Indoor model experiment system and experiment method for disease structure blasting

Abstract

The invention discloses an indoor model experiment system and method for disease structure blasting, and relates to the field of tunnel engineering, the system comprises a structure test piece, a seismic source system and a monitoring system, the seismic source system comprises a power supply, a control box, a capacitance box, a cannon head and a conductive medium, and the power supply, the control box, the capacitance box and the cannon head are sequentially connected through a cable; the structure test piece is provided with a disease explosion-facing side and an explosion-backing side, a blast hole used for installing the blast head is prefabricated in the disease explosion-facing side, and the blast hole is filled with the conducting medium; the non-explosive type seismic source system is adopted and is composed of the power source, the control box, the capacitance box, the cannon head and the cable, potential safety hazards caused by explosive use are avoided, the experiment process is safer and more reliable, the energy storage capacity and the discharge current of the capacitance box can be accurately controlled, the stability of electric spark blasting can be ensured, and the working efficiency is improved. Therefore, stable blasting stress waves are generated, and the stress condition of a disease structure in the blasting process can be accurately simulated and analyzed.

Description

Technical Field

[0001] The present invention relates to tunnel engineering technology, and particularly to an indoor model experiment system and an experimental method for blasting of damaged structures. Background Art

[0002] During the construction of a newly-built tunnel, it is often necessary to carry out construction beside an existing tunnel. Due to the long-term service of the lining structure of the existing tunnel and the influence of the surrounding complex geological environment, diseases such as cracks and cavities often occur. To ensure the safe and smooth progress of the construction of the newly-built tunnel and avoid damage to the surrounding existing damaged tunnels, it is particularly important to study an indoor model experiment system suitable for blasting of damaged structures. This system can simulate the stress conditions of damaged structures during blasting through experiments, providing technical support and safety guidance for the on-site construction of the newly-built tunnel.

[0003] However, most current indoor blasting experiments use explosives as the seismic source. Due to the extremely high danger of explosives, their use is strictly controlled, resulting in many challenges and limitations in using explosives for indoor experiments. Therefore, there is an urgent need to develop a safer, more environmentally friendly and easier-to-control non-explosive seismic source system to meet the needs of blasting experiments on damaged structures. Summary of the Invention

[0004] The purpose of the present invention is to provide an indoor model experiment system and an experimental method for blasting of damaged structures to solve the problems of potential safety hazards, environmental pollution and difficulty in accurately controlling blasting stress waves existing in using explosives as the seismic source in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] The present invention provides an indoor model experiment system for blasting of damaged structures, including a structural specimen, a seismic source system and a monitoring system;

[0007] The seismic source system includes: a power supply, a control box, a capacitor box, a gun head and a conductive medium, wherein the power supply, the control box, the capacitor box and the gun head are sequentially connected by a cable;

[0008] The structural specimen is provided with a damaged blast-facing side and a blast-back side, and a blast hole for installing the gun head is prefabricated on the damaged blast-facing side. The conductive medium is filled in the blast hole, and the lower end of the gun head is immersed in the conductive medium;

[0009] The monitoring system includes: two groups of piezoelectric intelligent sensing components, a signal collector, a signal amplifier and a computer. The piezoelectric intelligent sensing component includes a smart aggregate, a shielded wire and a BNC end connected in sequence. The smart aggregate is composed of an insulating shell encapsulating PZT lead zirconate titanate piezoelectric ceramic material;

[0010] Two groups of piezoelectric intelligent sensing components are respectively fixed on the blast-facing side and the blast-back side of the structural specimen, where:

[0011] The piezoelectric intelligent sensing component fixed on the blast-facing side serves as a signal receiver and is connected to a computer through a signal collector.

[0012] The piezoelectric intelligent sensing component fixed on the blast-back side serves as a signal driver and is connected to a computer through a signal amplifier and a signal collector.

[0013] Furthermore, the gun head includes an anode, a cathode, an iron disk, and a steel material. The lower end of the anode penetrates through the iron disk. The outside of the anode is wrapped with a polyethylene material, and the upper end of the anode is exposed and connected to a capacitor box through a cable;

[0014] The steel material is arranged at the bottom of the iron disk, and the steel material wraps the polyethylene material and the cathode. The cathode is connected to the iron disk through the steel material, and the iron disk is connected to the capacitor box through a cable.

[0015] Furthermore, the lower end of the anode is flush with the polyethylene material.

[0016] Furthermore, the conductive medium is water or a liquid containing electrolytes.

[0017] The present invention also provides an indoor model experiment method for blasting of a damaged structure, which is applicable to the indoor model experiment system for blasting of the damaged structure described above, and includes the following steps:

[0018] S1. Connect the power supply, control box, capacitor box, and gun head through cables. Fill the pre-drilled hole in the structural specimen with a conductive medium, and immerse the lower end of the anode and the cathode of the gun head in the conductive medium;

[0019] S2. Fix the piezoelectric intelligent sensing component connected to the signal collector on the blast-facing side of the damage of the structural specimen as a signal receiver;

[0020] Fix the piezoelectric intelligent sensing component connected to the signal amplifier on the blast-back side of the damage of the structural specimen as a signal driver;

[0021] S3. Control the signal driver to generate stress waves through a computer. The signal receiver collects the signals, and the signals are transmitted to the signal collector through the signal amplifier and converted into voltage signals, and then transmitted to the computer terminal. Record the monitoring result as the active monitoring signal around the structural damage before blasting;

[0022] S4. Remove the piezoelectric intelligent sensing component connected to the signal amplifier;

[0023] S5. Control the power supply to charge the capacitor bank through the control box. After the charging is completed, then control the capacitor bank to release energy to the gun head through the control box. At this time, an electric spark is generated between the anode and cathode ends of the gun head immersed in the conductive medium, breaking through the conductive medium to stimulate blasting stress waves to the surrounding rock mass. At the same time, the intelligent aggregate at the disease-facing explosion side of the structural specimen generates electric charges according to the intensity of the blasting stress waves and transmits them to the signal collector. The signal collector converts the charge signal into a voltage signal and transmits it to the computer terminal, and records the monitoring result as the passive monitoring signal at the instant of the first blasting.

[0024] S6. Repeat step S3, and record the monitoring result as the active monitoring signal around the structural disease after the first blasting.

[0025] S7. Repeat steps S4 to S5 for the second blasting, and record the monitoring result as the passive monitoring signal at the instant of the second blasting.

[0026] S8. Repeat steps S3 to S5. Analyze the instantaneous response law at the disease-facing explosion side of the structural disease through the passive monitoring signal recorded each time, and analyze the cumulative damage law of the structure around the structural disease by comparing the active monitoring signals before and after each blasting.

[0027] Further, in step S2, the intelligent aggregate in the piezoelectric intelligent sensing component is fixed on the structural specimen through a vaseline coupling agent.

[0028] Further, in step S8, the analysis of the passive monitoring signal includes the comparison of the response time difference and the peak intensity, and the analysis of the active monitoring signal includes the calculation of the time domain distribution and the frequency band energy distribution after the fast Fourier transform.

[0029] Further, the frequency band energy distribution is extracted by the wavelet packet decomposition method, which is used to quantify the frequency domain characteristics of the structural damage.

[0030] Further, the specific steps for extracting the frequency band energy distribution by the wavelet packet decomposition method are as follows:

[0031] Express each group of corresponding decomposed signals S j as:

[0032] S j ={S j'1 , S j'2 ,…S j'm};

[0033] In the formula, j is the signal frequency band, and m is the sampling amount;

[0034] Define the energy of the decomposed signal as:

[0035]

[0036] The signal energy vector at time i is as follows:

[0037]

[0038] The total signal energy received by the piezoelectric intelligent sensing component (8) at time i is expressed as:

[0039]

[0040] Compared with the prior art, an indoor model experiment system and an experiment method for blasting of a damaged structure provided by the present invention adopt a non-explosive vibration source system, which is composed of a power supply, a control box, a capacitor bank, a gun head and a cable, avoiding the safety hazards brought by the use of explosives, making the experiment process safer and more reliable. The energy storage capacity and discharge current of the capacitor bank can be accurately controlled, ensuring the stability of the electric spark blasting, thereby generating a stable blasting stress wave, which is beneficial to accurately simulating and analyzing the stress condition of the damaged structure during the blasting process;

[0041] The adopted monitoring system is composed of a piezoelectric intelligent sensing component, a signal collector, a signal amplifier and a computer. The intelligent aggregate is small in size and high in sensitivity, and is not only suitable for monitoring the change of the piezoelectric passive signal at the damaged part of the structure during blasting, but also can monitor the change of the piezoelectric active signal around the damaged part of the structure before and after blasting, so as to realize a comprehensive analysis of the instantaneous dynamic response law and the cumulative damage law at the damaged part of the structure. Brief Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0043] Figure 1 It is a schematic connection structure diagram of the power supply, the control box, the capacitor bank, the gun head and the cable provided by the embodiment of the present invention;

[0044] Figure 2 It is a schematic combination diagram of the anode, the cathode, the polyethylene material, the steel material and the iron disk provided by the embodiment of the present invention;

[0045] Figure 3 It is a schematic diagram of the piezoelectric intelligent sensing component, the signal collector, the signal amplifier and the computer provided by the embodiment of the present invention;

[0046] Figure 4 It is a schematic composition structure diagram of the piezoelectric intelligent sensing component provided by the embodiment of the present invention;

[0047] Figure 5Schematic diagram of the structure of the intelligent aggregate provided by an embodiment of the present invention;

[0048] Figure 6 Schematic diagram of a connection structure of a seismic source system, a monitoring system and a structural specimen provided by an embodiment of the present invention;

[0049] Figure 7 Schematic diagram of a connection structure of a seismic source system, a monitoring system and a structural specimen provided by an embodiment of the present invention;

[0050] Figure 8 Signal amplitude data graph of the passive monitoring signal provided by an embodiment of the present invention;

[0051] Figure 9 Signal amplitude, frequency domain signal amplitude and frequency band energy ratio data graph of the active monitoring signal provided by an embodiment of the present invention;

[0052] Figure 10 Principle diagram of wavelet packet decomposition provided by an embodiment of the present invention.

[0053] Explanation of reference numerals:

[0054] 1. Power supply; 2. Control box; 3. Capacitor box; 4. Gun head; 5. Conductive medium; 6. Cable; 7. Iron disk; 8. Piezoelectric intelligent sensing component; 9. Signal collector; 10. Signal amplifier; 11. Computer; 12. Intelligent aggregate; 13. Shielded wire; 14. BNC end; 15. Insulating shell; 16. PZT lead zirconate titanate piezoelectric ceramic material; 17. Anode; 18. Cathode; 19. Polyethylene material; 20. Steel material; 21. Blasthole; 22. Blasting stress wave; 23. Structural specimen. Detailed implementation manners

[0055] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0056] Please refer to Figures 1 to 7 , the present invention provides an indoor model experiment system for blasting of damaged structures, including a structural specimen 23, a seismic source system and a monitoring system;

[0057] The seismic source system includes: a power supply 1, a control box 2, a capacitor box 3, a gun head 4 and a conductive medium 5, wherein the power supply 1, the control box 2, the capacitor box 3 and the gun head 4 are sequentially connected through a cable 6. The capacitor box 3 can adopt a 4-stage parallel modular design, with a total capacity of 0.25 F to 1.0 F, a charging time ≤ 25 seconds, a peak discharge current ≥ 50 A, and an adjustable energy density of 5 KJ to 20 KJ, corresponding to a rock mass damage of 20 mm to 50 mm;

[0058] The structural specimen 23 is provided with a disease facing the explosion side and a back explosion side, and a blast hole 21 for installing the blasting head 4 is prefabricated on the disease facing the explosion side. The conductive medium 5 is filled in the blast hole 21, and the lower end of the blasting head 4 is immersed in the conductive medium 5. The disease area is located by the prefabricated blast hole 21, and the conductive medium 5 is filled to form a discharge circuit;

[0059] The monitoring system includes: two groups of piezoelectric intelligent sensing components 8, a signal collector 9, a signal amplifier 10 and a computer 11. The piezoelectric intelligent sensing component 8 includes a smart aggregate 12, a shielded wire 13 and a BNC end 14 connected in sequence. The smart aggregate 12 is composed of an insulating shell 15 encapsulating PZT lead zirconate titanate piezoelectric ceramic material 16;

[0060] The two groups of piezoelectric intelligent sensing components 8 are respectively fixed on the disease facing the explosion side and the back explosion side of the structural specimen 23, where:

[0061] The piezoelectric intelligent sensing component 8 fixed on the explosion facing side serves as a signal receiver and is connected to the computer 11 through the signal collector 9;

[0062] The piezoelectric intelligent sensing component 8 fixed on the back explosion side serves as a signal driver and is connected to the computer 11 through the signal amplifier 10 and the signal collector 9.

[0063] Specifically, the power supply 1 provides initial electrical energy for the system. The control box 2 is responsible for adjusting the charging voltage and the charge and discharge timing sequence to ensure the safe energy storage of the capacitor bank 3. The capacitor bank 3 receives the electrical energy from the power supply 1 through the control box 2 and stores it. The energy storage capacity of the capacitor bank 3 directly affects the intensity of the blasting stress wave 22. The stability of the electric spark blasting is ensured by precisely controlling the discharge current. The capacitor bank 3 adopts a modular design and supports multi-stage capacitor parallel connection or series connection to adapt to the energy requirements of different rock mass models;

[0064] The computer 11 controls the signal amplifier 10 to input an excitation voltage to the smart aggregate 12 to stimulate the PZT lead zirconate titanate piezoelectric ceramic material 16 to generate an active stress wave for detecting the initial state of the structural disease before blasting; the smart aggregate 12 senses the charge signal generated by the blasting stress wave 22 and transmits it to the signal collector 9 through the shielded wire 13 and converts it into a 0V - 10V voltage signal to achieve passive monitoring; the area on the explosion facing side where the blasting shock wave directly acts (such as at the crack of the tunnel lining), and the back explosion side is the far end of the shock wave propagation, which is used to compare the damage differences, so as to clarify the stress direction in the experiment and facilitate the analysis of the local and overall effects of blasting on the disease structure. And through the same sensing component with both driving and receiving functions, two-way monitoring is realized by switching the circuit, which simplifies the system complexity.

[0065] In one embodiment of the present invention, the gun head 4 includes an anode 17, a cathode 18, an iron disk 7, and a steel material 20. The lower end of the anode 17 penetrates through the iron disk 7. The outside of the anode 17 is wrapped with a polyethylene material 19, and the upper end of the anode 17 is exposed and connected to the capacitor bank 3 through a cable 6.

[0066] The steel material 20 is arranged at the bottom of the iron disk 7, and the steel material 20 wraps the polyethylene material 19 and the cathode 18. The cathode 18 is connected to the iron disk 7 through the steel material 20, and the iron disk 7 is connected to the capacitor bank 3 through a cable 6.

[0067] Specifically, the outside of the anode 17 is wrapped with the polyethylene material 19 for insulation, and only the lower end is exposed and immersed in the conductive medium 5. The cathode 18 is fixed through the steel material 20 and connected to the iron disk 7. When the capacitor bank 3 releases high-voltage electrical energy, the conductive medium 5 is broken down between the anode 17 and the cathode 18, generating a high-temperature plasma channel to form an electric spark blast. The design of the steel material 20 and the iron disk 7 enhances the mechanical strength of the electrode, prevents electrode loss caused by high-frequency discharge, extends the service life of the gun head 4, realizes non-explosive blasting, avoids safety hazards, and the conductive medium 5 enhances the current conduction efficiency to ensure the stable release of stress waves.

[0068] In one embodiment of the present invention, the lower end of the anode 17 is flush with the polyethylene material 19.

[0069] In one embodiment of the present invention, the conductive medium 5 is water or an electrolyte-containing liquid, forming a discharge medium to transfer electrical energy and convert it into mechanical energy, with low cost and controllable conductivity, suitable for different rock mass materials (such as concrete, sandstone).

[0070] Please refer to Figures 1 to 9 , the present invention also provides an indoor model experiment method for blasting of damaged structures, applicable to the indoor model experiment system for blasting of damaged structures as described above, including the following steps:

[0071] S1. Connect the power supply 1, the control box 2, the capacitor bank 3, and the gun head 4 through the cable 6. Fill the pre-drilled hole 21 of the structural specimen 23 with the conductive medium 5, and immerse the lower end of the anode 17 and the cathode 18 of the gun head 4 into the conductive medium 5.

[0072] S2. Fix and connect the piezoelectric intelligent sensing component 8 of the signal collector 9 on the damage-facing explosion side of the structural specimen 23 as the signal receiver;

[0073] Fix and connect the piezoelectric intelligent sensing component 8 of the signal amplifier 10 on the damage-opposite explosion side of the structural specimen 23 as the signal driver;

[0074] S3. Control the signal driver by the computer 11 to generate stress waves. The signal receiver collects the signals, and the signal amplifier 10 transmits the signals to the signal collector 9 to be converted into voltage signals, and then transmits them to the computer 11 side. Record the monitoring results as the active monitoring signals around the structural diseases before blasting;

[0075] The piezoelectric intelligent sensing component 8 on the back-blasting side acts as a signal driver, inputs high-frequency electrical signals, and excites the PZT lead zirconate titanate piezoelectric ceramic material 16 to generate stress waves; the piezoelectric intelligent sensing component 8 on the front-blasting side receives the signals, analyzes the time-domain / frequency-domain characteristics of the propagation path, obtains the initial state of the structure, and provides a benchmark for damage analysis;

[0076] S4. Remove the piezoelectric intelligent sensing component 8 connected to the signal amplifier 10;

[0077] S5. Control the power supply 1 to charge the capacitor bank 3 through the control box 2. After the charging is completed; then control the capacitor bank 3 to release energy to the gun head 4 through the control box 2. At this time, an electric spark is generated between the anode 17 and the cathode 18 ends of the gun head 4 immersed in the conductive medium 5 to break down the conductive medium 5 and excite blasting stress waves 22 to the surrounding rock mass; at the same time, the intelligent aggregate 12 at the disease front-blasting side of the structural specimen 23 generates charges according to the strength of the blasting stress waves 22 and transmits them to the signal collector 9. The signal collector 9 converts the charge signals into voltage signals and transmits them to the computer 11 side. Record the monitoring results as the passive monitoring signals at the instant of the first blasting;

[0078] S6. Repeat step S3 and record the monitoring results as the active monitoring signals around the structural diseases after the first blasting;

[0079] S7. Repeat steps S4 to S5 for the second blasting and record the monitoring results as the passive monitoring signals at the instant of the second blasting;

[0080] S8. Repeat steps S3 to S5. Analyze the instantaneous response law at the disease front-blasting side of the structure through the passive monitoring signals recorded at the instant of each blasting. Analyze the cumulative damage law of the structure around the structural diseases by comparing the active monitoring signals before and after each blasting. Repeat the multiple blasting load actions in the blasting simulation construction, and compare the active monitoring signals (such as the frequency band energy attenuation rate) before and after each blasting to quantify the cumulative damage.

[0081] In step S2, the intelligent aggregate 12 in the piezoelectric intelligent sensing component 8 is fixed on the structural specimen 23 through a vaseline coupling agent;

[0082] In step S8, the analysis of the passive monitoring signals includes the comparison of the response time difference and the peak intensity, and the analysis of the active monitoring signals includes the calculation of the time-domain distribution and the frequency band energy distribution after the fast Fourier transform;

[0083] At the instant of blasting, the time difference between the arrival time of the stress wave signal received by the piezoelectric intelligent sensing component on the blast-facing side of the structural disease and the blasting trigger time (i.e., the response time difference) reflects the propagation speed and path integrity of the stress wave in the structural specimen. By recording the blasting trigger moment (t0) and the time (t1) when the piezoelectric signal first exceeds the threshold value through a signal collector, calculate the time difference Δt = t1 - t0. Comparing the Δt values of multiple blasts, if Δt gradually increases, it indicates that structural damage leads to a decrease in wave speed (the stiffness of the material in the damaged area decreases).

[0084] The peak intensity of the passive monitoring signal directly reflects the instantaneous impact energy of the blasting stress wave on the structural specimen. The damage in the disease area will cause the attenuation of the stress wave energy, manifested as a decrease in the peak intensity. Extract the maximum value (Vmax) of the amplitude of the passive signal for each blast. Through normalization processing (such as taking the Vmax of the first blast as the reference value of 100%), calculate the peak attenuation rate of subsequent blasts to quantify the damage degree. For example, if the V_max of the second blast is 80% of the reference value, it indicates that a 20% stiffness loss has occurred in the disease area.

[0085] Evaluate the influence of structural diseases on the signal propagation path through the amplitude and waveform changes of the active excitation signal in the time domain. Compare the amplitudes of the active signals before and after blasting (such as the amplitude A1 before the first blast and the amplitude A2 after the blast), and calculate the attenuation rate: ΔA = (A1 - A2) / A1 × 100%. Through waveform similarity (such as correlation coefficient) analysis, judge interference phenomena such as reflected waves and scattered waves caused by damage. The amplitude attenuation and waveform distortion can locate the damaged area (such as cracks and cavities).

[0086] Structural damage will change the frequency components of the signal. The high-frequency energy decays due to reflection / scattering at the material interface, and the proportion of low-frequency energy increases. Perform FFT transformation on the active signal to convert the time-domain signal into a frequency-domain energy distribution. Extract the characteristic frequency bands (such as 0 - 100000Hz as the low-frequency band and 100000 - 500000Hz as the high-frequency band), and calculate the energy proportion of each frequency band. For example, if the energy proportion of the high-frequency band (100000 - 500000Hz) drops from 40% to 25% after blasting, it indicates that damage leads to high-frequency energy dissipation.

[0087] In an embodiment of the present invention, the frequency band energy distribution is extracted by the wavelet packet decomposition method, which is used to quantify the frequency-domain characteristics of structural damage. The wavelet packet decomposition decomposes the signal layer by layer into different frequency bands, extracts the energy distribution characteristics of each frequency band, and realizes the frequency-domain quantification of damage and the identification of damage types (such as microcracks, cavities, etc.).

[0088] Please refer to Figure 10 , the specific steps for extracting the frequency band energy distribution by the wavelet packet decomposition method are as follows:

[0089] Express each group of corresponding decomposed signals Sj as:

[0090] S j ={S j'1 ,S j'2 ,…S j'm};

[0091] Where j is the signal frequency band and m is the sampling quantity;

[0092] Define the energy of the decomposed signal as:

[0093]

[0094] E j represents the total sum of the signal vibration energy within this frequency band, and damage will cause a significant change in the energy of a specific frequency band;

[0095] The signal energy vector at time i is:

[0096]

[0097] describes the frequency-domain energy distribution characteristics of the signal at time i and is used for dynamic damage monitoring;

[0098] The total energy of the signal received by the piezoelectric intelligent sensing component 8 at time i is expressed as:

[0099]

[0100] Perform normalization processing to eliminate the interference of the absolute energy quantity and highlight the relative energy change caused by damage;

[0101] Through the above-mentioned wavelet packet decomposition method, multi-scale frequency-domain diagnosis of structural damage under blasting loads can be realized, providing a high-precision and quantifiable experimental basis for the evaluation of tunnel engineering diseases.

[0102] The structural specimen 23 was used to conduct the above experiment with dimensions of 500mm × 500mm × 200mm (C30 concrete), and the obtained results are as Figure 8 and Figure 9 shown, where Figure 9 Figure a in it is the signal amplitude data diagram of the active monitoring signal, Figure b is the frequency-domain signal amplitude data diagram of the active monitoring signal, and Figure c is the frequency-band energy proportion data diagram.

[0103] This application realizes the controllable and accurate analysis of the dynamic response and damage evolution law of the damaged structure under blasting loads through electric spark blasting simulation, piezoelectric two-way monitoring, and wavelet packet signal processing, providing a reliable experimental basis for the safe construction of tunnel engineering.

[0104] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. The meaning of "a plurality" is two or more unless specifically defined otherwise.

[0105] In the present invention, unless otherwise clearly specified and defined, terms such as "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0106] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0107] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example" or "some examples", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not have to be directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0108] In the drawings of the disclosed embodiments of the present invention, only the structures related to the disclosed embodiments are involved, and other structures can refer to the general design. Without conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

[0109] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An indoor model experiment system for the blasting of a disease structure, characterized in that, It includes a structural specimen (23), a seismic source system and a monitoring system; The seismic source system includes: a power supply (1), a control box (2), a capacitor bank (3), a gun head (4) and a conductive medium (5), where the power supply (1), the control box (2), the capacitor bank (3), and the gun head (4) are sequentially connected through a cable (6); On the structural specimen (23), there are a disease-facing explosion side and a back-explosion side, and a blast hole (21) for installing the gun head (4) is prefabricated on the disease-facing explosion side. The conductive medium (5) is filled in the blast hole (21), and the lower end of the gun head (4) is immersed in the conductive medium (5); The monitoring system includes: two groups of piezoelectric intelligent sensing components (8), a signal collector (9), a signal amplifier (10) and a computer (11). The piezoelectric intelligent sensing component (8) includes a smart aggregate (12), a shielded wire (13) and a BNC terminal (14) connected in sequence. The smart aggregate (12) is composed of an insulating shell (15) encapsulating PZT lead zirconate titanate piezoelectric ceramic material (16); The two groups of piezoelectric intelligent sensing components (8) are respectively fixed on the disease-facing explosion side and the back-explosion side of the structural specimen (23), where: The piezoelectric intelligent sensing component (8) fixed on the explosion-facing side serves as a signal receiver and is connected to the computer (11) through the signal collector (9); The piezoelectric intelligent sensing component (8) fixed on the back-explosion side serves as a signal driver and is connected to the computer (11) through the signal amplifier (10) and the signal collector (9).

2. The indoor model experiment system for blasting of a disease structure according to claim 1, characterized in that, The gun head (4) includes an anode (17), a cathode (18), an iron disk (7) and a steel material (20). The lower end of the anode (17) penetrates through the iron disk (7). The outside of the anode (17) is wrapped with a polyethylene material (19), and the upper end of the anode (17) is exposed and connected to the capacitor bank (3) through a cable (6); The steel material (20) is arranged at the bottom of the iron disk (7), and the steel material (20) wraps the polyethylene material (19) and the cathode (18). The cathode (18) is connected to the iron disk (7) through the steel material (20), and the iron disk (7) is connected to the capacitor bank (3) through a cable (6).

3. An indoor model experiment system for blasting of a disease structure according to claim 2, characterized in that, The lower end of the anode (17) is flush with the polyethylene material (19).

4. An indoor model experiment system for blasting of a disease structure according to claim 1, characterized in that, The conductive medium (5) is water or an electrolyte-containing liquid.

5. An indoor model experimental method for blasting a disease structure, characterized in that, An indoor model experiment system suitable for the blasting of the disease structure described in any one of the above claims 1-4 includes the following steps: S1. Connect the power supply (1), the control box (2), the capacitor bank (3), and the gun head (4) through a cable (6). Fill the prefabricated blast hole (21) of the structural specimen (23) with the conductive medium (5), and immerse the lower end of the anode (17) and the cathode (18) of the gun head (4) in the conductive medium (5); S2. Fix the piezoelectric intelligent sensing component (8) connected to the signal collector (9) on the disease-facing explosion side of the structural specimen (23) as a signal receiver; Fix the piezoelectric intelligent sensing component (8) connected to the signal amplifier (10) on the disease back-explosion side of the structural specimen (23) as a signal driver; S3. Control the signal driver by a computer (11) to generate stress waves, collect signals by a signal receiver, and transmit the signals to a signal collector (9) through a signal amplifier (10) to be converted into voltage signals, and then transmit them to the computer (11) side. Record the monitoring results as the active monitoring signals around the structural diseases before blasting. S4. Remove the piezoelectric intelligent sensing component (8) connected to the signal amplifier (10). S5. Control the power supply (1) to charge the capacitor bank (3) through the control box (2). After charging is completed, then control the capacitor bank (3) to release energy to the blast head (4) through the control box (2). At this time, an electric spark is generated between the anode (17) and the cathode (18) ends of the blast head (4) immersed in the conductive medium (5) to break down the conductive medium (5) and excite blasting stress waves (22) to the surrounding rock mass. At the same time, the intelligent aggregate (12) at the blast-facing side of the disease of the structural specimen (23) generates charges according to the intensity of the blasting stress waves (22), and transmits them to the signal collector (9). The signal collector (9) converts the charge signals into voltage signals and transmits them to the computer (11) side. Record the monitoring results as the passive monitoring signals at the instant of the first blasting. S6. Repeat step S3, and record the monitoring results as the active monitoring signals around the structural diseases after the first blasting. S7. Repeat steps S4 to S5 for the second blasting, and record the monitoring results as the passive monitoring signals at the instant of the second blasting. S8. Repeat steps S3 to S5. Analyze the instantaneous response law at the blast-facing side of the structural diseases by analyzing the passive monitoring signals at the instant of each recorded blasting, and analyze the cumulative damage law of the structure around the structural diseases by comparing the active monitoring signals before and after each blasting.

6. The indoor model experiment method for blasting of a disease structure according to claim 5, characterized in that, In step S2, the intelligent aggregate (12) in the piezoelectric intelligent sensing component (8) is fixed on the structural specimen (23) through a vaseline coupling agent.

7. An indoor model experiment method for blasting of a disease structure according to claim 5, characterized in that, In step S8, the analysis of the passive monitoring signals includes the comparison of the response time difference and the peak intensity, and the analysis of the active monitoring signals includes the calculation of the time-domain distribution and the frequency-band energy distribution after fast Fourier transform.

8. An indoor model experiment method for blasting of a disease structure according to claim 7, characterized in that, The frequency-band energy distribution is extracted by the wavelet packet decomposition method, which is used to quantify the frequency-domain characteristics of structural damage.

9. The indoor model experiment method for blasting of a disease structure according to claim 8, characterized in that The specific steps for extracting the frequency-band energy distribution by the wavelet packet decomposition method are as follows: Express each corresponding decomposed signal S j as: S j = {S j'1 , S j'2 , … S j'm}; In the formula, j is the signal frequency band, and m is the sampling amount. Define the energy of the decomposed signal as: The signal energy vector at time i is: The total energy of the signal received by the piezoelectric intelligent sensing component (8) at time i is expressed as:

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