Rock mass compressive strength testing device based on impact stress waves

Abstract

The invention relates to a rock mass compressive strength testing device based on impact stress waves, which belongs to the technical field of rock mass compressive strength prediction and comprises a shell, a wave velocity sensor, a driving assembly and a data processing module. The two groups of wave velocity sensors are arranged in the shell at intervals, one group of wave velocity sensors are located under the other group of wave velocity sensors, the wave velocity sensors are conical, and through holes for the wave velocity sensors to partially extend out are formed in the side wall of the shell; the driving assembly is used for applying impact force to the wave velocity sensor located at the top of the shell; the data processing module and the wave velocity sensor are connected with a data transmission line, and the data processing module is used for receiving and analyzing stress wave signals of the wave velocity sensor. The rock mass compressive strength testing device based on the impact stress wave is simple in structure and convenient to operate, can be suitable for complex working conditions, and can ensure the accuracy and reliability of a testing result.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas treatment, and in particular to a rock mass compressive strength testing device based on impact stress waves. Background Art

[0002] Traditional methods for determining rock compressive strength mainly rely on laboratory standard compression tests, which require large rock samples, are costly and time-consuming. However, in many practical applications, it is often unrealistic to obtain large intact rock samples, and laboratory tests cannot reflect the actual geological environment of the rock.

[0003] In recent years, in order to overcome the problem of being unable to reflect the actual geological environment of the rock mass, technical personnel in this field have proposed some non-destructive testing methods, including electromagnetic induction testing, infrared thermometer testing, resistivity testing, wave transmission testing, etc., that is, the technology of evaluating the performance, structure or integrity of the object being tested without damaging it. At present, the testing method using wave transmission can obtain more detailed information on the internal structure of the rock mass, but the existing testing equipment has defects such as complex operation, poor applicability, and unstable accuracy, especially in complex geological conditions. It is difficult to obtain large rock samples. In response to the above-mentioned technical phenomena, the inventor has invented a rock compressive strength testing device based on impact stress waves, which is easy to operate, accurate in measurement, simple in structure, and can be applied to complex working conditions. Summary of the invention

[0004] The purpose of the present invention is to provide a rock mass compressive strength testing device based on impact stress waves, so as to improve the applicability and stability of the testing device and facilitate operation by staff.

[0005] The present invention provides a rock mass compressive strength testing device based on impact stress wave, which adopts the following technical solution: A rock mass compressive strength testing device based on impact stress wave, comprising: a shell; The wave velocity sensor comprises two groups of wave velocity sensors arranged at intervals in the housing, one group of wave velocity sensors is located directly below the other group of wave velocity sensors, the wave velocity sensors are cone-shaped, and the side wall of the housing is provided with a through hole for the wave velocity sensor part to extend out; A driving assembly, the driving assembly is used to apply an impact force to the wave velocity sensor located at the top of the shell; A data processing module is connected to the wave velocity sensor via a data transmission line, and is used to receive and analyze stress wave signals from the wave velocity sensor.

[0006] Preferably, the driving assembly includes an electromagnet, a magnet, a push-pull rod and an impact ball; The electromagnet is fixedly arranged inside the shell, the magnet is arranged above the electromagnet, the magnet is slidably arranged inside the shell, the push-pull rod is fixedly connected to the side of the magnet away from the electromagnet, the end of the push-pull rod away from the magnet is connected to the impact ball, and the push-pull rod is used to change the contact and separation state of the impact ball and the wave velocity sensor; The extended end of the cable wound around the electromagnet is connected to a power source.

[0007] Preferably, one end of the wave velocity sensor located inside the shell is respectively connected to a compression spring.

[0008] Preferably, the housing comprises an outer cylinder and an inner shell; The outer cylinder is sleeved on the circumferential side of the inner shell, the through hole is opened on the side wall of the outer cylinder, a sensor groove is opened inside the inner shell, the wave velocity sensor is slidably set in the sensor groove, and the sensor grooves are respectively connected with the through holes, one end of the compression spring is connected to the side wall of the wave velocity sensor, and the other end of the compression spring is fixedly connected to the wall of the sensor groove.

[0009] Preferably, the inner shell is provided with a placement groove, a first slide groove, a rod groove and a second slide groove for placing the power magnet, the magnet, the push-pull rod and the impact ball respectively. The magnet is slidably arranged in the first slide groove, and the impact ball is reciprocatingly slid in the second slide groove toward or away from the wave velocity sensor.

[0010] Preferably, the push-pull rod is connected to the end of the impact ball away from the wave velocity sensor, the push-pull rod is curved, and the push-pull rod is made of flexible resin material.

[0011] Preferably, the end of the magnet facing away from the electromagnet is fixedly connected to a tension spring, and the end of the tension spring facing away from the magnet is fixedly connected to the wall of the second chute; In the initial state, the extension spring is in the original length state.

[0012] Preferably, a wiring groove is opened inside the inner shell, and the sensor groove and the placement groove are respectively connected to the wiring groove, and the wiring groove is used to place the data transmission line.

[0013] Preferably, the inner wall of the outer cylinder is provided with an inner groove which is consistent with the length direction of the outer cylinder; The inner wall of the outer cylinder is provided with two groups of horizontal annular grooves corresponding to the through holes respectively, each group of the annular grooves is located above the through hole corresponding to itself, one end of the annular groove is connected with the inner groove, and the other end of the annular groove is connected with the through hole via a through groove, and the length direction of the through groove is consistent with the length direction of the outer cylinder.

[0014] Preferably, the bottom end of the outer cylinder is detachably connected to multiple groups of extension tubes, the multiple groups of extension tubes are connected end to end along the length direction of the outer cylinder, the data transmission line is passed through the extension tube, and the data processing module and power supply are respectively located on the outside of the extension tube.

[0015] In summary, the present invention includes the following beneficial technical effects: 1. The rock compressive strength testing device based on impact stress waves in the present invention includes two groups of wave velocity sensors, which are arranged in an upper and lower position relationship at intervals inside a shell. The shell is deeply inserted into the drilled hole of the rock to be tested, and the wave velocity sensor part extends out of the through hole and abuts against the rock. The driving component is controlled to apply impact force to the wave velocity sensor located on the top of the shell. At this time, stress waves are formed inside the rock. The other group of wave velocity sensors is used to receive the stress waves generated on the rock. The two groups of wave velocity sensors transmit wave signals to a data processing module, which analyzes the wave signals and calculates the compressive strength of the rock based on stress wave data and a physical model of the rock. The testing device in the present invention has a simple structure, is easy to operate, and has high accuracy.

[0016] 2. The driving assembly in the present application includes an electromagnet, a magnet, a push-pull rod and an impact ball, wherein the electromagnet is electrically connected to a power source. When the power is on, the electromagnet and the magnet attract each other, and the magnet moves toward the direction close to the electromagnet. The tension spring exerts a continuous pulling force on the magnet. When the power is off, the magnet and the electromagnet lose their interaction force, and the magnet moves away from the electromagnet. The impact ball moves rapidly toward the direction close to the wave velocity sensor under the action of the push-pull rod until the impact ball hits the wave velocity sensor. The wave velocity sensor partially extends out of the through hole and hits the rock mass to form a stress wave on the rock mass. The process of controlling the impact ball by the electromagnet is highly reliable and easy to operate.

[0017] 3. In this application, a compression spring is provided to ensure that the wave velocity sensor can fit tightly to the rock surface.

[0018] 4. In this application, a tension spring is provided to speed up the movement of the magnet, thereby ensuring that the impact ball effectively impacts the wave velocity sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a rock mass compressive strength testing device based on impact stress waves provided by an embodiment of the present invention; Figure 2 It is a partial cross-sectional structural schematic diagram of a rock mass compressive strength testing device; Figure 3 It is a schematic diagram of the partial cross-sectional structure of the outer cylinder and the extension tube.

[0020] Explanation of the accompanying drawings: 1. Shell; 11. Outer cylinder; 111. Through hole; 112. Inner groove; 113. Ring groove; 114. Through groove; 12. Inner shell; 121. Sensor groove; 122. Placement groove; 123. First slide groove; 124. Rod groove; 125. Second slide groove; 126. Wiring groove; 2. Wave velocity sensor; 21. Compression spring; 3. Drive assembly; 31. Electromagnet; 311. Power supply; 32. Magnet; 321. Tension spring; 33. Push-pull rod; 34. Impact ball; 4. Data processing module; 41. Data transmission line; 5. Extension tube. DETAILED DESCRIPTION

[0021] The following is combined with Figure 1-3 The present invention is described in further detail.

[0022] Example 1 The present invention provides a rock mass compressive strength testing device based on impact stress wave. Figure 1 and Figure 2 , comprising a shell 1, a wave velocity sensor 2, a driving assembly 3 and a data processing module 4; the wave velocity sensor 2 comprises two groups arranged at intervals in the shell 1, the two groups of wave velocity sensors 2 are in an upper and lower position relationship, the wave velocity sensor 2 in this embodiment is a cone, and a through hole 111 is provided on the side wall of the shell 1 for the wave velocity sensor 2 to partially extend; the driving assembly 3 is used to apply an impact force to the wave velocity sensor 2 located at the top of the shell 1; the data processing module 4 is connected to the wave velocity sensor 2 by a data transmission line 41, and the data processing module 4 is used to receive and analyze the stress wave signal of the wave velocity sensor 2; That is, the tip of the wave velocity sensor 2 extends out of the through hole 111 and abuts against the surface of the rock mass. The wave velocity sensor 2 located on the top of the shell 1 is subjected to impact force under the action of the driving component 3, and impact stress waves appear inside the rock mass. Another set of wave velocity sensors 2 is used to receive stress waves diffused in the rock mass. The two sets of wave velocity sensors 2 transmit the wave signals to the data processing module 4. The data processing module 4 analyzes the wave signals and calculates the compressive strength of the rock mass based on the stress wave data and the physical model of the rock mass.

[0023] Reference Figure 1 and Figure 2The shell 1 includes an outer cylinder 11 and an inner shell 12. The outer cylinder 11 is slidably sleeved on the circumference of the inner shell 12. A through hole 111 is opened on the side wall of the outer cylinder 11. A sensor groove 121 for sliding the wave velocity sensor 2 is opened inside the inner shell 12. The sliding direction of the wave velocity sensor 2 is perpendicular to the central axis direction of the outer cylinder 11. The two groups of sensor grooves 121 are respectively connected with the two groups of through holes 111, that is, the wave velocity sensor 2 can partially slide out of the through holes 111 to abut against the rock surface; a compression spring 21 is provided at one end of the wave velocity sensor 2 located in the sensor groove 121, and the end of the compression spring 21 away from the wave velocity sensor 2 is fixedly connected to the groove wall of the sensor groove 121. The compression spring 21 supports the wave velocity sensor 2 to ensure that the wave velocity sensor 2 is closely abutted against the rock surface during the test.

[0024] Reference Figure 2 and Figure 3 The inner wall of the outer cylinder 11 is provided with an inner groove 112 which is consistent with the length direction of the outer cylinder 11, and the inner wall of the outer cylinder 11 is provided with two groups of horizontal annular grooves 113 which correspond to the through holes 111 respectively, and each group of annular grooves 113 is located above the through hole 111 corresponding to itself, and one end of the annular groove 113 is connected with the inner groove 112, and a through groove 114 is connected between the other end of the annular groove 113 and the through hole 111, and the length direction of the through groove 114 is consistent with the length direction of the outer cylinder 11; in the process of installing the inner shell 12 with the wave velocity sensor 2 installed inside the outer cylinder 11, first, press the wave velocity sensor 2 located at the bottom of the inner shell 12 into the sensor groove 121, and align the tip of the wave velocity sensor 2 with the inner groove 112, so as to slide the inner shell 12 into the outer cylinder 11, and under the action of the compression spring 21, the tip of the wave velocity sensor 2 is located in the inner groove 112, and then The wave velocity sensor 2 on the top of the inner shell 12 is pressed into the sensor groove 121, and the tip of the wave velocity sensor 2 is aligned with the inner groove 112, so that the inner shell 12 can completely slide into the outer cylinder 11, and the distance between the two groups of annular grooves 113 is equal to the distance between the two groups of wave velocity sensors 2. The inner shell 12 is rotated so that the tip of the wave velocity sensor 2 slides in the annular groove 113, and the tip of the wave velocity sensor 2 slides to the end of the annular groove 113 close to the through groove 114. At this time, the top of the inner shell 12 is located on the outside of the outer shell 11, thereby completing the installation work; during the test process, the outer cylinder is located in the borehole of the rock mass to be tested, and the top of the inner shell 12 located on the outside of the outer shell 11 is abutted against the inner wall of the borehole of the rock mass to be tested, and the outer shell 11 is pushed. At this time, the wave velocity sensor 2 slides along the through groove 114 into the through hole 111, and the tip of the wave velocity sensor 2 abuts against the wall of the rock mass rotation hole to be tested under the action of the compression spring 21.

[0025] Reference Figure 1 and Figure 2The driving assembly 3 includes an electromagnet 31, a magnet 32, a push-pull rod 33 and an impact ball 34. The inner shell 12 is provided with a placement groove 122, a first slide groove 123, a rod groove 124 and a second slide groove 125 for placing the electromagnet 31, the magnet 32, the push-pull rod 33 and the impact ball 34 respectively. The electromagnet 31 is fixedly arranged in the placement groove 122, the magnet 32 ​​is located above the electromagnet 31, and the magnet 32 ​​is slidably arranged in the first slide groove 123, the end of the magnet 32 ​​away from the electromagnet 31 is fixedly connected with a tension spring 321, and the end of the tension spring 321 away from the magnet 32 ​​is fixedly connected to the groove wall of the second slide groove 125, and in the initial state, the tension spring 321 is in the original length state; the push-pull rod 33 is fixedly connected to the side of the magnet 32 ​​away from the electromagnet 31, and the end of the push-pull rod 33 away from the magnet 32 ​​is fixedly connected to the impact ball 34, and the push-pull rod 33 is used to change the contact and separation state of the impact ball 34 and the wave velocity sensor 2, and the extended end of the cable wrapped around the electromagnet 31 is connected to the power supply 311; Under the action of the push-pull rod 33, the impact ball 34 is reciprocally slid in the second slide groove 125 in the direction of approaching or moving away from the wave velocity sensor 2. That is, when the power supply 311 for controlling the electromagnet 31 is turned on, the electromagnet 31 and the magnet 32 ​​are attracted to each other, and the magnet 32 ​​moves in the direction of approaching the electromagnet 31, and in the process of the extension spring 321 becoming longer, the magnet 32 ​​exerts a continuous pulling force on the magnet 32; when the power supply 311 for controlling the electromagnet 31 is turned off, the magnet 32 ​​and the electromagnet 31 lose the interaction force, and the magnet 32 ​​moves in the direction of moving away from the electromagnet 31. Under the action of the extension spring 321, the impact ball 34 moves quickly in the direction of approaching the wave velocity sensor 2 under the action of the push-pull rod 33, until the impact ball 34 hits the wave velocity sensor 2, and the tip of the wave velocity sensor 2 hits the rock mass to form a stress wave on the rock mass, and the impact ball 34 ends the impact work on the wave velocity sensor 2.

[0026] Reference Figure 2 The push-pull rod 33 is connected to the end of the impact ball 34 away from the wave velocity sensor 2. The push-pull rod 33 is made of flexible resin material and is curved. The shape of the rod groove 124 in this embodiment is similar to the shape of the push-pull rod 33. The rod groove 124 guides the push-pull rod 33 and avoids the problem that the push-pull rod 33 is too deformed and cannot return to its original shape.

[0027] Reference Figure 1 and Figure 2A wiring groove 126 is provided inside the inner shell 12, and the sensor groove 121 and the placement groove 122 are respectively connected to the wiring groove 126, that is, the wiring groove 126 is used to place the data transmission line 41 and the cable acting on the electromagnet 31. The bottom end of the outer cylinder 11 is detachably connected with multiple groups of extension tubes 5, and the multiple groups of extension tubes 5 are connected end to end along the length direction of the outer cylinder 11. The purpose of setting multiple groups of extension tubes 5 in this application is to enable the shell 1 to extend into a deeper rock borehole. The connection method between the multiple groups of extension tubes 5 in this embodiment adopts a threaded connection method to facilitate disassembly and assembly. The data transmission line 41 is inserted into the extension tube 5, and the data processing module 4 and the power supply 311 are respectively located on the outside of the extension tube 5.

[0028] Example 2 A rock mass compressive strength testing method based on impact stress wave, using the rock mass compressive strength testing device, comprises the following steps: S1. Drilling preparation: drilling a hole of preset depth and diameter in the rock mass to be tested; S2, installation of the testing device: inserting the rock mass compressive strength testing device into the borehole of step S1; S3, exciting the impact ball 34: starting the power supply 311, the electromagnet 31 generates an attraction force on the magnet 32, and the magnet 32 ​​moves toward the direction close to the electromagnet 31. The tension spring 321 exerts a continuous pulling force on the magnet 32 ​​during the process of lengthening. Turning off the power supply 311, the magnet 32 ​​and the electromagnet 31 lose the interaction force, and the magnet 32 ​​moves away from the electromagnet 31. Under the action of the tension spring 321, the impact ball 34 moves quickly toward the direction close to the wave velocity sensor 2 under the action of the push-pull rod 33. At this time, the impact ball 34 moves toward the direction of the wave velocity sensor 2 located at the top of the shell 1 and impacts the wave velocity sensor 2; S4, propagation of stress waves: the rock mass portion abutting against the wave velocity sensor 2 at the top of the shell 1 is the wave source, and stress waves are generated in the rock mass. The stress waves propagate in the rock mass and are captured by the wave velocity sensor 2 at the bottom of the shell 1 as an observation point; S5, data transmission and processing: the stress wave signals of the two groups of wave velocity sensors 2 are transmitted to the data processing module 4 through the data transmission line 41, and the data processing module 4 analyzes the stress wave signals; S6. Compressive strength estimation: Calculate the compressive strength of the rock mass based on stress wave data and rock mass physical model.

[0029] When the impact ball 34 in step S3 impacts the wave velocity sensor 2, the tip of the wave velocity sensor 2 contacts the rock mass, which generates a dynamic load. The magnitude of the load can be estimated using Newton's second law: F=m∙a (F is the force, m is the impact mass, and a is the acceleration of the impact ball 34); The velocity v of the stress wave in step S4 can be determined by the formula v=√(E / ρ), where E is the elastic modulus of the rock mass and ρ is the density of the rock mass; The propagation of stress waves in rock mass can be described by stress wave velocity and geometric parameters of rock mass. The intensity I of stress wave generated by impact can be expressed as: I=F / A (A is the distance from wave source to observation point); As the stress wave propagates in the rock mass, the wave intensity will decay. The attenuated wave intensity I′ can be expressed as: I'=I·e^(-αL), where α is the attenuation coefficient and L is the distance the wave propagates; Compressive strength of rock mass c It can be estimated approximately by the following relationship: c =k•I', k is a proportional constant, which depends on the type and state of the rock mass. The range of k values ​​for different rock masses is as follows: Sandstone: k≈0.1-0.3 Limestone: k≈0.2-0.5 Granite: k≈0.4-0.7 Shale: k≈0.05—0.2.

[0030] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A rock mass compressive strength testing device based on impact stress wave, characterized in that: include, Housing (1); The wave velocity sensors (2) include two groups of wave velocity sensors (2) arranged at intervals in the housing (1), one group of wave velocity sensors (2) being located directly below the other group of wave velocity sensors (2), the wave velocity sensors (2) being cone-shaped, and a through hole (111) through which a portion of the wave velocity sensors (2) are extended is provided on a side wall of the housing (1); A driving component (3), the driving component (3) being used to apply an impact force to the wave velocity sensor (2) located at the top of the housing (1); A data processing module (4), wherein the data processing module (4) and the wave velocity sensor (2) are connected via a data transmission line (41), and the data processing module (4) is used to receive and analyze stress wave signals from the wave velocity sensor (2).

2. The rock mass compressive strength testing device based on impact stress wave according to claim 1, characterized in that: The driving assembly (3) comprises an electromagnet (31), a magnet (32), a push-pull rod (33) and an impact ball (34); The electromagnet (31) is fixedly arranged inside the housing (1), the magnet (32) is arranged above the electromagnet (31), the magnet (32) is slidably arranged inside the housing (1), the push-pull rod (33) is fixedly connected to a side of the magnet (32) facing away from the electromagnet (31), and an end of the push-pull rod (33) away from the magnet (32) is connected to the impact ball (34), and the push-pull rod (33) is used to change the contact and separation state between the impact ball (34) and the wave velocity sensor (2); The extended end of the cable wound around the electromagnet (31) is connected to a power source (311).

3. The rock mass compressive strength testing device based on impact stress wave according to claim 2, characterized in that: One end of the wave velocity sensor (2) located inside the housing (1) is respectively connected to a compression spring (21).

4. The rock mass compressive strength testing device based on impact stress wave according to claim 3 is characterized in that: The housing (1) comprises an outer cylinder (11) and an inner shell (12); The outer cylinder (11) is sleeved on the circumferential side of the inner shell (12); the through hole (111) is provided on the side wall of the outer cylinder (11); a sensor groove (121) is provided inside the inner shell (12); the wave velocity sensor (2) is slidably arranged in the sensor groove (121); the sensor grooves (121) are respectively in a state of being connected with the through hole (111); one end of the compression spring (21) is connected to the side wall of the wave velocity sensor (2); and the other end of the compression spring (21) is fixedly connected to the groove wall of the sensor groove (121).

5. The rock mass compressive strength testing device based on impact stress wave according to claim 4, characterized in that: The inner shell (12) is further provided with a placement groove (122), a first slide groove (123), a rod groove (124) and a second slide groove (125) for placing the power magnet (31), the magnet (32), the push-pull rod (33) and the impact ball (34) respectively. The magnet (32) is slidably arranged in the first slide groove (123), and the impact ball (34) is reciprocatingly slidably arranged in the second slide groove (125) in a direction approaching or moving away from the wave velocity sensor (2).

6. The rock mass compressive strength testing device based on impact stress wave according to claim 2, characterized in that: The push-pull rod (33) is connected to an end of the impact ball (34) that is away from the wave velocity sensor (2); the push-pull rod (33) is curved; and the material of the push-pull rod (33) is a flexible resin material.

7. The rock mass compressive strength testing device based on impact stress wave according to claim 5, characterized in that: One end of the magnet (32) facing away from the electromagnet (31) is fixedly connected to a tension spring (321), and one end of the tension spring (321) facing away from the magnet (32) is fixedly connected to a groove wall of the second sliding groove (125); In the initial state, the tension spring (321) is in an original length state.

8. The rock mass compressive strength testing device based on impact stress wave according to claim 5, characterized in that: A wiring groove (126) is provided inside the inner shell (12); the sensor groove (121) and the placement groove (122) are respectively in communication with the wiring groove (126); and the wiring groove (126) is used to place a data transmission line (41).

9. The rock mass compressive strength testing device based on impact stress wave according to claim 4, characterized in that: The inner wall of the outer cylinder (11) is provided with an inner groove (112) which is consistent with the length direction of the outer cylinder (11); The inner wall of the outer cylinder (11) is provided with two groups of horizontal annular grooves (113) respectively corresponding to the through holes (111); each group of the annular grooves (113) is located above the through hole (111) corresponding to itself; one end of the annular groove (113) is connected to the inner groove (112); a through groove (114) is connected between the other end of the annular groove (113) and the through hole (111); the length direction of the through groove (114) is consistent with the length direction of the outer cylinder (11).

10. The rock mass compressive strength testing device based on impact stress wave according to claim 4, characterized in that: The bottom end of the outer cylinder (11) is detachably connected to a plurality of groups of extension tubes (5), the plurality of groups of extension tubes (5) being connected end to end along the length direction of the outer cylinder (11), the data transmission line (41) being passed through the extension tubes (5), and the data processing module (4) and the power supply (311) being respectively located outside the extension tubes (5).

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