Test system and test method for simulating stress wave action of columnar charge blasthole blasting

Abstract

The application discloses a test system and a test method for simulating the stress wave action of a columnar charge blast hole, and relates to the technical field of rock dynamics and blasting engineering. The test system comprises a dynamic loading system, an incidence system, a stress wave conversion body and a sample model. The dynamic loading system generates a plane stress wave. The plane stress wave is conducted to the stress wave conversion body through the incidence system. The stress wave conversion body is attached to the sample model half-cylindrical channel through a semi-cylindrical pressure-arc surface, and the plane stress wave is converted into a cylindrical stress wave acting on the sample. The application generates controllable plane stress waves through the dynamic loading system, and the plane stress waves are shaped and directed through the incidence system, so that the waveform is stable, the energy loss is low, and the input conditions are consistent. The stress wave conversion body converts the plane stress wave into a cylindrical stress wave attached to the columnar blast hole through a plane-arc structure, highly simulates the radial diffusion characteristics of the real blasting stress wave, and realizes the simulation of the columnar charge blast hole blasting stress wave loading in the laboratory.

Description

Technical Field

[0001] This invention relates to the fields of rock dynamics and blasting engineering technology, specifically to a test system and test method for simulating the stress wave effect of a cylindrical charge blast hole. Background Technology

[0002] In mining, tunnel excavation, and deep underground engineering, the stress waves generated by explosive blasting are the primary driving force behind rock mass fracturing and cracking. After the explosive detonates inside the borehole, the resulting high-temperature, high-pressure gas and intense shock waves act directly on the borehole wall, forming stress waves that radiate outwards. These radially distributed stress waves are the core driving force behind the initiation, propagation, and macroscopic pulverization of microcracks within the rock mass. Therefore, accurately simulating and studying the propagation laws of these blasting stress waves and the dynamic response process of rocks under laboratory conditions is of crucial scientific significance for revealing the blasting fracturing mechanism, optimizing on-site blasting parameters, and assessing the dynamic stability of engineering rock masses.

[0003] However, existing methods for testing blasting dynamic response have significant limitations. Currently, they mainly rely on two approaches: first, in-situ field tests, which, while close to real-world conditions, suffer from complex environments, high costs, and extremely high safety risks. Furthermore, the charge parameters are difficult to control precisely, leading to large data dispersion and poor repeatability. Second, laboratory micro-explosive loading, while generating realistic blasting loads, also faces high experimental risks, stringent site requirements, and the challenge of precisely controlling the charge amount, waveform, and energy release of micro-explosives, making quantitative scientific research difficult. On the other hand, while the commonly used split Hopkinson pressure bar device in laboratories can provide stable and controllable high strain rate loads, it only generates unidirectional plane stress waves, failing to simulate the radial cylindrical wave action expanding from the inside out within a real borehole. This results in a serious discrepancy between laboratory research results and actual engineering applications. This invention proposes a new solution to address these problems. Summary of the Invention

[0004] In order to overcome at least one of the above-mentioned disadvantages, the present invention provides a test system and test method for simulating the stress wave effect of a cylindrical charge blast hole.

[0005] The objective of this invention can be achieved by adopting the following technical solution:

[0006] The first aspect of this application provides a test system for simulating the stress wave effect of a cylindrical charge blast hole, comprising:

[0007] A dynamic loading system, wherein the dynamic loading system is used to generate impact kinetic energy and generate plane stress waves;

[0008] An incident system, located at the exit end of the dynamic loading system, is used to receive the plane stress wave and conduct it along the incident axis of the plane stress wave;

[0009] A stress wave converter is disposed at the end of the wave propagation path of the incident system. The stress wave converter includes a converter body, a loading plane located on one side of the converter, and a pressure-applying arc surface located on the other side of the converter. The loading plane is used to contact the incident system, and the pressure-applying arc surface is a convex semi-cylindrical surface.

[0010] A sample model, wherein a semi-cylindrical channel is provided on one side of the sample model, and the pressure-applying arc surface is embedded and fitted into the semi-cylindrical channel;

[0011] The dynamic loading system applies a plane stress wave to the stress wave converter via the incident system, and the plane stress wave applies a cylindrical stress wave to the sample model via the stress wave converter.

[0012] In one possible implementation, the sample model is made from a cubic rock sample. First, a columnar blast hole is opened downward from the top of the cubic rock sample. The height of the columnar blast hole is less than the height of the rock sample. Then, the rock sample is cut into a half-section rock sample along the plane of the axis of the columnar blast hole. The cut surface of the half-section rock sample forms the semi-cylindrical channel.

[0013] The semi-cylindrical channel is divided into a filling section and a loading section along its axial direction from top to bottom. Below the semi-cylindrical channel is a bedrock section integrally formed with the half-section rock sample. The pressure-applying arc surface of the stress wave converter is embedded in the channel portion corresponding to the loading section.

[0014] The filling section is filled with simulated filling material to simulate the filling structure of a blast hole during a cylindrical blast.

[0015] In one possible implementation, the wave impedance of the material of the stress wave converter is greater than or equal to the wave impedance of the incident rod in the incident system, and the radius of the pressure arc surface is consistent with the radius of the semi-cylindrical channel of the sample model.

[0016] In one possible implementation, a coupling medium is applied between the pressure-applying arc surface and the contact interface of the hole wall of the sample model. The coupling medium includes high-viscosity grease, petroleum jelly, or metal foil.

[0017] In one possible implementation, the dynamic loading system includes:

[0018] Gas source, which provides driving gas;

[0019] An air cannon is used to fire an impact projectile, which impacts the input end of the incident system to generate initial impact kinetic energy and form a plane stress wave.

[0020] A pressure vessel, connected to the gas source via the gas cannon, is used to store high-pressure gas supplied by the gas source and to stably transmit the pressure to the gas cannon.

[0021] In one possible implementation, the incident system includes:

[0022] An incident rod, the axis of which is aligned with the impact direction of the power loading system;

[0023] A first strain gauge is disposed on the incident rod and is used to monitor the incident stress wave signal transmitted by the incident rod.

[0024] In one possible implementation, the incident system includes a buffer transition assembly, the buffer transition assembly comprising:

[0025] A waveguide transition element is disposed at the input end of the incident rod. The cross-sectional area of ​​the waveguide transition element gradually increases from its impact end to its tail end. The waveguide transition element is a waveguide made of alloy steel.

[0026] A buffer element is disposed at the impact end of the waveguide transition element, and the buffer element comprises a soft, thin, layered material with a thickness in the range of 0.5 mm to 10 mm.

[0027] In one possible implementation, a projection system is further included, the projection system being disposed on the side of the specimen model opposite to the stress wave converter, for receiving and transmitting residual stress waves that have penetrated the specimen model, the projection system comprising:

[0028] A projection rod is disposed on the other side of the specimen model relative to the stress wave converter and is attached to the rear surface of the specimen model. It is used to receive and continue to transmit the residual stress wave that has penetrated the specimen model forward.

[0029] The second strain gauge is disposed on the projection rod and is used to monitor the transmitted stress wave signal transmitted by the projection rod;

[0030] An energy dissipation component, comprising an energy absorption block and a baffle, is used to absorb the remaining kinetic energy of the projection rod. The energy absorption block is disposed on the axial path of the end of the projection rod, and the baffle is disposed at the end of the energy absorption block.

[0031] In one possible implementation, a support and guiding mechanism is further included. The support and guiding mechanism is used to constrain and support the alignment and positioning of the incident rod, the stress wave converter, the sample model, and the projection rod, and allows the incident rod and the projection rod to slide along the axial direction after being subjected to axial impact. The support and guiding mechanism includes a main frame composed of an upper fixed frame rod, a lower fixed frame rod, and a fixed support. The upper fixed frame rod and the lower fixed frame rod are parallel. One end of the upper fixed frame rod and the lower fixed frame rod are fixed to the fixed support, and the other end of the upper fixed frame rod and the lower fixed frame rod are fixed to the fixed support by bolts. The lower fixed frame rod is provided with a first pulley group and a second pulley group located below the incident rod and the projection rod, respectively.

[0032] A second aspect of this application provides a test method for simulating the stress wave effect of a cylindrical charge blast hole, applicable to any of the test systems for simulating the stress wave effect of a cylindrical charge blast hole in the first aspect. The test method includes the following steps:

[0033] Prepare a sample model by machining a columnar borehole of a predetermined depth from the top of a cubic rock sample, cutting it to expose a semi-cylindrical channel, and then fixing the sample model.

[0034] After applying a coupling medium to the pressure-applying arc surface of the stress wave converter, it is embedded into the loading section of the semi-cylindrical channel of the sample model to ensure that the pressure-applying arc surface fits the hole wall.

[0035] Adjust and ensure that the end face of the incident rod of the incident system is aligned with and in parallel contact with the loading plane of the stress wave converter;

[0036] The dynamic loading system is activated, and an impact bullet is fired to generate a plane stress wave. The plane stress wave is transmitted to the stress wave converter through the incident system. The stress wave converter converts the incoming plane stress wave into a radial cylindrical stress wave that acts on the borehole wall, which is used to simulate the stress wave effect of a cylindrical charge explosion.

[0037] The beneficial technical effects of this invention are as follows: According to the present disclosure, the experimental system and method for simulating the stress wave effect of a cylindrical charge blast hole blasting can stably generate a plane stress wave through a dynamic loading system, providing a controllable initial power source for subsequent conversion. The incident system ensures the stability of the stress wave waveform and low energy loss during transmission by shaping and directionally transmitting the plane stress wave, effectively guaranteeing the consistency of the experimental input conditions. The stress wave converter, with its plane loading and arc-shaped pressure structure, transforms the incident plane stress wave into a cylindrical stress wave that conforms to the shape of the cylindrical blast hole, highly simulating the mechanical characteristics of the stress wave radially diffusing from the blast hole to the surrounding rock mass in real blasting. This realizes the simulation of stress wave loading for cylindrical charge blast hole blasting in a mine in the laboratory, solving the technical problem that traditional plane wave loading cannot simulate the spatial effect of cylindrical charges. Attached Figure Description

[0038] The following are given by way of example and without limitation in the accompanying drawings:

[0039] Figure 1 A three-dimensional structural view of the stress wave conversion body and the half-section rock block sample according to an embodiment of the present invention is shown;

[0040] Figure 2 A three-dimensional structural view of a half-section rock block sample according to an embodiment of the present invention is shown;

[0041] Figure 3 A three-dimensional structural view of the stress wave converter according to an embodiment of the present invention is shown;

[0042] Figure 4 A cross-sectional view of the rock block sample and the cylindrical charge borehole of an embodiment of the present invention is shown;

[0043] Figure 5 A cross-sectional view of the stress wave converter and sample model structure according to an embodiment of the present invention is shown;

[0044] Figure 6 A schematic diagram of the overall structure of the test system according to an embodiment of the present invention is shown;

[0045] Figure 7 A schematic diagram of the supporting guide mechanism according to an embodiment of the present invention is shown;

[0046] Figure 8 The numerical simulation of blasting stress damage diagram of the sample model according to an embodiment of the present invention is shown;

[0047] Figure 9 The simulation results of the sample model values ​​in the 3rd microsecond of an embodiment of the present invention are shown in the figure.

[0048] Figure 10 The simulation results of the sample model values ​​in the embodiment of the present invention at the 8th microsecond are shown in the figure.

[0049] Figure 11 The simulation results of the sample model values ​​in an embodiment of the present invention at the 15th microsecond are shown in the figure.

[0050] Figure 12 The simulation results of the sample model values ​​in an embodiment of the present invention at 30 microseconds are shown in the figure.

[0051] Figure 13 The diagram shows the stress-damage diagram of a single-hole blasting model in the prior art, based on numerical simulation.

[0052] Figure 14 The simulation results of the single-hole blasting model in the prior art at the 8th microsecond are shown;

[0053] Figure 15 The simulation results of the single-hole blasting model in the prior art at the 19th microsecond are shown;

[0054] Figure 16 The simulation results of the single-hole blasting model in the prior art at 30 microseconds are shown.

[0055] In the figure: 100, rock block specimen; 200, columnar borehole; 110, half-sectioned rock block specimen; 111, bedrock section; 112, loading section; 113, filling section; 1, dynamic loading system; 11, gas source; 12, gas cannon; 13, pressure vessel; 14, impact bullet; 2, incident system; 21, waveguide transition component; 22, buffer component; 23, incident rod; 24, first strain gauge; 3, stress wave converter; 31, converter body; 32, loading plane; 33, pressure arc surface; 4, specimen model; 5, projection system; 51, projection rod; 52, second strain gauge; 53, energy absorption block; 54, baffle; 6, support and guide mechanism; 61, upper fixed frame rod; 62, lower fixed frame rod; 63, fixed bracket; 64, fixed support; 65, bolt; 66, first pulley block; 67, second pulley block. Detailed Implementation

[0056] In the following detailed disclosure, these embodiments are fully described with reference to the accompanying drawings. In order to enable those skilled in the art to understand and clarify the technical solution of the present invention more clearly, the embodiments described below are not limited thereto. The present invention will be further described in detail below with reference to the embodiments and the accompanying drawings.

[0057] The first aspect of this application, as Figures 1-12As shown, an experimental system for simulating the effect of stress waves from the blasting of a cylindrical charge borehole is provided. The system includes a dynamic loading system 1, an incident system 2, a stress wave converter 3, and a sample model 4. The dynamic loading system 1 generates impact kinetic energy and produces a plane stress wave. The incident system 2, located at the exit end of the dynamic loading system 1, receives the plane stress wave and propagates it along the incident axis. The stress wave converter 3 is located at the end of the wave propagation path of the incident system 2. The stress wave converter 3 includes a converter body 31, a loading plane 32 on one side of the converter, and a pressure-applying arc surface 33 on the other side. The loading plane 32 contacts the incident system 2, and the pressure-applying arc surface 33 is a convex semi-cylindrical surface. One side of the sample model 4 has a semi-cylindrical channel, and the pressure-applying arc surface 33 is embedded and fitted within the semi-cylindrical channel. The dynamic loading system 1 applies a plane stress wave to the stress wave converter 3 via the incident system 2, and the plane stress wave, after passing through the stress wave converter 3, applies a cylindrical stress wave to the sample model 4.

[0058] The experimental system for simulating the stress wave effect of a cylindrical charge blast hole provided in this embodiment uses a dynamic loading system 1 to stably generate a plane stress wave, providing a controllable initial power source for subsequent conversion. The incident system 2 shapes and directs the plane stress wave, ensuring waveform stability and low energy loss during transmission, effectively guaranteeing the consistency of experimental input conditions. The stress wave converter 3, with its plane loading and arc-shaped pressure structure, converts the incident plane stress wave into a cylindrical stress wave conforming to the shape of the cylindrical blast hole 200. This highly simulates the mechanical characteristics of stress wave radial diffusion from the blast hole to the surrounding rock mass in real blasting. It realizes the simulation of stress wave loading for a cylindrical charge blast hole blast in a mine in the laboratory. The laboratory stress conversion loading replaces the traditional dangerous explosive blasting, with precise and controllable load parameters and extremely high safety, which has engineering guidance significance and scientific research practical value.

[0059] Among them, the semi-cylindrical channel of the sample model 4 and the arc surface of the stress wave converter 3 are designed to fit together, which further strengthens the geometric constraints of stress wave transmission, so that the cylindrical stress wave can act uniformly on the hole wall, truly reflecting the propagation law of blasting stress wave in rock mass, providing a reliable experimental basis for studying blasting response under different rock mass conditions, and greatly improving the authenticity and data accuracy of blasting mechanics test.

[0060] In one possible implementation, such as Figures 1-5 As shown, the sample model 4 is made from the rock block sample 100. First, a columnar blast hole 200 is opened downward from the top of the cubic rock block sample 100. The height of the columnar blast hole 200 is less than the height of the rock block sample 100. Then, the rock block sample 100 is cut into a half-section rock block sample 110 along the plane where the axis of the columnar blast hole 200 is located. The cutting surface of the half-section rock block sample 110 forms a semi-cylindrical channel.

[0061] In this embodiment, the sample model 4 is made by first opening columnar boreholes 200 in the cubic rock sample 100 and then cutting it along the axis. This process not only preserves the original mechanical properties of the rock sample 100, but also forms a semi-cylindrical channel on the cutting surface that is consistent with the shape of the real borehole. This perfectly reproduces the spatial structure of the columnar charge borehole, so that the pressure arc surface 33 of the stress wave converter 3 can fit tightly with the channel, ensuring that the energy loss during the stress wave transmission is extremely low, and maximally simulating the mechanical environment of stress wave diffusion from the borehole to the surrounding rock mass during real blasting.

[0062] The setting that the height of the columnar borehole 200 is less than the height of the rock block sample 100 provides sufficient research space for simulating the deep mechanical behavior of the rock mass after blasting, such as the residual stress distribution and crack propagation, and avoids the interference of boundary effects on the test results.

[0063] Understandably, compared to traditional complete borehole specimens, the half-section structure makes it easier to directly observe the damage evolution process of the borehole wall under stress wave action, providing an intuitive and reliable experimental basis for the refined study of blasting mechanics, and greatly improving the authenticity and analyzability of experimental data.

[0064] In one possible implementation, such as Figure 2 and Figure 5 As shown, the semi-cylindrical channel is divided into a filling section 113 and a loading section 112 along its axial direction from top to bottom. Below the semi-cylindrical channel is a bedrock section 111 integrally formed with the half-section rock sample 110. The pressure-applying arc surface 33 of the stress wave converter 3 is embedded in the channel portion corresponding to the loading section 112.

[0065] The semi-cylindrical channel is divided into a filling section 113 and a loading section 112 from top to bottom. The bedrock section 111, which is integrally formed with the rock block, is retained below the semi-cylindrical channel, which completely reproduces the real structural layers of the columnar charge blast hole from the filling layer to the charging area and then to the lower rock mass.

[0066] The loading section 112 corresponds to the embedding position of the pressure arc surface 33 of the stress wave converter 3, which is near the middle of the sample model 4. This ensures that the stress wave is concentrated on the simulated charge area, maximizing the restoration of the loading form and energy distribution of the initial stress wave during blasting. The filling section 113, by filling with the corresponding simulated filling material, simulates the constraint and influence of the borehole filling structure on the propagation of stress waves in real blasting, providing controllable experimental conditions for studying the filling effect. The integrally formed bedrock section 111 below retains the original mechanical continuity of the rock mass, avoiding abrupt changes in mechanical properties caused by artificial splicing. This makes the propagation process of stress waves from the loading section 112 to the surrounding rock mass more closely resemble the real blasting scenario, effectively reducing the interference of boundary effects on the test results. This provides a reliable structural foundation for accurately analyzing the propagation law of blasting stress waves, the evolution of rock mass damage, and other core issues.

[0067] In one possible implementation, such as Figure 5 As shown, the filling section 113 is filled with simulated filling material to simulate the filling structure of the blast hole during the blasting of the columnar blast hole 200.

[0068] In this experiment, simulated filler material, such as sand and gravel, was filled into the filling section 113 of the semi-cylindrical channel and solidified to a set strength. Through structural fit and constraint, it was used to simulate the end gas confinement effect brought about by the filler material in real blasting, thus reproducing the mechanical effect of the filler structure in the borehole in a real blasting scenario. The close fit between the simulated filler material and the channel wall can effectively constrain the axial propagation of stress waves, forcing the stress waves to diffuse more radially into the rock mass, which is closer to the energy distribution law during real blasting and greatly improves the simulation accuracy of the experiment for real blasting conditions.

[0069] In one possible implementation, such as Figures 1-3 As shown, the wave impedance of the material of the stress wave converter 3 is greater than or equal to the wave impedance of the incident rod 23 in the incident system 2, and the radius of the pressure arc surface 33 is consistent with the radius of the semi-cylindrical channel of the sample model 4.

[0070] Among them, the stress wave converter 3 adopts a flat-arc irregular structure and is subject to the geometric constraints of the rock borehole wall. The axial impact force is redirected on the contact surface. When the stress wave is transmitted from the stress wave converter 3 into the rock interior, its wavefront is transformed from a plane into a cylindrical wavefront that radiates outward from the borehole axis, thereby simulating the radial impact of real explosive detonation on the borehole wall.

[0071] Among them, the stress wave converter 3 can be made of steel. The stress wave converter 3 is made of a material with a wave impedance not lower than that of the incident rod 23. Combined with the pressure arc surface 33 that is perfectly matched with the radius of the semi-cylindrical channel, a highly efficient stress wave transmission structure that fits the real working conditions is constructed. The high wave impedance material design greatly reduces the energy reflection loss of the stress wave at the interface between the incident rod 23 and the converter, ensuring that the plane stress wave can be converted into the cylindrical stress wave acting on the channel to the greatest extent, thereby improving the energy utilization efficiency and loading accuracy.

[0072] Among them, the pressure-applying arc surface 33 is a convex semi-cylindrical surface. Its size and shape are precisely matched with the channel, which realizes the fit between the stress wave converter 3 and the sample hole wall. This avoids stress wave scattering and distortion caused by gaps, and allows the cylindrical stress wave to act evenly on the hole wall, highly restoring the mechanical characteristics of stress wave radial diffusion from the borehole to the rock mass in real blasting.

[0073] In one possible implementation, a coupling medium is applied between the pressure arc surface 33 and the contact interface of the hole wall of the sample model 4. The coupling medium includes high-viscosity grease, petroleum jelly, or metal foil.

[0074] In this process, a coupling medium is applied to the interface between the pressure arc surface 33 and the hole wall of the semi-hole rock sample. The thickness of the coupling medium can be about 0.1 mm, which can fully fill the tiny gaps and uneven areas between the interfaces, eliminate air gaps caused by poor contact, and avoid scattering, reflection or energy loss of stress waves during transmission. This ensures efficient transmission of stress waves from the stress wave converter 3 to the hole wall of the sample, and can effectively optimize the stress wave transmission efficiency and test accuracy.

[0075] The flexible or rigid adaptability of the coupling medium allows the pressure arc surface 33 to form a uniform contact state with the hole wall, avoiding initial damage to the hole wall caused by local stress concentration. This allows the cylindrical stress wave to act on the hole wall in a more uniform distribution form that closely resembles a real explosion, greatly improving the simulation accuracy of the explosion stress wave process in the experiment.

[0076] High-viscosity grease has good adhesion and damping properties, which can tightly fill the tiny gaps at the interface, reduce the energy loss and scattering of stress waves during transmission, and provide a buffer for the contact interface, reducing local stress concentration caused by impact.

[0077] Vaseline has good lubricity and stability, forming a uniform film at the interface to ensure the fit between the pressure arc surface 33 and the hole wall, thus avoiding stress wave distortion caused by poor contact.

[0078] Among them, metal foil, as a rigid coupling medium, can establish a rigid connection at the interface, maximizing the transmission of stress wave energy, and is especially suitable for test scenarios with high requirements for energy transmission efficiency.

[0079] Understandably, the coupling medium can be flexibly selected according to the experimental requirements, together providing reliable interface conditions for simulating the stress wave effect of blasting in a cylindrical charge borehole, thereby improving the authenticity and repeatability of the experimental data.

[0080] In one possible implementation, such as Figure 6 As shown, the power loading system 1 includes an air source 11, a pressure vessel 13, an air cannon 12, and an impact bullet 14. The air cannon 12 is used to fire the impact bullet 14, which is used to impact the input end of the incident system 2 to generate initial impact kinetic energy and form a plane stress wave. The air source 11 provides driving gas. The pressure vessel 13 is connected to the air source 11 through the air cannon 12 and is used to store the high-pressure gas provided by the air source 11 and stably transmit the pressure to the air cannon 12.

[0081] In this embodiment, the power loading system 1 uses the gas source 11 as the power source, which continuously provides a stable driving gas to the system, fundamentally ensuring the power supply capability of the entire system. The pressure vessel 13 is connected to the gas source 11, which not only achieves efficient storage of high-pressure gas, but also, with its stable pressure regulation capability, stabilizes the gas pressure output by the gas source 11 before transmitting it to the air cannon 12, effectively avoiding the interference caused by pressure fluctuations to the subsequent firing stage, and laying a solid foundation for the stable operation of the air cannon 12. After receiving the stable pressure gas, the air cannon 12 converts the energy into firing power, stably and efficiently pushing the impact bullet 14 out, ensuring the firing consistency of the impact bullet 14. Driven by the air cannon 12, the impact bullet 14 impacts the input end of the incident system 2, efficiently converting the initial impact kinetic energy into a plane stress wave. The energy transfer loss is extremely low throughout the process, realizing the generation, storage, regulation of gas to the final energy conversion and transfer.

[0082] In one possible implementation, such as Figure 6 As shown, the incident system 2 includes an incident rod 23 and a first strain gauge 24. The axis of the incident rod 23 is aligned with the impact direction of the dynamic loading system 1. The first strain gauge 24 is disposed on the incident rod 23 and is used to monitor the incident stress wave signal transmitted by the incident rod 23.

[0083] In this embodiment, the incident system 2 has an incident rod 23 as the core transmission component. Its axis is aligned with the impact direction of the power loading system 1 to avoid energy loss or stress wave direction deviation caused by axis offset. This ensures that the impact kinetic energy generated by the power loading system 1 can be efficiently transmitted to the incident rod 23 along a preset path. The incident rod 23 can directly receive and convert the kinetic energy into a plane stress wave along its own axis. This linear transmission structure minimizes the dispersion and loss of energy during transmission, ensuring that the stress wave can be transmitted forward in a stable form and with sufficient energy. The first strain gauge 24 is closely set on the incident rod 23 to capture the subtle deformation of the incident rod 23 in real time during the stress wave transmission process. It can simultaneously monitor key parameters such as the waveform, amplitude, and frequency of the stress wave, and then convert them into quantifiable electrical signals to achieve accurate monitoring of the incident stress wave signal.

[0084] The incident rod 23 end face is aligned with and in parallel contact with the plane impact end of the stress wave converter 3, which can maximize the axial consistency of the stress wave during transmission and avoid uneven stress distribution caused by eccentricity or tilt. This allows the plane stress wave to be transmitted from the incident rod 23 to the stress wave converter 3 efficiently and uniformly, reducing energy loss and signal distortion.

[0085] In one possible implementation, such as Figure 6As shown, the incident system 2 includes a buffer transition assembly, which includes a waveguide transition member 21 and a buffer member 22. The waveguide transition member 21 is disposed at the input end of the incident rod 23. The cross-sectional area of ​​the waveguide transition member 21 gradually increases from its impact end to its tail end. The waveguide transition member 21 is a waveguide made of alloy steel. The buffer member 22 is disposed at the impact end of the waveguide transition member 21. The buffer member 22 includes a soft, thin, layered material with a thickness in the range of 0.5 mm to 10 mm.

[0086] The waveguide transition element 21, through its gradually changing cross-sectional area design, achieves efficient transmission and optimization of stress waves. Its impact-receiving end has a smaller cross-sectional area, the size of which should be consistent with the function of the impact bullet 14, enabling precise reception of the initial impact kinetic energy transmitted by the bullet 14. Subsequently, the cross-sectional area gradually expands towards the tail end, with its tail end size needing to be larger than the diameter of the subsequent incident rod 23, ensuring a seamless connection at the joint. This gradually changing structure smoothly shapes the incident stress wave, avoiding stress wave reflection and energy loss caused by abrupt changes in cross-sectional area, ensuring the stability and continuity of the stress wave waveform during transmission. Simultaneously, the alloy steel material, such as 40Cr, endows the waveguide transition element 21 with excellent mechanical properties and wave impedance characteristics. It can not only withstand high-intensity impact loads but also achieve good wave impedance matching with the incident rod 23, further improving the transmission efficiency of stress waves and providing stable, high-quality incident conditions for subsequent stress wave conversion.

[0087] Among them, the buffer transition component can perform the function of stress wave shaping and transmission under a more stable impact load, ensuring that the impact energy after buffering can be fully converted into a stable stress wave and transmitted to the subsequent components. The waveguide transition component 21 and the buffer component 22 work together to improve the stability and reliability of the incident system 2 itself, and ensure the consistency and repeatability of the test input conditions.

[0088] Among them, the buffer 22 is made of a soft, thin, layered material with a thickness ranging from 0.5mm to 10mm. It plays a role in buffering and protecting during the impact. When the bullet 14 impacts the waveguide transition 21, the buffer 22 can absorb part of the impact energy through its own deformation, effectively reducing the peak load of the initial impact, avoiding local damage to the waveguide transition 21 or the incident rod 23 due to the instantaneous high-intensity impact, and extending its service life.

[0089] Understandably, the flexibility of thin, layered materials such as soft copper and cork can also make the impact load more evenly distributed on the impact end of the waveguide transition 21, reduce stress concentration, and ensure a more stable initial excitation of the stress wave.

[0090] In one possible implementation, such as Figure 6As shown, the test system simulating the stress wave effect of a cylindrical charge blast hole also includes a projection system 5. The projection system 5 is set on the side of the specimen model 4 away from the stress wave converter 3, and is used to receive and transmit the residual stress wave after penetrating the specimen model 4. The projection system 5 includes a projection rod 51, a second strain gauge 52, and an energy dissipation component. The projection rod 51 is set on the other side of the specimen model 4 relative to the stress wave converter 3 and is attached to the rear surface of the specimen model 4, and is used to receive and continue to transmit the residual stress wave after penetrating the specimen model 4 forward. The second strain gauge 52 is set on the projection rod 51 and is used to monitor the transmitted stress wave signal transmitted by the projection rod 51. The energy dissipation component includes an energy absorption block 53 and a baffle 54, and is used to absorb the remaining kinetic energy of the projection rod 51. The energy absorption block 53 is set on the axial path at the end of the projection rod 51, and the baffle 54 is set at the end of the energy absorption block 53.

[0091] In this embodiment, the projection system 5 forms a closed-loop system from loading, conversion, response to monitoring and energy termination. The projection rod 51 is in close contact with the rear surface of the sample model 4, which can receive the residual stress wave after penetrating the sample and stably transmit it along the axial direction to ensure the integrity and measurability of the transmitted signal. The second strain gauge 52 is arranged on the projection rod 51, which can capture and record the waveform characteristics of the transmitted stress wave in real time, providing key data support for analyzing the attenuation law and energy distribution of the stress wave in the rock mass. The energy dissipation component effectively absorbs the remaining kinetic energy at the end of the projection rod 51 through the synergistic effect of the energy absorption block 53 and the baffle 54, avoiding the stress wave reflection and back transmission from interfering with the test signal.

[0092] In one possible implementation, such as Figure 6 and Figure 7 As shown, the test system for simulating the stress wave effect of a cylindrical charge blast hole also includes a support and guide mechanism 6. The support and guide mechanism 6 is used to constrain and support the centering and positioning of the incident rod 23, the stress wave converter 3, the sample model 4, and the projection rod 51, and allows the incident rod 23 and the projection rod 51 to slide along the axial direction after being subjected to axial impact. The support and guide mechanism 6 includes a main frame consisting of an upper fixed frame rod 61, a lower fixed frame rod 62, and a fixed support 63. The upper fixed frame rod 61 and the lower fixed frame rod 62 are parallel. One end of the upper fixed frame rod 61 and the lower fixed frame rod 62 are fixed to the fixed support 63, and the other end of the upper fixed frame rod 61 and the lower fixed frame rod 62 are fixed to the fixed support 64 by bolts 65. The lower fixed frame rod 62 is provided with a first pulley group 66 and a second pulley group 67 located below the incident rod 23 and the projection rod 51, respectively.

[0093] In this embodiment, the support and guiding mechanism 6, with the upper fixed frame rod 61 and the lower fixed frame rod 62 connected by the fixed bracket 63 and the fixed support 64, forms a stable parallel support structure, providing rigid support for the incident rod 23, stress wave converter 3, sample model 4 and projection rod 51, ensuring that each component maintains precise axial alignment before the test; the first pulley group 66 set on the lower fixed frame rod 62 is located below the incident rod 23, and the second pulley group 67 is located below the projection rod 51, which not only bear the weight of the component, but also allow it to slide freely along the axial direction when subjected to axial impact, effectively reducing frictional resistance and ensuring the continuity and authenticity of stress wave transmission.

[0094] Furthermore, the support and guide mechanism 6 also includes a limiting guide component, which is set on the side of the stress wave converter to constrain the stress wave converter to only move in the radial direction of the semi-cylindrical borehole during the impact process, thereby avoiding lateral displacement or rotational instability and ensuring the continuous stability of the pressure arc surface 33 in contact with the borehole wall.

[0095] The second aspect of this application, as Figures 1-12 As shown, a test method for simulating the stress wave effect of a cylindrical charge blast hole is provided, applicable to any of the test systems for simulating the stress wave effect of a cylindrical charge blast hole in the first aspect. The test method includes the following steps: preparing a sample model 4; machining a cylindrical blast hole 200 of a set depth downwards from the top of a cubic rock sample 100, and cutting it to expose a semi-cylindrical channel, and fixing the sample model 4; applying a coupling medium to the pressure arc surface 33 of the stress wave converter 3, and embedding it into the loading section 112 of the semi-cylindrical channel of the sample model 4, ensuring that the pressure arc surface 33 is in contact with the hole wall; adjusting and ensuring that the end face of the incident rod 23 of the incident system 2 is aligned and in parallel contact with the loading plane 32 of the stress wave converter 3; starting the dynamic loading system 1, firing the impact bullet 14 to generate a plane stress wave, which is transmitted to the stress wave converter 3 via the incident system 2, and the stress wave converter 3 converts the transmitted plane stress wave into a radial cylindrical stress wave acting on the hole wall, used to simulate the stress wave effect of a cylindrical charge blast.

[0096] The experimental method for simulating the stress wave effect of a cylindrical charge blast hole provided in this embodiment achieves high-precision simulation of the stress wave effect of a cylindrical charge blast hole. When preparing the sample model 4, the cylindrical blast hole 200 is machined and cut to form a semi-cylindrical channel, providing geometric boundary conditions consistent with actual working conditions for subsequent stress wave loading, and ensuring the consistency and repeatability of the sample structure. After applying a coupling medium, the stress wave converter 3 is embedded, effectively improving the contact quality between the pressure arc surface 33 and the hole wall, reducing interface reflection and energy loss, and ensuring the continuity and uniformity of stress wave transmission. Adjusting the incident rod 23 and the stress wave... The centering and parallel contact of the converter 3 ensures the axial alignment of the stress wave on the transmission path, avoiding off-center loading or local stress concentration, and improving the reliability of the test data. After the dynamic loading system 1 is started, the plane stress wave generated by the impact bullet 14 is stably transmitted to the stress wave converter 3 through the incident system 2. The latter, with its plane-arc surface structure, efficiently converts the plane wave into a radially propagating cylindrical stress wave, accurately simulating the mechanical process of stress wave spreading from the borehole wall to the rock mass during explosive blasting. It realizes the full-process control from sample preparation and component assembly to dynamic loading, and significantly enhances the test's ability to reproduce the real blasting scene.

[0097] Before starting the dynamic loading system 1, the monitoring equipment is turned on and synchronized to prepare for observation of the loaded profile of the sample model 4. A high-speed camera with a sampling frequency of not less than 500,000 fps is turned on to conduct full-field observation of the profile. The dynamic loading system 1 is started to release kinetic energy and generate a plane stress wave. The plane stress wave is transmitted to the stress wave converter via the incident system 2 through the SHPB incident rod 23. Using the geometric boundary constraints of the stress wave converter, the plane stress wave is converted into a radial cylindrical wave load acting on the inner wall of the borehole. The incident waveform and the dynamic cracking process of the sample are recorded, and the dynamic loading and failure evolution observation process of the sample model 4 is completed.

[0098] In specific implementation, the numerical simulation of the blasting stress damage diagram of sample model 4 in the embodiment of this application is as follows: Figure 8 As shown in the figure, it can be clearly observed that the damage to the sample is no longer a central crushing failure like a borehole, but rather exhibits a more uniform and controllable stress damage state. Energy is transferred into the sample interior through the transmission arc surface of the stress wave converter 3, effectively avoiding interference from extreme local crushing zones. The simulation results of the sample model 4 in this embodiment at the 3rd microsecond are shown in the figure below. Figure 9 As shown, the initial impact kinetic energy has just acted on the small end face of the buffer transition component, and the initial stress wave has just been generated. At this time, the stress is in a highly concentrated point state. The simulation results of the sample model 4 in this embodiment of the application at the 8th microsecond are shown in the figure below. Figure 10 As shown, the simulation results of sample model 4 in this embodiment at the 15th microsecond are illustrated in the figure below. Figure 11As shown, during the period from the 8th to the 15th microsecond, the stress wave widens laterally as the cross-section of the buffer transition component expands, and the non-uniform stress wave gradually and smoothly transforms into the stress wave conversion body 3. The simulation results of the sample model 4 in this embodiment at the 30th microsecond are shown in the figure below. Figure 12 As shown, the plane stress wave has been successfully converted into a wide-amplitude uniform cylindrical stress wave, which is smoothly input into the rock sample and propagates forward.

[0099] In traditional single-hole blasting, the numerical simulation of blasting stress-damage diagrams in existing single-hole blasting models is as follows: Figure 13 As shown in the figure, after the detonation of a single-hole explosive charge, due to the extremely concentrated explosive energy, a severe fragmentation zone instantly forms around the borehole, subsequently generating numerous radial cracks that rapidly propagate towards the boundary. This damage exhibits strong localized destruction characteristics and non-uniformity. The simulation results of the existing single-hole blasting model at the 8th microsecond are shown in the figure below. Figure 14 The figure shows the early stage after traditional single-hole blasting detonation. At this stage, the explosive has just detonated, and the extreme high-pressure stress wave generated by the explosion has initially formed, with its energy largely concentrated in a small area around the central borehole. The simulation results of the existing single-hole blasting model at the 19th microsecond are shown in the figure below. Figure 15 As shown, this represents the initial radial divergence propagation stage of the stress wave. Over time, the high-pressure stress wave, centered on the central borehole, exhibits typical spherical wave characteristics, spreading radially outwards. The figure clearly shows the high-pressure area expanding significantly outwards in a circular pattern. The simulation results of the single-hole blasting model at 30 microseconds in the prior art are shown below. Figure 16 As shown, this represents the state where the stress wave propagates further over a longer distance, at which point the stress wave expands rapidly, affecting a larger area of ​​the sample.

[0100] The experimental system and method for simulating the stress wave effect of a cylindrical charge blast hole provided in this application successfully converts concentrated impact kinetic energy into a wide-amplitude uniform cylindrical wave, mitigating the interference of uneven local crushing and realizing the transformation and simulation of stress wave morphology. By converting the blast source into a dynamic loading source and performing waveform shaping, the local destructive effects of detonation gas and high temperature and pressure are isolated, enabling laboratory researchers to accurately capture and analyze the propagation, reflection, and fracturing mechanisms of explosive stress waves in media such as rock, thus mitigating the interference of uneven local crushing. Traditional blasting experiments are affected by uncertainties such as explosive equivalent and coupling medium, resulting in large data dispersion. Furthermore, the use of explosives in the laboratory poses significant safety hazards. The input energy used in this application can be precisely set, and the output waveform is highly stable and consistent, improving the controllability, repeatability, and safety of the experiment.

[0101] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0102] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0103] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which 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.

[0104] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A test system for simulating the stress wave effect of a cylindrical charge blast hole, characterized in that, include: A dynamic loading system (1) is used to generate impact kinetic energy and generate plane stress waves; An incident system (2) is located at the exit end of the dynamic loading system (1) and is used to receive the plane stress wave and conduct it along the incident axis of the plane stress wave. The stress wave converter (3) is disposed at the end of the wave propagation path of the incident system (2). The stress wave converter (3) includes a converter body (31), a loading plane (32) located on one side of the converter, and a pressure arc surface (33) located on the other side of the converter. The loading plane (32) is used to contact the incident system (2), and the pressure arc surface (33) is a convex semi-cylindrical surface. The sample model (4) has a semi-cylindrical channel on one side, and the pressure arc surface (33) is embedded and fits into the semi-cylindrical channel; The dynamic loading system (1) applies a plane stress wave to the stress wave converter (3) via the incident system (2), and the plane stress wave applies a cylindrical stress wave to the sample model (4) via the stress wave converter (3).

2. The experimental system for simulating the stress wave effect of a cylindrical charge blast hole according to claim 1, characterized in that, The sample model (4) is made from a cubic rock sample (100). First, a columnar blast hole (200) is opened downward from the top of the rock sample (100). The height of the columnar blast hole (200) is less than the height of the rock sample (100). Then, the rock sample (100) is cut into a half-section rock sample (110) along the plane where the axis of the columnar blast hole (200) is located. The cutting surface of the half-section rock sample (110) forms the semi-cylindrical channel. The semi-cylindrical channel is divided into a filling section (113) and a loading section (112) along its axial direction from top to bottom. Below the semi-cylindrical channel is a bedrock section (111) integrally formed with the half-section rock block sample (110). The pressure-applying arc surface (33) of the stress wave converter (3) is embedded in the channel portion corresponding to the loading section (112). The filling section (113) is filled with simulated filling material to simulate the filling structure of the blast hole (200) during blasting.

3. The experimental system for simulating the stress wave effect of a cylindrical charge blast hole according to claim 1, characterized in that, The material wave impedance of the stress wave converter (3) is greater than or equal to the wave impedance of the incident rod (23) in the incident system (2), and the radius of the pressure arc surface (33) is consistent with the radius of the semi-cylindrical channel of the sample model (4).

4. The experimental system for simulating the stress wave effect of a cylindrical charge blast hole according to claim 3, characterized in that, A coupling medium is applied between the pressure-applying arc surface (33) and the hole wall of the sample model (4). The coupling medium includes high-viscosity grease, petroleum jelly, or metal foil.

5. The experimental system for simulating the stress wave effect of a cylindrical charge blast hole according to claim 1, characterized in that, The dynamic loading system (1) includes: Gas source (11), which provides driving gas; An air cannon (12) is used to fire an impact bullet (14), which is used to impact the input end of the incident system (2) to generate initial impact kinetic energy and form a plane stress wave. Pressure vessel (13), which is connected to the gas source (11) via the gas cannon (12), is used to store high-pressure gas provided by the gas source (11) and to stably transmit the pressure to the gas cannon (12).

6. The experimental system for simulating the stress wave effect of a cylindrical charge blast hole according to claim 1, characterized in that, The incident system (2) includes: An incident rod (23) whose axis is aligned with the impact direction of the power loading system (1); The first strain gauge (24) is disposed on the incident rod (23) and is used to monitor the incident stress wave signal transmitted by the incident rod (23).

7. The experimental system for simulating the stress wave effect of a cylindrical charge blast hole according to claim 6, characterized in that, The incident system (2) includes a buffer transition component, the buffer transition component comprising: Waveguide transition element (21), the waveguide transition element (21) is disposed at the input end of the incident rod (23), the cross-sectional area of ​​the waveguide transition element (21) gradually increases from its impact end to its tail end, and the waveguide transition element (21) is a waveguide made of alloy steel; A buffer (22) is disposed at the impact end of the waveguide transition (21), and the buffer (22) comprises a soft sheet layered material with a thickness in the range of 0.5 mm to 10 mm.

8. The experimental system for simulating the stress wave effect of a cylindrical charge blast hole according to claim 6 or 7, characterized in that, It also includes a projection system (5), which is disposed on the side of the specimen model (4) away from the stress wave converter (3) for receiving and transmitting residual stress waves after penetrating the specimen model (4). The projection system (5) includes: The projection rod (51) is disposed on the other side of the sample model (4) relative to the stress wave converter (3) and is attached to the rear surface of the sample model (4) to receive and continue to transmit the residual stress wave that has penetrated the sample model (4) forward. The second strain gauge (52) is disposed on the projection rod (51) and is used to monitor the transmitted stress wave signal transmitted by the projection rod (51); An energy dissipation component, comprising an energy absorption block (53) and a baffle (54), for absorbing the remaining kinetic energy of the projection rod (51), wherein the energy absorption block (53) is disposed on the axial path of the end of the projection rod (51), and the baffle (54) is disposed at the end of the energy absorption block (53).

9. The experimental system for simulating the stress wave effect of a cylindrical charge blast hole according to claim 8, characterized in that, It also includes a support and guide mechanism (6), which is used to constrain and support the centering and positioning of the incident rod (23), the stress wave converter (3), the sample model (4), and the projection rod (51), and allows the incident rod (23) and the projection rod (51) to slide along the axial direction after being subjected to axial impact. The support and guide mechanism (6) includes a main frame composed of an upper fixed frame rod (61), a lower fixed frame rod (62), and a fixed bracket (63). The rod (61) is parallel to the lower fixed frame rod (62). One end of the upper fixed frame rod (61) and the lower fixed frame rod (62) are fixed on the fixed bracket (63). The other end of the upper fixed frame rod (61) and the lower fixed frame rod (62) are fixed on the fixed support (64) by bolts (65). The lower fixed frame rod (62) is provided with a first pulley group (66) and a second pulley group (67) located below the incident rod (23) and the projection rod (51), respectively.

10. A test method for simulating the stress wave effect of a cylindrical charge blast hole, characterized in that, The test system for simulating the stress wave effect of a cylindrical charge blast hole as described in any one of claims 1-9, the test method comprising the following steps: Prepare a sample model (4), process the top of the cubic rock sample (100) downward to make a columnar borehole (200) of a set depth, cut it to expose a semi-cylindrical channel, and fix the sample model (4). After applying coupling medium to the pressure arc surface (33) of the stress wave converter (3), it is embedded in the loading section (112) of the semi-cylindrical channel of the sample model (4) to ensure that the pressure arc surface (33) fits against the hole wall. Adjust and ensure that the end face of the incident rod (23) of the incident system (2) is aligned with and in parallel contact with the loading plane (32) of the stress wave converter (3); The dynamic loading system (1) is activated, and the impact bullet (14) is fired to generate a plane stress wave. The plane stress wave is transmitted to the stress wave converter (3) through the incident system (2). The stress wave converter (3) converts the incoming plane stress wave into a radial cylindrical stress wave acting on the hole wall, which is used to simulate the stress wave effect of columnar charge blasting.

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