Rock mass compressive strength testing device based on impact stress wave

Abstract

The present application relates to a kind of rock mass compressive strength test device based on impact stress wave, belong to rock mass compressive strength prediction technical field, including shell, wave velocity sensor, drive assembly and data processing module;Wave velocity sensor includes two groups spaced apart in the shell, one group of wave velocity sensor is located below another group of wave velocity sensor, the wave velocity sensor is conical body, the side wall of the shell is provided with the through hole for wave velocity sensor part to extend;Drive assembly is used to apply impact force to the wave velocity sensor located at the top of shell;The data processing module is connected with wave velocity sensor with data transmission line, and the data processing module is used to receive and analyze the stress wave signal of wave velocity sensor.The present application is a kind of rock mass compressive strength test device based on impact stress wave, simple structure, easy to operate, can be applied to complex working conditions, and can guarantee the accuracy and reliability of test result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flue gas treatment, in particular to a rock mass compressive strength testing device based on impact stress wave. BACKGROUND

[0002] The traditional rock mass compressive strength determination method mainly relies on the laboratory standard compression test, which requires large rock mass samples, is high in cost and time-consuming. However, in many practical applications, it is often unrealistic to obtain large intact rock mass samples, and the laboratory test cannot reflect the actual geological environment of the rock mass.

[0003] In recent years, in order to overcome the problem that the actual geological environment of the rock mass cannot be reflected, the technical personnel in the field have proposed some non-destructive testing methods, including electromagnetic induction testing method, infrared thermal imaging testing method, resistivity testing method, wave transmission testing method, etc., that is, the technology for evaluating the performance, structure or integrity of the object without damaging it. At present, the testing method using wave transmission can obtain more detailed internal structure information of the rock mass, but the existing testing equipment has defects such as complex operation, poor applicability, unstable precision, etc., especially in the case of difficult to obtain large rock mass samples under complex geological conditions. In view of the above technical phenomena, the inventor has invented a rock mass compressive strength testing device based on impact stress wave, which is convenient to operate, accurate in measurement, simple in structure, and can be applied to complex working conditions. SUMMARY

[0004] The present application relates to the technical field of flue gas treatment, in particular to a rock mass compressive strength testing device based on impact stress wave.

[0005] The present application provides a rock mass compressive strength testing device based on impact stress wave, which adopts the following technical scheme:

[0006] A rock mass compressive strength testing device based on impact stress wave comprises a shell.

[0007] The wave velocity sensor comprises two groups of wave velocity sensors arranged at intervals in the shell, one group of wave velocity sensors is located directly below the other group of wave velocity sensors, the wave velocity sensor is in the shape of a cone, and the shell side wall is provided with a through hole for the wave velocity sensor to partially extend out.

[0008] The driving assembly is used to apply impact force to the wave velocity sensor located at the top of the shell.

[0009] The data processing module is connected with the wave velocity sensor through a data transmission line, and the data processing module is used to receive and analyze the stress wave signal of the wave velocity sensor.

[0010] Preferably, the driving assembly comprises an electromagnet, a magnet, a push-pull rod and a hitting ball.

[0011] The electromagnet is fixedly arranged inside the shell, the magnet is arranged above the electromagnet, the magnet is slidingly arranged in the shell, the push-pull rod is fixedly connected to a side of the magnet away from the electromagnet, an end of the push-pull rod away from the magnet is connected with the hitting ball, and the push-pull rod is used to change the contact and separation state of the hitting ball and the wave speed sensor.

[0012] An extension end of a cable wound on the electromagnet is connected with a power supply.

[0013] Preferably, one end of the wave speed sensor inside the shell is connected with a compression spring.

[0014] Preferably, the shell comprises an outer cylinder and an inner shell.

[0015] The outer cylinder is sleeved on the periphery of the inner shell, the through hole is arranged on the side wall of the outer cylinder, the inner shell is provided with a sensor groove inside, the wave speed sensor is slidingly arranged in the sensor groove, the sensor groove is in communication with the through hole, one end of the compression spring is connected to the side wall of the wave speed sensor, and the other end of the compression spring is fixedly connected to the groove wall of the sensor groove.

[0016] Preferably, the inner shell is further provided with a placing groove, a first sliding groove, a rod groove and a second sliding groove for placing the electromagnet, the magnet, the push-pull rod and the hitting ball respectively, the magnet is slidingly arranged in the first sliding groove, and the hitting ball is reciprocatingly slidingly arranged in the second sliding groove towards or away from the wave speed sensor.

[0017] Preferably, the push-pull rod is connected to an end of the hitting ball away from the wave speed sensor, the push-pull rod is curved, and the material of the push-pull rod is flexible resin material.

[0018] Preferably, one end of the magnet away from the electromagnet is fixedly connected with a tension spring, and the other end of the tension spring away from the magnet is fixedly connected to the groove wall of the second sliding groove.

[0019] In the initial state, the tension spring is in the original length state.

[0020] Preferably, the inner shell is provided with a wiring groove inside, the sensor groove and the placing groove are in communication with the wiring groove, and the wiring groove is used to place a data transmission line.

[0021] Preferably, the inner wall of the outer cylinder is provided with an inner groove consistent with the length direction of the outer cylinder.

[0022] The outer cylinder inner wall is provided with two groups of horizontal annular grooves corresponding to the through holes, each group of annular grooves is located above the corresponding through hole, one end of the annular groove is communicated with the inner groove, and the other end of the annular groove is communicated with the through hole.

[0023] Preferably, the outer cylinder bottom end is detachably connected with a plurality of extension pipes, the plurality of extension pipes are connected end to end along the length direction of the outer cylinder, the data transmission line is arranged in the extension pipe, and the data processing module and the power supply are located outside the extension pipe.

[0024] In summary, the present application has the following beneficial technical effects:

[0025] 1. The rock mass compressive strength testing device based on impact stress wave in the application comprises two groups of wave velocity sensors, the two groups of wave velocity sensors are arranged in a top-down position relationship and are arranged in the interior of the shell, the shell is deeply arranged in the drill hole of the rock mass to be measured, the wave velocity sensor is partially arranged outside the through hole and abuts against the rock mass, a control driving assembly is arranged, the wave velocity sensor located at the top of the shell is impacted, at this time, stress waves are formed in the rock mass, the other wave velocity sensor is used for receiving the stress waves generated on the rock mass, the two groups of wave velocity sensors transmit wave signals to a data processing module, the data processing module analyzes the wave signals, and the compressive strength of the rock mass is calculated based on stress wave data and a physical model of the rock mass, the testing device in the application has the advantages of simple structure, convenient operation and high accuracy.

[0026] 2. The driving assembly in the application comprises an electromagnet, a magnet, a push-pull rod and an impact ball, the electromagnet is electrically connected with a power supply, in the state that the power supply is turned on, the electromagnet and the magnet are attracted to each other, the magnet moves towards the electromagnet, and the tension spring provides a continuous pulling force to the magnet, in the state that the power supply is turned off, the magnet loses the interaction force with the electromagnet, and the magnet moves away from the electromagnet, the impact ball moves towards the wave velocity sensor at a high speed under the action of the push-pull rod, until the impact ball impacts the wave velocity sensor, the wave velocity sensor partially extends outside the through hole and impacts the rock mass, so that stress waves are formed on the rock mass, and the process of controlling the impact ball by the electromagnet has the characteristics of high reliability and simple operation.

[0027] 3. The compression spring is arranged in the application, so that the wave velocity sensor can be closely attached to the surface of the rock mass.

[0028] 4. The tension spring is arranged in the application, so that the moving speed of the magnet is accelerated, and the impact ball can effectively impact the wave velocity sensor. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a structure schematic view of a rock mass compressive strength testing device based on impact stress wave provided by the embodiment of the application.

[0030] Figure 2 is a partial cross-sectional structural schematic diagram of the rock mass compressive strength testing device;

[0031] Figure 3 is a partial cross-sectional structural schematic diagram of the outer cylinder and the extension pipe.

[0032] Explanation of reference numerals: 1, housing; 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 sliding groove; 124, rod groove; 125, second sliding groove; 126, wiring groove; 2, wave speed sensor; 21, compression spring; 3, driving 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 pipe. DETAILED DESCRIPTION

[0033] The following will be described in detail with reference to the accompanying Figures 1-3 The present application is further described in detail.

[0034] Example 1

[0035] The present application provides a rock mass compressive strength testing device based on impact stress wave. Referring to Figure 1 and Figure 2 , comprising a housing 1, a wave speed sensor 2, a driving assembly 3 and a data processing module 4; the wave speed sensor 2 comprises two groups arranged at intervals in the housing 1, the two groups of wave speed sensors 2 are in an upper and lower position relationship, the wave speed sensor 2 in the present embodiment is a conical body, the side wall of the housing 1 is provided with a through hole 111 for the wave speed sensor 2 to partially extend out; the driving assembly 3 is used for applying an impact force to the wave speed sensor 2 located at the top of the housing 1; the data processing module 4 is connected with the wave speed sensor 2 through a data transmission line 41, and the data processing module 4 is used for receiving and analyzing the stress wave signal of the wave speed sensor 2;

[0036] that is, the tip of the wave speed sensor 2 extends out of the through hole 111 and abuts against the surface of the rock mass, the wave speed sensor 2 located at the top of the housing 1 is subjected to an impact force under the action of the driving assembly 3, impact stress waves appear inside the rock mass, the other group of wave speed sensors 2 is used for receiving the diffused stress waves inside the rock mass, the two groups of wave speed sensors 2 transmit the wave signals to the data processing module 4, the data processing module 4 analyzes the wave signals, and based on the stress wave data and the physical model of the rock mass, the compressive strength of the rock mass is calculated.

[0037] Referring to Figure 1 and Figure 2, the shell 1 includes an outer cylinder 11 and an inner shell 12, the outer cylinder 11 is sleeved on the side of the inner shell 12, the through hole 111 is arranged on the side wall of the outer cylinder 11, the inner shell 12 is internally provided with a sensor groove 121 for slidingly arranging the wave velocity sensor 2, the sliding direction of the wave velocity sensor 2 is perpendicular to the central axis direction of the outer cylinder 11, and the two groups of sensor grooves 121 are in communication with the two groups of through holes 111, that is, the wave velocity sensor 2 can partially slide out of the through hole 111 to abut against the rock mass surface; the wave velocity sensor 2 is provided with a compression spring 21 at one end in the sensor groove 121, one 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, and the compression spring 21 supports the wave velocity sensor 2 to ensure that the wave velocity sensor 2 is tightly abutted against the rock mass surface during the test.

[0038] Referring to Figure 2 and Figure 3 , the inner wall of the outer cylinder 11 is provided with an inner groove 112 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 ring grooves 113 corresponding to the through holes 111, each group of ring grooves 113 is located above the corresponding through hole 111, one end of the ring groove 113 is in communication with the inner groove 112, and the other end of the ring groove 113 is in communication with the through hole 111, and the through groove 114 is in communication between the other end of the ring 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; during installation of the inner shell 12 provided with the wave velocity sensor 2 in the outer cylinder 11, first, the wave velocity sensor 2 at the bottom 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 as to slide the inner shell 12 into the outer cylinder 11, under the action of the compression spring 21, the tip of the wave velocity sensor 2 is located in the inner groove 112, then the wave velocity sensor 2 at 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 is completely slid into the outer cylinder 11, the distance between the two groups of ring 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 is slid in the ring groove 113, and the tip of the wave velocity sensor 2 is slid to one end of the ring groove 113 close to the through groove 114, at this time, the top end of the inner shell 12 is located outside the outer shell 11, so that the installation work is completed; during the test, the outer cylinder is located in the rock mass drill hole to be tested, the top end of the inner shell 12 outside the outer shell 11 abuts against the inner wall of the rock mass drill hole to be tested, and the outer shell 11 is pushed, at this time, the wave velocity sensor 2 is slid along the through groove 114 into the through hole 111, and the tip of the wave velocity sensor 2 abuts against the inner wall of the rock mass drill hole to be tested under the action of the compression spring 21.

[0039] Referring to Figure 1 and Figure 2, the driving assembly 3 includes an electromagnet 31, a magnet 32, a push-pull rod 33 and a ball 34, and the inner shell 12 is internally provided with a placing groove 122, a first sliding groove 123, a rod groove 124 and a second sliding groove 125 for placing the electromagnet 31, the magnet 32, the push-pull rod 33 and the ball 34 respectively. The electromagnet 31 is fixedly arranged in the placing groove 122, the magnet 32 is located above the electromagnet 31, and the magnet 32 is slidingly arranged in the first sliding groove 123, one end of the magnet 32 away from the electromagnet 31 is fixedly connected with a tension spring 321, and one end of the tension spring 321 away from the magnet 32 is fixedly connected to the groove wall of the second sliding groove 125. In the initial state, the tension spring 321 is in the original length state; the push-pull rod 33 is fixedly connected to one side of the magnet 32 away from the electromagnet 31, and one end of the push-pull rod 33 away from the magnet 32 is fixedly connected with the ball 34, the push-pull rod 33 is used for changing the contact and separation state of the ball 34 and the wave speed sensor 2, and the extension end of the cable wound on the electromagnet 31 is connected with a power supply 311;

[0040] Under the action of the push-pull rod 33, the ball 34 reciprocatingly slides in the second sliding groove 125 towards the wave speed sensor 2. That is, in the open state of the power supply 311 controlling the electromagnet 31, the electromagnet 31 and the magnet 32 are attracted to each other, the magnet 32 moves towards the electromagnet 31, and the tension spring 321 provides a continuous pulling force to the magnet 32 during the lengthening process; in the closed state of the power supply 311 controlling the electromagnet 31, the magnet 32 loses the interaction force with the electromagnet 31, and moves away from the electromagnet 31, under the action of the tension spring 321, the ball 34 moves quickly towards the wave speed sensor 2 under the action of the push-pull rod 33, until the ball 34 hits the wave speed sensor 2, the tip of the wave speed sensor 2 hits the rock mass to form a stress wave on the rock mass, and the ball 34 ends the hitting work on the wave speed sensor 2.

[0041] Referring to Figure 2 , the push-pull rod 33 is connected to one end of the ball 34 away from the wave speed sensor 2, the material of the push-pull rod 33 is flexible resin material, and the push-pull rod 33 is curved, the shape of the rod groove 124 in the embodiment is similar to the shape of the push-pull rod 33, the rod groove 124 plays a guiding role on the push-pull rod 33, and avoids the problem that the push-pull rod 33 deforms too much and cannot restore the original shape.

[0042] Referring to Figure 1 and Figure 2The inner shell 12 is internally provided with a wiring groove 126, and the sensor groove 121 and the placement groove 122 are in a state of communication with the wiring groove 126, that is, the wiring groove 126 is used for placing the data transmission line 41 and the cable line acting on the electromagnet 31. A plurality of extension pipes 5 are detachably connected to the bottom end of the outer cylinder body 11, and the plurality of extension pipes 5 are connected end to end along the length direction of the outer cylinder body 11. The purpose of arranging the plurality of extension pipes 5 is to enable the shell 1 to extend into a deeper rock body borehole. In the embodiment, the connection mode between the plurality of extension pipes 5 is selected as a threaded connection mode to facilitate disassembly and assembly. The data transmission line 41 is arranged in the extension pipe 5, and the data processing module 4 and the power supply 311 are respectively located outside the extension pipe 5.

[0043] Embodiment 2

[0044] A rock mass compressive strength testing method based on impact stress wave, using the rock mass compressive strength testing device, comprising the following steps:

[0045] S1, borehole preparation: drilling a borehole with a predetermined depth and diameter in the rock mass to be tested;

[0046] S2, installation of the testing device: extending the rock mass compressive strength testing device into the borehole of step S1;

[0047] S3, exciting the impact ball 34: starting the power supply 311, the electromagnet 31 generates an attractive force on the magnet 32, the magnet 32 moves towards the electromagnet 31, and the tensile spring 321 provides a continuous pulling force on the magnet 32 during the lengthening process. Turning off the power supply 311, the magnet 32 loses the interaction force with the electromagnet 31, and moves away from the electromagnet 31. Under the action of the tensile spring 321, the impact ball 34 moves quickly towards the wave speed sensor 2 under the action of the push-pull rod 33. At this time, the impact ball 34 moves towards the wave speed sensor 2 located at the top end of the shell 1 and collides with the wave speed sensor 2;

[0048] S4, propagation of stress wave: the rock mass part in contact with the wave speed sensor 2 at the top end of the shell 1 is the wave source, and the stress wave is generated in the rock mass and propagates in the rock mass. The wave speed sensor 2 at the bottom end of the shell 1 captures the stress wave as an observation point;

[0049] S5, data transmission and processing: the stress wave signals of the two wave speed 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;

[0050] S6, compressive strength estimation: based on the stress wave data and the rock mass physical model, the compressive strength of the rock mass is calculated.

[0051] Wherein, when the impact ball 34 in step S3 hits the wave speed sensor 2, the tip of the wave speed sensor 2 is in contact with the rock mass, and a dynamic load is generated, and the size of the load can be estimated by Newton's second law:

[0052] F=m*a (F is force, m is impact mass, and a is the acceleration of the impact ball 34);

[0053] The speed v of the stress wave in step S4 can be determined by the formula v=√(E / ρ), E is the elastic modulus of the rock mass, and p is the density of the rock mass;

[0054] The propagation of the stress wave in the rock mass can be described by the stress wave speed and the geometric parameters of the rock mass, and the intensity I of the stress wave generated by the impact can be represented as: I=F / A (A is the distance from the wave source to the observation point);

[0055] With the propagation of the stress wave in the rock mass, the intensity of the wave will attenuate, and the attenuated wave intensity I' can be represented as: I'=I*e^(-aL), a is the attenuation coefficient, and L is the distance of wave propagation;

[0056] The compressive strength of the rock mass σ c can be approximately estimated by the following relationship: σ c =k*I', k is a proportional constant, which depends on the type and state of the rock mass, and the k value range of different rock masses is as follows:

[0057] Sandstone: k≈0.1-0.3

[0058] Limestone: k≈0.2-0.5

[0059] Granite: k≈0.4-0.7

[0060] Shale: k≈0.05-0.2.

[0061] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, therefore: any equivalent changes made in the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A rock mass compressive strength testing device based on impact stress wave, characterized in that, include, A housing (1) configured to be inserted into a borehole in the rock mass; The wave velocity sensor (2) includes two sets of wave velocity sensors (2) spaced apart inside the housing (1). One set of wave velocity sensors (2) is located directly below the other set of wave velocity sensors (2). The wave velocity sensor (2) located at the top of the housing (1) is used to generate waves, and the other set of wave velocity sensors (2) is used to receive waves. The wave velocity sensor (2) is cone-shaped. One end of the wave velocity sensor (2) located inside the housing (1) is connected to a compression spring (21). The side wall of the housing (1) is provided with a through hole (111) for the wave velocity sensor (2) to extend out. A drive assembly (3) is used to apply an impact force to a wave velocity sensor (2) located on top of the housing (1); the drive assembly (3) includes an electromagnet (31), a magnet (32), a push-pull rod (33) and an impact ball (34). The electromagnet (31) is fixedly installed inside the housing (1), the magnet (32) is installed above the electromagnet (31), the magnet (32) is slidably installed inside the housing (1), the push-pull rod (33) is fixedly connected to the side of the magnet (32) away from the electromagnet (31), the 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 of the impact ball (34) and the wave velocity sensor (2); The extension end of the cable wound around the electromagnet (31) is connected to a power source (311). The data processing module (4) is connected to the wave velocity sensor (2) by a data transmission line (41). The data processing module (4) is used to receive and analyze the stress wave signal of 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 shell (1) includes an outer cylinder (11) and an inner shell (12); The outer cylinder (11) is fitted around the inner shell (12). The through hole (111) is opened on the side wall of the outer cylinder (11). The inner shell (12) has a sensor groove (121) inside. The wave speed sensor (2) is slidably disposed in the sensor groove (121). The sensor groove (121) is in communication with the through hole (111). One end of the compression spring (21) is connected to the side wall of the wave speed sensor (2), and the other end of the compression spring (21) is fixedly connected to the groove wall of the sensor groove (121).

3. The rock mass compressive strength testing device based on impact stress wave according to claim 2, characterized in that, The inner shell (12) is also provided with a placement slot (122), a first sliding groove (123), a rod groove (124) and a second sliding groove (125) for placing the power magnet (31), magnet (32), push-pull rod (33) and impact ball (34) respectively. The magnet (32) is slidably disposed in the first sliding groove (123), and the impact ball (34) is slidably disposed in the second sliding groove (125) in the direction of moving closer to or away from the wave speed sensor (2).

4. The rock mass compressive strength testing device based on impact stress wave according to claim 1, characterized in that, 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 curved and is made of flexible resin.

5. The rock mass compressive strength testing device based on impact stress wave according to claim 3, characterized in that, A tension spring (321) is fixedly connected to one end of the magnet (32) away from the electromagnet (31), and the other end of the tension spring (321) away from the magnet (32) is fixedly connected to the wall of the second slide groove (125). In the initial state, the tension spring (321) is in its original length state.

6. The rock mass compressive strength testing device based on impact stress wave according to claim 3, characterized in that, The inner shell (12) has a wiring groove (126) inside. The sensor groove (121) and the placement groove (122) are respectively connected to the wiring groove (126). The wiring groove (126) is used to place the data transmission line (41).

7. The rock mass compressive strength testing device based on impact stress wave according to claim 2, characterized in that, The inner wall of the outer cylinder (11) is provided with an inner groove (112) that is consistent with the length direction of the outer cylinder (11). The inner wall of the outer cylinder (11) is provided with two sets of horizontal annular grooves (113) corresponding to the through holes (111). Each set of annular grooves (113) is located above its corresponding through hole (111). One end of the annular groove (113) is connected to the inner groove (112), and the other end of the annular groove (113) is connected to the through hole (111) by a through groove (114). The length direction of the through groove (114) is consistent with the length direction of the outer cylinder (11).

8. The rock mass compressive strength testing device based on impact stress wave according to claim 2, characterized in that, The bottom end of the outer cylinder (11) is detachably connected to multiple sets of extension tubes (5). The multiple sets of extension tubes (5) are connected end to end along the length direction of the outer cylinder (11). The data transmission line (41) is inserted inside the extension tube (5). The data processing module (4) and the power supply (311) are located outside the extension tube (5) respectively.

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