An underground explosion pressure test system and test method

Abstract

The present invention provides an underground explosion pressure test system and test method, relating to the field of pressure testing technology. This system addresses the technical issues of high workload and easily damaged sensors during underground explosion pressure testing. The system comprises an explosive device, at least one first unit, at least one second unit, and a control device located above ground. The explosive device, the first unit, and the second unit are all electrically connected to the control device. The first unit comprises a first sensor and a first tube, the wires of the first sensor passing through the first tube and electrically connected to the control device. The second unit comprises a second sensor and a second tube, the wires of the second sensor passing through the second tube and electrically connected to the control device. The first sensing surface of the first sensor faces the explosive device, while the second sensing surface of the second sensor faces laterally. This test system offers high testing efficiency and resists sensor damage.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure testing, and in particular to an underground explosion pressure testing system and a testing method. Background Art

[0002] Studying the propagation of stress waves in underground rock and soil is of great significance to explosive mining of minerals. Field testing is an important means of studying explosive stress in rock and soil. Therefore, a reasonable underground explosion pressure test system is an indispensable technical prerequisite and material support for such research.

[0003] In related technologies, the sensors used to measure stress waves are buried at the same depth as the explosives. Specifically, the sensors are pre-buried at a certain horizontal distance from the explosives. Within a tunnel dug within the area where the sensors are to be buried, multiple sensors are placed at selected measuring points along the tunnel's horizontal extension. Leads are connected along the sidewalls to the outside of the pit. The in-situ soil is then backfilled, and the sensor positions are fixed using a layer-by-layer backfilling method, with each layer compacted and tamped. After the test, the sensors must be removed from the rock and soil by excavation, which is labor-intensive and can lead to sensor damage due to handling, making the expensive sensors difficult to reuse. Summary of the Invention

[0004] The purpose of the present invention is to provide an underground explosion pressure test system and test method to solve the technical problems of large workload and easy damage of sensors in underground explosion pressure test.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides an underground explosion pressure test system, comprising an explosive device located in rock and soil, at least one first unit, at least one second unit, and a control device located above the ground, wherein the explosive device, the first unit, and the second unit are all electrically connected to the control device;

[0007] The first unit includes a first sensor and a first tube, wherein a wire of the first sensor passes through the first tube and is electrically connected to the control device;

[0008] The second unit includes a second sensor and a second tube, and a wire of the second sensor passes through the second tube and is electrically connected to the control device;

[0009] The first sensing surface of the first sensor faces the explosive device, and the second sensing surface of the second sensor faces laterally to the explosive device.

[0010] According to at least one embodiment of the present invention, the control device includes a data collector, and the data collector is electrically connected to the explosive device, the first sensor, and the second sensor respectively.

[0011] According to at least one embodiment of the present invention, the first unit corresponds to the second unit in a one-to-one manner.

[0012] According to at least one embodiment of the present invention, the horizontal distances between the first unit and the explosive device and the corresponding horizontal distances between the second unit and the explosive device are the same.

[0013] According to at least one embodiment of the present invention, a line connecting the first unit and the corresponding second unit passes through the center of the explosive device.

[0014] According to at least one embodiment of the present invention, when there are multiple first units and multiple second units, the horizontal distances between each first unit and the explosive device are different, and each first unit is evenly spaced along the circumference of the explosive device.

[0015] According to at least one embodiment of the present invention, the number of the first units and the second units at the same horizontal distance from the explosive device is plural and are evenly distributed along the circumference of the explosive device.

[0016] According to at least one embodiment of the present invention, the first pipe includes a plurality of detachably connected first pipe segments, and the second pipe includes a plurality of detachably connected second pipe segments.

[0017] According to at least one embodiment of the present invention, the length of the first tube and the length of the second tube are both greater than the burial depth of the explosive device.

[0018] In a second aspect, the present invention further provides an underground explosion pressure test method, which uses the test system described in the first aspect to conduct the test.

[0019] One or more technical solutions provided in the exemplary embodiments of the present invention can achieve at least one of the following beneficial effects.

[0020] The underground explosion pressure test system provided by the exemplary embodiment of the present invention uses a drill to drill a hole in the rock and soil, and places the explosive device in the center hole, while the first sensor and the second sensor are directly placed in the corresponding measuring holes through the first tube and the second tube, and compacted by backfilling the soil. Compared with the existing technology that adopts the form of excavating tunnels, the workload of excavation and backfilling is reduced. At the same time, the form of using steel pipes (first tube and second tube) to drive the corresponding sensors can be easily removed from the borehole, for example, the sensor tooling can be mechanically hoisted out through the steel pipe, without the need for large excavation to recover the used sensors, and it is not easy to damage the sensors. Furthermore, the drilling method is not limited by depth, and the explosion stress wave test can be carried out at a hole depth of tens to hundreds of meters, which expands the test range of stress waves.

[0021] Furthermore, the steel pipe of the exemplary embodiment of the present invention serves as a sensor pipe to lead the wire out of the ground and connect it to the control device, so that the steel pipe can protect the wire and avoid violent movement of rock and soil caused by explosion, which may cause damage to the buried wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0023] Figure 1 is a schematic structural diagram of a test system according to an embodiment of the present invention;

[0024] Figure 2 is an axonometric structural diagram of a first unit according to an embodiment of the present invention;

[0025] Figure 3 is a schematic cross-sectional structural diagram of a first unit according to an embodiment of the present invention;

[0026] Figure 4 is an axonometric structural diagram of a second unit according to an embodiment of the present invention;

[0027] Figure 5 is a schematic cross-sectional structural diagram of a second unit according to an embodiment of the present invention;

[0028] Figure 6 is a schematic diagram of a second packaging plate and an explosion stress wave according to an embodiment of the present invention;

[0029] Figure 7 is a peak stress fitting curve of the first sensor and the second sensor according to an embodiment of the present invention;

[0030] Figure 8 is a schematic diagram of the arrangement of the first unit and the second unit according to an embodiment of the present invention;

[0031] Figure 9 is a schematic diagram of the arrangement of the first unit and the second unit according to another embodiment of the present invention;

[0032] Figure 10 Schematic diagram of the structure of a steel pipe according to an embodiment of the present invention.

[0033] Figure numerals: 11, first packaging plate; 111, first surface; 12, first tube; 121, open-cell foam plastic; 122, wire mesh; 123, fluororubber layer; 13, third tube; 14, first sensing surface; 21, second packaging plate; 211, guide part; 22, second tube; 24, second sensing surface, 30, control device. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] In related technologies, stress wave testing in underground rock and soil is often performed using a model test method, where pressure sensors are directly buried for measurement. This method primarily involves creating a barrel-shaped model filled with the rock and soil to simulate the underground rock and soil environment. This barrel-shaped model structure is typically no longer than 10 meters, limiting the stress wave testing range. Directly burying pressure sensors requires extensive excavation, which is labor-intensive. Furthermore, the sensors are unprotected, and the hard rock and soil in the medium can easily damage the sensor wires. Furthermore, the pressure sensors are prone to deviating from their intended measurement points during installation, making it difficult to guarantee stress wave testing accuracy.

[0036] Figure 1 FIG. 1 is a schematic diagram of the structure of the test system according to an embodiment of the present invention. Figure 1 As shown, a central hole and two measuring holes with the same hole depth are drilled in the rock soil, wherein the distances between the two measuring holes and the central hole are the same.

[0037] In one example, a typical flat terrain is selected within the test site. A deep-hole drill is used to drill a measurement hole with a diameter sufficient to accommodate the first and second units. The measurement hole is positioned at the same distance from the center hole, ensuring that the measured first and second stress values ​​represent stress waves of the same intensity generated at the explosion center, thereby determining the accuracy of the first stress value.

[0038] In practical applications, the depths of the two measuring holes may be slightly greater than the depth of the central hole, so that there is room for adjustment of the positions of the first sensing surface 14 and the second sensing surface 24 .

[0039] Figure 2 is an axonometric structural diagram of a first unit according to an embodiment of the present invention; Figure 3 is a schematic cross-sectional structural diagram of a first unit according to an embodiment of the present invention; Figure 4 is an axonometric structural diagram of a second unit according to an embodiment of the present invention; Figure 5 : is a schematic cross-sectional view of the second unit according to an embodiment of the present invention. Figure 2-Figure 5 As shown, the explosive device is placed in the central hole, and the first unit and the second unit are placed in the two measuring holes respectively; wherein the first sensing surface 14 and the edge of the guide portion 211 away from the second tube 22 are both arranged opposite to the explosive device.

[0040] The first sensor and the second sensor can be placed at the bottom of the measuring hole respectively through the first tube 12 and the second tube 22. Specifically, the first tube 12 and the second tube 22 are adjusted so that the first sensing surface 14 of the first sensor faces the explosion center, while the second sensing surface 24 of the second sensor faces the explosion center laterally. That is, the sharp edge of the guide portion 211 facing away from the second tube 22 faces the explosion center.

[0041] Exemplarily, the first tube 12 and the second tube 22 are adjusted so that the center point of the first sensing surface 14 of the first sensor, the center point of the second sensing surface 24 of the second sensor, and the center point of the explosive device are located on the same horizontal plane.

[0042] The measuring hole is then backfilled with in-situ soil. During this process, the soil pit is tamped several times with a long stick so that the rock and soil density after backfilling is similar to that before drilling.

[0043] From the above, it can be seen that the depth of burying explosive devices by drilling is not limited. Even the stress waves generated by large-yield explosions can eliminate the influence of ground reflection on the test results, reduce the error of the experiment, and obtain a more accurate explosion stress. The depth of the center hole can be set to exceed the critical no-effect burial depth.

[0044] Compared with excavating tunnels for burial, the test method of the exemplary embodiment of the present invention not only saves a lot of backfill work, but also can be applied to the precise measurement of stress waves generated by large-yield explosions.

[0045] The explosive device can generate a spherically propagating stress wave and can be used to detonate small or large explosive charges, such as those weighing thousands of kilograms. The test method is applicable to detonating large explosive charges at great depths and within test ranges up to tens of meters.

[0046] In some embodiments, the borehole depth is determined based on the critical no-effect burial depth. Specifically, to eliminate the influence of ground reflection on the test results, reduce experimental errors, and obtain a more accurate magnitude of the explosion stress on the protective structure surface, the charge hole depth in the experimental design should exceed the corresponding critical no-effect burial depth. For rock and soil media, the critical no-effect burial depth is determined by Formula 1:

[0047] h l =kQ 1 / 3 , Formula 1;

[0048] Among them, h l is the critical no-effect burial depth, in m, Q is the equivalent TNT charge, in kg, and for rock and soil media, k is taken as 0.8 m kg -1 / 3 For example, for a 1kg TNT charge, when its charge is buried more than h l (0.8m), then the stress generated by the charge explosion will all act on the rock and soil, making the test results more accurate.

[0049] When selecting the range of the first sensor and the second sensor, it is necessary to select according to the experimental conditions. First, a preliminary stress peak estimation is required based on the experimental conditions, and then the sensor range is selected based on the estimation results. Here, to better adapt to the geotechnical testing environment, the first sensor and the second sensor can use quartz sensors with stable sensitivity. The stress peak estimation in geotechnical can be obtained according to formula 2:

[0050] σ r =A·Z -n , formula 2;

[0051] Among them, σ r is the test pressure, A and n are the stress wave attenuation coefficient and attenuation exponent respectively. Proportional distance Z=R / Q 1 / 3 , unit is m·kg -1 / 3 The reference values ​​of A and n in different media are shown in Table 1.

[0052] Table 1 Stress wave attenuation coefficient and attenuation index in different media

[0053]

[0054] like Figure 2 and Figure 3 As shown, the first unit includes a first sensor, a first tube 12 and a first packaging board 11 provided at the bottom end of the first tube 12 . The first surface 111 of the first packaging board 11 has a first opening for exposing the first sensing surface 14 of the first sensor.

[0055] In actual applications, the first sensor is encapsulated in the first packaging board 11, and its first sensing surface 14 is exposed through a first opening provided on the first surface 111 of the first packaging board 11, and can receive and sense stress waves. Exemplarily, the first sensor can be a pressure sensor, optionally a quartz sensor, which has stable sensitivity. The wire of the first sensor can extend from the ground through the first tube 12 to be connected to a data acquisition device. The first tube 12 can drive the first packaging board 11 to extend into the corresponding borehole to bury the first sensor in the borehole in a predetermined orientation. The wire of the first sensor can also be protected to prevent hard rock and soil from damaging the wire of the first sensor, resulting in damage to the insulation layer, excessive signal noise, or even cutting off the wire of the first sensor and no signal being detected.

[0056] For example, the top of the first packaging board 11 is positioned at the bottom of the first tube 12, and the first opening is located on the first surface 111 of the first packaging board 11, near the bottom. The first opening is consistent in shape and size with the first sensing surface 14 of the first sensor, and may be, for example, circular. The first sensing surface 14 is located below and away from the first tube 12, thereby reducing stress wave reflections from the first tube 12 that could affect the accuracy of data acquisition by the first sensor.

[0057] In one example, the first unit further includes a third tube 13 , both ends of which are vertically connected to the bottom end of the first tube 12 and the top end of the first packaging plate 11 , respectively, and the first opening is close to the bottom end of the first packaging plate 11 .

[0058] like Figure 2 As shown, the third tube 13 and the first packaging board 11 are arranged in an L-shape, and the third tube 13 and the first tube 12 are also arranged in an L-shape. The third tube 13 can be regarded as a cantilever, so that the first tube 12 and the first sensor are separated by a certain distance in the horizontal direction. The first sensing surface 14 of the first sensor is close to the bottom end of the first packaging board 11. In other words, there is a certain distance between the first sensing surface 14 and the first tube 12 in both the vertical and horizontal directions. This allows the reflection of the stress wave by the first tube 12 to minimize interference with the data of the first sensor.

[0059] When the third tube 13 is connected to the first tube 12 , the wire of the first sensor can pass through the third tube 13 and reach the ground.

[0060] For example, the bottom end of the first tube 12 can be closed or open, without affecting the protection of the wires therein.

[0061] In one example, the first packaging board 11 is made of a material that matches the rock and soil wave impedance, such as nylon, PVC plastic, etc., which can reduce the impact on the first sensor, thereby reducing experimental errors and more accurately measuring the forward pressure of the explosion.

[0062] like Figure 4 and Figure 5 As shown, the second unit provided by the exemplary embodiment of the present invention includes a second tube 22 and a second packaging plate 21 vertically arranged at the bottom end of the second tube 22, the second packaging plate 21 has two second surfaces distributed along the first direction, the axial direction of the second tube 22 is perpendicular to the first direction, and one second surface has a second opening for exposing the second sensing surface 24 of the second sensor; the second packaging plate 21 has a guide portion 211 surrounding the second sensing surface 24, and the thickness of the guide portion 211 gradually becomes thinner in the direction away from the second sensing surface 24.

[0063] The second packaging plate 21 and the second tube 22 are arranged in an L-shape, and the axial direction of the second tube 22 can be perpendicular to the second surface, that is, the first direction is the vertical direction. Figure 4 As shown, the axial direction of the second tube 22 may also be parallel to the second surface, that is, the first direction is the horizontal direction.

[0064] A second opening is formed on one of the two opposite second surfaces of the second packaging board 21 to expose the second sensing surface 24 of the second sensor packaged in the second packaging board 21 , and the wire of the second sensor can extend out of the ground through the second tube 22 .

[0065] The second opening is disposed at a portion of the second packaging plate 21 away from the second tube 22 , which can minimize the impact of stress waves reflected by the second tube 22 on the stress measurement accuracy of the second sensor.

[0066] A guide portion 211 is formed at one end of the second packaging plate 21 away from the second tube 22. The guide portion 211 is a pancake-shaped structure with a thick middle and thin edges, which surrounds part of the circumference of the second opening. When it is fixed in the drilled hole, the edge of the guide portion 211 faces the explosive device. Due to its sharp edge and gradually thickening in the middle, the stress wave can propagate unimpeded to the second opening, that is, to the second sensing surface 24 of the second sensor, so that the influence of the shape of the second packaging plate 21 itself on the stress wave is minimized, thereby improving the measurement accuracy of the second sensor.

[0067] In one example, the material of the second packaging board 21 is the same as that of the first packaging board 11 , the shape and size of the second opening is the same as that of the first opening, and the shape and thickness of the second tube 22 is the same as that of the first tube 12 , which are not described in detail here.

[0068] The first sensing surface 14 of the first sensor can face the explosive device and measure the normal stress of the stress wave; the second sensing surface 24 of the second sensor can face the explosive device and measure the lateral stress of the stress wave. Figure 6 As shown, Figure 6 FIG. 4 is a schematic diagram of a second packaging plate and an explosion stress wave according to an embodiment of the present invention.

[0069] Under the action of explosive stress waves, there is a certain relationship between the normal stress and lateral stress of rock and soil, as described below:

[0070] A. Rock and soil present elastic stress state under the action of explosion stress.

[0071] In the elastic state, the rock and soil present a triaxial stress state due to the blast stress. The blast stress σ at a point in the rock and soil is r It can be divided into three normal stress components and six shear stress components. The nine components are arranged according to certain rules, as shown in Formula 3.

[0072]

[0073] When the explosion stress reaches the second sensor, Figure 6 As shown, since the second sensing surface 24 of the second sensor is placed perpendicular to the explosion center, the three-dimensional stress on each surface element is only normal stress, and the shear stress is equal to 0. Equation 3 can be rewritten as Equation 4:

[0074]

[0075] The stress data recorded by the second sensor is σ perpendicular to the second sensing surface. zz The time course curve.

[0076] It should be noted that the stress waves tested by the first sensor and the second sensor are generated by the same explosive device, that is, the normal stress obtained by the first sensor is the explosion stress σ r , therefore, in the actual test process, the lateral stress σ 侧 will always be less than the normal stress σ 正 , both satisfy Equation 5.

[0077] σ zz =σ 侧 =σ r μ = σ 正 ·μ, formula 5;

[0078] Where μ is the Poisson's ratio of rock and soil.

[0079] Thus, the ratio of normal stress to lateral stress can be obtained, which satisfies Equation 6.

[0080]

[0081] B. The rock and soil are in a fluid state under the action of explosive stress.

[0082] Formula 3 can be rewritten as Formula 7,

[0083]

[0084] σ m is the stress in each direction, and the magnitudes of the three directions are equal. In the fluid state, the stress recorded by the first sensor and the second sensor are both volume stress, so we get formula 8:

[0085]

[0086] Thus, the ratio of normal stress to lateral stress can be obtained, which satisfies Equation 9.

[0087]

[0088] In the rock and soil explosion test, the rock and soil medium in the area near the explosive is in a fluid state, and in the area far from the explosive is in an elastic state. From the above formula 10,

[0089]

[0090] In the rock and soil explosion test, the normal stress and lateral stress obtained by the first sensor and the second sensor have a ratio between them in the range of [1, 1 / μ], where μ can be accurately expressed as the Poisson's ratio by field survey of the rock and soil.

[0091] In one example, the first tube 12 of an exemplary embodiment of the present invention includes multiple first tube segments, and the second tube 22 includes multiple second tube segments. Each first tube segment is threaded at both ends, allowing the multiple first tube segments to be assembled to form the first tube 12 according to the actual hole depth requirements. Each second tube segment is threaded at both ends, allowing the multiple second tube segments to be assembled to form the second tube 22 according to the actual hole depth requirements. For example, the multiple first tube segments and the multiple second tube segments can be fixed together using sleeves, allowing for flexible length adjustment and increasing the flexibility and practicality of the test.

[0092] Exemplarily, the first unit of the exemplary embodiment of the present invention further includes a first rubber tube, and the second unit further includes a second rubber tube.

[0093] In practice, the first sensor's wires are threaded through a first rubber tube, which is secured to the center axis of first tube 12. The second sensor's wires are threaded through a second rubber tube, which is secured to the center axis of second tube 22. The rubber tubes not only further protect the sensor wires but also reduce the transmission of vibration and shock. Within the steel pipe, securing the sensor wires in the center of the pipe prevents direct contact between the sensor wires and the pipe, thereby reducing wear and damage.

[0094] Furthermore, after the explosive device is activated, the data acquisition device collects a first stress value from the first sensor and a second stress value from the second sensor via corresponding wires. The control device determines whether the first stress value is an accurate stress value based on the ratio of the first stress value to the second stress value measured at the same distance from the detonation center.

[0095] When the ratio of the first stress value to the second stress value is 1 to 1 / μ, it indicates that the first stress value is accurate, and therefore, the first stress value is stored; when it is not within the above range, it indicates that the first stress value cannot accurately reflect the actual stress value, and the data is discarded.

[0096] In some embodiments, the arrangement of the first and second units, that is, the method for determining the circumferential distribution of measurement points at the explosion center, has two forms. To avoid the influence of mutual occlusion of measurement points on the sensor, the measurement holes are distributed circumferentially around the central hole at a certain angle.

[0097] In some embodiments, the first unit corresponds to the second unit in a one-to-one manner.

[0098] In some embodiments, the horizontal distance between the first unit and the explosive device and the horizontal distance between the corresponding second unit and the explosive device are the same.

[0099] In one example, a line connecting a first unit and a corresponding second unit passes through the center of the explosive device.

[0100] In some embodiments, when there are multiple first units and second units, the horizontal distances between each first unit and the explosive device are different, and each first unit is evenly spaced along the circumference of the explosive device.

[0101] In one example, the number of the first units and the second units at the same horizontal distance from the explosive device are both plural and evenly distributed along the circumference of the explosive device.

[0102] Solution 1: Place a first sensor and a second sensor at the same radial distance from the explosion center, such as Figure 8 As shown, Figure 8 FIG. 2 is a schematic diagram illustrating the arrangement of the first unit and the second unit according to an embodiment of the present invention.

[0103] When three or more control experiments are set up simultaneously for a charge of a certain mass in the test, in order to reduce the test workload, this scheme is selected for arrangement, that is, a first sensor and a second sensor are arranged at a certain radial distance respectively, so that the normal stress and lateral stress at a certain radial distance are obtained, and the accuracy of the experimental results is judged based on the proportional relationship between the first stress value and the second stress value.

[0104] In scheme 1, two measuring points are used for each radial distance. Measuring points B1, B3, and B5 use the first unit, and B2, B4, and B6 use the second unit. The sensors at the same radial distance are 180° apart in the circumferential direction, and at different radial distances, the sensors are 60° apart in the circumferential direction.

[0105] Solution 2: Arrange two first sensors and two second sensors at the same radial distance from the explosion center, such as Figure 9 As shown, Figure 9 FIG. 4 is a schematic diagram illustrating an arrangement of a first unit and a second unit according to another embodiment of the present invention.

[0106] When only one or two groups of experiments are set up for a charge of a certain mass in the test, in order to obtain more experimental data, option 2 is selected for arrangement, that is, two first sensors and two second sensors are arranged at a certain radial distance, so that the normal stress and lateral stress at a certain radial distance are obtained, and the accuracy of the experimental results is judged based on the proportional relationship between the first stress value and the second stress value.

[0107] In scheme 2, four measuring points are used for each radial distance. Measuring points B1, B3, B5, B7, B9, and B11 use the first unit, and B2, B4, B6, B8, B10, and B12 use the second unit. The sensors at the same radial distance are 90° apart along the circumferential direction, and at different radial distances, the sensors are 30° apart along the circumferential direction.

[0108] Figure 10 Schematic diagram of the structure of a steel pipe according to an embodiment of the present invention. Figure 10 As shown, the first tube 12 and the second tube have the same structure. The structure of the first tube 12 is used as an example for description below. The outer surface of the first tube 12 has a layer of buffering energy-absorbing material, such as open-cell foam plastic 121, with a thickness of 5 mm to 10 mm. The open-cell foam plastic 121 is fixed to the corresponding steel pipe using tape or special adhesive to prevent displacement during the explosion. A layer of wire mesh 122 is wrapped around the outside of the open-cell foam plastic 121. The wire mesh 122 should have sufficient strength and density to effectively block large particles and rocks produced by the explosion. The wire mesh 122 is fixed to the outside of the open-cell foam plastic 121 using straps to ensure that it is not easy to fall off or move under the impact of the explosion. The mesh size is selected to be able to filter large rocks but allow stress waves to pass through.

[0109] The outer layer of the wire mesh 122 also includes a fluororubber layer 123, which reduces the mutual constraints between the first tube 12 and the soil, allowing the first tube 12 to deform freely with the movement of the soil during the explosion. It can effectively absorb the shock wave generated by the explosion, reducing the direct transmission of the impact force, thereby reducing interference with the measurement results. The thickness of the fluororubber layer 123 is between 10mm and 20mm to ensure that it will not instantly rupture under the impact of the explosion. When the explosion wave acts on the rock and soil near the sensor, the fluororubber's high elasticity causes it to deform first and move with the rock and soil, reducing the impact of the first tube 12 on the overall test. The entire first tube 12 is approximately 20mm to 35mm thick.

[0110] In some embodiments, the wall thickness of the first tube 12 is 2 mm, the surface of the first tube 12 is hot-dip galvanized, and an epoxy resin coating is added outside the hot-dip galvanized layer to further enhance the wear resistance and corrosion resistance of the first tube 12 and improve its own rust and corrosion resistance.

[0111] The first pipe section is a uniform 2m in length, with 15mm threads at both ends. Waterproof sealing materials (such as fluororubber seals) are used to prevent the intrusion of moisture and soil. This facilitates the connection between the first pipe sections and the threading of the wires. Furthermore, the connection length of the first pipe can be adjusted to suit different burial depth requirements to ensure the flexibility and practicality of the experimental setup. The second pipe section is identical to the first and will not be described here.

[0112] For example, an appropriate length of the first and second tubes is reserved above ground level to facilitate identification and recovery of the tooling after the experiment. Clear identification markings, such as color coding or labels, are provided above the ground level to facilitate quick location and identification by experimenters.

[0113] In some embodiments, the control device 30, including the data acquisition device, is located above ground, ensuring more accurate and reliable test results. Furthermore, the first and second units are also installed above ground, ensuring the proper functioning of the buried sensors and the smooth conduct of the experiment. After the experiment, the sensor fixture can be removed by mechanically connecting the above-ground portions of the first and second tubes, eliminating the need for extensive excavation to retrieve the used sensors.

[0114] Specifically, the stress wave of the explosive device is equivalent to the stress wave generated by 1kg of TNT. The center hole is 1.6m deep. The sensors are arranged using the layout of Scheme 2, and a set of peak stresses are measured.

[0115] Figure 7 is a peak stress fitting curve of the first sensor and the second sensor according to an embodiment of the present invention. Figure 7 As shown, the peak stress σ measured by the first sensor is Band the peak stress σ measured by the second sensor F Fitting is performed to obtain Equation 11 and Equation 12 respectively.

[0116] σ B =0.188Z -2.44 , formula 11;

[0117] σ F =0.123Z -2.26 , formula twelve.

[0118] Where Z is the proportional distance in m·kg -1 / 3 .

[0119] As shown in Equations 11 and 12, the peak stress of the stress wave and the proportional distance satisfy the exponential decay law theoretically calculated in engineering manuals. This means that both the first sensor and the second sensor can accurately measure stress waves in rock and soil.

[0120] The exemplary embodiment of the present invention further provides an underground explosion pressure test method, which uses the test system of the above embodiment to perform the test. Specifically, it includes:

[0121] A central hole and two measuring holes of the same depth are drilled in the rock soil, wherein the two measuring holes are at the same distance from the central hole;

[0122] The explosive device is placed in the central hole, and the first unit and the second unit are placed in the two measuring holes respectively; wherein the first sensing surface and the edge of the guide portion facing away from the second tube are both arranged opposite to the stress wave generator;

[0123] A first stress value of the first sensor and a second stress value of the second sensor are collected; when the ratio of the first stress value to the second stress value is 1 to 1 / μ, the first stress value is stored; otherwise, the first stress value is discarded; wherein μ is the Poisson's ratio of the rock and soil.

[0124] It should be understood by those skilled in the art that the above embodiments are merely for the purpose of illustrating the present invention clearly, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and such changes or modifications are still within the scope of the present invention.

Claims

1. An underground explosion pressure test system, characterized in that: The explosive device comprises an explosive device, at least one first unit, at least one second unit and a control device located above the ground, wherein the explosive device, the first unit and the second unit are all electrically connected to the control device; The first unit includes a first sensor and a first tube, wherein a wire of the first sensor passes through the first tube and is electrically connected to the control device; The second unit includes a second sensor and a second tube, and a wire of the second sensor passes through the second tube and is electrically connected to the control device; The first tube and the second tube are used to place the first sensing sensor and the second sensing sensor at the bottom of two measuring holes respectively; the explosive device is placed in the central hole; The center point of the first sensing surface, the center point of the second sensing surface, and the center point of the explosive device are located on the same horizontal plane; Wherein, the two measuring holes and the center hole are formed by drilling downward from the ground using a deep hole drill bit, and the distances between the two measuring holes and the center hole are the same; The first sensing surface of the first sensor faces the explosive device, and the second sensing surface of the second sensor faces laterally to the explosive device.

2. The test system according to claim 1, characterized in that The control device includes a data collector, and the data collector is electrically connected to the explosive device, the first sensor, and the second sensor respectively.

3. The test system according to claim 2, characterized in that: The first unit corresponds to the second unit in a one-to-one manner.

4. The test system according to claim 3, characterized in that The horizontal distances between the first unit and the explosive device and the corresponding horizontal distances between the second unit and the explosive device are the same.

5. The test system according to claim 4, characterized in that: A line connecting the first unit and the corresponding second unit passes through the center of the explosive device.

6. The test system according to claim 5, characterized in that: When there are multiple first units and multiple second units, the horizontal distances between each first unit and the explosive device are different, and each first unit is evenly spaced along the circumference of the explosive device.

7. The test system according to claim 4, characterized in that: There are a plurality of the first units and the second units at the same horizontal distance from the explosive device, and the units are evenly distributed along the circumference of the explosive device.

8. The test system according to any one of claims 1 to 7, characterized in that: The first pipe includes a plurality of detachably connected first pipe sections, and the second pipe includes a plurality of detachably connected second pipe sections.

9. The test system according to claim 8, characterized in that: The length of the first tube and the length of the second tube are both greater than the burial depth of the explosive device.

10. An underground explosion pressure test method, characterized in that: The test is carried out using the test system according to any one of claims 1 to 9.

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