Rock mass property rapid evaluation method, equipment and system

Abstract

The invention relates to the technical field of rock mass property evaluation, in particular to a rock mass property rapid evaluation method, device and system, and the method comprises the steps: obtaining ultrasonic propagation data of a target rock mass in a plurality of measurement directions, based on the wave velocity difference of each depth position in different measurement directions and the wave velocity difference of each measurement direction at different depth positions under each frequency, determining refraction characteristics of the target rock mass at each depth position in each measurement direction; determining a refraction correction coefficient of the corresponding position based on the refraction characteristic; correcting the measurement wave velocity of each depth position based on the refraction correction coefficient to obtain a corrected equivalent wave velocity of each depth position; and evaluating the rock mass property of the target rock mass based on the corrected equivalent wave velocity of each depth position. According to the method, the real equivalent wave velocity of each depth position can be obtained, and then the rock mass property of the target rock mass can be accurately evaluated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rock mass property evaluation, and particularly relates to a rock mass property rapid evaluation method, device and system. BACKGROUND

[0002] In the related art, a transducer can be arranged on the surface of a rock mass or in a borehole, a high-frequency ultrasonic wave pulse is sent to the rock mass, the propagation time of the wave in the rock mass is measured, the wave velocity is calculated, and the integrity, density and mechanical parameters of the rock mass are calculated according to the wave velocity, so that the rock mass property is rapidly evaluated.

[0003] However, in the above method, the structures of different rock layers in the rock mass are significantly different, the ultrasonic wave is easy to be circumferentially refracted during propagation, the wave velocity obtained based on the propagation time of the ultrasonic wave in the rock mass can be inaccurate, and the result of evaluating the rock mass property based on the wave velocity is also inaccurate. SUMMARY

[0004] In order to solve the technical problem that the wave velocity obtained based on the propagation time of the ultrasonic wave in the rock mass can be inaccurate, and the result of evaluating the rock mass property based on the wave velocity is also inaccurate, the purpose of the present application is to provide a rock mass property rapid evaluation method, device and system, and the technical solution is as follows: The embodiment of the present application provides a rock mass property rapid evaluation method, which comprises the following steps: obtaining ultrasonic wave propagation data of a target rock mass in multiple measurement directions, the ultrasonic wave propagation data in one measurement direction comprising wave velocities at multiple frequency positions in multiple depths; determining refraction characteristics of each depth position in each measurement direction of the target rock mass based on wave velocity differences of each depth position in different measurement directions and wave velocity differences of each measurement direction at each frequency in different depth positions; determining refraction correction coefficients of each depth position in each measurement direction based on the refraction characteristics of each depth position in each measurement direction of the target rock mass; correcting the measured wave velocities of each depth position based on the refraction correction coefficients of each depth position in different measurement directions, to obtain corrected equivalent wave velocities of the each depth position; and evaluating the rock mass property of the target rock mass based on the corrected equivalent wave velocities of the each depth position.

[0005] Optionally, the multiple measurement directions comprise a first measurement direction, the multiple depth positions comprise a first depth position, and the determining the refraction feature of the target rock mass at the first depth position in the first measurement direction based on the wave velocity difference of the first depth position in different measurement directions and the wave velocity difference of the first measurement direction in different depth positions at each frequency comprises: determining a first anisotropy based on the wave velocity difference of the first depth position in different measurement directions, determining a first propagation refraction based on the wave velocity difference of the first measurement direction in different depth positions at each frequency, and determining a first refraction feature based on the first anisotropy and the first propagation refraction.

[0006] wherein the first anisotropy is an anisotropy of the first depth position in the first measurement direction, the first propagation refraction is a propagation refraction of the first depth position in the first measurement direction, and the first refraction feature is the refraction feature of the target rock mass at the first depth position in the first measurement direction.

[0007] Optionally, the determining the first anisotropy based on the wave velocity difference of the first depth position in different measurement directions comprises: determining a global wave velocity range of the first depth position and a neighborhood wave velocity range of the first depth position based on the wave velocity difference of the first depth position in different measurement directions, the global wave velocity range of the first depth position being a global wave velocity range of the first depth position in all measurement directions, the neighborhood wave velocity range of the first depth position being a neighborhood wave velocity range of the first depth position in a neighborhood range of the first measurement direction, the neighborhood range of the first measurement direction comprising the first measurement direction and a neighboring measurement direction of the first measurement direction; and determining the first anisotropy as a ratio of the neighborhood wave velocity range of the first depth position to the global wave velocity range of the first depth position.

[0008] Optionally, the determining the first propagation refraction based on the wave velocity difference of the first measurement direction in different depth positions at each frequency comprises: determining a wave velocity fluctuation of the first depth position in the first measurement direction at each frequency based on a wave velocity mean of a neighboring depth position of the first depth position in the first measurement direction at each frequency and a wave velocity range of the neighboring depth position of the first depth position in the first measurement direction at each frequency; and determining the first propagation refraction based on the wave velocity fluctuation of the first depth position in the first measurement direction at each frequency and a frequency sequence of the first measurement direction in the first depth position.

[0009] Optionally, the determining the first propagation refraction property based on the wave velocity fluctuation of the first depth position at each frequency in the first measurement direction and the frequency sequence of the first measurement direction at the first depth position comprises: determining a full-frequency wave velocity fluctuation mean of the first depth position in the first measurement direction based on the wave velocity fluctuation of the first depth position at each frequency in the first measurement direction; determining a frequency wave velocity correlation of the first depth position in the first measurement direction, the frequency wave velocity correlation being a correlation of the wave velocity fluctuation sequence of the first depth position at all frequencies in the first measurement direction and the frequency sequence of the first measurement direction at the first depth position; and determining the first propagation refraction property based on the full-frequency wave velocity fluctuation mean and the frequency wave velocity correlation.

[0010] Optionally, the determining the first refraction feature based on the first anisotropy and the first propagation refraction property comprises: determining a maximum propagation refraction property and a minimum propagation refraction property of the first depth position in a neighborhood range of the first measurement direction; determining a first structural complexity of the first depth position in the first measurement direction based on the maximum propagation refraction property, the minimum propagation refraction property, and the first propagation refraction property; and determining the first refraction feature based on the first anisotropy and the first structural complexity.

[0011] Optionally, the determining the refraction correction coefficient of the first depth position in the first measurement direction based on the first refraction feature comprises: determining a product of the first refraction feature and the first propagation refraction property as the refraction correction coefficient of the first depth position in the first measurement direction.

[0012] Optionally, the correcting the measured wave velocity of the first depth position based on the refraction correction coefficient of the first depth position in each measurement direction to obtain a corrected equivalent wave velocity of the first depth position comprises: determining an inverse of the refraction correction coefficient of the first depth position in each measurement direction as a weight of the first depth position in each measurement direction; and determining the corrected equivalent wave velocity of the first depth position in each measurement direction based on the weight of the first depth position in each measurement direction and the measured wave velocity of the first depth position in each measurement direction.

[0013] Embodiments of the present application provide a rock mass property rapid evaluation device, which comprises a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements any one of the rock mass property rapid evaluation methods described above when executing the computer program.

[0014] The application further provides a rock mass property rapid evaluation system, which comprises a data acquisition module, a refraction characteristic determination module, a refraction correction coefficient determination module, a wave velocity correction module and an evaluation module; the data acquisition module is configured to acquire ultrasonic wave propagation data of a target rock mass in multiple measurement directions, wherein the ultrasonic wave propagation data in one measurement direction comprises wave velocities at multiple frequencies at multiple depth positions; the refraction characteristic determination module is configured to determine a refraction characteristic of each depth position in each measurement direction of the target rock mass based on wave velocity differences of each depth position in different measurement directions and wave velocity differences of each measurement direction at each frequency at different depth positions; the refraction correction coefficient determination module is configured to determine a refraction correction coefficient of each depth position in each measurement direction based on the refraction characteristic of each depth position in each measurement direction of the target rock mass; the wave velocity correction module is configured to correct the measured wave velocity of each depth position based on the refraction correction coefficient of each depth position in different measurement directions, so as to obtain a corrected equivalent wave velocity of each depth position; and the evaluation module is configured to evaluate the rock mass property of the target rock mass based on the corrected equivalent wave velocity of each depth position.

[0015] The application has the following beneficial effects: In the embodiments of the application, the ultrasonic wave propagation data in multiple measurement directions, multiple depth positions and multiple frequencies are acquired, so that the comprehensiveness of the collected data is ensured. Then, the refraction differences of the same depth position in different measurement directions are identified by analyzing the wave velocity differences, the refraction effect layer distribution characteristics caused by different rock layer interfaces are identified by analyzing the wave velocity differences of the same measurement direction at different depth positions, and both macroscopic structures and microscopic defects are reflected by analyzing the wave velocity differences of the same depth position at different frequencies, so that the refraction characteristics of each depth position in each measurement direction are accurately and comprehensively analyzed. Further, the refraction correction coefficients of each depth position in each measurement direction are determined based on the refraction characteristics of each depth position in each measurement direction of the target rock mass, and the measured wave velocity of each depth position is corrected based on the refraction correction coefficients of each depth position in different measurement directions, so that the anisotropic deviation caused by circumferential refraction is eliminated, the real equivalent wave velocity of each depth position is obtained, and the rock mass property of the target rock mass is accurately evaluated based on the corrected equivalent wave velocity of each depth position. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, and the advantages thereof, a brief introduction will be given to the drawings needed in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can be obtained without creative effort.

[0017] Figure 1 A method flow chart of a rock mass property rapid evaluation method provided by one embodiment of the present application; Figure 2 A method flow chart of another rock mass property rapid evaluation method provided by one embodiment of the present application; Figure 3 A structural diagram of a rock mass property rapid evaluation device provided by one embodiment of the present application; Figure 4 A structural diagram of a rock mass property rapid evaluation system provided by one embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined purposes, the specific embodiments, structures, features and effects of a rock mass property rapid evaluation method, device and system according to the present application are described in detail as follows in combination with the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0020] Rock mass property is an important basic parameter for underground engineering design, construction and safety evaluation, and directly affects the stability of tunnels, mines, slopes and hydropower projects. In actual engineering, due to the narrow space of the excavation surface and the tight construction period, a high-efficiency, low-disturbance, real-time key index evaluation method is needed, which can quickly reflect the rock mass structure characteristics and also consider accuracy to meet the needs of dynamic design and construction control. Ultrasonic method is a commonly used non-destructive testing method for rock mass property, which can send high-frequency ultrasonic pulses to the rock mass by arranging transducers on the surface of the rock mass or in the borehole, measure the propagation time of the wave in the rock mass, calculate the wave velocity, and then calculate the integrity, density and mechanical parameters of the rock mass, and realize the rapid evaluation of rock mass property.

[0021] In the prior art, the elastic modulus and wave velocity of different rock layers of the rock mass are significantly different, and ultrasonic waves are prone to circumferential refraction during propagation, causing the wave velocity distribution to exhibit obvious anisotropy. If the traditional method based on a single direction wave velocity or a simple average is still used for integrity and strength evaluation, the result will deviate, such as the wave velocity measured along the hard rock direction being too high, and the wave velocity measured along the soft rock direction being too low, which hides the heterogeneity of the rock mass and the risk of potential weak plane, not only affecting the accurate judgment of the properties of the rock mass, but also possibly leading to safety hazards in the design and construction links. Therefore, the present application collects the ultrasonic wave propagation data of the rock mass through multiple measurements, analyzes the ultrasonic wave refraction characteristics of different directions of the rock mass, identifies and corrects the measurement deviation caused by the circumferential refraction of the ultrasonic wave due to the structure of the rock mass, and improves the accuracy of rapid evaluation of the properties of the rock mass.

[0022] The specific schemes of the rock mass property rapid evaluation method, device and system provided by the present application will be specifically described below in combination with the drawings.

[0023] Please refer to Figure 1 , which shows a method flowchart of a rock mass property rapid evaluation method provided by an embodiment of the present application.

[0024] As Figure 1 indicated, the rock mass property rapid evaluation method includes S101-S105.

[0025] S101, acquiring ultrasonic wave propagation data of a target rock mass in multiple measurement directions.

[0026] The ultrasonic wave propagation data in one measurement direction includes wave velocities at multiple frequencies at multiple depth positions.

[0027] In an optional implementation, a plurality of transmitting points and receiving points can be arranged on the surface of the target rock mass to form a measurement grid covering different directions and paths, and then a plurality of measurement directions are determined based on the plurality of transmitting points and the plurality of receiving points, and ultrasonic wave signals of multiple frequencies are transmitted in each measurement direction.

[0028] Optionally, the plurality of frequencies includes low frequency, medium frequency and high frequency.

[0029] It should be understood that low-frequency ultrasonic waves can penetrate deeper rock layers and reflect overall structural characteristics, while high-frequency ultrasonic waves are more sensitive to fine cracks and bedding interfaces, thereby revealing microscopic defects inside the rock mass. Obtaining ultrasonic wave signals of multiple frequencies for analysis can avoid the problem of uneven response of a single frequency to the internal structure of the rock mass.

[0030] It can be understood that determining a plurality of measurement directions based on a plurality of transmitting points and a plurality of receiving points can achieve full-coverage scanning in multiple directions and multiple frequencies, and can determine that the collected data is fully representative.

[0031] It should be understood that the depth position in one measurement direction is a different depth level or point along the measurement direction inside the target rock mass.

[0032] Optionally, the arrival time and waveform variation of the ultrasonic signal of each frequency are recorded at the receiving point, and by analyzing the response difference of the ultrasonic wave under different propagation times and different frequencies, the wave speed at multiple depth positions in each measurement direction can be obtained.

[0033] S102, based on the wave speed difference of each depth position in different measurement directions, and the wave speed difference of each measurement direction at each frequency at different depth positions, the refraction characteristics of the target rock mass at each depth position in each measurement direction are determined.

[0034] It should be understood that the soft and hard interbedding, joint or fracture interface in the rock mass will cause refraction of the ultrasonic wave during propagation, so that the wave speed in certain directions is significantly higher or lower, thereby producing obvious directional difference. Therefore, by analyzing the wave speed difference of each depth position in different measurement directions, the strength and spatial distribution of the refraction effect can be quantified, and the area of velocity anomaly or wave speed deviation caused by bedding or structural interface can be identified.

[0035] It can be understood that the inhomogeneity and potential weak plane of the rock mass will generally cause local fluctuations in wave speed at adjacent depths, and therefore, by analyzing the wave speed difference of each measurement direction at different depth positions, the discontinuity or local anomaly of the internal structure of the target rock mass can be quantified.

[0036] It should be understood that the refraction characteristics of a depth position are used to characterize the refraction effect caused by the rock mass structure at the depth position, and when the refraction characteristics of the depth position are higher, the wave speed measured at the depth position is less reliable.

[0037] S103, based on the refraction characteristics of the target rock mass at each depth position in each measurement direction, a refraction correction coefficient of each depth position in each measurement direction is determined.

[0038] It should be understood that the refraction correction coefficient of a depth position in a measurement direction is used to correct the refraction degree of the depth position in the measurement direction, including the wave speed deviation caused by refraction.

[0039] In an optional implementation, the refraction characteristics of each depth position in each measurement direction can be determined as the refraction correction coefficient of each depth position in each measurement direction.

[0040] S104, based on the refraction correction coefficient of each depth position in different measurement directions, the measured wave speed of each depth position is corrected to obtain the corrected equivalent wave speed of each depth position.

[0041] It should be understood that the corrected equivalent wave velocity is closer to the real wave velocity based on the refraction correction coefficient for correcting the measured wave velocity.

[0042] It can be understood that the refraction correction coefficients at different depth positions in different measurement directions are different, and the wave velocity in each direction is corrected by weighting based on the refraction correction coefficient. When the refraction correction coefficient is larger, it indicates that the refraction at the depth position in the measurement direction has a greater impact, and the measured wave velocity needs to occupy a smaller weight. Based on the weighting correction method, the abnormality caused by local refraction can be eliminated, and the equivalent wave velocity closer to the real mechanical properties of the rock mass can be obtained.

[0043] In an optional implementation, the plurality of depth positions include a first depth position. Taking the first depth position as an example, the reciprocal of the refraction correction coefficient of the first depth position in each measurement direction can be determined as the weight of the first depth position in each measurement direction. Then, based on the weight of the first depth position in each measurement direction and the measured wave velocity of the first depth position in each measurement direction, the corrected equivalent wave velocity of the first depth position in each measurement direction is determined.

[0044] It can be understood that the reciprocal of the refraction correction coefficient in a measurement direction is determined as the weight of the measurement direction, so that the larger the refraction correction coefficient is, the smaller the weight of the measured wave velocity in the measurement direction is.

[0045] Optionally, the equivalent wave velocity of a depth position satisfies the following formula: wherein, denotes the equivalent wave velocity of the depth position of the target rock mass, denotes the refraction correction coefficient of the depth position of the target rock mass in the i-th measurement direction, denotes the measured wave velocity of the depth position of the target rock mass in the i-th measurement direction, denotes the number of measurement directions.

[0046] S105, based on the corrected equivalent wave velocity of each depth position, evaluating the rock mass properties of the target rock mass.

[0047] It should be understood that since the corrected equivalent wave velocity is closer to the real wave velocity, the evaluation of the rock mass properties of the target rock mass based on the equivalent wave velocity is more accurate.

[0048] It can be understood that if the corrected equivalent wave velocity changes smoothly at different depth positions, it indicates that the target rock mass has uniform structure and good integrity. ​​​​​

[0049] In an optional implementation, the bulk modulus and the elastic modulus of the target rock mass can be obtained by the rock mass density of the target rock mass and the corrected equivalent wave velocity at different depth positions, and since the bulk modulus and the elastic modulus can reflect the overall stiffness and bearing capacity of the rock mass, the bulk modulus and the elastic modulus can be converted into the compressive strength and the shear strength by the rock mass engineering criterion, so as to evaluate the rock mass properties of the target rock mass according to the compressive strength and the shear strength.

[0050] Optionally, the rock mass engineering criterion can be the Hoek-Brown strength criterion, the international standard for results management (ISRM).

[0051] In another optional implementation, the heterogeneity and the potential weak plane distribution of the rock mass can also be evaluated by using the spatial continuity of the corrected equivalent wave velocity and the local wave velocity fluctuation, and the positions with large wave velocity mutations or large differences usually correspond to the joint dense area or the fracture zone, and the rock mass integrity score or the rock mass rating (RMR) can be generated by statistical analysis.

[0052] Optionally, the strength index, the integrity score parameter and the like can be comprehensively statistically processed to form a rock mass property rapid evaluation model at each depth position.

[0053] Optionally, a numerical method (such as a normalized score, a weighted average or a multi-parameter threshold judgment) can also be used to generate an intuitive rock mass property profile or three-dimensional distribution diagram, so as to facilitate the engineering design, the support scheme optimization and the construction safety evaluation.

[0054] In this embodiment, by acquiring ultrasonic propagation data from multiple measurement directions, multiple depth locations, and multiple frequencies, the comprehensiveness of the collected data is ensured. Then, by analyzing the wave velocity differences at the same depth location in different measurement directions, the refraction differences at that depth location in different directions can be identified. By analyzing the wave velocity differences at different depth locations in the same measurement direction, the stratified distribution characteristics of the refraction effect caused by different rock layer interfaces can be identified. By analyzing the wave velocity differences at different frequencies in the same depth and direction, both macroscopic structures and microscopic defects can be reflected, accurately and comprehensively analyzing the refraction characteristics at each depth location in each measurement direction. Furthermore, based on the refraction characteristics of the target rock mass at each depth location in each measurement direction, the refraction correction coefficient for each depth location in each measurement direction is determined, and the measured wave velocity at each depth location is corrected based on the refraction correction coefficient for each depth location in different measurement directions. This eliminates the anisotropic deviation caused by circumferential refraction and can reflect the true equivalent wave velocity at each depth location. Based on the corrected equivalent wave velocity at each depth location, the rock mass properties of the target rock mass can be accurately assessed.

[0055] Combination Figure 1 ,like Figure 2 As shown, in one implementation of this application embodiment, multiple measurement directions include a first measurement direction, and multiple depth positions include a first depth position. Taking the determination of the refraction characteristics of the first depth position in the first measurement direction as an example, the refraction characteristics of the target rock mass at the first depth position in the first measurement direction are determined based on the wave velocity difference of the first depth position in different measurement directions and the wave velocity difference at each frequency at different depth positions in the first measurement direction. Specifically, this includes S201-S203.

[0056] S201. Based on the wave velocity difference at the first depth position in different measurement directions, determine the first anisotropy.

[0057] Wherein, the first anisotropy is the anisotropy of the first depth position in the first measurement direction.

[0058] It should be understood that the anisotropy of a depth location in a measurement direction characterizes the different manifestations of that location in different directions and can reflect the structural inhomogeneity of the rock mass at that depth location.

[0059] It should be understood that the interlayering of hard and soft rock, joints, and fissures in the rock mass can cause differences in the velocity of ultrasonic waves as they propagate in different directions. When the difference between the maximum and minimum wave velocities in different directions at a certain depth is large, i.e., the wave velocity range is large, it indicates that a refraction effect may have occurred. It is difficult to accurately reflect the true anisotropy by relying solely on data from a single point or a single direction. Therefore, it is possible to compare the wave velocity changes in various directions within the neighborhood of the measurement direction. When the wave velocity change in the neighborhood of that direction is large, and the wave velocity range in all directions is still large, it indicates that the anisotropy at that location in that direction is large.

[0060] In one alternative implementation, the global wave velocity range and the neighborhood wave velocity range of the first depth position can be determined based on the wave velocity differences of the first depth position in different measurement directions, and then the ratio of the neighborhood wave velocity range of the first depth position to the global wave velocity range of the first depth position is determined as the first anisotropy.

[0061] Wherein, the global wave velocity range of the first depth position is the global wave velocity range of the first depth position in all measurement directions, and the neighborhood wave velocity range of the first depth position is the neighborhood wave velocity range of the first depth position in the neighborhood range of the first measurement direction. The neighborhood range of the first measurement direction includes the first measurement direction and the adjacent measurement directions of the first measurement direction.

[0062] Optionally, the anisotropy at a depth location in a measurement direction satisfies the following formula: in, The first [unit] representing the target rock mass The depth position is in the measurement direction. Anisotropy on Indicates the first The depth position is in the measurement direction. The maximum wave velocity in the neighborhood of . Indicates the first The depth position is in the measurement direction. The minimum wave velocity within the neighborhood of . Indicates the first The maximum wave velocity at a depth location in all measurement directions. Indicates the first The minimum wave velocity at a depth location in all measurement directions. Indicates the first The neighborhood wave velocity difference at a certain depth Indicates the first The global wave velocity difference at a depth of 1.

[0063] Based on the above formula, it should be understood that when the first... This measurement direction is at a depth position. When the neighborhood wave velocity range is larger than the global wave velocity range, it indicates that the... The depth position is in the measurement direction. The amplitude of the wave velocity fluctuation in the vicinity is greater than the overall fluctuation amplitude. The depth position is in the measurement direction. The greater the anisotropy on the surface, the greater the anisotropy.

[0064] S202. Based on the difference in wave velocity at each frequency at different depth positions in the first measurement direction, determine the first propagation refractive property.

[0065] Wherein, the first propagation refractive property is the propagation refractive property at the first depth position in the first measurement direction.

[0066] It should be understood that the homogeneity and potential weaknesses of rock masses often cause local fluctuations in wave velocity at adjacent depths. When the wave velocity variation at a certain depth is large, and the difference in wave velocity before and after that depth is also large, it indicates that this depth may be a soft-hard interlayer interface in the rock mass structure. Since different frequencies of ultrasound have varying sensitivities to the internal structure of rock masses, low-frequency waves reflect overall structural characteristics, while high-frequency waves are more sensitive to local fractures or soft-hard interfaces. Therefore, differences in wave velocity at multiple frequencies can reveal the strength and spatial distribution of refraction effects. Because high-frequency waves are more sensitive to changes in rock mass structure, depths with large fluctuations in wave velocity within the rock mass may have experienced propagation and refraction effects.

[0067] In one alternative implementation, the wave velocity fluctuation of the first depth position at each frequency in the first measurement direction is determined based on the average wave velocity of adjacent depth positions at each frequency in the first measurement direction and the wave velocity range of adjacent depth positions at each frequency in the first measurement direction; then, the first propagation refractive property is determined based on the wave velocity fluctuation of the first depth position at each frequency in the first measurement direction and the frequency sequence of the first depth position in the first measurement direction.

[0068] It should be understood that the wave velocity fluctuation at a depth location is used to characterize the wave velocity variation at that depth location, and the adjacent depth locations of a depth location include the previous adjacent depth location and the next adjacent depth location.

[0069] Optionally, the wave velocity fluctuation at a depth location in a measurement direction at a certain frequency satisfies the following formula: in, Indicates the direction of measurement Upper Each depth location at frequency the wave velocity fluctuation of the first depth position in the first measurement direction at each frequency, the measurement direction the first depth position the average wave velocity of the preceding depth position of the first depth position in the measurement direction at the frequency, the measurement direction the first depth position the average wave velocity of the following depth position of the first depth position in the measurement direction at the frequency, the measurement direction the first depth position the wave velocity range of the adjacent depth position of the first depth position in the measurement direction at the frequency.

[0070] In an optional implementation, the full-frequency wave velocity fluctuation average of the first depth position in the first measurement direction is determined based on the wave velocity fluctuation of the first depth position in the first measurement direction at each frequency; the frequency wave velocity correlation of the first depth position in the first measurement direction is determined; and the first propagation refraction is determined based on the full-frequency wave velocity fluctuation average and the frequency wave velocity correlation.

[0071] The frequency wave velocity correlation is a correlation between a wave velocity fluctuation sequence of the first depth position in the first measurement direction at all frequencies and a frequency sequence of the first measurement direction at the first depth position.

[0072] It should be understood that after the wave velocity fluctuation of the first depth position in the first measurement direction at each frequency is obtained, the full-frequency wave velocity fluctuation average of the first depth position in the first measurement direction can be obtained by averaging the wave velocity fluctuation at each frequency.

[0073] It can be understood that the wave velocity fluctuation sequence of the first depth position in the first measurement direction at all frequencies includes the wave velocity fluctuation of the first depth position in the first measurement direction at each frequency, and the wave velocity fluctuation included in the wave velocity fluctuation sequence corresponds to the frequency included in the frequency sequence in a one-to-one manner.

[0074] Optionally, the correlation between the wave velocity fluctuation sequence and the frequency sequence can be determined based on a Pearson correlation coefficient.

[0075] Optionally, the product of the full-frequency wave velocity fluctuation average and the frequency wave velocity correlation can be determined as the first propagation refraction.

[0076] Optionally, the propagation refraction of a depth position in a measurement direction satisfies the following formula: wherein, the measurement direction the first depth position propagation refraction of the depth position, measurement direction first average of full-frequency wave velocity fluctuation of the depth position, measurement direction first wave velocity fluctuation sequence of the depth position at all frequencies, measurement direction first frequency sequence of the depth position, indicates correlation with .

[0077] In combination with the above formula, it should be understood that the greater the frequency of the ultrasonic wave and the greater the wave velocity fluctuation of the ultrasonic wave propagating to the depth position, the greater the propagation refraction of the depth position.

[0078] S203, determining a first refraction feature based on the first anisotropy and the first propagation refraction.

[0079] wherein the first refraction feature is a refraction feature of the target rock mass at the first depth position in the first measurement direction.

[0080] It should be understood that the first anisotropy reflects the refraction in different directions, and the first propagation refraction reflects the refraction at the propagation depth, and based on both, the refraction feature of the first depth position in the first measurement direction can be determined.

[0081] It can be understood that the soft and hard interbedding, joints or fractures inside the rock mass will cause refraction of the ultrasonic wave, resulting in local fluctuation of the wave velocity in space, and the degree of local fluctuation of the wave velocity in space can reflect the non-homogeneity and complexity of the structure of the rock mass. After determining the propagation refraction of a depth position in a measurement direction, the propagation refractions of the depth position in different measurement directions can be further compared to determine the structural complexity of the depth position in different directions.

[0082] In an optional implementation, the maximum propagation refraction and the minimum propagation refraction of the first depth position in the neighborhood range of the first measurement direction can be determined first; then the first structural complexity is determined based on the maximum propagation refraction, the minimum propagation refraction, and the first propagation refraction, and the first refraction feature is determined based on the first anisotropy and the first structural complexity.

[0083] wherein the first structural complexity is a structural complexity of the first depth position in the first measurement direction.

[0084] It can be understood that the greater the difference in propagation refraction of the first depth position in different measurement directions, the more complex the structure of the first depth position in different measurement directions.

[0085] Optionally, the structural complexity of a depth position in a measurement direction satisfies the following formula: wherein, represents the structural complexity of the first depth position in the measurement direction . represents the propagation refraction of the first depth position in the measurement direction . represents the minimum value of the propagation refraction of the first depth position in the neighborhood range of the measurement direction . represents the maximum value of the propagation refraction of the first depth position in the neighborhood range of the measurement direction .

[0086] The above formula can be understood as a maximum-minimum value normalization method, the overall fluctuation range of the propagation refraction of the first depth position in the neighborhood range of the measurement direction , and the formula takes the range as a comparison standard, quantifies the structural complexity of the first depth position in the measurement direction by comparing the difference in refraction propagation between the current measurement direction and the neighborhood, and realizes normalization through the denominator. Based on the formula, the greater the difference between the propagation refraction in the first measurement direction and the minimum value of the propagation refraction in the neighborhood range, the more complex the structure in the first measurement direction. It can be understood that in combination with the anisotropy of the first depth position in the first measurement direction, if the anisotropy of the first depth position in the first measurement direction is high and the structural complexity at the position is also high, it indicates that strong refraction will be generated at the position, and the refraction feature should also be high.

[0087]

[0088] Optionally, the refraction feature of a depth position in a measurement direction satisfies the following formula: wherein, represents the refraction feature of the first depth position in the measurement direction . represents the minimum value of the propagation refraction of the first depth position in the neighborhood range of the measurement direction . ​​​​​​​anisotropy of each depth position, indicates a measurement direction upper structural complexity of each depth position.

[0089] In combination with the above formula, it should be understood that since the above-obtained structural complexity is less than 1, adding 1 to the structural complexity can amplify the influence of the structural complexity.

[0090] In the embodiments of the present application, the anisotropy calculated based on the wave velocity difference of the first depth position in different measurement directions can directly reflect the directional deviation of the wave velocity caused by the difference in elastic modulus and fracture distribution of the rock mass in different directions, and accurately capture the refraction caused by the lateral structure. The propagation refraction calculated based on the wave velocity difference of the first measurement direction in different depth positions can reflect the refraction caused by the longitudinal structure of the rock mass. Through two-dimensional analysis of the lateral difference and the longitudinal difference, the connotation of the refraction feature can be more complete and closer to the real structure of the rock mass.

[0091] In one implementation manner of the embodiments of the present application, based on the first refraction feature, a refraction correction coefficient of the first depth position in the first measurement direction is determined, which can specifically be that the product of the first refraction feature and the first propagation refraction is determined as the refraction correction coefficient of the first depth position in the first measurement direction.

[0092] It should be understood that the refraction feature can quantify the local refraction effect, the propagation refraction can evaluate the refraction intensity, and the refraction correction coefficient determined based on the product of the two can accurately obtain the magnitude that needs to be corrected.

[0093] In the embodiments of the present application, the ultrasonic wave propagation data of the rock mass in different directions is obtained through multi-directional measurement, the circumferential refraction feature is analyzed in depth, the anisotropy deviation caused by the difference in elastic modulus and wave velocity of the rock layer is effectively identified, and the measurement result is corrected, which can reduce the error caused by the traditional evaluation based on single direction or average wave velocity, and can also truly reflect the heterogeneity and potential weak plane distribution of the rock mass, improve the rapid evaluation accuracy of the integrity, strength and safety of the rock mass, and enhance the reliability of the engineering design and construction risk control.

[0094] Specifically, the region where refraction error is prone to occur is identified through ultrasonic detection data, and uncorrected wave velocity results are avoided in these regions, thereby reducing evaluation deviation and improving the reliability of rock mass property evaluation; through multi-directional ultrasonic testing, the law of wave velocity change with direction is revealed, and anisotropy strength and refraction characteristic parameters are extracted, which can intuitively reflect the influence of structural plane on wave propagation path and provide quantitative basis for subsequent correction, and more refined characterization of complex structural rock mass is realized; the correction coefficient is calculated by using the refraction characteristic, the directional correction of wave velocity is realized, the systematic error caused by path bending and propagation speed difference is eliminated, and the calculated mechanical parameters are closer to the true value; the correction results in different directions are integrated to avoid one-sidedness caused by single-direction measurement, and the accuracy and representativeness of rock mass integrity, strength and stability evaluation are significantly improved, thereby providing reliable basis for support design and construction safety.

[0095] The embodiment of the present application further provides a rock mass property rapid evaluation device, as shown in the figure, the rock mass property rapid evaluation device 30 comprises a memory 301, a processor 302 and a computer program stored in the memory and running on the processor, and the processor implements any one of the above rock mass property rapid evaluation methods when executing the computer program. Figure 3

[0096] The embodiment of the present application further provides a rock mass property rapid evaluation system, as shown in the figure, the rock mass property rapid evaluation system 40 comprises a data acquisition module 401, a refraction characteristic determination module 402, a refraction correction coefficient determination module 403, a wave velocity correction module 404 and an evaluation module 405. Figure 4

[0097] The data acquisition module 401 is used for acquiring ultrasonic propagation data of a target rock mass in multiple measurement directions, and the ultrasonic propagation data in one measurement direction comprises wave velocities at multiple frequency positions.

[0098] The refraction characteristic determination module 402 is used for determining the refraction characteristic of each depth position in each measurement direction of the target rock mass based on the wave velocity difference of each depth position in different measurement directions and the wave velocity difference of each frequency at each depth position in each measurement direction.

[0099] The refraction correction coefficient determination module 403 is used for determining the refraction correction coefficient of each depth position in each measurement direction based on the refraction characteristic of each depth position in each measurement direction of the target rock mass.

[0100] The wave velocity correction module 404 is used for correcting the measured wave velocity of each depth position based on the refraction correction coefficient of each depth position in different measurement directions, to obtain the corrected equivalent wave velocity of the each depth position. ​​

[0101] The evaluation module 405 is configured to evaluate the rock mass property of the target rock mass based on the equivalent wave velocity after the correction of each depth position. The system comprises the rock mass property rapid evaluation device.

[0102] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0103] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments.

Claims

1. A method for rapid rock mass property assessment, characterized by, The method comprises: acquiring ultrasonic propagation data of a target rock mass in multiple measurement directions, the ultrasonic propagation data in a measurement direction comprising wave velocities at multiple frequencies at multiple depth positions; determining a refraction characteristic of the target rock mass at each depth position in each measurement direction based on wave velocity differences of each depth position in different measurement directions and wave velocity differences of each measurement direction at each frequency at different depth positions; determining a refraction correction coefficient of each depth position in each measurement direction based on the refraction characteristic of the target rock mass at each depth position in each measurement direction; correcting a measured wave velocity of each depth position based on the refraction correction coefficient of each depth position in different measurement directions to obtain a corrected equivalent wave velocity of each depth position; evaluating a rock mass property of the target rock mass based on the corrected equivalent wave velocity of each depth position.

2. The method for rapid rock mass property evaluation according to claim 1, characterized in that, The multiple measurement directions comprise a first measurement direction, and the multiple depth positions comprise a first depth position. The refraction characteristic of the target rock mass at the first depth position in the first measurement direction is determined based on wave velocity differences of the first depth position in different measurement directions and wave velocity differences of the first measurement direction at each frequency at different depth positions, comprising: determining a first anisotropy based on the wave velocity differences of the first depth position in different measurement directions, the first anisotropy being anisotropy of the first depth position in the first measurement direction; determining a first propagation refraction based on the wave velocity differences of the first measurement direction at each frequency at different depth positions, the first propagation refraction being a propagation refraction of the first depth position in the first measurement direction; determining a first refraction characteristic based on the first anisotropy and the first propagation refraction, the first refraction characteristic being the refraction characteristic of the target rock mass at the first depth position in the first measurement direction.

3. The method for rapid rock mass property evaluation according to claim 2, characterized in that, The determination of the first anisotropy based on the wave velocity differences of the first depth position in different measurement directions comprises: determining a global wave velocity range of the first depth position and a neighborhood wave velocity range of the first depth position based on the wave velocity differences of the first depth position in different measurement directions, the global wave velocity range of the first depth position being a global wave velocity range of the first depth position in all measurement directions, and the neighborhood wave velocity range of the first depth position being a neighborhood wave velocity range of the first depth position in a neighborhood range of the first measurement direction, the neighborhood range of the first measurement direction comprising the first measurement direction and a neighboring measurement direction of the first measurement direction; determining the first anisotropy as a ratio of the neighborhood wave velocity range of the first depth position to the global wave velocity range of the first depth position.

4. The method for rapid rock mass property evaluation according to claim 2, characterized in that, The determination of the first propagation refraction based on the wave velocity differences of the first measurement direction at each frequency at different depth positions comprises: determining, based on the mean of the wave velocities of the adjacent depth positions of the first depth position in the first measurement direction at each frequency and the range of the wave velocities of the adjacent depth positions of the first depth position in the first measurement direction at each frequency, a wave velocity fluctuation of the first depth position in the first measurement direction at each frequency; determining, based on the wave velocity fluctuation of the first depth position in the first measurement direction at each frequency and the frequency sequence of the first measurement direction at the first depth position, the first propagation refraction.

5. The method for rapid rock mass property evaluation according to claim 4, characterized in that, The determining, based on the wave velocity fluctuation of the first depth position in the first measurement direction at each frequency and the frequency sequence of the first measurement direction at the first depth position, the first propagation refraction, comprises: determining a full-frequency wave velocity fluctuation mean of the first depth position in the first measurement direction based on the wave velocity fluctuation of the first depth position in the first measurement direction at each frequency; determining a frequency wave velocity correlation of the first depth position in the first measurement direction, the frequency wave velocity correlation being a correlation between a wave velocity fluctuation sequence of the first depth position in the first measurement direction at all frequencies and the frequency sequence of the first measurement direction at the first depth position; determining the first propagation refraction based on the full-frequency wave velocity fluctuation mean and the frequency wave velocity correlation.

6. The method for rapid rock mass property evaluation according to claim 2, characterized in that, The determining, based on the first anisotropy and the first propagation refraction, the first refraction feature, comprises: determining a maximum propagation refraction and a minimum propagation refraction of the first depth position in a neighborhood range of the first measurement direction; determining a first structural complexity of the first depth position in the first measurement direction based on the maximum propagation refraction, the minimum propagation refraction, and the first propagation refraction, the first structural complexity being a structural complexity of the first depth position in the first measurement direction; determining the first refraction feature based on the first anisotropy and the first structural complexity.

7. The method for rapid rock mass property evaluation according to claim 6, characterized in that, The determining, based on the first refraction feature, a refraction correction coefficient of the first depth position in the first measurement direction, comprises: determining, as the refraction correction coefficient of the first depth position in the first measurement direction, a product of the first refraction feature and the first propagation refraction.

8. The method for rapid rock mass property evaluation according to claim 1, characterized in that, The correcting, based on the refraction correction coefficient of the first depth position in each measurement direction, a measured wave velocity of the first depth position, to obtain a corrected equivalent wave velocity of the first depth position, comprises: determining, as a weight of the first depth position in each measurement direction, an inverse of the refraction correction coefficient of the first depth position in each measurement direction; determining, based on the weight of the first depth position in each measurement direction and the measured wave velocity of the first depth position in each measurement direction, the corrected equivalent wave velocity of the first depth position in each measurement direction.

9. A rock mass property rapid assessment device, characterized by, The device comprises a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements the method for quickly evaluating rock mass properties according to any one of claims 1-8 when the computer program is executed.

10. A system for rapid rock mass property assessment, characterized by, The system comprises a data acquisition module, a refraction characteristic determination module, a refraction correction coefficient determination module, a wave velocity correction module, and an evaluation module; The data acquisition module is configured to acquire ultrasonic wave propagation data of a target rock mass in multiple measurement directions, wherein the ultrasonic wave propagation data in one measurement direction comprises wave velocities at multiple frequency positions in multiple depths; The refraction characteristic determination module is configured to determine refraction characteristics of the target rock mass at each depth position in each measurement direction based on wave velocity differences of each depth position in different measurement directions and wave velocity differences of each measurement direction at each frequency in different depths; The refraction correction coefficient determination module is configured to determine refraction correction coefficients of each depth position in each measurement direction based on the refraction characteristics of the target rock mass at each depth position in each measurement direction; The wave velocity correction module is configured to correct the measured wave velocities of each depth position based on the refraction correction coefficients of each depth position in different measurement directions to obtain corrected equivalent wave velocities of each depth position; The evaluation module is configured to evaluate rock mass properties of the target rock mass based on the corrected equivalent wave velocities of each depth position.

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