Multi-field coupling sandstone ore blasting vibration simulation experiment device and experiment method

Abstract

The invention belongs to the field of engineering blasting, and discloses a multi-field coupling sandstone mine blasting vibration simulation experiment device and method, and the device comprises a fluid driving mechanism and an interval adjusting assembly linked with the fluid driving mechanism; water flow impacts the impeller, the impeller rotates, a rotating shaft of the impeller wraps the connecting rope, the connecting rope pulls the piston to move upwards, negative pressure is formed between the water storage barrel and the water storage bag, water in the water storage bag is pumped through the hose, and the weight of the water in the water storage bag is reduced. The thickness of the air interlayer changes when the elastic piece generates axial elastic deformation, passive adjustment of the air interlayer spacing is achieved through fluid mechanics characteristics, dynamic balance is formed between the air interlayer displacement amount and the water injection amount, an experimenter can remotely control the water body size in the water-containing fractured rock mass, and the experiment efficiency is improved. The position of the air spacing layer in the PVC pipe can be adaptively adjusted according to the size of a water body, so that potential safety hazards are reduced.

Description

Technical Field

[0001] The present invention belongs to the field of engineering blasting, and in particular relates to a multi-field coupled sandstone mine blasting vibration simulation experimental device and an experimental method. Background Art

[0002] With the rapid development of infrastructure construction in my country, the demand for efficient and green mining of quartz sandstone ore, as an important raw material for cement production, is becoming increasingly urgent. In open-pit mining, deep-hole step blasting technology is widely used due to its high efficiency and low cost. However, the rock mass in the mining area is well-developed with joints and fissures and contains water all year round, which leads to a high rate of large blocks and excessive blasting vibration intensity during the blasting process, which not only affects the mining efficiency and increases the cost of secondary crushing, but also poses a safety hazard to nearby buildings. For example, a method, system, equipment and medium for controlling block size in mine blasting construction with application number CN119618006A establishes a quantitative relationship between the thickness of the air interval layer and the total length of the charge, and manually adjusts the thickness of the air interval layer to perform multiple blastings to obtain different changes in explosive stress caused by different thicknesses of the air interval layer; and by using the same method, the rock mass to be blasted is replaced with a water-containing rock mass, and by observing the distribution of rock blocks after the explosion, the influence of the water in the rock mass on the stress propagation characteristics of the rock mass during the explosion of the explosive can be obtained; However, when it is directly applied to water-bearing rock mass, the volume in the cracks becomes unstable due to the entry of gravel into the cracks during the excavation of the rock mass, resulting in the water remaining in the cracks having a volume different from that of the originally planned experimental water mass, while the air interval layer between the explosives remains unchanged. If the thickness of the air interval layer is greater than the predetermined thickness of the originally planned experimental water mass, the blasting vibration will be less intense than expected in the experiment, resulting in incomplete blasting of the rock mass around the water mass, especially when the water mass weakens the stress generated by the blasting. If the thickness of the air interval layer is less than the predetermined thickness of the originally planned experimental water mass, the explosion stress will be concentrated and damage will be caused to the surrounding rock mass and buildings, increasing safety risks. The rock mass structure is unstable after excavation, and manual adjustment of the air layer interval between the explosives is prone to safety hazards. Summary of the invention

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a multi-field coupled sandstone mine blasting vibration simulation experimental device and experimental method, which solves the problem in the prior art that during the rock excavation process, gravel enters the cracks, resulting in the water body remaining in the cracks being different from the original water body volume, and artificially adjusting the air layer interval between explosives is prone to safety hazards.

[0004] The purpose of this disclosure can be achieved through the following technical solutions: A multi-field coupled sandstone mine blasting vibration simulation experimental device comprises: a fluid driving mechanism and an interval adjustment component linked to the fluid driving mechanism; The fluid driving mechanism includes a flow channel communicating with the water tank and an impeller disposed in the water filling tank. The water in the water tank moves through the water filling tank into the groove body opened in the rock mass to simulate the water body in the water-containing fractured rock mass under natural conditions. The interval adjusting assembly includes a vertical water storage cylinder. A piston in sealed sliding fit is provided in the inner cavity of the water storage cylinder. The rotating shaft supporting the rotation of the impeller is connected to the top of the piston through a connecting rope. A hose connects the water storage cylinder and the water storage bag. The bottom of the water storage bag supports one end of a vertically placed PVC straight pipe filled with explosives. The water storage bag forms a vertically downward pressure load on the PVC straight pipe through its own weight. Elastic members are arranged between adjacent explosives in the PVC straight pipe, and the elastic members keep an air interval layer formed between adjacent explosives. The water flow impacts the impeller, and the impeller rotates. The rotating shaft of the impeller winds the connecting rope, and the connecting rope pulls the piston upward, creating a negative pressure between the water storage cylinder and the water storage bag. The water in the water storage bag is pumped out through the hose, reducing the weight of the water in the water storage bag. The pressure change of the water storage bag on the PVC straight pipe causes the elastic members in the PVC straight pipe to produce axial elastic deformation. When the elastic members produce axial elastic deformation, the thickness of the air interval layer also changes, thereby adjusting the thickness of the air interval layer between adjacent explosives in real time, so that the blasting vibrations generated by the two explosives are within a preset range.

[0005] In some disclosures, the impeller is fixed inside the water filling tank through an impeller frame. The rotating shaft of the impeller is arranged perpendicular to the water flow direction. The water flow flowing out of the flow channel contacts the blades at the bottom of the impeller and drives the impeller to rotate counterclockwise.

[0006] In some disclosures, a positioning hole penetrating the support platform is provided between the water tank and the water filling tank, and a cylinder is arranged through the inner side of the positioning hole. A slotting assembly is provided at the lower end of the cylinder.

[0007] In some disclosures, a water guide plate is fixed at the lower end of the water filling tank, and a spring rope is fixed between the slotting assembly and the water guide plate.

[0008] In some disclosures, the slotting assembly includes a motor, a milling cutter disc and a dust shield. The motor is fixed at the lower end of the cylinder. The output end of the motor is fixed with a milling cutter disc. A dust shield is coaxially fixed outside the milling cutter disc. One side of the spring rope away from the water guide plate is fixed to the dust shield.

[0009] In some disclosures, an electric telescopic rod is fixed at one end of the motor away from the milling cutter disc. A slider is fixed on the upper end surface of the motor, and the upper end of the slider is fixed to the lower end of the cylinder. The moving path of the slider is parallel to the moving path of the electric telescopic rod.

[0010] In some disclosures, the PVC straight pipe includes a fixing cylinder, a limiting plate, a reset spring, and a supporting plate. The lower end of the water storage cylinder is clamped with the fixing cylinder, and the limiting plate is slidably arranged inside the fixing cylinder. A reset spring is fixed to the lower end surface of the limiting plate, and a supporting plate is fixed to the bottom of the reset spring. The space supported by the reset spring between the limiting plate and the supporting plate is an air spacer layer, and a plurality of explosives are placed inside the fixing cylinder, and the explosives are respectively placed on both sides of the air spacer layer. The reset spring is made of natural rubber material and has a thickness of 1-2 cm.

[0011] In some disclosures, a positioning groove is formed at the upper end of the fixing cylinder, and a clamping rod adapted to the positioning groove is fixed to the bottom of the fixing cylinder.

[0012] In some disclosures, a clamping ring is fixed to the bottom of the water storage cylinder, and a limiting protrusion adapted to the clamping ring is fixed to the outer wall of the uppermost fixing cylinder.

[0013] The multi-field coupling sandstone mine blasting vibration simulation experiment method includes the following steps: S1. Prepare standard rock samples. First, make a plurality of complete rock mass samples according to the sandstone hardness, and then make cylindrical rock specimens with the same hardness as the sandstone. Measure the load when the rock is damaged by a compressor, and calculate the point load intensity. S2. Vertically place the explosive in a roll shape into the fixing cylinder. The upper and lower ends of the explosive are respectively attached to the supporting plate and the limiting plate. The interval between the supporting plate and the limiting plate between adjacent explosives is the air spacer layer. S3. Place a suitable rock mass inside the support frame, and place the predetermined crack position corresponding to the milling cutter head up and down. Start the motor to drive the milling cutter head to rotate at a high speed, and then start the cylinder. The cylinder drives the milling cutter head to move vertically downward until the milling cutter head contacts the rock mass and cuts the inside of the rock mass to form a groove on the rock mass surface to simulate the cracks of the water-containing cracked rock mass in the natural state. And drill blast holes around the cracks through a drilling machine. Fix the probe connected to the blasting vibration instrument on the ground near the rock. Start the instrument before blasting. S4. At this time, place the PVC straight pipe with explosives inside the blast hole, and the upper end of the PVC straight pipe is directly below the water storage cylinder. The water storage bag exerts a downward pressure on the explosives and the reset spring, so that the reset spring is in a compressed state at this time, and the air spacer layer between adjacent explosives is the smallest. S5. At this time, start the water pump outside the water tank, so that the water in the water tank flows along the flow channel. When it flows to the water filling tank, the water body impacts the blades on the impact impeller and drives the impeller to rotate. After the water body impacts the impeller, the kinetic energy of the water body weakens, and it flows downward to the water guide plate under the influence of gravity, and enters the crack along the spring rope and the milling cutter head to simulate the situation where rainwater remains in the rock crack to form a water-containing rock mass in the real situation. At this time, spray a developer on the crack surface through a drone. S6. Meanwhile, when the impeller rotates, the connecting rope is wound around the middle of the impeller, driving the piston to move upward, thereby pumping the liquid in the water storage bag into the water storage cylinder through the hose. At this time, the axial pressure exerted by the water storage bag on the explosive and the reset spring decays linearly. S7. After the pressure of the water storage bag on the explosive weakens, the reset spring in the fixed cylinder undergoes elastic recovery, driving the air spacer layer between the explosives to gradually increase, enabling the thickness of the air spacer layer in the PVC straight pipe to be adaptively adjusted according to the size of the water body entering the crack, so that the thickness of the air spacer layer matches the volume of the water body entering the crack. S8. After the explosion, the probe converts the physical quantity of vibration into an electrical signal, records the detected vibration speed and frequency parameters. By changing the rock mass, changing the size of the groove through the grooving component, and replacing the water volume multiple times for experiments, the distribution of the exploded rock blocks around the crack when the water volume in the crack is different, as well as the dynamic strength of the rock mass and the propagation characteristics of the stress wave in the rock mass when the rock mass crack contains water, are obtained respectively.

[0014] The explanations of the nouns, conjunctions or adjectives involved in the above technical solutions are as follows: Fixed connection means that after the parts or components are fixed, there is no relative movement between them. Rotational connection means that the connection between parts allows the parts to rotate relative to each other. Threaded connection is a detachable fixed connection, which has the advantages of simple structure, reliable connection, convenient installation and disassembly, etc., and is widely used in the fields of mechanical engineering and connection structures. Sliding connection means that the connection between parts allows the parts to slide relative to each other.

[0015] Advantages of the present disclosure: Before the air layer between the explosives is installed at the point to be exploded, the position of the air spacer layer is unified. When injecting water into the water-containing crack rock mass, using the kinetic energy of water injection as the driving source, the passive adjustment of the air layer spacing is realized through the hydrodynamic characteristics, so that the displacement of the air layer forms a dynamic balance with the water injection volume. When the experimenter remotely controls the size of the water body in the water-containing crack rock mass, the size of the air spacer layer in the PVC pipe can be adaptively adjusted according to the size of the water body, reducing the safety hazards of manual adjustment. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is the overall structural schematic diagram of an embodiment of the present disclosure; Figure 2 is the overall structural schematic diagram from another perspective of an embodiment of the present disclosure; Figure 3 is the overall structural schematic diagram of the impeller and the interval adjustment assembly of an embodiment of the present disclosure; Figure 4 is of an embodiment of the present disclosure Figure 3 internal sectional structural schematic diagram; Figure 5 is the overall structural schematic diagram of the PVC straight pipe of an embodiment of the present disclosure; Figure 6 is the overall structural schematic diagram of the grooving assembly of an embodiment of the present disclosure; Figure 7 is the connection schematic diagram of the grooving assembly and the electric telescopic rod of an embodiment of the present disclosure.

[0018] In the figure: 1, support frame; 2, support table; 21, water filling tank; 22, positioning hole; 211, water guide plate; 3, water tank; 4, flow channel; 5, impeller; 6, interval adjustment assembly; 61, water storage cylinder; 62, connecting rope; 63, piston; 64, water storage bag; 611, hose; 612, snap ring; 7, grooving assembly; 71, motor; 72, milling cutter head; 73, dust shield; 711, electric telescopic rod; 8, spring rope; 9, PVC straight pipe; 91, fixed cylinder; 92, limiting plate; 93, return spring; 94, support plate; 911, positioning groove; 912, engaging rod; 913, limiting protrusion; 10, cylinder. Detailed implementation manners

[0019] Next, the technical solutions in the embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present disclosure.

[0020] Please refer to Figures 1 to 7 , a multi-field coupling sandstone mine blasting vibration simulation experimental device, including: a fluid driving mechanism and an interval adjustment assembly 6 linked to the fluid driving mechanism; The fluid driving mechanism includes a flow channel 4 communicated with the water tank 3 and an impeller 5 arranged in the water filling tank 21. The water body in the water tank 3 moves through the water filling tank 21 into the groove body opened in the rock mass to simulate the water body in the water-containing fractured rock mass under natural conditions; The interval adjusting assembly 6 includes a vertical water storage cylinder 61. A piston 63 in sealed sliding fit is arranged in the inner cavity of the water storage cylinder 61. The rotating shaft supporting the impeller 5 is connected to the top of the piston 63 through a connecting rope 62; A hose 611 communicates the water storage cylinder 61 with the water storage bag 64. The bottom of the water storage bag 64 is supported on one end of a vertically placed PVC straight pipe 9 filled with explosives. The water storage bag 64 forms a vertically downward pressure load on the PVC straight pipe 9; Elastic members are arranged between adjacent explosives in the PVC straight pipe 9, and the elastic members keep an air interval layer formed between adjacent explosives; Water flow impacts the impeller 5, and the impeller 5 rotates. The rotating shaft of the impeller 5 winds the connecting rope 62, and the connecting rope 62 pulls the piston 63 to move upward, so as to form a negative pressure between the water storage cylinder 61 and the water storage bag 64, and the water in the water storage bag 64 is extracted through the hose 611, so that the weight of the water in the water storage bag 64 is reduced. The pressure change of the water storage bag 64 on the PVC straight pipe 9 causes the elastic members in the PVC straight pipe 9 to generate axial elastic deformation, so that when the elastic members generate axial elastic deformation, the thickness of the air interval layer will also change, thereby adjusting the thickness of the air interval layer between adjacent explosives in real time, making the blasting vibrations generated by the two explosives within a preset range, and at this time, the thickness of the air interval layer that can make the explosives explode within the preset range is a reasonable range.

[0021] During use, clean water or damping liquid is injected into the water storage cylinder 61 and the water storage bag 64. Initially, the lower end surface of the piston 63 fits with the inner bottom wall of the water storage cylinder 61. At this time, the elastic members are in a compressed state, and the air interval layer between the explosives is 15 cm. A slot hole is drilled directly below the water storage cylinder 61 through a drilling machine, and then the PVC straight pipe 9 is coaxially installed with the water storage cylinder 61. At the same time, the outer wall of the piston 63 forms an airtight fit with the inner wall of the water storage cylinder 61, and the piston 63 divides the water storage cylinder 61 into upper and lower ends. When the piston 63 moves upward, the volume of the bottom space of the water storage cylinder 61 increases, and the gas pressure in the water storage cylinder 61 will decrease accordingly. According to the principle of atmospheric pressure, the external atmospheric pressure is greater than the air pressure in the water storage cylinder 61. Therefore, under the action of the external atmospheric pressure, the liquid will be pressed into the water storage cylinder from the water storage bag. This structure is similar to the principle of a syringe for injection to absorb water, and the hose 611 is similar to the injection head of a syringe. The bottom surface of the water storage bag 64 fits with the PVC straight pipe 9. After the water storage bag 64 is filled with water, the PVC straight pipe 9 is compressed to the minimum value by the water in the water storage bag 64, and at this time, the air interval layer in the PVC straight pipe 9 is the smallest; A water pump is installed at the connection between the water tank 3 and the flow channel 4 to control the water flow rate through the water pump. The water pump is a Wilo PVME series variable-frequency pump, which can automatically adjust the rotation speed according to the actual water usage situation to change the flow rate. Its model is PVME20-6. The water flow rate in the flow channel 4 is controlled by the water pump. The volume of water can be controlled by the water flow rate and the outflow time. At the same time, by controlling the water flow rate, the rotation speed of the impeller 5 and the upward movement amount of the piston 63 can be changed. An elastic member with appropriate elastic deformation ability is set so that when the liquid in the water storage bag 64 is pumped out, the displacement amount of the elastic member during recovery matches the water flow rate, so that when the increased volume of water injected into the crack matches the elongation displacement amount of the elastic member. That is, when 1L of water is injected into the crack, 100ml of the liquid in the water storage bag 64 is pumped out, the elastic member recovers 1-2cm, and the increase in the air gap layer between the explosives is 2cm. At this time, the air gap layer between the explosives is within a reasonable range, that is, for every 1L increase in water volume, the air gap layer increases by 1-2cm. The reasonable range means that after adding 1L of water volume at the crack, the thickness of the air gap adjustment at this time can ensure that the explosion power of the explosives can explode the rock blocks around the water body and cause less damage to the surrounding rock mass and buildings. During this adjustment process, the thickness of the air gap layer is adapted to the volume of water entering the crack. At the same time, in the actual scenario, the reasonable range will change according to the distance between the rock mass and the surrounding environment and the distance between the crack and the explosives. At this time, adjust its water flow rate according to the water pump, and use an elastic member with appropriate length and rigidity coefficient to meet the requirements; So that even when the volume of water in the crack is less than the original experimental water volume, and the thickness of the air gap layer is greater than the predetermined thickness when the original experimental water volume, the energy buffering force of the water body during explosion is small, resulting in the concentration of explosion stress after explosion and damage to the surrounding rock mass and buildings. If the air gap layer is preset when the water volume in the crack is the least, after the water volume increases, the energy after blasting is difficult to penetrate the water body in the crack, easily leading to incomplete blasting, making the explosion fragments around the crack water body not obvious. If it is too small, it will increase the safety risk, and the rock mass structure is unstable after excavation. It is easy to have potential safety hazards when manually adjusting the air layer interval between the explosives. The reasonable range of the air gap layer between the explosives when the water volume is 1L is between 15-18cm. At the same time, if the distance between the blast hole and the crack at the site is too far or too close, the thickness of the air gap layer can be adaptively improved according to the explosion power of the explosives, and the water flow rate in the flow channel 4 is greater than the gravity of the piston 63, which can push the impeller 5 to drive the piston 63 to move upward. Then, a crack is excavated and formed at the upper end of the rock mass. At this time, start the water pump to make the water in the water tank 3 flow along the flow channel 4. When it moves to the water filling tank 21, the water impacts the blades on the impeller 5 and drives the impeller 5 to rotate. After the water impacts the impeller 5, the kinetic energy of the water body weakens and enters the rock mass crack under the influence of gravity, filling the crack with water to simulate the situation where rainwater remains in the rock mass crack to form a water-containing rock mass in the actual situation; However, while the impeller 5 rotates, it drives the connecting rope 62 to wind around the middle of the impeller 5, and drives the piston 63 to move vertically upward along the inner wall of the water storage cylinder 61, thereby forming a negative pressure space at the bottom of the water storage cylinder 61, and pumping the water in the water storage bag 64 upward into the water storage cylinder 61 through the hose 611. At this time, the axial pressure exerted by the water storage bag 64 on the PVC straight pipe 9 decays linearly, and a dynamic pressure regulation model is constructed, enabling the experimenter to passively and precisely regulate the air spacer in the PVC straight pipe 9 by controlling the water outflow volume, so that the displacement of the air spacer and the water injection volume form a dynamic balance. When the crack is filled with gravel during the excavation process, the water storage volume in the crack changes. If the volume of water is to be adapted to the air spacer in the PVC straight pipe 9, the PVC straight pipe 9 needs to be adjusted again to change the air spacer after the water is poured in. However, for the excavated rock mass, the stability of the rock mass itself decreases. At this time, if climbing onto the rock mass to take out or install the PVC straight pipe 9, safety hazards are likely to occur. Moreover, if the experimenter climbs onto the rock mass on one side of the crack, it is easy to separate the entire rock mass at the crack, causing the rock mass crack to increase and the water in the crack to flow to the bottom, resulting in experimental errors. In addition, the impact force exerted by the explosive on the interval adjustment component 6 after the explosion will be absorbed by the water in the water storage cylinder 61, which is beneficial to protecting the interval adjustment component 6 after a single explosion and increasing the service life of the interval adjustment component 6. And the water stored in the water storage cylinder 61 can be injected into the water storage bag 64 again, facilitating recycling and saving water. At the same time, if the explosion intensity is relatively large, the water in the water storage cylinder 61 can be replaced with damping fluid. The molecular chains of the high molecular polymer in the damping fluid undergo reversible deformation under shear stress, converting mechanical energy into heat energy, which can improve the buffering effect compared with water. At the same time, the interval adjustment component 6 has a simple structure and fewer rigid structures, effectively avoiding brittle fracture caused by stress concentration in traditional rigid components.

[0022] Please refer to Figures 1 to 2 , the impeller 5 is fixed inside the flushing tank 21 through an impeller bracket. The rotation axis of the impeller 5 is perpendicular to the water flow direction. The water flow flowing out from the flow channel 4 contacts the blades at the bottom of the impeller 5 and drives the impeller 5 to rotate counterclockwise. During use, the water flowing out through the flow channel 4 impacts the blades at the bottom of the impeller 5 and drives the bottom blades to move away from the flow channel 4, thereby causing the impeller 5 to rotate counterclockwise along the rotation axis.

[0023] Please refer to Figures 1 to 2 , a positioning hole 22 penetrating the support platform 2 is provided between the water tank 3 and the flushing tank 21, and a cylinder 10 is disposed through the inside of the positioning hole 22. A grooving component 7 is provided at the lower end of the cylinder 10. During use, the output end of the cylinder 10 is disposed through the positioning hole 22, and the grooving component 7 is fixed at the lower end of the cylinder 10. The position of the grooving component 7 is changed by the extension and shortening of the cylinder 10, and the volume of the grooved body is changed.

[0024] A water guide plate 211 is fixed to the lower end of the water filling tank 21, a grooving assembly 7 is fixed to the lower end of the air cylinder 10, and a spring rope 8 is fixed between the grooving assembly 7 and the water guide plate 211. The water body that has lost kinetic energy falls above the water guide plate 211 under the influence of gravity and moves along the spring rope 8 to the side wall of the grooving assembly 7, keeping the grooving assembly 7 moist, which is beneficial to significantly reducing mechanical wear. And the grooving assembly 7 is located directly below the crack, so that the water body flowing along the grooving assembly 7 can accurately flow into the crack, which is beneficial to restricting the movement route of the water body and making the water body infiltrate along the axis of the rock mass crack. And by setting the spring rope 8 and using the characteristic that the spring rope 8 can freely expand and contract, when the grooving assembly 7 moves up and down, the spring rope 8 can elongate and deform as the grooving assembly 7 moves up and down, so as to prevent the spring rope 8 from being broken.

[0025] Please refer to Figure 6 and Figure 7 As shown in, the grooving assembly 7 includes a motor 71, a milling cutter disc 72 and a dust shield 73. The motor 71 is fixed to the lower end of the air cylinder 10, the output end of the motor 71 is fixed with the milling cutter disc 72, a dust shield 73 is coaxially fixed to the outside of the milling cutter disc 72, and the side of the spring rope 8 away from the water guide plate 211 is fixedly connected to the dust shield 73.

[0026] During use, the air cylinder 10 drives the milling cutter disc 72 to move up and down, and the bottom of the milling cutter disc 72 is a sharp end. The motor 71 drives the milling cutter disc 72 to rotate at a high speed. By using the friction and shearing action during the rotation of the milling cutter disc 72, cracks are generated on the upper end surface of the rock mass and gradually cut, and a relatively regular notch is cut in the original complete rock mass sample, so that the notch can store water, to simulate the water-containing rock mass formed by rainwater stored inside the rock mass in the natural environment. At the same time, by controlling the descending height of the milling cutter disc 72, the size of the crack and the volume of water that can be accommodated in the crack can be adjusted.

[0027] One end of the electric motor 71 away from the milling cutter head 72 is fixed with an electric telescopic rod 711. The upper end surface of the electric motor 71 is fixed with a slider 712, and the upper end of the slider 712 is fixedly connected to the lower end of the air cylinder 10. Moreover, the moving path of the slider 712 is parallel to the moving path of the electric telescopic rod 711. When it is necessary to change the width of the crack, drive the electric telescopic rod 711, drive the grooving assembly 7 to move horizontally through the electric telescopic rod 711, and then change the width of the crack. When studying the relationship between the position of the water body and the stress field in the rock mass, the length of the inward contraction of the electric telescopic rod 711 can be shortened to change the width of the crack. At this time, when the water body is poured on the inner side of the crack, the center of gravity of the water body is in the middle of the rock mass. As the inward contraction distance of the electric telescopic rod 711 increases, the width of the crack within the same height increases, so that the same volume of water body is poured on the inner side of the crack. At this time, the center of gravity of the water body is located at the upper part of the rock mass, which is beneficial to providing programmable experimental conditions for studying the coupling relationship between different seepage positions and the stress field of the rock mass.

[0028] Please refer to Figures 3 to 5 , the PVC straight pipe 9 includes a fixed cylinder 91, a limit plate 92, a return spring 93 and a support plate 94. The lower end of the water storage cylinder 61 is clamped with the fixed cylinder 91, and a limit plate 92 is slidably arranged inside the fixed cylinder 91. A return spring 93 is fixed to the lower end surface of the limit plate 92, and a support plate 94 is fixed to the bottom of the return spring 93. The space supported by the return spring 93 between the limit plate 92 and the support plate 94 is an air spacer layer. Moreover, a plurality of explosives are arranged inside the fixed cylinder 91, and the explosives are respectively arranged on both sides of the air spacer layer. The return spring 93 is made of natural rubber material, with a thickness of 1 - 2 cm, a length of 35 - 40 cm, and a rigidity coefficient of 50 - 100 N / mm. In the initial state, the return spring 93 is compressed by 15 cm under the pressure of the explosives, the water storage bag 64 and the water body inside the water storage bag 64. As the liquid inside the water storage bag 64 is pumped out, the return spring 93 is gradually restored.

[0029] When in use, the explosive is placed inside the fixed tube 91, and the bottom of the explosive is fitted with the upper end surface of the limiting plate 92, and then multiple fixed tubes 91 are coaxially clamped and arranged, and the lower end surface of the supporting plate 94 on the upper fixed tube 91 is fitted with the upper end surface of the explosive in the fixed tube 91 below it, and multiple air gap layers are formed between the multiple explosives by the elastic supporting force of the reset spring 93. When the uppermost explosive is squeezed by the gravity of the water storage bag 64, the multiple explosive limiting plates 92 and the supporting plate 94 slide downward, thereby changing the size of the air gap layer inside the explosive. At the same time, when the water flows out, the impeller 5 drives the connecting rope 62 and the piston 63 to move upward. At this time, the piston 63 moves upward and draws the liquid in the water bag 64 into the water storage cylinder 61, so that the weight of the water bag 64 is gradually reduced. At the same time, the pressure of the water bag 64 on the explosive is gradually reduced, so that the multiple reset springs 93 gradually recover elastically, thereby increasing the thickness of the air interval layer formed by the reset springs 93. The weight change of the water bag 64 is converted into the elastic potential energy adjustment of the reset spring 93 through the mechanical transmission of the impeller 5 and the piston 63, so that the thickness of the air interval layer changes with the water injection amount to match the explosion energy release demand in real time.

[0030] Please refer to Figure 4 and Figure 5 , a positioning groove 911 is provided at the upper end of the fixed cylinder 91, and a clamping rod 912 adapted to the positioning groove 911 is fixed at the bottom of the fixed cylinder 91. During assembly, the clamping rods 912 of multiple fixed cylinders 91 are inserted into the positioning groove 911 in the adjacent lower fixed cylinder 91, and a protrusion is fixed on the side of the bottom end of the clamping rod 912 close to the axis of the fixed cylinder 91. When the two end surfaces of two adjacent fixed cylinders 91 are fitted, the protrusion of the clamping rod 912 is just inserted into the appropriate position at the bottom of the positioning groove 911, and multiple fixed cylinders 91 are assembled at the same time.

[0031] A snap ring 612 is fixed to the bottom of the water storage cylinder 61, and a limiting protrusion 913 adapted to the snap ring 612 is fixed to the outer wall of the uppermost fixed cylinder 91. When the fixed cylinder 91 explodes, the impact force generated by the explosion drives the snap ring 612 to move upward, so that the limiting protrusion 913 and the snap ring 612 are staggered, and then the snap ring 612 is driven to move upward by the impact force of the explosion when the explosive explodes, so that the uppermost fixed cylinder 91 is separated from the water storage cylinder 61, which is beneficial to protecting the integrity of the interval adjustment assembly 6.

[0032] The following further describes the multi-field coupled sandstone mine blasting vibration simulation experimental device and experimental method provided by the present invention in conjunction with the accompanying drawings and implementation modes.

[0033] S1. Prepare standard rock samples. First, make multiple complete rock samples according to the hardness of sandstone, and then make cylindrical rock samples with the same hardness as sandstone. Use a compressor to measure the load when the rock is destroyed and calculate the point load strength. S2, put the explosive in a roll shape vertically into the fixed tube 91, the upper and lower ends of the explosive are respectively attached to the support plate 94 and the limit plate 92, and the space between the support plate 94 and the limit plate 92 between two adjacent explosives is the air spacer; S3, place a suitable rock mass on the inner side of the support frame 1, and place the predetermined position of the crack corresponding to the milling cutter disc 72 up and down, start the motor 71 to drive the milling cutter disc 72 to rotate at a high speed, and then start the cylinder 10, the cylinder 10 drives the milling cutter disc 72 to move vertically downward until the milling cutter disc 72 contacts the rock mass and cuts the inner side of the rock mass, grooves are made on the surface of the rock mass to simulate the cracks of the water-containing cracked rock mass under the natural state, and blast holes are opened around the cracks by a drilling machine, and the probe connected to the blasting vibrator is fixed on the ground near the rock, and the instrument is started before blasting; S4, at this time, the PVC straight tube 9 with explosives is placed inside the blasthole, and the upper end of the PVC straight tube 9 is located directly below the water storage cylinder 61, and the water storage bag 64 applies downward pressure to the explosives and the return spring 93, so that the return spring 93 is in a compressed state at this time, and the air interval layer between adjacent explosives is minimized; S5. At this time, the water pump outside the water tank 3 is started, so that the water in the water tank 3 flows along the flow channel 4. When the water flows to the water tank 21, the water body impacts the blades on the impeller 5 and drives the impeller 5 to rotate. After the water body impacts the impeller 5, the kinetic energy of the water body is weakened, and under the influence of gravity, it flows downward to the water guide plate 211 and enters the crack along the spring rope 8 and the milling cutter disc 72 to simulate the rainwater remaining in the rock crack to form a water-containing rock mass in the actual situation. At this time, the developer is sprayed on the crack surface by the drone; S6, when the impeller 5 rotates, the connecting rope 62 is wound around the middle of the impeller 5, and the piston 63 is driven to move upward, so that the liquid in the water storage bag 64 is pumped into the water storage cylinder 61 through the hose 611. At this time, the axial pressure exerted by the water storage bag 64 on the explosive and the return spring 93 decays linearly; S7, after the pressure of the water bag 64 on the explosive is weakened, the return spring 93 in the fixed tube 91 recovers elastically and drives the air gap layer between the explosives to gradually increase, so that the thickness of the air gap layer in the PVC straight tube 9 can be adaptively adjusted according to the size of the water entering the crack, so that the thickness of the air gap layer is adapted to the volume of the water entering the crack; S8. After the explosion, the physical quantity of vibration is converted into an electrical signal through the probe, and the vibration speed and frequency parameters are recorded and detected. By changing the rock mass, changing the slot size through the slot assembly 7, and re-changing the water volume, multiple experiments are carried out to obtain the distribution of the exploded rock blocks around the cracks when the water volume in the cracks is different, as well as the dynamic strength of the rock mass and the stress wave propagation characteristics in the rock mass when water is contained in the rock cracks.

[0034] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0035] The foregoing has shown and described the basic principles, main features and advantages of the present disclosure. Those skilled in the art should understand that the present disclosure is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present disclosure. Without departing from the spirit and scope of the present disclosure, the present disclosure will have various changes and improvements, and these changes and improvements fall within the scope of the present disclosure claimed.

Claims

1. Multi-field coupled sandstone mine blasting vibration simulation experimental device, characterized in that: include: A fluid driving mechanism and a spacing adjustment component (6) linked to the fluid driving mechanism; The fluid driving mechanism comprises a flow channel (4) connected to the water tank (3) and an impeller (5) arranged in a water filling tank (21); water in the water tank (3) is moved into a tank body opened in the rock mass through the water filling tank (21) to simulate water in a water-containing fractured rock mass in a natural state; The interval adjustment assembly (6) comprises a vertical water storage cylinder (61), the inner cavity of the water storage cylinder (61) is provided with a piston (63) with a sealing and sliding fit, and the rotating shaft supporting the rotation of the impeller (5) is connected to the top of the piston (63) via a connecting rope (62); The hose (611) connects the water storage cylinder (61) and the water storage bag (64), and the bottom of the water storage bag (64) is supported on one end of a vertically placed PVC straight pipe (9) encapsulating explosives, so that the water storage bag (64) forms a vertical downward pressure load on the PVC straight pipe (9) through its own weight; An elastic member is provided between adjacent explosives in the PVC straight tube (9), and the elastic member maintains an air spacing layer between adjacent explosives; The water flow impacts the impeller (5), causing the impeller (5) to rotate. The rotating shaft of the impeller (5) wraps around the connecting rope (62), and the connecting rope (62) pulls the piston (63) upward, so that negative pressure is formed between the water storage cylinder (61) and the water storage bag (64). The water in the water storage bag (64) is extracted through the hose (611), so that the weight of the water in the water storage bag (64) is reduced. The pressure change of the water storage bag (64) on the PVC straight pipe (9) causes the elastic member in the PVC straight pipe (9) to produce axial elastic deformation. When the elastic member produces axial elastic deformation, the thickness of the air spacer layer also changes, thereby adjusting the thickness of the air spacer layer between adjacent explosives in real time, so that the blasting vibration generated by the two explosives is within a preset range.

2. The multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 1 is characterized in that: The impeller (5) is fixed to the inner side of the irrigation trough (21) via an impeller frame, and the rotation axis of the impeller (5) is arranged perpendicular to the direction of water flow. The water flowing out of the flow channel (4) contacts the blades at the bottom of the impeller (5), and drives the impeller (5) to rotate counterclockwise.

3. The multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 2 is characterized in that: A positioning hole (22) penetrating the support platform (2) is provided between the water tank (3) and the water trough (21), and a cylinder (10) is provided penetratingly inside the positioning hole (22), and a slotting assembly (7) is provided at the lower end of the cylinder (10).

4. The multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 3 is characterized in that: A water guide plate (211) is fixed at the lower end of the water trough (21), and a spring rope (8) is fixed between the slot assembly (7) and the water guide plate (211).

5. The multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 4 is characterized in that: The slotting assembly (7) comprises a motor (71), a milling cutter disc (72) and a dust cover (73); the motor (71) is fixed to the lower end of the cylinder (10), the milling cutter disc (72) is fixed to the output end of the motor (71), the dust cover (73) is coaxially fixed to the outer side of the milling cutter disc (72), and the side of the spring rope (8) away from the water guide plate (211) is fixedly connected to the dust cover (73).

6. The multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 5 is characterized in that: An electric telescopic rod (711) is fixed to one end of the motor (71) away from the milling cutter disc (72), a slider (712) is fixed to the upper end surface of the motor (71), the upper end of the slider (712) is fixedly connected to the lower end of the cylinder (10), and the moving path of the slider (712) is parallel to the moving path of the electric telescopic rod (711).

7. The multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 6 is characterized in that: The PVC straight pipe (9) comprises a fixed cylinder (91), a limit plate (92), a return spring (93) and a support plate (94); the lower end of the water storage cylinder (61) is engaged with the fixed cylinder (91), and the limit plate (92) is slidably arranged inside the fixed cylinder (91); the lower end surface of the limit plate (92) is fixed with a return spring (93); the elastic member is the return spring (93), and the bottom of the return spring (93) is fixed with a support plate (94); the space between the limit plate (92) and the support plate (94) supported by the return spring (93) is an air spacer layer, and a plurality of explosives are placed inside the fixed cylinder (91), and the explosives are placed on both sides of the air spacer layer respectively; the return spring (93) is made of natural rubber material and has a thickness of 1-2 cm.

8. The multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 7 is characterized in that: A positioning groove (911) is provided at the upper end of the fixing cylinder (91), and a clamping rod (912) adapted to the positioning groove (911) is fixed at the bottom of the fixing cylinder (91).

9. The multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 8 is characterized in that: A clamping ring (612) is fixed to the bottom of the water storage cylinder (61), and a limiting protrusion (913) adapted to the clamping ring (612) is fixed to the outer wall of the uppermost fixed cylinder (91).

10. An experimental method for multi-field coupled sandstone mine blasting vibration simulation experiment, comprising the multi-field coupled sandstone mine blasting vibration simulation experimental device according to claim 9, characterized in that: The following steps are involved: S1. Prepare standard rock samples. First, make multiple complete rock samples according to the hardness of sandstone, and then make cylindrical rock samples with the same hardness as sandstone. Use a compressor to measure the load when the rock is destroyed and calculate the point load strength. S2, placing the explosive in a roll shape vertically into the fixed cylinder (91), with the upper and lower ends of the explosive respectively attached to the support plate (94) and the limit plate (92), and the space between the support plate (94) and the limit plate (92) between two adjacent explosives being the air spacer; S3, placing a suitable rock mass on the inner side of the support frame (1), and placing the predetermined position of the crack corresponding to the milling cutter disc (72) up and down, starting the motor (71) to drive the milling cutter disc (72) to rotate at a high speed, and then starting the cylinder (10), the cylinder (10) drives the milling cutter disc (72) to move vertically downward until the milling cutter disc (72) contacts the rock mass and cuts the inner side of the rock mass, and grooves are cut on the surface of the rock mass to simulate the cracks of the water-containing cracked rock mass under the natural state, and blast holes are opened around the cracks by a drilling machine, and a probe connected to the blasting vibration instrument is fixed on the ground near the rock, and the instrument is started before blasting; S4, at this time, the PVC straight tube (9) with explosives is placed inside the blasthole, and the upper end of the PVC straight tube (9) is located directly below the water storage cylinder (61), and the water storage bag (64) applies downward pressure to the explosives and the return spring (93), so that the return spring (93) is in a compressed state at this time, and the air gap layer between adjacent explosives is minimized; S5. At this time, the water pump outside the water tank (3) is started, so that the water in the water tank (3) flows along the flow channel (4). When the water flows to the water tank (21), the water body impacts the blades on the impeller (5) and drives the impeller (5) to rotate. After the water body impacts the impeller (5), the kinetic energy of the water body is weakened, and under the influence of gravity, the water body flows downward to the water guide plate (211) and enters the crack along the spring rope (8) and the milling cutter disc (72) to simulate the rainwater remaining in the rock crack to form a water-containing rock mass under real conditions. At this time, the developer is sprayed on the crack surface by the drone; S6. When the impeller (5) rotates, the connecting rope (62) is wound around the middle of the impeller (5), and the piston (63) is driven to move upward, so that the liquid in the water storage bag (64) is pumped into the water storage cylinder (61) through the hose (611). At this time, the axial pressure exerted by the water storage bag (64) on the explosive and the return spring (93) is attenuated; S7, after the pressure of the water storage bag (64) on the explosive is reduced, the return spring (93) in the fixed tube (91) recovers elastically and drives the air gap layer between the explosives to gradually increase, so that the thickness of the air gap layer in the PVC straight tube (9) can be adaptively adjusted according to the size of the water body entering the crack, so that the thickness of the air gap layer is adapted to the volume of the water body entering the crack; S8. After the explosion, the physical quantity of vibration is converted into an electrical signal through the probe, and the vibration speed and frequency parameters are recorded and detected. By changing the rock mass, changing the slot size through the slot assembly (7), and re-changing the water volume, multiple experiments are carried out to obtain the distribution of the exploded rock blocks around the cracks when the water volume in the cracks is different, as well as the dynamic strength of the rock mass and the stress wave propagation characteristics in the rock mass when water is contained in the rock mass cracks.

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