An indoor model experimental system and method for blasting of damaged structures.

Abstract

This invention discloses an indoor model experimental system and method for blasting damaged structures, relating to the field of tunnel engineering. It includes a structural specimen, a seismic source system, and a monitoring system. The seismic source system comprises a power supply, a control box, a capacitor box, a blast head, and a conductive medium. The power supply, control box, capacitor box, and blast head are connected sequentially via cables. The structural specimen has a blast-facing side and a blast-back side, with a pre-drilled blast hole on the blast-facing side for mounting the blast head. The conductive medium fills the blast hole. This invention, by employing a non-explosive seismic source system consisting of a power supply, control box, capacitor box, blast head, and cables, avoids the safety hazards associated with using explosives, making the experimental process safer and more reliable. It can precisely control the energy storage capacity and discharge current of the capacitor box, ensuring the stability of the electric spark blasting and generating a stable blasting stress wave, which is beneficial for accurately simulating and analyzing the stress state of the damaged structure during the blasting process.

Description

Technical Field

[0001] This invention relates to tunnel engineering technology, specifically to an indoor model experimental system and method for blasting damaged structures. Background Technology

[0002] During the construction of new tunnels, it is often necessary to work alongside existing tunnels. However, due to long-term service and the influence of complex surrounding geological environments, the lining structures of existing tunnels frequently exhibit defects such as cracks and voids. To ensure the safe and smooth progress of new tunnel construction while avoiding damage to surrounding existing tunnels with defects, it is particularly important to develop an indoor model experimental system suitable for the blasting of defective structures. This system can simulate the stress conditions of defective structures during blasting, providing technical support and safety guidance for on-site construction of new tunnels.

[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, leading to numerous challenges and limitations in indoor experiments using explosives. 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 this invention is to provide an indoor model experimental system and method for blasting damaged structures, in order to solve the problems of safety hazards, environmental pollution, and difficulty in accurately controlling blasting stress waves in existing technologies that use explosives as the seismic source for indoor blasting experiments.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides an indoor model experimental system for the explosion of a damaged structure, 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 probe, and a conductive medium, wherein the power supply, control box, capacitor box, and probe are connected in sequence via cables;

[0008] The structural specimen has a defect-facing side and a defect-back side, and a pre-drilled borehole for installing the gun head is located on the defect-facing side. The borehole is filled with a conductive medium, and the lower end of the gun head is immersed in the conductive medium.

[0009] The monitoring system includes: two sets of piezoelectric smart sensing components, a signal acquisition unit, a signal amplifier, and a computer. The piezoelectric smart sensing components include smart aggregate, shielded wire, and BNC terminal connected in sequence. The smart aggregate is composed of PZT lead zirconate titanate piezoelectric ceramic material encapsulated in an insulating shell.

[0010] Two sets of piezoelectric smart sensing components are fixed to the blast-facing side and the blast-back side of the structural specimen, respectively, wherein:

[0011] The piezoelectric intelligent sensing component fixed on the explosion-facing side serves as a signal receiver and is connected to a computer via a signal acquisition device.

[0012] The piezoelectric smart sensing component fixed to the back explosion side acts as a signal driver and is connected to the computer through a signal amplifier and a signal acquisition device.

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

[0014] A steel material is placed at the bottom of an iron disc, and the steel material wraps around the polyethylene material and the cathode. The cathode is connected to the iron disc through the steel material, and the iron disc 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] This invention also provides an indoor model test method for the blasting of damaged structures, applicable to the indoor model test system for the blasting of damaged structures described above, comprising the following steps:

[0018] S1. Connect the power supply, control box, capacitor box, and gun head through cables. Fill the prefabricated gun holes in the structural specimen with conductive medium and immerse the lower end of the anode and cathode of the gun head in the conductive medium.

[0019] S2. A piezoelectric intelligent sensing component of a signal acquisition device is fixedly connected to the explosion-facing side of the structural specimen as a signal receiver.

[0020] A piezoelectric intelligent sensing component of a signal amplifier is fixedly connected to the defective back-explosion side of the structural specimen as a signal driver.

[0021] S3. Stress waves are generated by a computer-controlled signal driver, the signal receiver collects the signal, and the signal is transmitted to the signal acquisition unit through the signal amplifier to be converted into a voltage signal and then transmitted to the computer. The monitoring result is recorded as an active monitoring signal around the structural defects before the blasting.

[0022] S4. Remove the piezoelectric smart sensor component connected to the signal amplifier.

[0023] S5. The power supply is controlled by the control box to charge the capacitor box. After charging is completed, the capacitor box is controlled by the control box to release energy to the blast head. At this time, an electric spark is generated between the anode and cathode ends of the blast head immersed in the conductive medium, which breaks down the conductive medium and excites blasting stress waves to the surrounding rock mass. At the same time, the smart aggregate at the blast-facing side of the structural specimen generates charge according to the strength of the blasting stress wave and transmits it to the signal acquisition device. The signal acquisition device converts the charge signal into a voltage signal and transmits it to the computer. The monitoring result is recorded as the passive monitoring signal at the moment of the first blast.

[0024] S6. Repeat step S3 and record the monitoring results as active monitoring signals around the structural defects after the first blasting.

[0025] S7. Repeat steps S4 to S5 to perform a second blast, and record the monitoring results as the passive monitoring signal at the moment of the second blast.

[0026] S8. Repeat steps S3 to S5. Analyze the instantaneous response pattern of the structural defect on the blast-facing side by analyzing the passive monitoring signals recorded at the moment of each blast. Analyze the cumulative damage pattern of the structure surrounding the structural defect by comparing the active monitoring signals before and after each blast.

[0027] Furthermore, in step S2, the smart aggregate within the piezoelectric smart sensing component is fixed to the structural specimen using Vaseline coupling agent.

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

[0029] Furthermore, the frequency band energy distribution is extracted using wavelet packet decomposition to quantify the frequency domain characteristics of structural damage.

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

[0031] The corresponding decomposed signal S of each group j Represented 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 quantity;

[0034] The energy of the decomposed signal is defined as:

[0035]

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

[0037]

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

[0039]

[0040] Compared with existing technologies, the present invention provides an indoor model experimental system and method for blasting damaged structures. By adopting a non-explosive source system, consisting of a power supply, control box, capacitor box, blast head and cable, it avoids the safety hazards caused by the use of explosives, making the experimental process safer and more reliable. It can precisely control the energy storage capacity and discharge current of the capacitor box, which can ensure the stability of the electric spark blasting, thereby generating a stable blasting stress wave, which is beneficial for accurately simulating and analyzing the stress situation of the damaged structure during the blasting process.

[0041] The monitoring system consists of piezoelectric intelligent sensing components, signal acquisition devices, signal amplifiers, and a computer. The intelligent aggregate is small in size and highly sensitive. It is not only suitable for monitoring the changes in piezoelectric passive signals at structural defects during blasting, but also for monitoring the changes in piezoelectric active signals around structural defects before and after blasting. This enables a comprehensive analysis of the instantaneous dynamic response and cumulative damage patterns at structural defects. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0043] Figure 1 A schematic diagram of the connection structure of the power supply, control box, capacitor box, gun head and cable provided in an embodiment of the present invention;

[0044] Figure 2 A schematic diagram illustrating the combination of the anode, cathode, polyethylene material, steel material, and iron disk provided in an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of the piezoelectric intelligent sensing component, signal acquisition unit, signal amplifier, and computer provided in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the composition structure of the piezoelectric smart sensing component provided in an embodiment of the present invention;

[0047] Figure 5This is a schematic diagram of the structure of the smart aggregate provided in an embodiment of the present invention;

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

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

[0050] Figure 8 This is a signal amplitude data diagram of the passive monitoring signal provided in an embodiment of the present invention;

[0051] Figure 9 This invention provides a graph showing the signal amplitude, frequency domain signal amplitude, and frequency band energy percentage of the active monitoring signal in an embodiment of the invention.

[0052] Figure 10 This is a schematic diagram of wavelet packet decomposition provided in an embodiment of the present invention.

[0053] Explanation of reference numerals in the attached figures:

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

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

[0056] Please see Figures 1 to 7 The present invention provides an indoor model experimental system for the explosion of a damaged structure, including a structural specimen 23, a seismic source system and a monitoring system;

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

[0058] The structural specimen 23 has a defect-facing side and a defect-back side, and a pre-made borehole 21 for installing the gun head 4 is located on the defect-facing side. The conductive medium 5 is filled in the borehole 21, and the lower end of the gun head 4 is immersed in the conductive medium 5. The defect area is located through the pre-made borehole 21, and the conductive medium 5 is filled to form a discharge circuit.

[0059] The monitoring system includes: two sets of piezoelectric intelligent sensing components 8, a signal acquisition unit 9, a signal amplifier 10, and a computer 11. The piezoelectric intelligent sensing components 8 include intelligent aggregate 12, shielded wire 13, and BNC terminal 14 connected in sequence. The intelligent aggregate 12 is composed of PZT lead zirconate titanate piezoelectric ceramic material 16 encapsulated in an insulating shell 15.

[0060] Two sets of piezoelectric smart sensing components 8 are respectively fixed to the blast-facing side and the blast-back side of the structural specimen 23, wherein:

[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 via the signal acquisition device 9.

[0062] The piezoelectric smart sensor component 8, fixed to the back explosion side, serves as a signal driver and is connected to the computer 11 via the signal amplifier 10 and the signal acquisition device 9.

[0063] Specifically, power supply 1 provides initial electrical energy to the system, control box 2 is responsible for adjusting the charging voltage and charging / discharging sequence to ensure the safe energy storage of capacitor box 3. Capacitor box 3 receives and stores electrical energy from power supply 1 through control box 2. The energy storage capacity of capacitor box 3 directly affects the intensity of the blasting stress wave 22. The stability of electric spark blasting is ensured by precisely controlling the discharge current. Capacitor box 3 adopts a modular design and supports multi-level capacitors in parallel 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 the excitation voltage to the smart aggregate 12, which excites the PZT lead zirconate titanate piezoelectric ceramic material 16 to generate an active stress wave, used to detect the initial state of structural defects before blasting. The smart aggregate 12 senses the charge signal generated by the blasting stress wave 22, transmits it to the signal acquisition unit 9 through the shielded wire 13, and converts it into a 0V~10V voltage signal to achieve passive monitoring. The blast-facing side simulates the area directly affected by the blasting shock wave (such as the crack in the tunnel lining), while the blast-back side is the far end of the shock wave propagation, used to compare damage differences, thereby clarifying the direction of force in the experiment, facilitating the analysis of the local and overall impact of blasting on the defective structure. Furthermore, the same sensing component has both driving and receiving functions, and bidirectional monitoring is achieved through switching circuits, simplifying the system complexity.

[0065] In one embodiment of the present invention, the gun head 4 includes an anode 17, a cathode 18, an iron disc 7 and a steel material 20. The lower end of the anode 17 penetrates through the iron disc 7. 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 box 3 through a cable 6.

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

[0067] Specifically, the anode 17 is wrapped with polyethylene material 19 for insulation, with only the lower end exposed and immersed in the conductive medium 5. The cathode 18 is fixed by steel material 20 and connected to iron disc 7. When the capacitor box 3 releases high-voltage electrical energy, the conductive medium 5 between the anode 17 and the cathode 18 breaks down, generating a high-temperature plasma channel and forming an electric spark explosion. The design of steel material 20 and iron disc 7 enhances the mechanical strength of the electrodes, prevents electrode wear caused by high-frequency discharge, extends the life of the gun head 4, realizes non-explosive explosion, avoids safety hazards, and the conductive medium 5 enhances the current conduction efficiency to ensure 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 a liquid containing electrolytes, forming a discharge medium that transmits electrical energy and converts it into mechanical energy. It is low in cost and has controllable conductivity, making it suitable for different rock materials (such as concrete and sandstone).

[0070] Please see Figures 1 to 9 The present invention also provides an indoor model test method for the blasting of damaged structures, applicable to the aforementioned indoor model test system for the blasting of damaged structures, comprising the following steps:

[0071] S1. Connect the power supply 1, control box 2, capacitor box 3, and gun head 4 through cable 6. Fill the prefabricated gun hole 21 of the structural specimen 23 with 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. The piezoelectric intelligent sensing component 8 of the signal acquisition device 9 is fixedly connected to the explosion-facing side of the structural specimen 23 as a signal receiver.

[0073] The piezoelectric intelligent sensing component 8 of the signal amplifier 10 is fixedly connected to the defective back-explosion side of the structural specimen 23 as a signal driver.

[0074] S3. The computer 11 controls the signal driver to generate stress waves, the signal receiver collects the signal, and the signal amplifier 10 transmits the signal to the signal collector 9 to convert it into a voltage signal, which is then transmitted to the computer 11. The monitoring result is recorded as an active monitoring signal around the structural defects before the blasting.

[0075] The piezoelectric intelligent sensing component 8 on the back blast side acts as a signal driver, inputting a high-frequency electrical signal to excite the PZT lead zirconate titanate piezoelectric ceramic material 16 to generate stress waves; the piezoelectric intelligent sensing component 8 on the front blast side receives the signal, 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 smart sensing component 8 connected to the signal amplifier 10;

[0077] S5. The power supply 1 is controlled by the control box 2 to charge the capacitor box 3. After charging is completed, the capacitor box 3 is controlled by the control box 2 to release energy to the blast head 4. At this time, an electric spark is generated between the anode 17 and cathode 18 ends of the blast head 4 immersed in the conductive medium 5, which breaks down the conductive medium 5 and generates blasting stress wave 22 to the surrounding rock mass. At the same time, the smart aggregate 12 at the defective blast-facing side of the structural specimen 23 generates charge according to the strength of the blasting stress wave 22 and transmits it to the signal acquisition device 9. The signal acquisition device 9 converts the charge signal into a voltage signal and transmits it to the computer 11. The monitoring result is recorded as the passive monitoring signal at the moment of the first blast.

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

[0079] S7. Repeat steps S4 to S5 to perform a second blast, and record the monitoring results as the passive monitoring signal at the moment of the second blast.

[0080] S8. Repeat steps S3 to S5. Analyze the instantaneous response pattern of the structural defect on the blast-facing side by recording the passive monitoring signal at the moment of each blast. Analyze the cumulative damage pattern of the structure surrounding the structural defect by comparing the active monitoring signal before and after each blast. Repeat the blasting to simulate multiple blasting loads during construction. Quantify the cumulative damage by comparing the active monitoring signal (such as the frequency band energy attenuation rate) before and after each blast.

[0081] In step S2, the smart aggregate 12 in the piezoelectric smart sensing component 8 is fixed to the structural specimen 23 by Vaseline coupling agent;

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

[0083] At the moment of blasting, the 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 defect and the blast 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 blast trigger time (t0) and the time when the piezoelectric signal first exceeds the threshold (t1) through the signal acquisition device, the time difference Δt = t1 - t0 is calculated. By comparing the Δt values ​​of multiple blasts, if Δt gradually increases, it indicates that the structural damage leads to a decrease in wave velocity (a decrease in the material stiffness of the damaged area).

[0084] The peak intensity of the passive monitoring signal directly reflects the instantaneous impact energy of the blasting stress wave on the structural specimen. Damage to the affected area will cause the stress wave energy to attenuate, which is manifested as a decrease in peak intensity. The maximum amplitude (Vmax) of the passive signal of each blast is extracted and normalized (e.g., using the Vmax of the first blast as the baseline value of 100%) to calculate the peak attenuation rate of subsequent blasts and quantify the degree of damage. If the Vmax of the second blast is 80% of the baseline value, it indicates that the affected area has suffered a 20% stiffness loss.

[0085] By analyzing the amplitude and waveform changes of the active excitation signal in the time domain, the impact of structural defects on the signal propagation path is assessed. The amplitude of the active signal before and after blasting (e.g., amplitude A1 before the first blast and amplitude A2 after the blast) is compared, and the attenuation rate is calculated: ΔA=(A1-A2) / A1×100%. Through waveform similarity analysis (e.g., correlation coefficient), interference phenomena such as reflected waves and scattered waves caused by damage are identified. Amplitude attenuation and waveform distortion can locate the damaged area (e.g., cracks and cavities).

[0086] Structural damage alters the frequency composition of a signal. High-frequency energy attenuates due to reflection / scattering at the material interface, while the proportion of low-frequency energy increases. By performing an FFT transform on the active signal, the time-domain signal is converted into a frequency-domain energy distribution. Feature frequency bands are extracted (e.g., 0-100000Hz is the low-frequency band, and 100000-500000Hz is the high-frequency band), and the energy proportion of each frequency band is calculated. If the energy proportion of the high-frequency band (100000-500000Hz) drops from 40% to 25% after the blast, it indicates that the damage has led to the dissipation of high-frequency energy.

[0087] In one embodiment of the present invention, the frequency band energy distribution is extracted by wavelet packet decomposition to quantify the frequency domain features of structural damage. Wavelet packet decomposition decomposes the signal into different frequency bands layer by layer, extracts the energy distribution features of each frequency band, and realizes frequency domain quantification of damage and damage type identification (such as microcracks, voids, etc.).

[0088] Please see Figure 10 The specific steps for extracting frequency band energy distribution using wavelet packet decomposition are as follows:

[0089] The decomposed signal Sj corresponding to each group is represented as:

[0090] S j ={S j'1 ,S j'2 ,…S j'm};

[0091] In the formula, j is the signal frequency band, and m is the sampling quantity;

[0092] The energy of the decomposed signal is defined as:

[0093]

[0094] E j This represents the total energy of signal vibration within this frequency band; damage will cause significant changes in the energy of a specific frequency band.

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

[0096]

[0097] It 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 smart sensing component 8 at time i is expressed as:

[0099]

[0100] Normalization eliminates interference from absolute energy quantities and highlights the relative energy changes caused by damage.

[0101] The wavelet packet decomposition method described above can be used to achieve multi-scale frequency domain diagnosis of structural damage under blasting loads, providing high-precision and quantifiable experimental evidence for the assessment of tunnel engineering defects.

[0102] Structural specimen 23, measuring 500mm × 500mm × 200mm (C30 concrete), was used for the above experiment, and the results are as follows. Figure 8 and Figure 9 As shown, where Figure 9 Figure a shows the signal amplitude data of the active monitoring signal, Figure b shows the frequency domain signal amplitude data of the active monitoring signal, and Figure c shows the frequency band energy ratio data.

[0103] This application achieves controllable and precise analysis of the dynamic response and damage evolution of damaged structures under blasting loads through electric spark blasting simulation, piezoelectric bidirectional monitoring, and wavelet packet signal processing, providing reliable experimental basis for safe construction of tunnel engineering.

[0104] In the description of this 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 number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. "A plurality of" means two or more, unless otherwise explicitly specified.

[0105] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0106] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0107] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0108] The accompanying drawings of the embodiments disclosed in this invention only involve structures relevant to the embodiments disclosed in this invention. Other structures can be referred to with common designs. Unless otherwise specified, the same embodiment and different embodiments of this 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 make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An experimental method for a laboratory model experiment system suitable for disease structure blasting, characterized in that, The experimental system comprises a structural test piece (23), a seismic source system and a monitoring system; The seismic source system comprises a power supply (1), a control box (2), a capacitor box (3), a gun head (4) and a conductive medium (5); The gun head (4) comprises an anode (17), a cathode (18), an iron disc (7) and a steel material (20); The structural test piece (23) is provided with a disease blast-facing side and a blast-back side, and a blast hole (21) for mounting the gun head (4) is prefabricated on the disease blast-facing side; The monitoring system comprises two groups of piezoelectric intelligent sensing components (8), a signal collector (9), a signal amplifier (10) and a computer (11), and the piezoelectric intelligent sensing components (8) comprise intelligent aggregates (12), shielded wires (13) and BNC end heads (14) connected in sequence; The experimental method comprises: S1, connecting the power supply (1), the control box (2), the capacitor box (3) and the gun head (4) through the cable (6), filling the conductive medium (5) in the prefabricated blast hole (21) of the structural test piece (23), and immersing the lower end of the anode (17) and the cathode (18) of the gun head (4) in the conductive medium (5); S2, fixing and connecting the piezoelectric intelligent sensing components (8) of the signal collector (9) on the disease blast-facing side of the structural test piece (23) as a signal receiver; Fixing and connecting the piezoelectric intelligent sensing components (8) of the signal amplifier (10) on the disease blast-back side of the structural test piece (23) as a signal driver; S3, generating stress waves by the computer (11) controlling the signal driver, collecting signals by the signal receiver, and transmitting the signals to the signal amplifier (10) to convert them into voltage signals, and then transmitting the voltage signals to the computer (11) end, and recording the monitoring results as the active monitoring signals around the structural disease before blasting; S4, removing the piezoelectric intelligent sensing components (8) connected with the signal amplifier (10); S5, charging the capacitor box (3) by the control box (2) controlling the power supply (1), and after the charging is completed, discharging energy from the capacitor box (3) to the gun head (4) by the control box (2), at this time, an electric spark is generated between the anode (17) and the cathode (18) of the gun head (4) immersed in the conductive medium (5) to break through the conductive medium (5) to excite blasting stress waves (22) to the surrounding rock mass; at the same time, the intelligent aggregates (12) on the disease blast-facing side of the structural test piece (23) generate electric charges according to the strength of the blasting stress waves (22) and transmit the electric charges to the signal collector (9), and the signal collector (9) converts the electric charge signals into voltage signals and transmits the voltage signals to the computer (11) end, and records the monitoring results as the passive monitoring signals at the first blasting moment; S6, repeating step S3, and recording the monitoring results as the active monitoring signals around the structural disease after the first blasting; S7, repeating steps S4 to S5 to perform the second blasting, and recording the monitoring results as the passive monitoring signals at the second blasting moment; S8, repeat steps S3 to S5, analyze the instantaneous response law of the structure disease on the blasting side by passive monitoring signal analysis of each recorded blasting instant, and analyze the cumulative damage law of the structure around the structure disease by comparing the active monitoring signal before and after each blasting.

2. The experimental method of claim 1, wherein, The lower end of the anode (17) penetrates the iron disc (7), the anode (17) is wrapped with polyethylene material (19) outside, and the upper end of the anode (17) is exposed and connected with the capacitor box (3) through the cable (6).

3. The experimental method of claim 2, wherein, The lower end of the anode (17) is flush with the polyethylene material (19).

4. The experimental method of claim 1, wherein, The conductive medium (5) is water or electrolyte-containing liquid.

5. The experimental method of claim 1, wherein, In step S2, the smart aggregate (12) in the piezoelectric intelligent sensing assembly (8) is fixed on the structure test piece (23) by vaseline coupling agent.

6. The experimental method of claim 1, wherein, In step S8, the analysis of passive monitoring signal includes response time difference and peak intensity comparison, and the analysis of active monitoring signal includes time domain distribution and frequency band energy distribution calculation after fast Fourier transform.

7. The experimental method of claim 6, wherein, The frequency band energy distribution is extracted by wavelet packet decomposition method, which is used to quantify the frequency domain characteristics of structure damage.

8. The experimental method of claim 7, wherein, The specific steps of wavelet packet decomposition method to extract frequency band energy distribution are as follows: Each of the corresponding decomposed signals S j is represented as: ； In the formula, j is the signal frequency band, and m is the sampling amount; The energy of the decomposed signal is defined as: ； The signal energy vector at time i is: ； The total energy of the signal received by the piezoelectric intelligent sensing assembly (8) at time i is represented as: 。 9. The experimental method of claim 2, wherein, The steel material (20) is arranged at the bottom of the iron disc (7), and the steel material (20) wraps the polyethylene material (19) and the cathode (18), the cathode (18) is connected with the iron disc (7) through the steel material (20), and the iron disc (7) is connected with the capacitor box (3) through the cable (6).

10. The experimental method of claim 1, wherein, The smart aggregate (12) is composed of PZT zirconium titanate lead piezoelectric ceramic material (16) encapsulated by insulating shell (15).

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