dynamic phenomenon characterized by the sudden release of elastic energy accumulated within the rock mass of underground engineering structures during excavation or external disturbances, resulting in the rupture and ejection of the surrounding rock. These phenomena are highly sudden, random, and dangerous. Based on their initiation mechanisms, rockburst types can be divided into strain-type rockbursts, strain-structural surface sliding rockbursts, and fracture-type rockbursts. The initiation mechanisms, fracture mechanisms, and damage scales of these different rockburst types vary significantly. Strain-structural surface sliding rockbursts occur more frequently in deep tunnels, affect a larger area, and exert greater destructive force, potentially triggering subsequent rockbursts. Therefore, it is necessary to develop appropriate rockburst warnings for strain-structural surface sliding rockbursts, and studying the damage mechanism of strain-structural surface sliding rockbursts is a primary prerequisite for developing such warnings.

[0003] Microseismic monitoring technology is currently being widely used in safety monitoring projects such as mines, underground laboratories, slopes, and tunnels in many countries, achieving a series of research results. Microseismic monitoring technology uses microseismic sensors deployed in different spatial locations to capture seismic wave information emitted by rock microfractures. This information is analyzed and processed to determine the time, location, magnitude, and energy release of the microseismic event. Based on this information, the internal stress state and damage status of the rock mass can be inferred, thereby providing early warning and assessment of rock mass stability.

[0004] Rockbursts in deep drill-and-blast tunnels are complex geological hazards, and their failure mechanisms have long been a hot topic of research in both engineering and academia. Existing research primarily focuses on rockburst types, causes, prediction, and prevention. However, in-depth analysis of the failure mechanisms of strain-structure plane slip rockbursts in deep tunnels remains lacking.

[0005] Furthermore, for the potential strain-structural surface slip rockbursts, experts and scholars primarily rely on early geological survey results or previously revealed on-site geological information to predict potential rockbursts, followed by failure mechanism analysis. However, due to the limited availability of this information and the fact that on-site geological surveys may indicate that structural surface slip has not yet been revealed, timely prediction of the rockburst failure mechanism is impossible, resulting in inaccurate early warning results and delayed warning times for strain-structural surface slip rockbursts. In summary, a specific analytical method for the failure mechanism of strain-structural surface slip rockbursts has yet to be established.

[0006] Therefore, by applying microseismic monitoring technology in deep-buried drilling and blasting tunnel construction, the microseismic activity information of strain-structural surface sliding type rockbursts that have occurred is analyzed to confirm the rockburst microseismic warning area. Therefore, it is necessary to propose a set of methods to systematically analyze the failure mechanism of rock mass under complex stress conditions, which can be used to distinguish the respective roles of tension and shear in the rock mass failure process and comprehensively analyze the failure mechanism of strain-structural surface sliding type rockbursts. Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present invention provides a method for analyzing the strain-structural surface sliding type rockburst failure mechanism of deep-buried drilling and blasting tunnels; it solves the problem that strain-structural surface sliding type rockburst is difficult to warn during the excavation of deep-buried drilling and blasting tunnels. By analyzing the laws of microseismic activity and the number of structural surface occurrences, the strain-structural surface sliding type rockburst failure mechanism of deep-buried drilling and blasting tunnels is obtained, laying the foundation for the accurate prediction and forecast of deep-buried hard rock tunnel disasters.

[0008] A method for analyzing the strain-structure plane sliding type rockburst failure mechanism of a tunnel using the drilling and blasting method comprises the following steps:

[0009] Step S1: Based on engineering geological conditions, stress conditions, and external disturbance conditions, the strain-structural surface slip rockburst risk area is divided, microseismic monitoring is carried out in the rockburst risk area, and the rockburst warning area is determined;

[0010] The engineering geological conditions of the strain-structural surface slip rockburst risk zone are that the structural surface is developed, the tunnel tangential stress intersects with the structural surface horizontally or at an angle less than a set angle, the external disturbance condition is blasting dynamic disturbance, and there is a disturbance source in the strain-structural surface slip rockburst risk zone;

[0011] The rockburst warning area is determined by studying the spatial distribution of rockburst risk areas within the tunnel. The rockburst warning area includes: the distribution range of microseismic events in front of and behind the tunnel face, the distribution range of microseismic events on the left and right sides perpendicular to the tunnel axis, and the distribution range of microseismic events above and below the tunnel axis.

[0012] Step S2: Analyze the occurrence and quantity of the structural surface of the strain-structural surface sliding type rock burst that has occurred;

[0013] The structural surface attitude of strain-structural surface sliding type rockburst includes the inclination and dip of the structural surface, and the number of structural surfaces of strain-structural surface sliding type rockburst is reflected by the comprehensive index of the structural surface.

[0014] The comprehensive index is calculated according to the following formula:

[0015] L P =(L1+L2+L3+.......L N ) / A

[0016] Among them, L P Represents the comprehensive index of the structural surface, A represents the area of ​​a window, L N Represents N structural surfaces within the window.

[0017] Step S3: Collect and process the microseismic monitoring information in the rockburst warning area, including data cleaning, waveform recognition, time-based picking, and format conversion;

[0018] The microseismic monitoring information includes: spatial distribution characteristics of microseismic events, microseismic energy evolution law, cumulative energy release rate during rockburst incubation, dynamic stress drop evolution characteristics during rockburst incubation, and evolution of rock fracture types at different stages of strain-structural surface slip rockburst;

[0019] The spatial distribution characteristics of the microseismic events are obtained by collecting and processing microseismic monitoring data;

[0020] Step S4: Comprehensively analyze the occurrence and quantity of the strain-structure surface sliding type rockburst structural surface obtained in S2 and S3, and the microseismic monitoring information, to obtain the occurrence and quantity laws of the structural surface and the characteristic laws of microseismic activity, and analyze them in combination with the strain-structure surface sliding type rockburst rupture mechanism.

[0021] By extracting microseismic monitoring information, the corner frequency in the seismic moment frequency domain and the shear wave velocity parameters near the earthquake source are obtained, the dynamic stress drop is calculated, and the evolution characteristic law of the dynamic stress drop is obtained. The calculation formula is:

[0022]

[0023] Where Δσ represents the dynamic stress drop, M0 represents the seismic moment, and f c represents the corner frequency in the frequency domain, β represents the source shear wave velocity, and k represents the corner frequency f c The relationship between the earthquake source rupture radius r.

[0024] Secondary processing of microseismic monitoring information is performed to evaluate the rupture type, which is specifically obtained from the P-wave development degree. D The definition is as follows:

[0025]

[0026] Where N is the number of sensors triggered by the microseismic event; is the amplitude of the first P-wave motion recorded in the triggered i-th sensor; is the maximum amplitude of the waveform recorded in the triggered i-th sensor.

[0027] Step S5: Based on the P-wave development, combined with on-site and electron microscope scanning, the judgment criteria for the rupture type are comprehensively analyzed as follows:

[0028]

[0029] The beneficial effects of adopting the above technical solution are:

[0030] The present invention provides a method for analyzing the failure mechanism of strain-structural surface sliding-type rockburst in deep-buried drilling and blasting tunnels. The present invention solves the problem of difficulty in early warning of strain-structural surface sliding-type rockburst during the excavation of deep-buried drilling and blasting tunnels. By analyzing the laws of microseismic activity and the number of structural surface occurrences, the present invention obtains the failure mechanism of strain-structural surface sliding-type rockburst in deep-buried drilling and blasting tunnels. This method lays the foundation for the accurate prediction and forecasting of disasters in deep-buried hard rock tunnels, provides a scientific basis for early warning and prevention of strain-structural surface sliding-type rockbursts, and has important engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of the analysis method in an embodiment of the present invention;

[0032] Figure 2 A spatial distribution diagram of microseismic events in an embodiment of the present invention;

[0033] Figure (a) shows the distribution characteristics of microseismic events along the tunnel axis, and Figure (b) shows the distribution characteristics of microseismic events along the tunnel cross section.

[0034] Figure 3 is the microseismic energy evolution law in the embodiment of the present invention;

[0035] Figure (a) shows the incubation process of strain-structure surface sliding type rockburst, and Figure (b) shows the energy characteristic analysis of microseismic rockburst of strain-structure surface sliding type.

[0036] Figure 4 The dynamic stress drop evolution characteristic law in the embodiment of the present invention;

[0037] Figure 5 is the evolution law of the fracture type in the embodiment of the present invention;

[0038] Figure 6 It is the structural surface layout diagram and window in the embodiment of the present invention. DETAILED DESCRIPTION

[0039] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0040] The present invention utilizes the law of energy evolution to obtain the energy generated by shear rupture and tensile rupture during the occurrence of strain-structural surface sliding type rockburst; utilizes dynamic stress drop to determine at which stage the stress change is concentrated and the evolution of microcracks during the occurrence of strain-structural surface sliding type rockburst; through the evolution of strain-structural surface sliding type rockburst rupture type, the proportion of tension and shear and the released energy after destruction can be determined; through on-site investigation, the properties of the structural surface of the rockburst area are determined, and finally, a comprehensive analysis is conducted to determine the specific strain-structural surface sliding type rockburst failure mechanism of the deep buried drilling and blasting tunnel.

[0041] A drilling and blasting tunnel strain-structure surface sliding type rockburst failure mechanism analysis method, such as Figure 1 As shown, the following steps are included:

[0042] Step S1: Based on engineering geological conditions, stress conditions, and external disturbance conditions, the strain-structural surface slip rockburst risk area is divided, microseismic monitoring is carried out in the rockburst risk area, and the rockburst warning area is determined;

[0043] The engineering geological conditions of the strain-structural surface slip rockburst risk zone are that the structural surface is developed, the tunnel tangential stress intersects with the structural surface horizontally or at an angle less than a set angle, the external disturbance condition is blasting dynamic disturbance, and there is a disturbance source in the strain-structural surface slip rockburst risk zone;

[0044] The rockburst warning area is determined by studying the spatial distribution of rockburst risk areas within the tunnel. The rockburst warning area includes: the distribution range of microseismic events in front of and behind the tunnel face, the distribution range of microseismic events on the left and right sides perpendicular to the tunnel axis, and the distribution range of microseismic events above and below the tunnel axis.

[0045] In this embodiment, strain-structural surface slip rockburst risk zones are divided based on engineering geological conditions, on-site stress conditions, and external disturbance conditions. Microseismic monitoring is carried out in rockburst risk zones. The monitoring area is determined by studying the spatial distribution of rockburst and microseismic activity within the tunnel. Generally, an early warning unit is defined as the area 15 m in front of the tunnel face and 20 m away from the tunnel face.

[0046] Step S2: Analyze the occurrence and quantity of the structural surface of the strain-structural surface sliding type rock burst that has occurred;

[0047] The structural surface attitude of strain-structural surface sliding type rockburst includes the inclination and dip of the structural surface, and the number of structural surfaces of strain-structural surface sliding type rockburst is reflected by the comprehensive index of the structural surface.

[0048] In this embodiment, microseismic information in the warning area is selected, such as when a strain-structure surface slip rock burst occurs, and microseismic information analysis is performed to obtain spatial distribution characteristics of microseismic events.

[0049] The comprehensive index is calculated according to the following formula:

[0050] L P =(L1+L2+L3+.......L N ) / A

[0051] Among them, L P Represents the comprehensive index of the structural surface, A represents the area of ​​a window, L N Represents N structural surfaces within the window.

[0052] Step S3: Collect and process the microseismic monitoring information in the rockburst warning area, including data cleaning, waveform recognition, time picking, and format conversion, to ensure the accuracy and availability of the data.

[0053] The microseismic monitoring information includes: spatial distribution characteristics of microseismic events, microseismic energy evolution law, cumulative energy release rate during rockburst incubation, dynamic stress drop evolution characteristics during rockburst incubation, and evolution of rock fracture types at different stages of strain-structural surface slip rockburst;

[0054] The spatial distribution characteristics of the microseismic events are obtained by collecting and processing microseismic monitoring data;

[0055] By processing and analyzing microseismic information, the collected data is processed, including data cleaning, waveform recognition, arrival time picking, format conversion, etc., to obtain the spatial distribution characteristics of microseismic events, such as Figure 3 shown.

[0056] Step S4: Comprehensively analyze the occurrence and quantity of the strain-structure surface sliding type rockburst structural surface obtained in S2 and S3, and the microseismic monitoring information, to obtain the occurrence and quantity laws of the structural surface and the characteristic laws of microseismic activity, and analyze them in combination with the strain-structure surface sliding type rockburst rupture mechanism.

[0057] By extracting microseismic monitoring information, the corner frequency in the seismic moment frequency domain and the shear wave velocity parameters near the earthquake source are obtained, the dynamic stress drop is calculated, and the evolution characteristic law of the dynamic stress drop is obtained. The calculation formula is:

[0058]

[0059] Where Δσ represents the dynamic stress drop, M0 represents the seismic moment, and f c represents the corner frequency in the frequency domain, β represents the source shear wave velocity, and k represents the correlation of the corner frequency f depending on the type of model used. c The relationship between the earthquake source rupture radius r.

[0060] Secondary processing of microseismic monitoring information is performed to evaluate the rupture type, which is specifically obtained from the P-wave development degree. D The definition is as follows:

[0061]

[0062] Where N is the number of sensors triggered by the microseismic event; is the amplitude of the first P-wave motion recorded in the triggered i-th sensor; is the maximum amplitude of the waveform recorded in the triggered i-th sensor.

[0063] Step S5: Based on the P-wave development, combined with on-site and electron microscope scanning, the judgment criteria for the rupture type are comprehensively analyzed as follows:

[0064]

[0065] Example 1 is as follows:

[0066] Figure 1 A flow chart of a method for analyzing the failure mechanism of strain-structural surface sliding-type rockburst in a deep-buried tunnel using the drilling and blasting method is provided in an embodiment of the present invention. In the present invention, a strain-structural surface sliding-type rockburst risk area is first divided, and microseismic monitoring is carried out in the rockburst risk area to establish a strain-structural surface sliding-type rockburst early warning area. Microseismic monitoring information in the early warning area during the incubation process of the strain-structural surface sliding-type rockburst is obtained and analyzed.

[0067] Based on the strain-structure surface slip-type rockburst microseismic monitoring information obtained in the rockburst warning area, the spatial distribution characteristics of microseismic events were obtained, the energy evolution law was obtained, and the dynamic stress drop Δσ and the P-wave development degree of each rupture event were calculated. A P-wave development degree greater than or equal to 0.047 indicates tensile failure, and a P-wave development degree less than 0.047 indicates shear failure.

[0068] Then, the occurrence of the structural surface in the rockburst area and the comprehensive evaluation index of the structural surface are statistically analyzed, and the strain-structural surface sliding type rockburst failure mechanism of the specific deep buried drilling and blasting tunnel is determined by comprehensive analysis.

[0069] The method for analyzing the strain-structure plane slip rockburst failure mechanism of deep drilling and blasting tunnels includes the following steps:

[0070] During the excavation of this project, a total of 36 strain-structure surface slip rockbursts occurred. Based on the 36 strain-structure surface slip rockburst cases, the strain-structure surface slip rockburst warning area was determined. The following selects one typical strain-structure surface slip rockburst for analysis:

[0071] Based on the microseismic information of a strain-structure surface sliding rockburst warning area in a deep-buried drilling and blasting tunnel, the spatial distribution characteristics of microseismic events are obtained. Figure 2As shown, Figure (a) shows the distribution characteristics of microseismic events along the tunnel axis, and Figure (b) shows the distribution characteristics of microseismic events along the tunnel cross section; the microseismic monitoring data of steps S3, S4, and S5 are processed;

[0072] First, the energy evolution law of the strain-structure surface sliding type rock burst incubation process is obtained by processing the microseismic information, such as Figure 3 As shown in Figure (a), the incubation process of strain-structural surface sliding type rockburst, and Figure (b) the analysis of microseismic energy characteristics of strain-structural surface sliding type rockburst; it is worth noting that the microseismic energy released is large when the rockburst occurs, and the number of microseismic events continues to increase. The microseismic energy of 36 strain-structural surface sliding type rockburst cases is integrated. The strain-structural surface sliding type rockburst usually produces a large number of events at the 60% and 90% positions in the incubation process, and also produces large energy events. This is a significant feature and signal of microseismic information in the incubation process of strain-structural surface sliding type rockburst.

[0073] Then, the processed and analyzed microseismic information is extracted to obtain characteristic parameters such as the corner frequency in the earthquake moment frequency domain and the shear wave velocity near the earthquake source. The dynamic stress drop Δσ is calculated to obtain the dynamic stress drop evolution characteristics of the strain-structure surface slip rockburst incubation and occurrence process, such as Figure 4 As shown in the figure, the maximum dynamic stress drop during the rockburst generation phase is 0.15 MPa. This relatively high dynamic stress drop value indicates that the energy accumulated in the rock mass has not yet been fully released. The dynamic stress drop during the strain-structural plane slip rockburst generation phase is higher than that during the incubation phase. During the strain-structural plane slip rockburst generation phase, the dynamic stress drop is concentrated closer to the structural plane or distributed on the structural plane.

[0074] The microseismic information is processed secondary to obtain the P-wave development degree and visualize the data to evaluate the evolution of microcracks in the destruction process, and to obtain the proportion of tension and shear action and the evolution law of rupture type, such as Figure 5 As shown in the figure. Rock failure events in the early stages of a rockburst are primarily tensile, with generally low microseismic energy. In the middle and late stages of a rockburst, shear failure events increase in energy and are relatively high. During the rockburst development phase, shear and tensile failure events alternate in a similar ratio, with shear failure events exhibiting relatively high microseismic energy. Furthermore, high-energy, low-volume shear failure events also occurred during the development phase of a strain-slip rockburst, indicating that a certain amount of slip and dislocation occurred before a strain-slip rockburst, with these shear failure events distributed near or on the structural plane.

[0075] Finally, the structural surface information of the strain-structural surface sliding rockburst area, including the dip and inclination, is obtained and the windows are divided, such as Figure 6 As shown in Table 1, the statistical calculation results show that the comprehensive index L of the structural surface near the rock burst area is P ;

[0076] Table 1. Structural surface occurrence and comprehensive evaluation indicators in rockburst areas

[0077]

[0078]

[0079] During the subsequent excavation of this project, rock burst microseismic monitoring will be carried out in the rock burst area to obtain microseismic monitoring information in the warning area, and the spatial distribution characteristics of microseismic events, the microseismic time series of the strain-structural surface sliding type rock burst incubation process, the dynamic stress drop evolution characteristics and the fracture type evolution law during the strain-structural surface sliding type rock burst incubation and occurrence process will be obtained. Finally, through on-site investigation, information on the structural surface near the rock burst area will be obtained.

[0080] The energy evolution law can be used to obtain the energy generated by shear fracture and tensile fracture during the occurrence of strain-structural surface sliding type rockburst; the dynamic stress drop can be used to obtain the stage at which the stress change is concentrated and the evolution of microcracks when the strain-structural surface sliding type rockburst occurs; the evolution of the strain-structural surface sliding type rockburst rupture type can determine the proportion of tension and shear and the released energy after the destruction; through on-site investigation, the properties of the structural surface of the rockburst area can be determined, and finally a comprehensive analysis is conducted to determine the specific strain-structural surface sliding type rockburst failure mechanism of the deep buried drilling and blasting tunnel. The present invention provides a practical and feasible innovative idea for revealing the strain-structural surface sliding type rockburst failure mechanism of the deep buried drilling and blasting tunnel.

[0081] The above description is merely a preferred embodiment of the present disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also encompass other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the above-mentioned inventive concept. For example, a technical solution formed by mutually replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in the embodiments of the present disclosure.

Claims

1. A method for analyzing the strain-structure surface sliding type rockburst failure mechanism of a tunnel using the drilling and blasting method, characterized in that: The following steps are involved: Step S1: Based on engineering geological conditions, stress conditions, and external disturbance conditions, the strain-structural surface slip rockburst risk area is divided, microseismic monitoring is carried out in the rockburst risk area, and the rockburst warning area is determined; Step S2: Analyze the occurrence and quantity of the structural surface of the strain-structural surface sliding type rock burst that has occurred; Step S3: Collect and process the microseismic monitoring information in the rockburst warning area, including data cleaning, waveform recognition, time-based picking, and format conversion; Step S4: Comprehensively analyze the occurrence and quantity of the strain-structure surface slip rockburst structural surface obtained in S2 and S3, and the microseismic monitoring information, to obtain the regularity of the occurrence and quantity of the structural surface and the characteristic regularity of the microseismic activity, and analyze the rupture mechanism of the strain-structure surface slip rockburst; Step S5: Based on the P-wave development, combined with on-site and electron microscope scanning, the rupture type is comprehensively analyzed; The engineering geological conditions of the strain-structural surface slip type rockburst risk zone in step S1 are that the structural surface is developed, the tunnel tangential stress intersects the structural surface horizontally or at an angle less than a set angle, the external disturbance condition is blasting dynamic disturbance, and there is a disturbance source in the strain-structural surface slip type rockburst risk zone; The rockburst warning area in step S1 is determined by studying the spatial distribution of rockburst risk areas in the tunnel. The rockburst warning area includes: the distribution range of microseismic events in front of and behind the tunnel face, the distribution range of microseismic events on the left and right sides perpendicular to the tunnel axis, and the distribution range of microseismic events above and below the tunnel axis. Step S2 is specifically as follows: The structural surface occurrence of strain-structural surface sliding type rockburst includes the reflection of the structural surface's inclination and dip angle, and the number of structural surfaces of strain-structural surface sliding type rockburst is reflected by the comprehensive index of the structural surface. The comprehensive index is calculated according to the following formula: <h2 style=";text-align:left;direction:ltr">L<h2 style=";text-align:left;direction:ltr"> P <h2 style=";text-align:left;direction:ltr"> (L1+L2+L3+.......L)<h2 style=";text-align:left;direction:ltr"> N <h2 style=";text-align:left;direction:ltr"> ) / A Among them, L P Represents the comprehensive index of the structural surface, A represents the area of ​​a window, L N Represents N structural surfaces within the window; The microseismic monitoring information in step S3 includes: spatial distribution characteristics of microseismic events, microseismic energy evolution law, cumulative energy release rate during rockburst incubation, dynamic stress drop evolution characteristics during rockburst incubation, and rock fracture type evolution at different stages of strain-structural surface slip rockburst; wherein the spatial distribution characteristics of microseismic events are obtained based on the collection and processing of microseismic monitoring data; The step S4 is specifically as follows: By extracting microseismic monitoring information, the corner frequency in the seismic moment frequency domain and the shear wave velocity parameters near the earthquake source are obtained, the dynamic stress drop is calculated, and the evolution characteristic law of the dynamic stress drop is obtained. The calculation formula is: Where Δσ represents the dynamic stress drop, M0 represents the seismic moment, and f c represents the corner frequency in the frequency domain, β represents the source shear wave velocity, and k represents the corner frequency f c and the relationship between the earthquake source rupture radius r; Secondary processing of microseismic monitoring information is performed to evaluate the rupture type, which is specifically obtained from the P-wave development degree. D The definition is as follows: Where N is the number of sensors triggered by the microseismic event; is the amplitude of the first P-wave motion recorded in the triggered i-th sensor; is the maximum amplitude of the waveform recorded in the triggered i-th sensor; The criteria for judging the rupture type in step S5 are as follows:

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