Controllable shock wave-based underground engineering advanced geological prediction method and system

Abstract

The present application relates to the technical field of underground engineering monitoring, in particular to a method and system for advanced geological prediction of underground engineering based on controllable shock wave, the method comprising the following steps: S1: constructing a prediction system on the side wall behind the tunnel face; S2: executing an active spectrum matching process; S3: quantitatively and driving a variable seismic source to execute adjustment; S4: executing closed-loop feedback detection; S5: collecting multi-channel seismic wave data and reconstructing a three-dimensional wave velocity model of the geological body in front of the tunnel; S6: grading and interpreting the underground engineering, and a prediction system is also disclosed, which comprises a variable seismic source, a signal acquisition and feedback module array, a high-voltage generation and energy storage module, and a central control terminal, and is applied in the aforementioned prediction method, uses a variable electrically-driven seismic source to realize independent and accurate regulation of the energy and spectrum of the seismic source, and constructs an active spectrum matching and source-detection linkage feedback function, thereby improving the adaptability and data quality under complex geological conditions.

Description

Technical Field

[0001] This invention relates to the field of underground engineering monitoring technology, and in particular to a method and system for advanced geological prediction of underground engineering based on controllable shock waves. Background Technology

[0002] In the construction of tunnels, mines, and underground caverns, the faults, fracture zones, karst caves, and water-rich areas hidden in front of the working face are the main causes of major safety accidents such as collapses and water inrushes. Therefore, accurately grasping the geological conditions in front of the working face, i.e., advanced geological forecasting, is the key to ensuring construction safety.

[0003] Traditional advanced geological forecasting primarily relies on explosive or mechanically driven seismic sources. Explosive sources offer high energy and deep penetration, but also pose significant safety risks, cumbersome approval processes, and substantial damage to surrounding rock. Furthermore, the spectral characteristics of explosive sources are largely dependent on the amount of explosive, making it impossible to adjust the waveform according to geological conditions and hindering precise control of physical parameters. While mechanically driven seismic sources are safer, their energy is limited, and their spectrum is singular, with high-frequency components attenuating rapidly with distance. This results in a sharp decline in resolution over long distances, making accurate predictions difficult. More importantly, existing detection methods often involve operators setting parameters and then blindly firing the equipment, failing to optimize the next firing parameters based on the actual absorption feedback from the strata. This leads to data acquisition often having poor signal-to-noise ratios or insufficient resolution. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for advanced geological prediction of underground engineering based on controllable shock waves. The prediction method introduces the active matching concept of detection before optimization, and changes the electrical and mechanical parameters of the discharge circuit to accurately control the energy and spectrum of the shock wave. The prediction system uses the electrohydraulic effect of an adjustable source to generate a precisely controllable shock wave, meeting the needs of intelligent and precise detection.

[0005] To achieve the above objectives, this invention provides a method for advanced geological prediction of underground engineering based on controllable shock waves, comprising the following steps: S1: Construct a prediction system on the sidewall behind the tunnel face, including multiple variable seismic sources, signal acquisition and feedback module arrays, and a central control terminal, and establish a source-detection linkage feedback mechanism. S2: Execute the active spectrum matching process, the variable source emits a single pilot signal, and the system calculates the rock mass quality factor. Q With the spectral attenuation parameter, the main frequency is locked at the optimal detection main frequency. f opt ; S3: Based on the optimal detection frequency and preset detection distance, the central control terminal quantitatively calculates the source parameters according to the shock wave front pressure calculation formula and the RLC discharge circuit oscillation equation, and drives the variable source to perform adjustments. S4: Execute closed-loop feedback detection. Each variable source is continuously excited. The signal acquisition and feedback module array monitors the signal-to-noise ratio and spectrum integrity of the echo data in real time. If the index deviates from the preset threshold, the preset threshold is the signal-to-noise ratio SNR<3, or the main frequency of the received signal is attenuated by more than 20% of the target main frequency. Then, the correction command is fed back to each variable source in real time to dynamically adjust the source parameters for the next cycle. S5 acquires multi-channel seismic wave data and uses deterministic deconvolution and full waveform inversion algorithms to reconstruct a three-dimensional wave velocity model of the geological body in front of the tunnel. S6 generates advanced geological forecast results reports and visualization models, marks the location, scale and nature of adverse geological bodies, and classifies and interprets underground engineering based on the wave velocity change rate and change characteristics obtained from the inversion.

[0006] Step S1: System construction and initialization are performed. The detection system is deployed at the tunnel face, with multiple flexible coupled excitation probes containing water-filled bags arranged sequentially against the tunnel sidewall. A high-speed wireless or wired data link is established between the source control unit and the signal acquisition array. The source parameters are initialized with medium capacitance and medium electrode spacing. The signal acquisition array typically consists of 5 to 20 signal acquisition units arranged along the sidewall.

[0007] Step S2: Active spectrum matching is completed. The seismic source emits a single low-energy "pilot pulse," and the signal acquisition unit receives the echo signal propagating through the rock mass. The built-in algorithm calculates the rock mass's quality factor Q and spectral attenuation curve in real time. The data processing unit, based on the preset target distance and the Q value, inversely calculates the highest frequency fopt that can reach that distance while maintaining a sufficient signal-to-noise ratio, thus solving the signal loss problem caused by blindly selecting frequencies in traditional methods.

[0008] Step S3: The central control terminal automatically queries the parameter mapping table based on fopt and the required energy, and sends instructions to the hardware actuator: Step S4: Enter the formal acquisition stage. The seismic source is excited, the detector receives the signal, and the system executes source-detector linkage feedback: Energy feedback: If the signal-to-noise ratio of the echo from a deep target is detected to be lower than the threshold, a feedback command is triggered, and the voltage of the next shot increases. Spectrum feedback: If high-frequency components are found to attenuate too quickly, a feedback command is triggered, and the inductor decreases.

[0009] Consistency verification: During continuous excitation, if the waveform correlation coefficient decreases, it indicates that the electrode may be worn, triggering automatic compensation and fine-tuning of the electrode.

[0010] The preset threshold is set according to the geophysical exploration data quality control standards, and specifically includes: Signal-to-noise ratio (SNR) monitoring: The system sets a preset threshold of 3 for the SNR. If the SNR of the deep target echo is detected to be less than 3, the signal is easily submerged by background noise, affecting the accuracy of deep inversion. The system sends a feedback command to the central control terminal to trigger the high-voltage generator and the energy storage module to boost the voltage or increase the number of capacitors connected in parallel to improve the firing energy of the next shot.

[0011] Spectrum Integrity Monitoring: The system sets the preset attenuation threshold for spectrum integrity to 20%. If the attenuation of the center value of the received signal's main frequency exceeds 20% compared to the target main frequency set during transmission, the loss of high-frequency components leads to insufficient spatial resolution. The system sends a feedback command to the central control terminal, triggering the adjustable inductor coil inside the adjustable source to reduce its charge, thereby increasing the proportion of high-frequency energy at the transmitting end for spectrum compensation.

[0012] Step S5: Perform multi-mode data fusion and imaging. Acquire seismic wave data from different frequency bands, such as high-frequency fine scanning and low-frequency deep scanning. Utilize the highly consistent wavelet characteristics of the spark source to perform deterministic deconvolution processing and compress wavelet sidelobes. Employ full-waveform inversion or reverse-time migration algorithms to fuse multi-frequency data and generate high-precision three-dimensional imaging maps of geological body wave velocity distribution and wave impedance.

[0013] S6: Generates a forecast report containing the location, scale, and properties of adverse geological bodies (faults, karst caves, aquifers) ahead of the tunnel face, and displays them in a 3D visualization model. Simultaneously, based on the wave velocity change rate and characteristics obtained from the inversion, the system performs a graded interpretation against the proposed risk warning assessment criteria, providing direct evidence for construction decisions.

[0014] Furthermore, the positional constraints of the plurality of variable seismic sources are as follows: Longitudinal distance of the first variable seismic source from the working face d 1 satisfy , Wherein, the width of the working face is W; the height is H; and α is the avoidance coefficient. Adjacent variable source spacing ∆L n satisfy , in, ∆L The spacing between the nth and (n-1)th (n>1) variable seismic sources ， γ is the non-uniform growth coefficient; The distance of the nth variable seismic source from the working face d n satisfy .

[0015] To ensure the integrity of wavefield sampling and avoid spatial frequency distortion, the arrangement of seismic sources must be strictly determined according to the following formula: Let the distance from the nth seismic source to the working face be... d n (n=1, 2...N), typically 4 to 10 variable-parameter seismic sources are used. The distance of the first source from the working face is... d 1 The width of the excavation section at the tunnel face is defined as the distance between the left and right side walls, W, and the distance from the bottom plate to the arch crown, i.e., the height, is defined as H.

[0016] Longitudinal location of the first epicenter d 1 for: Where: α is the avoidance coefficient, with a value range of 0.5~1.5, used to avoid the loosening zone of the excavation face and suppress the nearest lateral reflection interference.

[0017] The distance between adjacent seismic sources increases geometrically with respect to the tunnel face. Let ∆L be the distance between the nth and (n-1)th (n>1)th seismic sources, then: Wherein: γ is the non-uniform growth coefficient, with a value range of 1.05~1.3.

[0018] The first spacing should meet the following requirements: in: V min The minimum wave velocity of the surrounding rock. f max This is the highest effective frequency.

[0019] The distance from the working face of the nth epicenter d n for: Furthermore, the variable source is an adjustable source excitation probe.

[0020] The adjustable seismic source excitation probe generates shock waves by utilizing the electrohydraulic effect produced by the discharge of high voltage in a liquid. The energy and spectrum of the shock waves can be precisely controlled by changing the electrical and mechanical parameters of the discharge circuit, such as inductance and capacitance. At the same time, the active matching concept of detection before optimization is introduced to achieve intelligent and precise detection.

[0021] Furthermore, the source parameter is inductance. L Capacity C and electrode spacing d .

[0022] The described quantitative calculation of the seismic source parameters includes, based on the target main frequency f opt , using the underdamped oscillation frequency approximation formula to initially select the combination of L and C, and based on the target energy E req , using the energy storage formula to determine the charging voltage; correcting the electrode spacing according to Paschen's law d , setting the breakdown voltage Ub = k·d , where k is the breakdown field strength coefficient, ensuring U b <U and the impedance of the discharge channel is matched to obtain a steep pulse rising edge.

[0023] Further, in step S3, the calculation formula for the shock wave front pressure is: In the formula, A is the conversion efficiency coefficient; B is the working condition correction coefficient; ρ is the medium density; U0 is the discharge voltage; L is the inductance of the discharge circuit; l0 is the length of the discharge gap; R i is the distance from the hole wall to the discharge location; δ is the coefficient of change of discharge efficiency with time; t is the shock wave movement time; σ[T - t] is the explosion function; ρ 极 is the medium density in the bladder; C 极 is the wave speed of the medium in the bladder; ρ r is the rock density; C r is the rock wave speed.

[0024] Spectrum control: Equivalent the discharge circuit to an RLC series circuit, and its underdamped oscillation frequency is: Where: β is the frequency correction coefficient, and its value range is 0.8 - 1.0; L is the variable inductance; C is the capacitance.

[0025] By adjusting the combination of the variable inductance L and selecting the capacitance C, it accurately approximates f opt . If high frequency (high resolution at short distance) is required, control the stepper motor to increase the electrode spacing d, increase the breakdown voltage, steepen the rising edge, and at the same time switch to the low inductance L gear. If low frequency (deep penetration at long distance) is required, reduce d and increase L to widen the pulse.

[0026] Energy and pressure control: To quantitatively control the pressure of the shock wave reaching the target distance r, establish the following physical model: Where: A is the conversion efficiency coefficient, and its value range is -0.1 - -0.02; l0 is the length of the discharge gap; R iδ is the distance from the hole wall to the discharge point; δ is the discharge efficiency coefficient with time, ranging from 3.0 to 5.0; t is the shock wave travel time; σ[Tt] is the explosion function.

[0027] P m The maximum value of the impact pressure is calculated as follows: Where: B is the operating condition correction coefficient, with a value range of 0.1~0.8; ρ is the dielectric density; U0 is the discharge voltage; and L is the discharge circuit inductance.

[0028] ξ is the wave impedance correction factor, which is calculated as follows: Where: ρ is the density of the medium inside the capsule; C is the wave velocity of the medium inside the capsule; ρr is the rock density; Cr is the rock wave velocity.

[0029] The initial energy E of the shock wave is determined by the energy storage formula: Based on the required detection distance, a corresponding number of pulse capacitors C are connected through a relay array, and the charging voltage U is adjusted to achieve graded energy output.

[0030] Pulse steepness control model: Where: a and b are constants related to the gas composition; p is the gas pressure; and d is the distance between the electrodes.

[0031] To obtain abundant high-frequency components (steep rising edges), d needs to be increased to improve... U b At the same time, ensure U b Slightly less than the charging voltage U to ensure reliable breakdown.

[0032] Based on the above calculation results, the automatic drive stepper motor adjusts d, switches the inductor coil taps to change L, and changes C through a relay combination.

[0033] This invention also discloses an advanced geological prediction system for underground engineering based on controllable shock waves, comprising: Multiple variable seismic sources are arranged longitudinally behind the tunnel face to generate shock waves using the electrohydraulic effect produced by the discharge of high voltage electricity in the liquid. The signal acquisition and feedback module array is connected to each of the variable seismic sources and transmits signals and control commands through a communication link. The central control terminal, based on the collected signals, issues real-time control commands to the source parameters of the variable seismic source; and, The high-voltage generation and energy storage module is placed on a trolley or in a safe area to be connected to each variable vibration source via high-voltage cables.

[0034] Furthermore, in step S4, the preset threshold is set according to the geophysical exploration data quality control standard, specifically including: Signal-to-noise ratio (SNR) monitoring: The system sets a preset threshold of 3 for the SNR. If the SNR of the deep target echo is detected to be less than 3, the signal is easily submerged by background noise, affecting the accuracy of deep inversion. The system sends a feedback command to the central control terminal to trigger the high-voltage generator and the energy storage module to boost the voltage or increase the number of capacitors connected in parallel to improve the firing energy of the next shot.

[0035] Spectrum Integrity Monitoring: The system sets the preset attenuation threshold for spectrum integrity to 20%. If the attenuation of the center value of the received signal's main frequency exceeds 20% compared to the target main frequency set during transmission, the loss of high-frequency components leads to insufficient spatial resolution. The system sends a feedback command to the central control terminal, triggering the adjustable inductor coil inside the adjustable source to reduce its charge, thereby increasing the proportion of high-frequency energy at the transmitting end for spectrum compensation.

[0036] This invention discloses an advanced geological prediction method and system for underground engineering based on controllable shock waves. By utilizing a variable electrically driven seismic source, it achieves independent and precise control of the source energy and spectrum, and constructs active spectrum matching and source-detector linkage feedback functions, transforming the detection process from blind monitoring to precise guidance, which greatly improves the adaptability and data quality under complex geological conditions. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart of an advanced geological prediction method for underground engineering based on controllable shock waves, according to the present invention.

[0039] Figure 2 This is a schematic diagram of the structure of an underground engineering advanced geological prediction system based on controllable shock waves according to the present invention.

[0040] Figure 3 This is a schematic diagram comparing the time-domain waveform and spectrum of the shock wave under different parameter adjustments according to the present invention.

[0041] 1. Variable seismic source; 2. Signal acquisition and feedback module array; 3. Central control terminal; 4. High voltage generation and energy storage module; 5. Working face. Detailed Implementation

[0042] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0043] Please see Figures 1 to 3 This invention discloses a method and system for advanced geological prediction of underground engineering based on controllable shock waves. The method for advanced geological prediction of underground engineering based on controllable shock waves includes the following steps: S1: Construct a prediction system on the sidewall behind the tunnel face 5, including multiple variable seismic sources 1, signal acquisition and feedback module array 2, high voltage generation and energy storage module 4, and central control terminal 3, and establish a source-detection linkage feedback mechanism. S2: Execute the active spectrum matching process. Variable source 1 transmits a single pilot signal. The system calculates the rock mass quality factor and spectrum attenuation parameters, and locks the main frequency to the optimal detection main frequency. S3: Based on the optimal detection frequency and preset detection distance, the central control terminal 3 calculates the source parameters quantitatively according to the shock wave front pressure calculation formula and the RLC discharge circuit oscillation equation, and drives the variable source 1 to perform adjustments. S4: Execute closed-loop feedback detection. Each variable source 1 officially starts continuous excitation. The signal acquisition and feedback module array 2 monitors the signal-to-noise ratio and spectrum integrity of the echo data in real time. If the index deviates from the preset threshold, the correction command is fed back to each variable source 1 in real time to dynamically adjust the source parameters of the next cycle. S5 acquires multi-channel seismic wave data and uses deterministic deconvolution and full waveform inversion algorithms to reconstruct a three-dimensional wave velocity model of the geological body in front of the tunnel. S6 generates advanced geological forecast results reports and visualization models, marks the location, scale and nature of adverse geological bodies, and classifies and interprets underground engineering based on the wave velocity change rate and change characteristics obtained from the inversion.

[0044] This invention also discloses an advanced geological prediction system for underground engineering based on controllable shock waves, comprising: Multiple variable seismic sources 1 are arranged longitudinally behind the tunnel face 5 to generate shock waves using the electrohydraulic effect generated by the discharge of high voltage in the liquid. The signal acquisition and feedback module array 2 is connected to each of the variable vibration sources 1 and is connected via a communication link. The central control terminal 3, based on the collected signals, performs real-time control of the source parameters of the variable seismic source 1; and, The high-voltage generation and energy storage module 4 is placed on the trolley or in a safe area to be connected to all adjustable source excitation probes via high-voltage cables.

[0045] In step S3, the adaptive adjustment of parameters includes: For close-range high-resolution detection at 0-30m, it automatically switches to a low inductance, low capacitance mode and controls the stepper motor to increase the electrode spacing to steepen the pulse rising edge and generate high-frequency broadband. For long-distance deep penetration detection of 30-100m and above, it automatically switches to a large inductance and large capacitance mode and reduces the electrode spacing to generate low-frequency high-energy pulses.

[0046] In step S4, multiple seismic source devices work together to achieve phased array directional transmission through millisecond-level time delay control, so that the main lobe of the synthetic beam is pointed to a specific anomalous area and lateral interference is suppressed.

[0047] The present invention will be further described below with reference to a specific embodiment of a large tunnel, which includes the following steps: Step S1: System deployment and connection.

[0048] The high-voltage generation and energy storage module 4 is placed on a trolley or in a safe area and connected to all adjustable seismic source excitation probes via high-voltage cables. The probes are encased in water-filled flexible bags to ensure good acoustic coupling with the rock face. The location of the first seismic source is determined using relevant parameters from the working face 5, thus obtaining the specific location of each seismic source from the working face 5. A signal acquisition and feedback module is installed, using a high-sensitivity accelerometer or hydrophone in the rock face or borehole. The central control terminal 3 is activated, automatically establishing connections between the modules via optical fiber.

[0049] Step S2: Pilot excitation and environmental parameter calculation.

[0050] The system automatically executes the test procedure, exciting the target once with a 500V voltage and the minimum capacitance setting. The acquisition unit captures the direct wave and the first wave signal, and uses the spectral ratio method to calculate the absorption coefficient α and quality factor Q of the surrounding rock at the face 5. Assuming the calculation results show that the rock mass is relatively fractured, the Q value is low, meaning high-frequency attenuation is rapid, and the target detection distance is 80 meters, the system calculates that the optimal center frequency should be around 150Hz.

[0051] Step S3: Parameter optimization and hardware execution.

[0052] Based on the target frequency of 150Hz and the distance of 80 meters, the central control terminal 3 determines the optimal combination of parameters: Inductance L: Switch to the maximum setting (e.g., 200μH) to widen the current pulse.

[0053] Capacitor C: Connect to the third-stage capacitor bank (e.g., 200μF) to provide sufficient energy.

[0054] Electrode spacing d: When the stepper motor moves, the spacing is reduced to 3mm, which lowers the breakdown threshold. Combined with the large inductor, a low-frequency wave is generated. All mechanical and circuit switching is completed within milliseconds.

[0055] Step S4: Closed-loop feedback acquisition.

[0056] The seismic source began to continuously excite at preset intervals.

[0057] First-round feedback: The acquisition unit detected a weak reflected wave at 80 meters, with a signal-to-noise ratio of only 1.5, lower than the set 3.0.

[0058] Instant Adjustment: The acquisition unit immediately sends a "low energy" flag to the control terminal. The control terminal then instructs the high-voltage power supply to increase the charging voltage from 3kV to 4kV.

[0059] Second firing: After energy boost, the signal-to-noise ratio reaches 3.5, the data is valid, and it is saved.

[0060] Step S5: Data processing and imaging.

[0061] The acquired multi-channel time-series signals were uploaded to the processing workstation, where the data underwent preprocessing. Deconvolution was performed using source wavelet records to eliminate the influence of bubble pulsations. Kirchhoff integral migration or reverse time migration techniques were employed to convert the time-domain signals into spatial-domain geological images. Red areas indicate low-velocity anomalies, which may be karst caves or fracture zones, while blue areas indicate normal rock masses with high-velocity waves.

[0062] Step S6: Report generation and alerts.

[0063] The system automatically generates daily forecasts. If a strong reflective interface is found 15-20 meters ahead and the wave velocity is significantly reduced, refer to Table 1. The risk warning assessment criteria comparison chart shows that the system automatically marks the area as "Level III risk source (potentially containing water-bearing fractured zone)" in the 3D model and pops up a warning prompt box, suggesting that advanced drilling verification be used in the next cycle.

[0064] Table 1 The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for advanced geological prediction of underground engineering based on controllable shock waves, characterized in that, Includes the following steps: S1: Construct a prediction system on the sidewall behind the tunnel face (5) including multiple variable seismic sources (1), signal acquisition and feedback module array (2), high voltage generation and energy storage module (4) and central control terminal (3) to establish a source-detection linkage feedback mechanism. S2: Execute the active spectrum matching process. The variable source (1) emits a single pilot signal. The system calculates the rock mass quality factor and spectrum attenuation parameters and locks the main frequency to the optimal detection main frequency. S3: Based on the optimal detection frequency and preset detection distance, the central control terminal (3) calculates the source parameters quantitatively according to the shock wave front pressure calculation formula and the RLC discharge circuit oscillation equation, and drives the variable source (1) to perform adjustment. S4: Execute closed-loop feedback detection. Each variable source (1) is continuously excited. The signal acquisition and feedback module array (2) monitors the signal-to-noise ratio and spectrum integrity of the echo data in real time. If the index deviates from the preset threshold, the correction command is fed back to each variable source (1) in real time to dynamically adjust the source parameters of the next cycle. S5 acquires multi-channel seismic wave data and uses deterministic deconvolution and full waveform inversion algorithms to reconstruct a three-dimensional wave velocity model of the geological body in front of the tunnel. S6 generates advanced geological forecast results reports and visualization models, marks the location, scale and nature of adverse geological bodies, and classifies and interprets underground engineering based on the wave velocity change rate and change characteristics obtained from the inversion.

2. The method for advanced geological prediction of underground engineering based on controllable shock waves as described in claim 1, characterized in that, The positional constraints of the multiple variable seismic sources (1) are as follows: Longitudinal distance of the first variable source (1) from the working face (5) d 1 satisfy , Among them, the width of the working face (5) is W; the height is H, and α is the avoidance coefficient; Adjacent variable seismic sources (1) ∆L n satisfy , in, ∆L The spacing between the nth and (n-1)th (n > 1) variable seismic sources (1) ， γ is the non-uniform growth coefficient; The distance of the nth variable source (1) from the working face (5) d n satisfy .

3. A method for advanced geological prediction of underground engineering based on controllable shock waves as described in claim 1 or 2, characterized in that, The source parameter is inductance. L Capacity C and electrode spacing d .

4. A method for advanced geological prediction of underground engineering based on controllable shock waves as described in claim 1 or 2, characterized in that, In step S3, the formula for calculating the shock wave front pressure is: In the formula, A is the conversion efficiency coefficient; B is the operating condition correction coefficient; ρ is the dielectric density; U0 is the discharge voltage; L is the discharge circuit inductance; l0 is the length of the discharge gap; R i denoted as the distance from the hole wall to the discharge point; δ is the coefficient of discharge efficiency as a function of time; t is the shock wave travel time; σ[Tt] is the explosion function. ρ 极 C is the density of the medium inside the capsule. 极 ρ is the wave velocity of the medium inside the capsule. r C is the density of the rock. r The wave velocity of the rock.

5. The method for advanced geological prediction of underground engineering based on controllable shock waves as described in claim 1, characterized in that, In step S3, the source parameters include inductance, capacitance, and electrode spacing.

6. The method for advanced geological prediction of underground engineering based on controllable shock waves as described in claim 1, characterized in that, In step S4, the execution of closed-loop feedback detection includes the following steps: Construct an energy adaptive loop. When the signal-to-noise ratio (SNR) of the deep reflection signal is detected to be < 3, automatically trigger the variable source (1) to boost the voltage or increase the number of capacitors in parallel. A frequency band compensation circuit is constructed. When the high-frequency components of the received signal are detected to be attenuating too quickly, resulting in insufficient resolution, the discharge circuit inductance is automatically reduced and the electrode spacing is finely adjusted.

7. The method for advanced geological prediction of underground engineering based on controllable shock waves as described in claim 1, characterized in that, In step S6, the method for calculating the wave velocity change rate is as follows: in, V bg For background wave velocity, V ano The wave velocity of the anomalous body.

8. A controlled shock wave-based advanced geological prediction system for underground engineering, characterized in that, include: Multiple variable seismic sources (1) are arranged longitudinally behind the tunnel face (5) to generate shock waves by utilizing the electrohydraulic effect generated by the discharge of high voltage in the liquid. The signal acquisition and feedback module array (2) is connected to each of the variable seismic sources (1) and transmits signals and control commands through a communication link; The central control terminal (3), based on the collected signals, issues real-time control commands to the source parameters of the variable source (1); and, The high-voltage generation and energy storage module (4) is placed on the trolley or in a safe area to be connected to each variable vibration source (1) via a high-voltage cable.

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