A hole wall strain type three-dimensional real-time stress monitoring device

Abstract

The present invention relates to a hole wall strain type three-dimensional real-time stress monitoring device, which belongs to the technical field of real-time three-dimensional stress monitoring of drilling holes for measuring engineering excavation disturbance secondary redistribution stress. It includes a glue injection piston, a wire slot body, a platform body and a cable; the glue injection piston is provided with a glue injection hole, one end is a glue injection end, and the other end is a piston end; an axial blind hole, i.e., a piston cavity, is opened at one end of the wire slot body, three groups of wire slots are evenly arranged on the outer cylindrical surface of the other end, and three groups of strain gauges are evenly arranged on the outer cylindrical surface of the middle part; an axial hole is opened in the axial direction of the platform body, and the cable is located in the axial hole, a cable slot is opened radially at one end, and a fixed terminal is arranged on the outer cylindrical surface of the other end; multiple wires in the cable are respectively fixedly connected to the fixed terminal and the three groups of strain gauges; when in use, AB glue is poured into the piston cavity of the wire slot body, and the piston end of the glue injection piston is matched and located in the piston cavity. The present invention has a simple structure, is easy to operate, and can realize real-time, three-dimensional stress monitoring of engineering ground pressure.

Description

Technical Field

[0001] The invention belongs to the technical field of real-time three-dimensional stress monitoring of drilling holes for measuring secondary redistribution stress of engineering excavation disturbance, and specifically relates to a real-time three-dimensional stress monitoring device for rock masses such as mines, tunnels and underground chambers. Background Art

[0002] In the actual production of mines, frequent ground pressure activities are likely to cause casualties, causing the production of the mining area to come to a partial halt, and may even lead to huge disasters and huge economic losses. In order to effectively prevent the occurrence of mine disasters and accidents and ensure the steady progress of safe production in mining areas, it is of great positive and important significance to monitor the changes in ground pressure in mine production based on the actual ground pressure management and optimize the design for safe production in mines. Therefore, the design and development of intelligent geotechnical engineering sensors and their gradual promotion and application in activities such as monitoring, assessment and early warning of mine ground pressure disasters can increasingly highlight their indispensable role and status.

[0003] At present, there are related products on the market that can be purchased, such as mine ground pressure monitoring stress gauges, but they are mainly concentrated in one-dimensional stress gauges and some pseudo three-dimensional stress gauges. One-dimensional stress gauges can only be used for stress monitoring of columnar engineering structures, and are not suitable for three-dimensional situations; although pseudo three-dimensional stress gauges can realize three-dimensional stress monitoring, they need to predict the direction of action of the three principal stresses, and cannot obtain all-round and multi-angle spatial mechanical parameters, so it is difficult to fully predict the distribution law of stress at any position in space. In addition, the surrounding environment changes rapidly, and we need to capture ground pressure disaster data within a certain time range. They can only be used for a short period of time or in an instantaneous state, which makes it difficult to meet the actual monitoring and real-time data collection needs of secondary redistribution of engineering rock stress in complex environments.

[0004] In order to solve the problem of real-time monitoring of three-dimensional stress in mine ground pressure disasters, the present invention designs a hole wall strain type three-dimensional real-time stress meter device. By combining manual on-site centralized collection and integrated circuit real-time connection, the three-dimensional stress parameters of any stress probe contact part in multiple spaces can be obtained: the magnitude, direction and inclination of the three principal stresses, as well as the principal stress difference in each direction, etc., and it can achieve a high accuracy and application range, providing a valuable and reliable data source for the complete and accurate evaluation of the law of ground pressure changes; and the structure is connected to a power supply module, and the collection frequency can be set independently, which makes it possible to realize long-term real-time monitoring and data storage outdoors. Summary of the invention

[0005] In order to solve the problem of real-time monitoring of three-dimensional stress of ground pressure disasters in mines, the present invention provides a hole wall strain type three-dimensional real-time stress monitoring device.

[0006] A hole wall strain type three-dimensional real-time stress monitoring device comprises a glue injection piston 1, a wire slot body 2, a platform body 3 and a cable 38 which are coaxially connected in sequence;

[0007] The injection piston 1 is a cylinder, and a through injection hole 11 is provided in the axial middle part; one end of the injection piston 1 is the injection end, and the other end is the piston end, and a pair of fixing holes 13 are provided in the radial direction of the piston end and pass through the injection hole 11;

[0008] The wire slot body 2 is a cylinder, and an axial blind hole is provided at one end of the wire slot body 2, which is a piston chamber 21. A pair of radially penetrating pin holes 26 are provided at the end of the piston chamber 21, and the pair of pin holes 26 correspond to the pair of fixing holes 13 on the injection piston 1. Three groups of wire slots 24 are arranged on the outer cylindrical surface of the other end of the wire slot body 2, and three groups of strain gauges 25 are arranged on the outer cylindrical surface of the middle part of the wire slot body 2.

[0009] The platform body 3 is a column with an axial hole on the axis; one end of the platform body 3 is a cylinder 33, and a cable duct 35 penetrating to the axial hole is radially opened on the cylinder 33, and a fixing plug 36 is provided in the cable duct 35; the other end is a triangular prism 32, and a fixing terminal 37 is provided on the outer cylindrical surface of the triangular prism 32;

[0010] The end of the triangular prism 32 is fixedly connected to the end surface of the cylindrical end of the wire trough body 2;

[0011] The cable 38 is located in the axial hole of the platform body 3 and fixed by a fixing plug 36; one wire of the cable 38 is fixedly connected to the fixing terminal 37, and the other wires of the cable 38 are connected to the three sets of strain gauges 25 through the three sets of wire slots 24 on the wire slot body 2;

[0012] When in use, the AB glue 44 is poured into the piston cavity 21 of the wire slot body 2 , and the piston end of the glue injection piston 1 is fitted and located in the piston cavity 21 of the wire slot body 2 .

[0013] The technical solution is further defined as follows:

[0014] A cross-shaped glue overflow groove 12 is provided on the end surface of the glue injection end of the glue injection piston 1 , and the glue injection hole 11 is located at the center of the cross-shaped glue overflow groove 12 .

[0015] Each group of wire slots 24 is provided with three or more wire slots.

[0016] Each group of strain gauges 25 is provided with three or more strain gauges.

[0017] The outer cylindrical surface in the middle of the wire trough body 2 is an inwardly concave ring 22 , and the three groups of strain gauges 25 are all arranged on the concave ring 22 .

[0018] An arc-shaped blind hole 34 is provided on the platform body 3 radially corresponding to the fixing plug 36 .

[0019] The beneficial technical effects of the present invention are embodied in the following aspects:

[0020] 1. The present invention is a borehole wall strain type three-dimensional real-time stress monitoring device, the special structure of which can ensure the integrity of the experimental device when the staff conducts stress monitoring on the engineering rock mass in mines, tunnels and underground chambers in the field, and further ensure the authenticity, accuracy and effectiveness of the collected ground pressure data, thereby providing information support for the subsequent data processing, statistical analysis and output report in the ground pressure monitoring software. The present invention sets an annular groove at the position of the strain gauge of the stress probe body, so that the high-sensitivity micro-sensing strain gauge is placed in the annular groove below the probe surface, and in the process of carrying, installation and field measurement, the strain gauge can be prevented from directly contacting with the borehole rock wall to cause friction and sliding, thereby damaging the probe; the present invention also sets three sets of strain gauge wire grooves on the surface of the stress probe body, and the fragile and easily broken strain gauge metal leads can be placed in the sunken grooves respectively, and the straight delivery during the monitoring and installation process can be closely combined with the use of the strain gauge, and the sinking together can ensure that the probe will not touch the strain gauge lead when the friction and displacement between the probe and the borehole rock wall occur accidentally, thereby causing the lead to break and cannot be used normally. The setting of annular grooves and wire grooves on the surface of the stress probe body effectively ensures that the sensitive and fragile strain gauges and leads are intact during use, so that the required ground pressure disaster data can be accurately collected, providing a prerequisite for the subsequent result generation and analysis.

[0021] 2. The richness of the types of three-dimensional spatial parameters obtained by the hole wall strain-type three-dimensional real-time stress monitoring device of the present invention and the real-time monitoring of ground pressure can provide sufficient data sources for the effective assessment of ground pressure disasters and disaster warnings, greatly broadening the applicable occasions for product application and practice. In the actual engineering rock stress monitoring process, the magnitude, direction and orientation of stress are uncertain in advance, and will change at any time with the changes in the complex environment. If the stress mechanical parameters of any required position cannot be measured accurately and for a long time, it will have a significant impact on the subsequent analysis and judgment. The stress gauge device of the present invention can realize three-dimensional real-time monitoring of stress and effectively solve the current problems. The rated compressive strength of the present invention can reach 150MPa, which can achieve 10 -6The invention meets the requirements of accuracy within the range of use. After the stress probe is extended into the borehole rock wall by using the acquisition circuit module, 12 detailed mechanical parameter values ​​such as the size, orientation, inclination and principal stress difference of the three principal stresses in the three dimensions of space at any contact position can be accurately collected. The composition and distribution of the force at this position at this moment can be fully defined and described by acquiring three-dimensional data. The present invention also utilizes the function that the power supply module can be connected to a portable mobile power supply, that is, it gets rid of the power supply limitation of the working equipment during monitoring, making it possible to monitor the ground pressure of the project in the area without electricity supply in real time, and can independently set the acquisition frequency (generally >5min) and automatically store the ground pressure disaster data. When the surrounding environment changes complexly and thus causes changes in rock stress, it can flexibly and variably adapt to the acquisition needs of the secondary redistribution of stress and achieve the purpose of long-term acquisition and observation of stress data changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the present invention.

[0023] Figure 2 An exploded view of the piston cavity of the wire trough body and the piston end of the injection piston.

[0024] Figure 3 This is a schematic diagram of the injection piston structure.

[0025] Figure 4 for Figure 3 Rear view stereogram.

[0026] Figure 5 This is a schematic diagram of the main structure of the cable duct.

[0027] Figure 6 for Figure 5 Rear view stereogram.

[0028] Figure 7 This is a schematic diagram of the main structure of the platform.

[0029] Figure 8 for Figure 7 Exploded diagram.

[0030] Fig. 9 for Figure 8 Rear view exploded diagram.

[0031] Fig.10 This is a state diagram of the real-time stress monitoring device located outside the surrounding rock being monitored.

[0032] Fig.11 It is a state diagram for the real-time stress monitoring device to enter the surrounding rock being detected.

[0033] Fig.12 This is a diagram of the state after glue spraying.

[0034] Serial numbers in the above figure: glue injection piston 1, wire trough body 2, platform body 3, glue injection hole 11, glue overflow groove 12, fixing hole 13, piston cavity 21, concave ring 22, wire trough tube cavity 23, wire trough 24, strain gauge 25, pin hole 26, measuring line transition arc surface 31, triangular prism 32, cylinder 33, arc blind hole 34, cable trough 35, fixing plug 36, fixing terminal 37, cable 38, mounting rod 39, power supply module 40, acquisition circuit module 41, handheld acquisition terminal 42, drill hole 43, AB glue 44, surrounding rock 45. DETAILED DESCRIPTION

[0035] The present invention will be further described below by way of embodiments in conjunction with the accompanying drawings.

[0036] See also Figure 1 A hole wall strain type three-dimensional real-time stress monitoring device includes a glue injection piston 1, a wire groove body 2, a platform body 3 and a cable 38 which are coaxially connected in sequence.

[0037] See also Figure 2 and Figure 4 The injection piston 1 is a cylinder, with an injection hole 11 extending through it in the middle of the axial direction; one end of the injection piston 1 is the injection end, and the other end is the piston end. A pair of fixing holes 13 extending through the injection hole 11 are provided in the radial direction of the piston end. Figure 3 A cross-shaped glue overflow groove 12 is provided on the end surface of the glue injection end of the glue injection piston 1 , and the glue injection hole 11 is located at the center of the cross-shaped glue overflow groove 12 .

[0038] See also Figure 2 and Figure 4 The wire trough body 2 is a cylinder, and an axial blind hole is opened at one end of the wire trough body 2, and the axial blind hole is the piston cavity 21; see Figure 5 and Figure 6 A pair of pin holes 26 are provided in the radial direction of the port of the piston cavity 21, and the pair of pin holes 26 correspond to the pair of fixing holes 13 on the injection piston 1. Three groups of wire grooves 24 are arranged on the outer cylindrical surface of the other end of the wire groove body 2, and three groups of strain gauges 25 are arranged on the outer cylindrical surface of the middle part of the wire groove body 2. Each group of wire grooves 24 has five wire grooves, and each group of strain gauges 25 has four strain gauges.

[0039] See also Figure 7 , Figure 8 and Fig. 9 The platform body 3 is a column with an axial hole on the axis; one end of the platform body 3 is a cylinder 33, and a cable duct 35 penetrating to the axial hole is radially opened in the cylinder 33, and a fixing plug 36 is provided in the cable duct 35; the other end is a triangular prism 32, and a fixing terminal 37 is provided on the outer cylindrical surface of the triangular prism 32; the end of the triangular prism 32 is fixedly connected to the end face of the cylindrical end of the duct body 2.

[0040] The cable 38 is located in the axial hole of the platform body 3 and is fixed by a fixing plug 36; one wire of the cable 38 is fixedly connected to the fixed terminal 37, and the other wires of the cable 38 are connected to four groups of strain gauges 25 through five groups of wire grooves 24 on the wire groove body 2.

[0041] The specific monitoring operation process is described as follows:

[0042] In the actual monitoring process, a borehole 43 with a diameter of 40 mm and a depth of 1 to 1.2 m is usually drilled downward at an inclination of 1° to 2° in front of the measuring point to be tested, and the gravel in the hole is blown away with a high-pressure air pipe, so as to prepare for the subsequent insertion of the real-time stress monitoring device.

[0043] AB glue 44 is poured into the piston cavity 21 of the wire slot body 2, the piston end of the glue injection piston 1 is fitted in the piston cavity 21 of the wire slot body 2, and is securely fixed at the fitting position of a pair of pin holes 26 and a pair of fixing holes 13 with a fuse or pencil lead with a diameter of 2 mm, and the excess overflowed AB glue 44 is evenly spread on the outer wall of the piston cavity 21 to ensure that the real-time stress monitoring device can be in close contact with the surrounding rock 45 wall.

[0044] See also Fig.10 , insert the prepared mounting rod 39 into the arc-shaped blind hole 34 at the bottom of the monitoring device, and fit the fixing plug 36 into the cable duct 35 with the fixing plug 36 facing downward.

[0045] See also Fig.11 When the real-time stress monitoring device is inserted into the borehole 43 and the injection end of the injection piston 1 has not yet contacted the rock wall of the surrounding rock 45, it is slowly moved forward at a uniform speed without rotating the mounting rod 39 until the injection end of the injection piston 1 is sent to the bottom of the test borehole 43, ensuring that the marking line at the end of the mounting rod 39 is placed directly above.

[0046] See also Fig.12 When the injection end of the injection piston 1 contacts the wall of the surrounding rock 45 and cannot move forward, the installation rod 39 is pushed hard to break the fuse. The hand can be withdrawn after 10 seconds when the hand cannot be pushed forward any more. Then the installation rod 39 is slowly pulled out. Then the AB glue 44 inside the piston cavity 21 is squeezed by the injection piston 1 and overflows from the injection hole 11 and wraps the entire injection end of the injection piston 1, achieving complete and close contact with the wall of the surrounding rock 45. Finally, the real-time monitoring device will be left at the bottom of the tested borehole 43, and the three-dimensional stress real-time monitoring data will be obtained through the handheld acquisition terminal 42 connected to the cable 38.

Claims

1. A hole wall strain type three-dimensional real-time stress monitoring device, characterized in that: It comprises a glue injection piston (1), a wire trough body (2), a platform body (3) and a cable (38) which are coaxially connected in sequence; The glue injection piston (1) is a cylinder, and a glue injection hole (11) is provided in the axial middle part thereof; one end of the glue injection piston (1) is a glue injection end, and the other end is a piston end; a pair of fixing holes (13) are provided in the radial direction of the piston end and pass through the glue injection hole (11); The wire slot body (2) is a cylinder, one end of the wire slot body (2) is provided with an axial blind hole, the axial blind hole being the piston chamber (21), a pair of radially penetrating pin holes (26) are provided at the end of the piston chamber (21), and the pair of pin holes (26) correspond to the pair of fixing holes (13) on the injection piston (1); three groups of wire slots (24) are arranged on the outer cylindrical surface of the other end of the wire slot body (2), and three groups of strain gauges (25) are arranged on the outer cylindrical surface of the middle part of the wire slot body (2); The platform body (3) is a column with an axial hole formed on the axis; one end of the platform body (3) is a cylinder (33), a cable duct (35) extending from the axial hole is formed in the radial direction of the cylinder (33), and a fixing plug (36) is provided in the cable duct (35); the other end is a triangular prism (32), and a fixing terminal (37) is provided on the outer cylindrical surface of the triangular prism (32); The end of the triangular prism (32) is fixedly connected to the end surface of the cylindrical end of the wire trough body (2); The cable (38) is located in the axial hole of the platform body (3) and is fixed by a fixing plug (36); one wire of the cable (38) is fixedly connected to the fixing terminal (37), and the other wires of the cable (38) are respectively connected to three groups of strain gauges (25) through three groups of wire grooves (24) on the wire groove body (2); a cross-shaped overflow groove (12) is provided on the end surface of the injection end of the glue injection piston (1), and the glue injection hole (11) is located at the center of the cross-shaped overflow groove (12); each group of wire grooves (24) is provided with more than three wire grooves; an arc-shaped blind hole (34) is provided on the platform body (3) radially corresponding to the fixing plug (36); When in use, AB glue (44) is poured into the piston cavity (21) of the wire groove body (2), and the piston end of the glue injection piston (1) is positioned in the piston cavity (21) of the wire groove body (2).

2. The hole wall strain type three-dimensional real-time stress monitoring device according to claim 1, characterized in that: Each group of strain gauges (25) is provided with more than three strain gauges.

3. The hole wall strain type three-dimensional real-time stress monitoring device according to claim 1, characterized in that: The outer cylindrical surface in the middle of the wire trough body (2) is an inwardly concave ring (22), and the three groups of strain gauges (25) are all arranged on the concave ring (22).

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