Earth surface vibration prediction method and device for tunnel blasting construction in seasonal frozen region

Abstract

The invention provides a surface vibration prediction method and device for tunnel blasting construction in a seasonal frozen area, and relates to the technical field of surface vibration prediction methods for tunnel blasting construction, the reflected wave propagation time of each measurement transverse line is obtained, and the thickness of a frozen layer of each measurement transverse line is calculated; defining the wave velocity propagation velocity of each measurement transverse line by adopting a piecewise function; adopting an exponential decay method to construct an axial temperature distribution item of the measurement transverse line; and constructing a vibration speed prediction model to calculate the predicted vibration speed corresponding to each measurement transverse line, and calculating the predicted vibration speed corresponding to any axis coordinate by adopting a distance interpolation method based on the predicted vibration speed corresponding to the adjacent measurement transverse lines. An axial vibration velocity interpolation method is introduced, full-tunnel axial continuous prediction is realized through vibration velocity data of adjacent measurement transverse lines, a frozen layer thickness model is constructed based on electromagnetic wave reflection time and an axial node constant, and non-uniform distribution characteristics of the frozen layer thickness in the axial direction of the tunnel are accurately described.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel blasting construction ground surface vibration prediction method, in particular to a kind of seasonal frozen region tunnel blasting construction ground surface vibration prediction method and device. BACKGROUND

[0002] In seasonal frozen region tunnel blasting construction, ground surface vibration prediction faces complex challenges: the dramatic change of stratum physical property caused by freeze-thaw cycle leads to dynamic fluctuation of rock mass wave velocity, traditional vibration model often ignores the nonlinear influence of freezing layer thickness spatial heterogeneity and axial temperature gradient on wave velocity, resulting in significant prediction error. Existing technology relies on local drilling data or single temperature assumption, and it is difficult to accurately characterize the wave velocity gradient of the transition zone between frozen layer and unfrozen area, and lacks quantitative modeling of the coupling effect of axial temperature distribution and wave velocity. In addition, the propagation of blasting vibration energy in frozen soil area is greatly affected by the sudden change of propagation impedance, and the existing impedance model does not combine the temperature-modified wave velocity parameter, which cannot adapt to the dynamic environment of seasonal frozen region, restricting the accuracy of vibration control.

[0003] In the prior art, the publication number CN116258285A discloses a small clear distance tunnel blasting vibration velocity calculation method by studying the reduction factor of blasting seismic wave in different media. However, this method does not consider the spatial distribution of frozen layer, does not quantify the wave velocity attenuation gradient near the frozen layer interface, is prone to wave velocity distortion, does not embed the time-varying influence of temperature gradient on wave velocity into vibration prediction, makes the corrected wave velocity more consistent with the actual thermodynamic state of seasonal frozen region, and does not dynamically reflect the interface energy dissipation characteristics of frozen layer through impedance parameters. Therefore, there is an urgent need for an efficient and reliable vibration prediction method.

[0004] The above information disclosed in the background section is only used to enhance the understanding of the background of the present disclosure, and therefore it can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0005] The purpose of the present application is to provide a seasonal frozen region tunnel blasting construction ground surface vibration prediction method and device to solve the problems raised in the background.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A seasonal frozen region tunnel blasting construction ground surface vibration prediction method, comprising the following specific steps: S1: taking the blasting point as the origin, setting a measurement horizontal line on the inner wall of the tunnel surrounding rock every fixed interval along the axial direction of the tunnel that has been mined, and uniformly setting a plurality of measurement points on each measurement horizontal line, and using the geological radar method to determine the reflection wave propagation time at each measurement point; S2: The frozen layer thickness of each measurement line is obtained by weighting the frozen layer thickness of each measurement point on each measurement line using the inverse distance weighting method, and the wave velocity propagation speed of each measurement line is defined based on the frozen layer thickness of each measurement line and the minimum distance of each measurement line from the origin using the depth distance method; S3: The constant temperature of the tunnel and the average temperature of the ground surface are obtained as parameters of the temperature distribution term, and the exponential decay method is used to construct the temperature distribution term of the measurement line in the axial direction, and the temperature distribution term in the axial direction is used as a correction term of the wave velocity propagation speed to obtain the corrected wave velocity propagation speed. S4: Based on the corrected wave velocity propagation speed, the temperature distribution term gradient product method is used to define the propagation impedance at the measurement line; based on the propagation impedance, a vibration velocity prediction model is constructed to calculate the predicted vibration velocity corresponding to each measurement line, and based on the predicted vibration velocity corresponding to the adjacent measurement lines, the distance interpolation method is used to calculate the predicted vibration velocity corresponding to any axial coordinate.

[0007] Further, the frozen layer thickness of each measurement line is obtained, and the specific steps are as follows: For each measurement point on each measurement line, the distance between each measurement point and the center point of the measurement line is determined as the first distance, and a non-zero constant is introduced, and the reciprocal of the sum of the first distance and the non-zero constant is represented as the position weight of the measurement point on the measurement line; The position weights of each measurement point in each measurement line are superimposed and summed up, and the total weight of the measurement line is marked. The reflection wave propagation time at each measurement point is determined using the ground penetrating radar method, and the first time is marked, the product of the first time and the position weight of each measurement point in each measurement line is obtained, and the sum of all products is marked as the relative propagation time at the measurement line. For each measurement line, the ratio of the relative propagation time and the total weight is taken as the reflection wave propagation time of the measurement line.

[0008] Further, the constant temperature of the tunnel and the average temperature of the ground surface are obtained, and the specific steps are as follows: The temperature of each measurement point is obtained in real time to form a first temperature set, the maximum and minimum values of the first temperature set are removed, and the temperature average of the remaining temperature values is calculated as the constant temperature of the tunnel, The constant temperature of the tunnel and the average temperature of the ground surface are obtained, and the specific steps are as follows: The temperature of each measurement point is obtained in real time to form a first temperature set, the maximum and minimum values of the first temperature set are removed, and the temperature average of the remaining temperature values is calculated as the constant temperature of the tunnel, and the average temperature of the ground surface is the average ground surface temperature of the region where the tunnel to be blasted is located.

[0009] Further, the step of obtaining the frozen layer thickness of each measuring line comprises: Half of the product of the reflection wave propagation time of each measuring line and the propagation speed of the electromagnetic wave is designated as the single-pass propagation time; The arithmetic square root of the dielectric constant of the permafrost layer in the region where the tunnel to be blasted is located is designated as the propagation correction coefficient; The ratio of the single-pass propagation time corresponding to each measuring line and the propagation correction coefficient is designated as the frozen layer thickness at the measuring line.

[0010] Further, the step of defining the wave propagation speed of each measuring line by using the depth distance method comprises: The frozen layer thickness of each measuring line is designated as the first threshold value of the measuring line, and the sum of the frozen layer thickness and the typical freeze-thaw interface influence width is designated as the second threshold value of the measuring line; If the minimum distance of the measuring line from the origin is not greater than the first threshold value, the wave propagation speed of the measuring line is designated as the wave propagation speed of the frozen layer; If the minimum distance of the measuring line from the origin is greater than the first threshold value and not greater than the second threshold value, the wave propagation speed of the measuring line is designated as the difference between the wave propagation speed of the frozen layer and the decay speed; If the minimum distance of the measuring line from the origin is greater than the second threshold value, the wave propagation speed of the measuring line is designated as the wave propagation speed of the unfrozen layer; The step of obtaining the decay speed comprises: The difference between the minimum distance of the measuring line from the origin and the frozen layer thickness is obtained, and the ratio of the difference and the typical freeze-thaw interface influence width is designated as the decay coefficient; The difference between the wave propagation speed of the frozen layer and the wave propagation speed of the unfrozen layer is obtained as the wave speed variation, and the product of the decay coefficient of the measuring line and the wave speed variation is designated as the decay speed corresponding to the measuring line.

[0011] Further, the step of constructing the temperature distribution term of the measuring line in the axial direction by using the exponential decay method comprises: The negative of the product of the natural constant as the base number, the minimum distance of the measuring line from the origin, and the temperature decay coefficient of the measuring line is designated as the index to construct an exponential function as the first decay index, and the difference between 1 and the first decay index is designated as the second decay index; The product of the constant temperature of the tunnel and the first decay index is designated as the first temperature distribution term corresponding to the measuring line, and the product of the average temperature of the ground surface and the second decay index is designated as the second temperature distribution term corresponding to the measuring line; The sum of the superposition of the first temperature distribution term and the second temperature distribution term is designated as the temperature distribution term corresponding to the measuring line.

[0012] Further, the corrected wave velocity propagation speed is obtained, specifically comprising the following steps: The wave velocity of the original measurement line is multiplied by a correction factor to obtain the corrected wave velocity propagation speed, and the correction factor is calculated as follows: 1 is subtracted from the product of the maximum wave velocity attenuation speed and the temperature sensitivity function, wherein the maximum wave velocity attenuation speed is obtained by laboratory calibration measurement, and the temperature sensitivity function is obtained by The difference between the current temperature and the phase transition critical temperature is calculated by the function, and the product of the maximum wave velocity attenuation speed and the temperature sensitivity function is multiplied by the relative deviation between the current temperature and the reference temperature of the frozen layer to form the corrected wave velocity propagation speed.

[0013] Further, the propagation impedance of the measurement line is defined by the temperature distribution term gradient product method, and the specific steps are as follows: The corrected wave velocity propagation speed at the measurement line is multiplied by the corresponding temperature gradient to obtain the propagation impedance of the corresponding measurement line, wherein the temperature gradient at the corresponding measurement line is obtained by taking the derivative of the corresponding temperature distribution term with respect to the depth distance.

[0014] Further, the predicted vibration speed corresponding to any axis coordinate is calculated by the distance interpolation method, and the specific steps are as follows: The product of the propagation impedance of the measurement line and the parameter term with the depth distance as the base and the rock medium parameters as the exponent is taken as the denominator, the product of the site correction coefficient and the negative exponential decay term with the natural constant as the base and the product of the temperature distribution term of the measurement line and the depth distance is multiplied, and the result is taken as the numerator term to construct the vibration speed prediction model; For any axis coordinate, find its two adjacent measurement lines and number them in order, and the predicted vibration speed at any axis position is constructed by the sum of the product of the distance weight factor and the wave velocity propagation speed at the corresponding measurement line, wherein the distance weight factor is calculated as follows: The axis coordinate of the left measurement line is subtracted from the axis coordinate of the target position, and then divided by the difference between the left and right axis coordinates to obtain the weight coefficient of the left measurement line; The axis coordinate of the target position is subtracted from the axis coordinate of the right measurement line, and then divided by the difference between the left and right axis coordinates to obtain the weight coefficient of the right measurement line.

[0015] The application further provides a seasonal frozen region tunnel blasting construction ground surface vibration prediction device, the prediction device is used for executing the prediction method, and comprises: The data acquisition module is configured to set a measurement horizontal line on the inner wall of the surrounding rock of the tunnel at a fixed interval along an axial direction of the tunnel at the blasting point as an origin, and uniformly set a plurality of measurement points on each measurement horizontal line, and determine a reflection wave propagation time at each measurement point using a geological radar method; The wave velocity calculation module is configured to perform weighted processing on the frozen layer thickness of the measurement points on each measurement horizontal line using an inverse distance weighting method to obtain the frozen layer thickness of each measurement horizontal line, and define a wave velocity propagation speed of each measurement horizontal line using a depth distance method based on the frozen layer thickness of each measurement horizontal line and the minimum distance of each measurement horizontal line from the origin. The wave velocity correction module is configured to obtain a constant temperature of the tunnel and an average temperature of the ground surface as parameters of a temperature distribution term, construct the temperature distribution term of the axial direction of the measurement horizontal line using an exponential decay method, take the temperature distribution term of the axial direction as a correction term of the wave velocity propagation speed, and obtain a corrected wave velocity propagation speed. The vibration prediction module is configured to define a propagation impedance at the measurement horizontal line using a temperature distribution term gradient product method based on the corrected wave velocity propagation speed, construct a vibration speed prediction model based on the propagation impedance to calculate a predicted vibration speed corresponding to each measurement horizontal line, and calculate a predicted vibration speed corresponding to an arbitrary axial coordinate using a distance interpolation method based on the predicted vibration speeds corresponding to adjacent measurement horizontal lines.

[0016] Compared with the prior art, the present application has the following advantages: By using the inverse distance weighting method to fuse the multi-point data of the geological radar, local abnormal interference is suppressed, and the spatial distribution of the frozen layer thickness is accurately reconstructed. The depth distance method is used to define the wave velocity, the linear transition model of the wave velocity inside and outside the frozen layer is used to quantify the wave velocity decay gradient near the freeze-thaw interface, and the distortion problem of the traditional step wave velocity assumption is overcome. The axial temperature distribution correction term is introduced, the constant temperature of the tunnel and the average temperature of the ground surface are related based on the exponential decay, and the time-varying influence of the temperature gradient on the wave velocity is embedded in the vibration prediction, so that the corrected wave velocity is more consistent with the actual thermodynamic state in the seasonal frozen region. A temperature-wave velocity gradient product mode of the propagation impedance is proposed, the energy dissipation characteristics of the freeze-thaw interface are dynamically reflected through the impedance parameter, and the distance interpolation method is used to realize continuous prediction of the axial vibration speed of the whole tunnel, thereby reducing the prediction error of the vibration speed. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The figure is a schematic diagram of the overall method of the present application; Figure 2 The figure is a schematic diagram of the change of the propagation impedance and the vibration speed of the present application; Figure 3 The figure is a schematic diagram of the change of the depth distance and the vibration speed of the present application; Figure 4 The figure is a schematic diagram of the change of the temperature distribution term and the vibration speed of the present application; Figure 5 The overall device structure diagram of the present application is shown in the figure. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with specific examples.

[0019] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present application should be understood as the common meanings understood by those with ordinary skills in the art to which the present application belongs. The terms "first", "second" and similar terms used in the present application do not represent any order, number or importance, but are only used to distinguish different components. The terms "include" or "contain" and similar terms mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, without excluding other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like are only used to represent relative positional relationships, which can change accordingly when the absolute positions of the described objects change.

[0020] Embodiment: Please refer to Figures 1-4 The present application provides a technical solution: A tunnel blasting construction ground surface vibration prediction method in a seasonal frozen region, the specific steps comprising: S1: Taking the blasting point as the origin, setting a measurement horizontal line on the inner wall of the tunnel surrounding rock every fixed interval along the axial direction of the tunnel that has been mined, and uniformly setting a plurality of measurement points on each measurement horizontal line, and using the geological radar method to determine the reflection wave propagation time at each measurement point; Obtaining the thickness of the frozen layer of each measurement horizontal line, the specific steps are: For each measurement point on each measurement horizontal line, the distance between each measurement point and the center point of the measurement horizontal line is calibrated as the first distance, and a non-zero constant is introduced, and the reciprocal of the sum of the first distance and the non-zero constant is characterized as the position weight of the measurement point on the measurement horizontal line; Superimposing and summing the position weights of each measurement point in each measurement horizontal line to calibrate the total weight of the measurement horizontal line; Using the geological radar method to determine the reflection wave propagation time at each measurement point, and calibrating the first time, obtaining the product of the first time and the position weight of each measurement point in each measurement horizontal line, and calibrating the relative propagation time at the measurement horizontal line as the sum of all products; For each measurement line, the ratio of the relative propagation time and the total weight is taken as the reflection wave propagation time of the measurement line.

[0021] The formula used in the above process is: The measurement line numbered has measurement points, the distance from the th measurement point to the center point of the measurement line is , and the reflection wave propagation time at each measurement point is determined using the ground penetrating radar method. The reflection wave propagation time of each measurement point is multiplied by its corresponding weight , and then summed, and divided by the sum of all weights, to obtain the reflection wave propagation time of the measurement line numbered , wherein the weight is calculated using the reciprocal of the sum of the distance from the measurement point to the center of the measurement line and the zero-exclusion constant , and the formula used in the above process is: ; wherein, ; represents the reflection wave propagation time at the th measurement point on the measurement line numbered ; represents the weight coefficient at the th measurement point on the measurement line numbered ; represents the distance from the th measurement point on the measurement line numbered to the center point of the measurement line, i.e. the first distance; represents the measurement point number index.

[0022] The principle of the above process is to use the weighted average method to combine the reflection wave propagation times of multiple measurement points on the measurement line numbered into a representative reflection wave propagation time , wherein the weight is calculated according to the distance from the measurement point to the center point of the measurement line and the zero-exclusion constant The reciprocal of the sum of the distances, the farther the weight is smaller, the closer the weight is larger, thereby giving the measuring point close to the center higher influence, the weighting processing effectively reduces the noise or instability that the remote measuring point may introduce, enhances the accuracy and reliability of the reflection wave propagation time calculation, and can more accurately represent the overall geological radar reflection wave propagation time of the measurement cross line, making it comprehensive and representative.

[0023] The constant temperature of the tunnel and the average temperature of the ground are obtained, and the specific steps are as follows: The temperature of each measuring point is obtained in real time to form a first temperature set, the maximum and minimum temperatures in the first temperature set are removed, and the average temperature of the remaining temperature values is calculated as the constant temperature of the tunnel, The constant temperature of the tunnel and the average temperature of the ground are obtained, and the specific steps are as follows: The temperature of each measuring point is obtained in real time to form a first temperature set, the maximum and minimum temperatures in the first temperature set are removed, and the average temperature of the remaining temperature values is calculated as the constant temperature of the tunnel, and the average temperature of the ground is the average ground temperature of the region where the tunnel to be blasted is located.

[0024] S2: The inverse distance weighting method is used to weight the frozen layer thickness of each measuring point on each measuring cross line to obtain the frozen layer thickness of each measuring cross line, and the depth distance method is used to define the wave velocity propagation speed based on the frozen layer thickness of each measuring cross line and the minimum distance of each measuring cross line from the origin; The steps for obtaining the frozen layer thickness of each measuring cross line include: Half of the product of the reflection wave propagation time of each measuring cross line and the propagation speed of the electromagnetic wave is calibrated as the one-way propagation time; The arithmetic square root of the dielectric constant of the permafrost layer in the region where the tunnel to be blasted is located is taken as the propagation correction coefficient; The ratio of the one-way propagation time corresponding to each measuring cross line to the propagation correction coefficient is calibrated as the frozen layer thickness at the measuring cross line.

[0025] The frozen layer thickness of each measuring cross line is obtained, and the specific formula is: ; The dielectric constant of the permafrost layer is represented by The coordinates of the axial measuring cross line numbered with the blasting point as the origin are represented by The reflection wave propagation time of the measuring cross line numbered is represented by The frozen layer thickness of the measuring cross line numbered extending from the inner wall of the tunnel surrounding rock to the outside is represented by The propagation speed of electromagnetic wave.

[0026] In the above formula, the frozen soil boundary position is obtained by electromagnetic wave reflection time inversion, and the frozen layer thickness is quickly and non-destructively measured by fusing the electromagnetic wave propagation characteristics and the dielectric response of frozen soil, And positively correlated, The longer, the thicker the frozen layer, and the larger the dielectric constant The smaller the frozen layer thickness, The propagation speed of electromagnetic wave, the time is converted into a scale factor of the actual propagation distance, ensuring that the thickness calculation conforms to the electromagnetic wave propagation theory.

[0027] The frozen layer thickness refers to the soil layer formed by freezing outside the inner wall of the tunnel surrounding rock, and the solid state of the water in the frozen layer has a higher dielectric constant, which affects the propagation characteristics of electromagnetic waves, Reflects the depth of the frozen area extending outward from the tunnel inner wall.

[0028] The specific steps of defining the wave propagation speed of each measurement line using the depth distance method include: The frozen layer thickness of each measurement line is taken as the first threshold value of the measurement line, and the sum of the frozen layer thickness and the typical freeze-thaw interface influence width is taken as the second threshold value of the measurement line; If the minimum distance of the measurement line from the origin is not greater than the first threshold value, the wave propagation speed of the measurement line is marked as the wave propagation speed of the frozen layer; If the minimum distance of the measurement line from the origin is greater than the first threshold value and not greater than the second threshold value, the wave propagation speed of the measurement line is marked as the difference between the wave propagation speed of the frozen layer and the attenuation speed; If the minimum distance of the measurement line from the origin is greater than the second threshold value, the wave propagation speed of the measurement line is marked as the wave propagation speed of the unfrozen layer; The attenuation speed acquisition step includes: Obtain the difference between the minimum distance of the measurement line from the origin and the frozen layer thickness, and take the ratio of the difference and the typical freeze-thaw interface influence width as the attenuation coefficient; Obtain the difference between the wave propagation speed of the frozen layer and the wave propagation speed of the unfrozen layer as the wave speed variation, and take the product of the attenuation coefficient of the measurement line and the wave speed variation as the attenuation speed of the corresponding measurement line.

[0029] The specific formula for defining the wave propagation speed of each measurement line using the depth distance method is: ; The number is the depth distance of the measurement traverse extending outward along the inner wall surface of the tunnel surrounding rock is the wave velocity propagation speed, the first threshold value represents , and the second threshold value represents .

[0030] In the above formula, the wave velocity is defined by segmentation to depict the wave velocity gradient characteristics near the freezing-thawing interface. When , it indicates that the rock mass is frozen, and the wave velocity is constant; when , the wave velocity decreases linearly with the increase of , corresponding to the transition zone, until it stabilizes in the wave velocity of the unfrozen area. In the transition zone, i.e. , and present a negative correlation, reflecting the characteristic that the stiffness of the material near the freezing-thawing interface decreases with the depth; in the frozen layer and the unfrozen layer , and have no direct correlation, respectively maintaining a constant high wave velocity and a constant low wave velocity; wherein m represents the typical freezing-thawing interface influence width, the wave velocity propagation speed of the frozen layer is 3250 meters per second, which is derived from the longitudinal wave velocity of the frozen layer measured in experiments. Since the density increases due to frost heaving after the soil freezes, the longitudinal wave velocity is large, and the wave velocity propagation speed of the unfrozen layer is which is derived from the geological exploration measurement data, and 1350 represents the difference between the wave velocity propagation speed of the frozen layer and the wave velocity propagation speed of the unfrozen layer, i.e., the wave velocity variation.

[0031] S3: Obtain the constant temperature of the tunnel and the average temperature of the ground as parameters of the temperature distribution term, construct the temperature distribution term of the measurement traverse in the axial direction using the exponential decay method, take the temperature distribution term in the axial direction as a correction term of the wave velocity propagation speed, and obtain the corrected wave velocity propagation speed; The specific steps are as follows: Take the negative of the product of the minimum distance of the measurement traverse from the origin and the temperature decay coefficient of the measurement traverse as the exponent to construct an exponential function as the first decay exponent, and take the difference between 1 and the first decay exponent as the second decay exponent; Take the product of the constant temperature of the tunnel and the first decay exponent as the first temperature distribution term corresponding to the measurement traverse, and take the product of the average temperature of the ground and the second decay exponent as the second temperature distribution term corresponding to the measurement traverse; Take the sum of the first temperature distribution term and the second temperature distribution term as the temperature distribution term corresponding to the measurement traverse.

[0032] The exponential decay method is used to construct the temperature distribution term of the measuring horizontal line in the axial direction, and the specific formula is: ; Wherein, ; represents the constant temperature of the tunnel; represents the average temperature of the ground surface; represents the temperature decay coefficient of the measuring horizontal line numbered ; represents the basic temperature decay coefficient of the surrounding rock; represents the freezing layer thickness correction coefficient; represents the maximum freezing layer thickness of the tunnel in the axial direction; represents the temperature distribution term of the measuring horizontal line numbered , which extends outward along the inner wall surface of the tunnel surrounding rock by a depth distance of ; the first decay index refers to ; represents the first temperature distribution term; represents the second temperature distribution term; In the above formula, The decay coefficient dynamically reflects the influence of the local freezing layer thickness on the temperature gradient, and describes the non-uniform distribution characteristics of the axial temperature field; and respectively determine the starting point and the ending point of the temperature distribution, when , when tends to infinity, ; is used to quantify the adjusting effect of the local freezing state on the temperature decay rate, the greater, the higher the temperature gradient, that is, the smaller the influence range of the tunnel temperature; and the tunnel temperature term present a negative correlation, the greater, the smaller the tunnel temperature; and present a positive correlation, the greater, the greater the ground surface temperature; the greater, the greater, which leads to the temperature distribution approaching the ground surface temperature faster.

[0033] The corrected wave propagation speed is obtained, specifically including the following steps: The wave velocity of the original measurement horizontal line is multiplied by a correction factor to obtain a corrected wave velocity propagation speed, and the correction factor is calculated in the following manner: The maximum wave velocity attenuation rate is multiplied by a temperature sensitivity function, wherein the maximum wave velocity attenuation rate is measured through laboratory calibration, and the temperature sensitivity function is calculated by The difference between the current temperature and the phase transition critical temperature is calculated by the function, and the result of multiplying the maximum wave velocity attenuation rate by the temperature sensitivity function is multiplied by the relative deviation between the current temperature and the reference temperature of the frozen layer to form the corrected wave velocity propagation speed.

[0034] The corrected wave velocity propagation speed is obtained, specifically including the following formula: ; Wherein, represents the measurement horizontal line numbered , and the depth distance extending outward along the inner wall surface of the tunnel surrounding rock is The corrected wave velocity propagation speed is The maximum wave velocity attenuation rate is measured by laboratory calibration. The reference temperature of the frozen layer is The phase transition critical temperature is

[0035] In the above formula, The temperature sensitivity function The combination of the function and the linear temperature term dynamically quantifies the nonlinear attenuation characteristics of the wave velocity near the freezing and thawing phase transition critical temperature Significantly improves the temperature correction accuracy of the wave velocity of the frozen layer, and avoids the problem of insufficient adaptability of the traditional linear correction model in the phase transition temperature zone; The sigmoid function Controls the nonlinear attenuation weight of the phase transition critical zone, and the linear term Quantifies the proportional effect of the temperature deviation from the reference value, and together constitutes a composite correction mechanism of temperature on wave velocity; Limits the maximum wave velocity attenuation amplitude, and determines the sensitivity of the material to temperature change through laboratory calibration. The greater the value, the more significant the wave velocity attenuation caused by temperature change; And Present a positive correlation, embodying the direct transmission of the original wave velocity to the correction result; And Present a negative correlation, reflecting the physical law that temperature rise leads to wave velocity attenuation; when Approaches to , the gradient of the sigmoid function number is maximum, The temperature change is most sensitive, which embodies the wave velocity mutation characteristics of the phase transition zone.

[0036] S4: defining the propagation impedance of the measurement horizontal line based on the modified wave velocity propagation speed by using the temperature distribution term gradient multiplication method; constructing a vibration speed prediction model based on the propagation impedance to calculate the predicted vibration speed corresponding to each measurement horizontal line, and calculating the predicted vibration speed corresponding to any axis coordinate by using the distance interpolation method based on the predicted vibration speeds corresponding to adjacent measurement horizontal lines.

[0037] The specific steps of defining the propagation impedance of the measurement horizontal line by using the temperature distribution term gradient multiplication method are as follows: The modified wave velocity propagation speed at the measurement horizontal line is multiplied by the corresponding temperature gradient to obtain the propagation impedance of the corresponding measurement horizontal line, wherein the temperature gradient at the corresponding measurement horizontal line is obtained by deriving the corresponding temperature distribution term with respect to the depth distance.

[0038] The specific formula for defining the propagation impedance of the measurement horizontal line by using the temperature distribution term gradient multiplication method is as follows: ; Wherein, ; represents the measurement horizontal line numbered , and the depth distance extending outward along the inner wall surface of the tunnel surrounding rock is ; represents the gradient of the temperature distribution along , which is obtained by deriving the temperature distribution term with respect to the depth distance.

[0039] In the above formula, Through the multiplication relationship between wave velocity and temperature gradient, the impedance characteristics of the non-uniform temperature field of the frozen layer on the vibration wave propagation path are directly represented, and the coupling effect of wave velocity attenuation and temperature sudden change in the ice-water phase change zone is dynamically reflected, As the reference dimension of impedance, the greater the value, the greater the propagation impedance, which reflects the dominant influence of wave velocity on energy propagation efficiency; The gradient absolute value quantifies the severity of the radial temperature change of the surrounding rock, and the greater the temperature gradient, i.e. near the frozen layer, the impedance significantly increases, reflecting the additional dissipation effect of temperature mutation on vibration wave energy; The amplitude of the temperature gradient is controlled by the temperature gradient expression , When the thickness of the frozen layer increases, the gradient amplitude increases in the near-tunnel area, i.e. small , resulting in the local increase of the impedance ; And the depth Negative correlation, representing the physical law that impedance attenuates with the increase of surrounding rock depth; With Positive correlation, reflecting the intensification effect of temperature mutation on impedance.

[0040] The distance interpolation method is used to calculate the predicted vibration velocity corresponding to the arbitrary axis coordinate, and the specific steps are: The propagation impedance of the measurement horizontal line is multiplied by the product of the parameter term with the rock medium parameter as the index and the depth distance as the base, to obtain the denominator, the site correction coefficient is multiplied by the negative of the exponential decay term composed of the natural constant, the temperature distribution term of the measurement horizontal line and the depth distance, to obtain the numerator term, and the vibration velocity prediction model is constructed; For any axis coordinate, find its two adjacent measurement horizontal lines and number them in order, and use the sum of the product of the distance weight factor and the wave velocity propagation speed at the corresponding measurement horizontal line to construct the predicted vibration velocity at the arbitrary axis position, wherein the calculation of the distance weight factor is: Subtract the axis coordinate of the target position from the axis coordinate of the left measurement horizontal line, and then divide by the difference between the left and right axis coordinates, to obtain the weight coefficient of the left measurement horizontal line; Subtract the axis coordinate of the right measurement horizontal line from the axis coordinate of the target position, and then divide by the difference between the left and right axis coordinates, to obtain the weight coefficient of the right measurement horizontal line.

[0041] The distance interpolation method is used to calculate the predicted vibration velocity corresponding to the arbitrary axis coordinate, and the specific steps are: Based on the propagation impedance, a vibration velocity prediction model is constructed, which specifically includes the following formula: ; Wherein, represents the measurement horizontal line numbered , the vibration velocity extending outward along the inner wall surface of the tunnel surrounding rock with a depth distance of ; represents the medium parameter of the tunnel rock, which is usually 1.5; represents the site correction coefficient, which is calibrated by field blasting experiment, and is usually 0.15; In the above formula, represents the impedance and the temperature-distance decay term cooperate to quantitatively characterize the spatial distribution rule of vibration energy in the frozen layer of non-uniform medium, and the impedance is greater, the vibration energy propagation efficiency is lower, resulting in the decrease of vibration velocity , which reflects the direct regulation of impedance on energy dissipation; when the temperature rises, the exponential term decays intensively, and the vibration velocity The significant reduction reflects the enhanced effect of temperature on wave propagation energy absorption; this is achieved through the geometric attenuation term. and temperature decay term The dual effect of vibration velocity with depth The increase exhibits nonlinear decay, which conforms to the physical diffusion law of vibration waves.

[0042] In the above embodiments, the dependent variable, vibration velocity, and the independent variables, namely impedance and depth distance, are given. In addition, 10 sets of data for the temperature distribution term reflect the relationship between vibration velocity and the various independent variables, as shown in Tables 1-3: Table 1: Relationship between vibration velocity and propagation impedance

[0043] As can be seen from Table 1 above, fixed , As the propagation impedance increases, its vibration velocity gradually decreases, conforming to the impedance... The larger the value, the lower the efficiency of vibration energy propagation, resulting in a decrease in vibration velocity. The situation of reduction.

[0044] Table 2: Relationship between vibration velocity and depth

[0045] As can be seen from Table 2 above, the fixed , As the depth increases, the vibration velocity gradually decreases, which conforms to the physical diffusion law of vibration waves.

[0046] Table 3: Relationship between vibration velocity and temperature distribution term

[0047] As can be seen from Table 3 above, fixed , At that time, as the temperature distribution term increases, the exponential term... Attenuation intensifies, vibration speed The significant reduction reflects the enhanced effect of temperature on the absorption of wave propagation energy.

[0048] Set any axis coordinate as And find the labels of its two adjacent measurement lines that satisfy: ; in, ; Indicates label the axis coordinate corresponding to the measurement traverse of the right side of the arbitrary axis line denotes the arbitrary axis coordinate the number of the measurement traverse of the right side of the arbitrary axis line Based on the vibration velocity of the adjacent measurement traverse, the distance weight factor product is used to construct the predicted vibration velocity of the arbitrary axis position: denotes the measurement traverse numbered , the depth distance extending outward along the inner wall surface of the tunnel surrounding rock is , and the predicted vibration velocity is denotes the distance weight factor of the measurement traverse numbered denotes the distance weight factor of the measurement traverse numbered

[0049] In the above formula, the continuous prediction of the vibration velocity at the arbitrary axis position is realized through the normalized linear combination of the distance weight factors and , breaking through the spatial limitation of discrete measurement point data, and as the interpolation base value, the numerical value directly determines the order of magnitude range of , the higher the measured or predicted velocity of the adjacent points, the closer the overall trend of the interpolation result to the high value area; and through the normalized weight distribution, the relative distance influence of the target position to the adjacent and is quantified, the greater the weight factor, the more significant the contribution of the velocity of the corresponding measurement point to ; the axis position drives the interpolation result to smoothly transition in space, ensuring the continuity of the vibration velocity prediction;

[0050] and are negatively correlated, indicating that the farther the distance , the weaker the weight contribution; and are negatively correlated, reflecting that the farther the distance , the greater the weight contribution.

[0051] Please refer to Figure 5 ​​​​​​The application further provides a device for predicting ground surface vibration in a tunnel blasting construction in a seasonal freezing area, which is used for executing the above-mentioned prediction method and comprises: The data acquisition module is configured to set a measurement horizontal line on the inner wall of the tunnel surrounding rock every fixed interval along the axial direction of the tunnel in the blasting point as the origin, and uniformly set a plurality of measurement points on each measurement horizontal line, and determine the reflection wave propagation time at each measurement point by using the geological radar method. The wave velocity calculation module is configured to obtain the frozen layer thickness of each measurement horizontal line by using the inverse distance weighting method to perform weighted processing on the frozen layer thickness of the measurement points on each measurement horizontal line, and define the wave velocity propagation speed of each measurement horizontal line based on the frozen layer thickness of each measurement horizontal line and the minimum distance of each measurement horizontal line from the origin by using the depth distance method. The wave velocity correction module is configured to obtain the constant temperature of the tunnel and the average temperature of the ground surface as parameters of the temperature distribution term, construct the temperature distribution term of the axial direction of the measurement horizontal line by using the exponential decay method, take the temperature distribution term of the axial direction as a correction term of the wave velocity propagation speed, and obtain the corrected wave velocity propagation speed. The vibration prediction module is configured to define the propagation impedance at the measurement horizontal line by using the temperature distribution term gradient product method based on the corrected wave velocity propagation speed, construct a vibration velocity prediction model to calculate the predicted vibration velocity corresponding to each measurement horizontal line based on the propagation impedance, and calculate the predicted vibration velocity corresponding to any axial coordinate by using the distance interpolation method based on the predicted vibration velocities corresponding to the adjacent measurement horizontal lines.

[0052] The above formulas are all dimensionless numerical calculations, and the formulas are obtained by software simulation of a large amount of data to obtain a formula closest to the actual situation, and the preset parameters in the formula are set by a person skilled in the art according to the actual situation.

[0053] The above-mentioned embodiments can be realized by software, hardware, firmware or any combination thereof, in whole or in part. When realized by software, the above-mentioned embodiments can be realized in the form of a computer program product in whole or in part. Those skilled in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized by hardware or software methods depends on the specific application and design constraints of the technical solutions.

[0054] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, which can be located in one place or distributed on multiple network units. Part or all of the units can be selected to achieve the purpose of the embodiment according to actual needs.

[0055] The above description is only the specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A method for predicting ground surface vibration in tunnel blasting construction in a seasonal freezing region, characterized by the steps of Comprise: S1: set a measuring horizontal line on the inner wall of the tunnel surrounding rock every fixed interval along the axial direction of the tunnel mined with the blasting point as the origin, and uniformly set a plurality of measuring points on each measuring horizontal line, and determine the reflection wave propagation time at each measuring point using the geological radar method; S2: the thickness of the frozen layer of each measuring point on each measuring horizontal line is weighted using the inverse distance weighting method to obtain the frozen layer thickness of each measuring horizontal line, and the wave velocity propagation speed of each measuring horizontal line is defined based on the frozen layer thickness of each measuring horizontal line and the minimum distance of each measuring horizontal line from the origin using the depth distance method; S3: obtain the constant temperature of the tunnel and the average temperature of the ground as the parameters of the temperature distribution term, and construct the temperature distribution term of the axial direction of the measuring horizontal line using the exponential decay method, and take the temperature distribution term of the axial direction as the correction term of the wave velocity propagation speed to obtain the corrected wave velocity propagation speed; S4: based on the corrected wave velocity propagation speed, the propagation impedance at the measuring horizontal line is defined using the temperature distribution term gradient product method; Based on the propagation impedance, a vibration velocity prediction model is constructed to calculate the predicted vibration velocity corresponding to each measuring horizontal line, and based on the predicted vibration velocity corresponding to the adjacent measuring horizontal line, the distance interpolation method is used to calculate the predicted vibration velocity corresponding to any axial coordinate.

2. The method according to claim 1, wherein, The specific steps for obtaining the frozen layer thickness of each measuring horizontal line are as follows: For each measuring point on each measuring horizontal line, the distance between each measuring point and the center point of the measuring horizontal line is determined as the first distance, and a non-zero constant is introduced, and the reciprocal of the sum of the first distance and the non-zero constant is represented as the position weight of the measuring point on the measuring horizontal line; The position weights of each measuring point in each measuring horizontal line are superimposed and summed to be marked as the total weight of the measuring horizontal line; The reflection wave propagation time at each measuring point is determined using the geological radar method, and is marked as the first time, the product of the first time and the position weight of each measuring point in each measuring horizontal line is obtained, and the sum of all products is marked as the relative propagation time at the measuring horizontal line; For each measuring horizontal line, the ratio of the relative propagation time and the total weight is taken as the reflection wave propagation time of the measuring horizontal line.

3. The method according to claim 2, wherein, The specific steps for obtaining the constant temperature of the tunnel and the average temperature of the ground are as follows: Real-time acquisition of the temperature of each measuring point constitutes a first temperature set, the maximum and minimum values of the first temperature set are removed, and the temperature average value of the remaining temperature values is calculated as the constant temperature of the tunnel, The specific steps for obtaining the constant temperature of the tunnel and the average temperature of the ground are as follows: Real-time acquisition of the temperature of each measuring point constitutes a first temperature set, the maximum and minimum values of the first temperature set are removed, and the temperature average value of the remaining temperature values is calculated as the constant temperature of the tunnel, and the average ground temperature of the region where the tunnel to be blasted is located.

4. The method according to claim 2, wherein, The steps for obtaining the frozen layer thickness of each measuring horizontal line include: Half of the product of the reflection wave propagation time of each measuring horizontal line and the propagation speed of electromagnetic waves is marked as the one-way propagation time; The arithmetic square root of the dielectric constant of the frozen soil layer in the region where the tunnel to be blasted is located is taken as the propagation correction coefficient; The ratio of the single-pass propagation time corresponding to each measurement line and the propagation correction coefficient is calibrated as the frozen layer thickness at the measurement line.

5. The method according to claim 1, wherein, The wave velocity propagation velocity of each measurement line is defined by using the depth distance method, and the specific steps include: The frozen layer thickness of each measurement line is taken as the first threshold value of the measurement line, and the sum of the frozen layer thickness and the typical freeze-thaw interface influence width is taken as the second threshold value of the measurement line; If the minimum distance of the measurement line from the origin is not greater than the first threshold value, the wave velocity propagation velocity of the measurement line is calibrated as the wave velocity propagation velocity of the frozen layer; If the minimum distance of the measurement line from the origin is greater than the first threshold value and not greater than the second threshold value, the wave velocity propagation velocity of the measurement line is calibrated as the difference between the wave velocity propagation velocity of the frozen layer and the attenuation velocity; If the minimum distance of the measurement line from the origin is greater than the second threshold value, the wave velocity propagation velocity of the measurement line is calibrated as the wave velocity propagation velocity of the unfrozen layer. The attenuation velocity is obtained by the steps of: The difference between the minimum distance of the measurement line from the origin and the frozen layer thickness is obtained, and the ratio of the difference and the typical freeze-thaw interface influence width is taken as the attenuation coefficient; The difference between the wave velocity propagation velocity of the frozen layer and the wave velocity propagation velocity of the unfrozen layer is taken as the wave velocity variation, and the product of the attenuation coefficient of the measurement line and the wave velocity variation is taken as the attenuation velocity corresponding to the measurement line.

6. The method according to claim 4, wherein The temperature distribution term of the measurement line in the axial direction is constructed by using the exponential decay method, and the specific steps are: The product of the natural constant, the minimum distance of the measurement line from the origin, and the temperature attenuation coefficient of the measurement line is taken as the negative number of the exponential to construct an exponential function as a first attenuation exponential, and the difference between 1 and the first attenuation exponential is taken as a second attenuation exponential; The product of the constant temperature of the tunnel and the first attenuation exponential is taken as the first temperature distribution term corresponding to the measurement line, and the product of the average temperature of the ground surface and the second attenuation exponential is taken as the second temperature distribution term corresponding to the measurement line; The sum of the first temperature distribution term and the second temperature distribution term is taken as the temperature distribution term corresponding to the measurement line.

7. The method according to claim 1, wherein The specific steps of obtaining the corrected wave velocity propagation velocity include: The wave velocity of the original measurement line is multiplied by a correction factor to obtain the corrected wave velocity propagation velocity, and the correction factor is calculated in the following manner: Subtracting the product of the maximum rate of wave velocity attenuation and the temperature sensitivity function from 1, where the maximum rate of wave velocity attenuation is measured through laboratory calibration and the temperature sensitivity function is calculated from the difference between the current temperature and the critical temperature of phase change The product of the maximum rate of wave velocity attenuation and the temperature sensitivity function is multiplied by the relative deviation between the current temperature and the reference base temperature of the frozen layer, and the result constitutes the corrected wave propagation velocity.

8. The method according to claim 1, wherein, The specific steps of defining the propagation impedance of the measurement line by using the temperature distribution term gradient product method include: The product of the corrected wave velocity propagation velocity at the measurement line and the corresponding temperature gradient is taken to obtain the propagation impedance of the measurement line, wherein the temperature gradient at the measurement line is obtained by taking the derivative of the corresponding temperature distribution term with respect to the depth distance.

9. The method according to claim 1, wherein the method is characterized by, The specific steps of calculating the predicted vibration velocity corresponding to any axial coordinate by using the distance interpolation method include: The product of the propagation impedance of the measurement line and the parameter term with the depth distance as the base and the rock medium parameters as the exponent is taken as the denominator, the product of the site correction coefficient and the exponential decay term with the natural constant as the base and the product of the temperature distribution term of the measurement line and the depth distance as the negative number is taken, and the result is taken as the numerator term to construct a vibration velocity prediction model. For any axis coordinate, find its adjacent two measurement lines respectively numbered in order, and use the sum of the product of the distance weight factor and the wave velocity propagation speed at the corresponding measurement line to construct the predicted vibration speed of the arbitrary axis position, wherein the calculation of the distance weight factor is: The weight coefficient of the left measurement line is constructed by subtracting the axis coordinate of the target position from the axis coordinate of the left measurement line and then dividing by the difference between the left and right axis coordinates. The weight coefficient of the right measurement line is constructed by subtracting the axis coordinate of the right measurement line from the axis coordinate of the target position and then dividing by the difference between the left and right axis coordinates.

10. A device for predicting ground surface vibration in tunnel blasting construction in a seasonal freezing region, characterized by comprising: a tunnel blasting construction ground surface vibration prediction device according to any one of claims 1 to 9. The prediction device is used to execute the prediction method of any one of claims 1-9, comprising: A data acquisition module is used to set measurement lines on the inner wall of the tunnel surrounding rock every fixed interval along the axial direction of the tunnel, and uniformly set multiple measurement points on each measurement line, and use the geological radar method to determine the reflection wave propagation time at each measurement point. A wave velocity calculation module is used to use the inverse distance weighting method to weight the frozen layer thickness of each measurement point on each measurement line to obtain the frozen layer thickness of each measurement line, and based on the frozen layer thickness of each measurement line and the minimum distance of each measurement line from the origin, use the depth distance method to define the wave velocity propagation speed of each measurement line. A wave velocity correction module is used to obtain the constant temperature of the tunnel and the average temperature of the ground surface as the parameters of the temperature distribution term, and use the exponential decay method to construct the temperature distribution term of the axial direction of the measurement line, and use the temperature distribution term of the axial direction as the correction term of the wave velocity propagation speed to obtain the corrected wave velocity propagation speed. A vibration prediction module is used to define the propagation impedance at the measurement line based on the corrected wave velocity propagation speed using the temperature distribution term gradient product method, and based on the propagation impedance, construct a vibration speed prediction model to calculate the predicted vibration speed corresponding to each measurement line, and based on the predicted vibration speed corresponding to the adjacent measurement lines, use the distance interpolation method to calculate the predicted vibration speed corresponding to any axis coordinate.

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