A device for measuring internal deformation of rock and soil for geotechnical model test

Abstract

The present invention discloses a rock and soil internal deformation measuring device for geotechnical model test, which relates to the field of civil engineering technology, including a plurality of magnetically linked capsule units, each of which includes a shell, end one, end two and a magnetic control connection assembly, the magnetic control connection assembly includes a variable pole and a constant pole, the constant pole and the variable pole are respectively arranged in end one and end two, and end one and end two are respectively connected to the upper and lower ends of the shell; when the rock and soil deforms, the pressure-sensitive membrane converts the internal pressure of the rock and soil into an electrical signal and transmits it to the magnetic control connection assembly, which receives the electrical signal and controls the switching electrodes of the variable poles to separate adjacent capsule units. The present invention adopts a rock and soil internal deformation measuring device for geotechnical model test with the above structure, which not only effectively eliminates the reinforcement effect of the buried measuring device on the soil, but also avoids the disturbance of the measurement results by excavation observation.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a rock and soil body internal deformation measuring device used for geotechnical model tests. Background Art

[0002] Although granite residual soil has good structural properties, its strong water sensitivity makes it easy to suffer structural damage such as instability and sliding under conditions of short-term heavy rainfall or repeated rainfall. Therefore, indoor test simulation of slopes with different slopes under different engineering environmental conditions is of great practical significance for exploring the slope failure mechanism, inhibiting slope deformation, and proposing economical and reasonable reinforcement plans.

[0003] The main evaluation indicators of slope failure deformation are the horizontal deformation, vertical deformation and failure slip surface of the slope. However, in the existing indoor model test device of slope, except for the electronic measurement of deformation displacement using Piv particle image velocimetry technology, the rest mostly use pre-buried sensor measurement points and use laser displacement sensors to measure deformation values. However, the price of Piv equipment is high and the penetration rate of the device is low. Although the pre-buried sensor measurement points use laser displacement sensors to measure displacement deformation, which is cheap, convenient and feasible, when the pre-buried sensor measurement points are used, if the measured values ​​are to be accurate, the sensors need to be buried deep, which will cause reinforcement to the soil and have an additional effect on the deformation of the slope, and it is impossible to obtain more accurate and effective slope failure simulation test values. Therefore, a geotechnical model test deformation measurement device that is low-cost, easy to install, simple and effective, and does not have a reinforcement effect on the soil is proposed, which has a strong practical significance for realizing high-precision deformation measurement of geotechnical model tests. Summary of the invention

[0004] The purpose of the present invention is to provide a rock and soil internal deformation measuring device for geotechnical model test, so as to solve the problem that the existing measuring device cannot obtain accurate and effective slope failure simulation test values.

[0005] To achieve the above-mentioned purpose, the present invention provides a rock and soil internal deformation measuring device for geotechnical model tests, including a plurality of magnetically linked capsule units, each of which includes a shell, end one, end two and a magnetically controlled connection assembly, the magnetically controlled connection assembly includes a variable pole and a constant pole, the constant pole and the variable pole are respectively arranged in the end one and the end two, and the end one and the end two are respectively connected to the upper and lower ends of the shell.

[0006] Preferably, the shell is configured as a hollow structure and is surrounded by side walls, a pressure-sensitive membrane is provided on the outer side of the side walls, and an output pin is provided on the pressure-sensitive membrane; the pressure-sensitive membrane is used to receive the internal pressure value of the rock and soil body, and adjust the resistance value of the output pin according to the pressure value, and transmit the pressure value to the magnetically controlled connection component in the form of an electrical signal, and the magnetically controlled connection component controls the switching electrode of the transformer end according to the received electrical signal to separate adjacent capsule units.

[0007] Preferably, the constant pole includes a permanent magnet, and the permanent magnet is arranged at the center of the arc top of the end one.

[0008] Preferably, the transformer end includes an iron core arranged inside the second end, a coil is arranged outside the iron core, and a forward coil power supply and a reverse coil power supply are respectively connected to the two sides of the coil, the forward coil power supply and the reverse coil power supply are both connected to the output end of the double-position relay, the input end of the double-position relay is connected to the relay power supply, the relay power supply is connected to the sensor transmitter, and the sensor transmitter is connected to the pressure sensitive membrane through the output pin.

[0009] Preferably, the two-position relay, the relay power supply, the sensor transmitter, the output pin and the pressure-sensitive membrane are connected in series to form a first loop; the two-position relay, the forward coil power supply, the coil and the iron core are connected in series to form a second loop; the two-position relay, the reverse coil power supply, the coil and the iron core are connected in series to form a third loop;

[0010] After receiving the electrical signal from the pressure-sensitive film, the two-position relay in the first circuit switches to connect the second circuit or the third circuit, so that the transformer extreme switches the electrode;

[0011] The sensor transmitter senses and determines the magnitude of the current in the first loop, and transmits a radio frequency signal to the outside.

[0012] Preferably, the forward coil power supply and the reverse coil power supply are respectively connected to the coil via wires to supply power.

[0013] Preferably, the coil is wound around the outer periphery of the iron core, the iron core is arranged at the center of the arc top of the second end, and the lower end surface of the iron core and the center of the arc top of the second end are coplanar and do not move outward.

[0014] Preferably, an opening is provided on the side wall, and the output pin passes through the opening to be connected to the sensor transmitter.

[0015] Preferably, both the end head 1 and the end head 2 are connected to the shell via threads.

[0016] A method for measuring the internal deformation of a rock and soil body used in a geotechnical model test comprises the following steps:

[0017] Step S1: According to the measurement requirements and the thickness of the soil layer of the slope model, a certain number of capsule units are selected, and the capsule units are assembled in the order of connecting the variable extreme point and the constant extreme point to form a multi-section capsule unit;

[0018] Step S2: Before filling the slope model, the multi-section capsule units are placed in a direction perpendicular to the preset slope surface, and the soil is covered and compacted in layers according to the test design requirements until the compacted surface of the soil reaches the preset slope surface, and the buried direction and position of the multi-section capsule units are marked on the side wall of the slope model box;

[0019] Step S3: demodulating the radio frequency signal emitted by the sensor transmitter, setting the pressure data obtained after demodulation to zero, and the obtained position of the multi-section capsule unit is the initial position;

[0020] Step S4: performing a slope model destruction test, obtaining and recording the position and pressure changes of the multi-section capsule unit during the destruction process;

[0021] Step S5: After the test is completed, the soil deformation and displacement conditions before and after the soil deformation are compared to obtain the final soil deformation and displacement data in the slope model test.

[0022] Therefore, the present invention adopts a rock and soil internal deformation measurement device for geotechnical model test with the above structure, which has the following beneficial effects:

[0023] (1) The present invention adopts a multi-section capsule unit to measure the deformation and displacement of soil in geotechnical tests. Compared with the traditional deformation measuring device, the structure is more intuitive and obvious in measuring the deformation and displacement of soil, avoiding the disturbance of excavation observation on the measurement results of soil deformation and displacement, and greatly reducing the cost of soil deformation measurement equipment during the experiment. Compared with the traditional measuring device, it is more accurate and has a wider applicability.

[0024] (2) The side walls and two end heads of the capsule unit of the present invention are made of high-strength and low-density materials, which can ensure the performance of its own strength structure and prevent the capsule unit from being deformed under the soil pressure, while reducing its own weight to the greatest extent, ensuring that the capsule unit can be deformed in coordination with the soil during the deformation of the soil, thereby achieving accurate measurement of the soil deformation. In addition, the use of assembled structural splicing greatly improves the monomer utilization rate of the structural unit, realizes the replacement of the internal device of the capsule unit, effectively prolongs the service life of the overall structure, avoids the situation where the measuring device can only be used once, and realizes the recycling and reuse of the measuring device.

[0025] (3) The present invention realizes real-time monitoring of the displacement of the capsule in the soil and the soil pressure by changing the magnitude of the input loop current and using a sensor transmitter to realize real-time transmission of the position of the single capsule in the soil and the pressure on the pressure-sensitive membrane. At the same time, from the perspective of reinforcement, the deadweight of the capsule unit is reduced, and the reaction force on the soil when it deforms and displaces is reduced, so that the deformation of the soil is closer to the actual state, further improving the accuracy of soil deformation measurement.

[0026] (4) The capsule unit pressure-sensitive membrane of the deformation measuring device for geotechnical model testing of the present invention utilizes the change in resistance of the output pin of the pressure-sensitive membrane under the action of external pressure, thereby realizing the control of the input circuit current of the two-position relay, and then realizing the control of the internal contact position of the two-position relay, realizing the switching of different output circuits, and realizing the magnetization of the iron core and the control of the magnetic poles by means of the Biot-Savart law and Ampere's law, effectively utilizing the pressure change occurring when the soil is deformed, and using this as a handle to effectively transform it, not only the soil pressure under the soil deformation state is monitored in real time by the capsule unit pressure-sensitive membrane with multi-point linkage, but also the purpose of controlling the connection state of the structure by the internal stress state is achieved.

[0027] (5) The magnetically controlled connection system of the present invention realizes the conversion between pressure signals and electrical signals through a pressure-sensitive membrane to control the dual-position relay, thereby realizing the adjustment of the extreme magnetic pole of the transformer. By utilizing the principle of "like poles repel each other and opposite poles attract each other", the vertical constraint requirements during the structural installation process are effectively guaranteed. At the same time, when the soil is deformed and stressed, the magnetic pole adjustment is automatically realized to control the separation of adjacent connected capsule units to ensure the operation of the capsule units. This effectively weakens or even eliminates the reinforcement effect of the soil caused by the connection of adjacent capsule units when the soil is deformed and displaced, thereby ensuring the free deformation of the soil in the geotechnical model test, realizing the deformation measurement of the displacement and deformation of the soil by the capsule unit that is close to the real state, and improving the accuracy of the soil deformation measurement.

[0028] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the connection structure of an embodiment of a rock and soil body internal deformation measurement device for geotechnical model test of the present invention;

[0030] Figure 2 It is a structural schematic diagram of a capsule unit of a rock and soil body internal deformation measurement device for geotechnical model test according to the present invention;

[0031] Figure 3 It is a cross-sectional connection diagram of a side wall and a pressure-sensitive membrane of a rock and soil body internal deformation measurement device for geotechnical model test according to the present invention;

[0032] Figure 4 It is a schematic diagram of the vertical connection between the side wall and the pressure-sensitive membrane of a rock and soil body internal deformation measurement device for geotechnical model test according to the present invention;

[0033] Figure 5 It is a front cross-sectional view of an end portion 1 of a rock and soil body internal deformation measuring device for geotechnical model test of the present invention;

[0034] Figure 6 A top cross-sectional view of an end portion of a rock and soil body internal deformation measuring device for geotechnical model testing according to the present invention;

[0035] Figure 7 It is a front cross-sectional view of the second end of a rock and soil body internal deformation measuring device for geotechnical model test according to the present invention;

[0036] Figure 8 It is a top cross-sectional view of the second end of a rock and soil body internal deformation measuring device for geotechnical model test according to the present invention;

[0037] Fig. 9 It is a schematic diagram of the connection between the second end and the side wall of a rock and soil body internal deformation measuring device for geotechnical model test according to the present invention;

[0038] Fig.10 It is a structural schematic diagram of an input circuit of a rock and soil body internal deformation measurement device for geotechnical model test according to the present invention;

[0039] Fig.11 It is a structural schematic diagram of an output circuit of a rock and soil body internal deformation measurement device for geotechnical model test according to the present invention;

[0040] Fig.12 This is a flow chart of the working principle of the capsule unit input circuit structure of a rock and soil body internal deformation measurement device for geotechnical model test of the present invention;

[0041] Fig.13 This is a flow chart of the working principle of the capsule unit output circuit structure of a rock and soil body internal deformation measurement device for geotechnical model test of the present invention;

[0042] Reference numerals: 1, housing; 11, side wall; 12, thread; 13, threaded sleeve; 2, terminal one; 3, terminal two; 4, magnetic control connection assembly; 41, variable terminal; 411, iron core; 412, coil; 413, forward coil power supply; 414, reverse coil power supply; 415, two-position relay; 416, relay power supply; 417, sensor transmitter; 418, wire; 42, constant terminal; 421, permanent magnet; 5, pressure-sensitive membrane; 51, output pin; DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0044] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0045] Example

[0046] See also Figure 1-13 The present invention provides a rock and soil internal deformation measurement device for geotechnical model testing, including a plurality of magnetically linked capsule units, each of which includes a shell 1, an end 1 2, an end 2 3 and a magnetically controlled connection assembly 4, and the magnetically controlled connection assembly 4 is used to achieve a close fitting connection between two adjacent capsule units. The magnetically controlled connection assembly 4 includes a variable pole 41 and a constant pole 42, and the constant pole 42 and the variable pole 41 are respectively arranged in the end 1 2 and the end 2 3, and the end 1 2 and the end 2 3 are respectively connected to the upper and lower ends of the shell 1. The side wall 11 of the capsule unit is made of high-strength and low-density material, which effectively reduces the deadweight of the structure while ensuring the strength of the structure itself. When the soil body slips and deforms, the characterization of the soil body slip deformation is more accurate.

[0047] The shell 1 is set as a hollow structure and is surrounded by a side wall 11. A pressure-sensitive membrane 5 is set on the outer side of the side wall 11, and an output pin 51 is set on the pressure-sensitive membrane 5; the pressure-sensitive membrane 5 is used to receive the internal pressure value of the rock and soil body, and adjust the resistance value of the output pin 51 according to the pressure value, and transmit the pressure value to the magnetic control connection component 4 in the form of an electrical signal. The magnetic control connection component 4 controls the switching electrode of the transformer end 41 according to the received electrical signal to separate adjacent capsule units.

[0048] The constant pole 42 includes a permanent magnet 421, which is arranged at the center of the arc top of the end 2, and the cross-sectional area of ​​the permanent magnet 421 is equal to the interface area of ​​the horizontal part. The permanent magnet 421 realizes the connection and separation of adjacent capsule units through the attraction and mutual repulsion with the magnetic block of the connected variable pole 41, which effectively weakens the reinforcement effect between adjacent capsule units in the actual use stage while ensuring the structural integrity in the installation stage, ensuring the structural freedom of the monomer, and realizing accurate measurement closer to the actual change.

[0049] The magnetism of the transformer end 41 is variable. When the rock and soil body is deformed, the pressure-sensitive membrane 5 is subjected to pressure. The pressure-sensitive membrane 5 adjusts the resistance of the output pin 51 according to the internal pressure of the rock and soil body, changes the size of the loop current, and transmits it to the magnetic control connection component 4 in the form of an electrical signal. The magnetic control connection component 4 controls the transformer end 41 to switch the electrodes according to the received electrical signal, so that the adjacent capsule units are separated. The transformer end 41 includes an iron core 411 arranged inside the end 23, and a coil 412 is arranged outside the iron core 411. The two sides of the coil 412 are respectively connected to a forward coil power supply 413 and a reverse coil power supply 414. The forward coil power supply 413 and the reverse coil power supply 414 are both connected to the output end of the double-position relay 415 through a wire 418. The reverse coil power supply 414 and the forward coil power supply 413 are both micro power supplies, which can realize the magnetization of the iron core 411 after the coil 412 is energized, and at the same time ensure that when the adjacent magnetic bodies repel each other, the repulsive force is slightly smaller than the weight of the structure itself.

[0050] The input end of the two-position relay 415 is connected to a relay power supply 416 via a wire 418. The relay power supply 416 is a micro power supply that can meet the requirements of the current size change of the two-position relay 415 and control the internal contact position of the two-position relay 415. The relay power supply 416 is connected to a sensor transmitter 417, and the sensor transmitter 417 is connected to the pressure-sensitive film 5 via an output pin 51.

[0051] The double position relay 415, the relay power supply 416, the sensor transmitter 417, the output pin 51 and the pressure-sensitive film 5 are connected in series to form a first loop; the double position relay 415, the forward coil power supply 413, the coil 412 and the iron core 411 are connected in series to form a second loop; the double position relay 415, the reverse coil power supply 414, the coil 412 and the iron core 411 are connected in series to form a third loop. The upper and lower position contacts at the output end of the double position relay 415 are respectively connected to the reserved interfaces at both ends of the coil 412 and the corresponding coil power supply through the wire 418, and the connection order of the upper and lower position contacts at the output end is reversed.

[0052] After the dual-position relay 415 in the first circuit receives the electrical signal from the pressure-sensitive membrane 5, it senses and judges the current size to control the position of the internal contacts of the dual-position relay 415, and controls the direction of the output current by means of the different connection sequences of the wires connected to the output contacts, switches to connect the second circuit or the third circuit, controls the switching electrodes of the transformer end 41, realizes the magnetic change, and separates the adjacent capsule units.

[0053] The sensor transmitter 417 senses and determines the current size in the first loop, and transmits a radio frequency signal to the outside. The radio frequency signal is demodulated by an external demodulator to achieve real-time acquisition and analysis of the soil pressure state and displacement deformation.

[0054] The forward coil power supply 413 and the reverse coil power supply 414 are connected to the coil 412 through the wire 418 for power supply, and the coil 412 is connected to the two wires through the reserved interface. The forward coil power supply 413 and the reverse coil power supply 414 are respectively connected to different output circuits to achieve opposite current directions in different output circuits, thereby achieving the change of the magnetic pole of the iron core 411 wound around the coil 412, and achieving the repulsion and attraction of the variable pole 41 and the constant pole 42 on both sides of the connection interface of adjacent capsule units, thereby achieving the connection and separation of adjacent capsule units.

[0055] The coil 412 is wound around the outer periphery of the iron core 411, and the iron core 411 and the coil 412 are closely connected. The iron core 411 is set at the center of the arc top of the terminal 2 3, and the lower end surface of the iron core 411 and the arc top center of the terminal 2 3 are coplanar and equal in area, and do not move outward. The coil 412 and the iron core 411 surrounded by it use the Biot-Savart law, that is, the law of electromagnetism, so that the iron core 411 generates magnetism under power-on conditions; the coil 412 has reserved interfaces to connect two wires 418 respectively, which are connected to the upper and lower position contacts of the output end to control the direction of the current inside the coil 412, and determine the magnetic poles with the help of Ampere's law, so as to achieve the determination and control of the magnetic poles of the magnetized core 411.

[0056] like Figure 2 As shown, the pressure-sensitive membrane 5 and the side wall 11 are tightly fitted, and an opening is provided at the lower part of the side wall 11. The output pin 51 passes through the opening and is connected to the sensor transmitter 417, and is then connected in series with the relay power supply 416 and the dual-position relay 415 through a wire 418 to form an input circuit. The resistance value of the output pin 51 changes due to the pressure change sensed by the pressure-sensitive membrane 5, thereby controlling the current size of the input circuit, and then the sensor transmitter 417 transmits the pressure change of the pressure-sensitive membrane 5 to the outside and controls the switching of the output circuit of the dual-position relay 415, thereby realizing the conversion and transmission of the capsule unit position signal and the external pressure signal of the pressure-sensitive membrane 5.

[0057] like Fig. 9As shown, both the terminal 1 2 and the terminal 2 3 are connected to the housing 1 through the thread 12. A threaded sleeve 13 matching the thread 12 is provided on the side wall 11. The arrangement of the threaded sleeve 13 and the thread 12 realizes the twist connection between the terminal 1 2 and the terminal 2 3 and the housing 1, realizes the assembly type assembly of the capsule unit, and enables the internal device of the capsule unit to be replaced, effectively prolonging the service life of the overall structure and realizing the recycling and reuse.

[0058] The steps for assembling the capsule unit are as follows:

[0059] (1) Place the various component units of the capsule unit at preset positions and assemble them according to the splicing sequence.

[0060] (2) After the assembly is completed, the transformer poles 41 of each capsule unit are placed close to the two ends of the magnet. If the reaction state of the transformer poles 41 of the capsule unit close to the two ends of the magnet is one repulsion and one attraction, and the reactions of each capsule unit close to the two ends of the magnet are consistent, it indicates that the structure of the transformer poles 41 of the capsule unit is correctly installed and the transformer poles are working normally.

[0061] (3) Place the constant end 42 of each capsule unit close to the variable end 41 of another capsule unit. If the variable end 41 and the constant end 42 attract each other, it indicates that the constant end 42 of the capsule unit is correctly installed and the constant end 42 is working normally.

[0062] (4) According to the measurement requirements and the thickness of the soil layer of the slope model, an appropriate number of capsule units are selected and assembled in the order of connecting the variable pole 41 and the constant pole 42 to form a multi-section capsule unit.

[0063] A method for measuring the internal deformation of a rock and soil body used in a geotechnical model test comprises the following steps:

[0064] Step S1: According to the measurement requirements and the thickness of the soil layer of the slope model, a certain number of capsule units are selected, and the capsule units are assembled in the order of connecting the variable pole 41 and the constant pole 42 to form a multi-section capsule unit;

[0065] Step S2: Before filling the slope model, the multi-section capsule units are placed in a direction perpendicular to the preset slope surface, and the soil is covered and compacted in layers according to the test design requirements until the compacted surface of the soil reaches the preset slope surface, and the buried direction and position of the multi-section capsule units are marked on the side wall of the slope model box;

[0066] Step S3: demodulating the radio frequency signal transmitted by the sensor transmitter 417, setting the pressure data obtained after demodulation to zero, and the obtained position of the multi-section capsule unit is the initial position;

[0067] Step S4: performing a slope model destruction test, obtaining and recording the position and pressure changes of the multi-section capsule unit during the destruction process;

[0068] Step S5: After the test is completed, the soil deformation and displacement conditions before and after the soil deformation are compared to obtain the final soil deformation and displacement data in the slope model test.

[0069] The deformation measuring device of the present invention is placed in the soil during use to monitor the deformation displacement caused by soil damage. Therefore, the soil pressure it is subjected to is divided into two types: static soil pressure and active soil pressure. According to the basic formula of soil mechanics, the static soil pressure is σ0=K0γz, and the active soil pressure of non-cohesive soil is σ a =γzK a The active earth pressure of clay soil is

[0070] It can be found from the above formula that the soil pressure is proportional to the soil depth. Therefore, after the deformation measuring device is buried in the soil, regardless of whether the soil deforms or slides, the deformation measuring device is subjected to the earth pressure in all directions exerted on it by the soil.

[0071] The working principle of the present invention is as follows: the capsule units are connected via a magnetically controlled connection assembly 4, wherein the constant pole 42 of one capsule unit in adjacent capsule units is magnetically connected to the variable pole 41 of another capsule unit.

[0072] When the soil deformation produces pressure changes, on the one hand, when the pressure-sensitive membrane 5 in the capsule unit is continuously subjected to a pressure greater than or equal to 0.8N, the pressure-sensitive membrane 5 converts the pressure signal into an electrical signal, and transmits the electrical signal to the magnetically controlled connection component 4. The variable pole 41 in the magnetically controlled connection component 4 switches the electrode, and the magnetic properties of the switched electrode are the same as the magnetic properties of the permanent magnet 421 at the constant pole 42, so that adjacent capsule units are separated, eliminating the reinforcement effect between adjacent capsule units when the soil is deformed and displaced, and realizing the deformation measurement of the soil displacement by the capsule unit that is close to the real state.

[0073] On the other hand, the pressure-sensitive membrane 5 in the capsule unit is subjected to pressure, and the electrical signal of the pressure-sensitive membrane 5 is transmitted to the sensor transmitter 417. The sensor transmitter 417 receives the electrical signal of the pressure-sensitive membrane 5 and transmits the electrical signal and the position information of the capsule unit to the outside. The electrical signal can represent the pressure on the pressure-sensitive membrane, and is demodulated by the demodulator to achieve real-time acquisition and analysis of the soil pressure state and displacement deformation.

[0074] Therefore, the present invention adopts a rock and soil internal deformation measuring device with the above structure for geotechnical model testing, which not only effectively eliminates the reinforcement effect of the buried measuring device on the soil, but also avoids the disturbance of the measurement results caused by excavation observation, making it more accurate than traditional measuring devices, and also has a wider applicability.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A device for measuring internal deformation of rock and soil for geotechnical model test, characterized in that: A plurality of magnetically linked capsule units are included, each of which includes a shell, a first end, a second end, and a magnetically controlled connection assembly, wherein the magnetically controlled connection assembly includes a variable end and a constant end, wherein the constant end and the variable end are respectively arranged in the first end and the second end, and the first end and the second end are respectively connected to the upper and lower ends of the shell; The shell is configured as a hollow structure and is surrounded by side walls. A pressure-sensitive membrane is disposed on the outer side of the side wall, and an output pin is disposed on the pressure-sensitive membrane. The pressure-sensitive membrane is used to receive the internal pressure value of the rock and soil body, and adjust the resistance value of the output pin according to the pressure value, and transmit the pressure value to the magnetic control connection component in the form of an electrical signal. The magnetic control connection component controls the switching electrode of the transformer pole according to the received electrical signal to separate adjacent capsule units. The constant pole end includes a permanent magnet, and the permanent magnet is arranged at the center of the arc top of the first end; The transformer end includes an iron core arranged inside the second terminal, a coil is arranged outside the iron core, and a forward coil power supply and a reverse coil power supply are respectively connected to the two sides of the coil. The forward coil power supply and the reverse coil power supply are both connected to the output end of the double-position relay, the input end of the double-position relay is connected to the relay power supply, the relay power supply is connected to the sensor transmitter, and the sensor transmitter is connected to the pressure-sensitive membrane through the output pin.

2. The rock and soil internal deformation measuring device for geotechnical model test according to claim 1, characterized in that: The two-position relay, the relay power supply, the sensor transmitter, the output pin and the pressure-sensitive membrane are connected in series to form a first loop; the two-position relay, the forward coil power supply, the coil and the iron core are connected in series to form a second loop; the two-position relay, the reverse coil power supply, the coil and the iron core are connected in series to form a third loop; After receiving the electrical signal from the pressure-sensitive film, the two-position relay in the first circuit switches to connect the second circuit or the third circuit, so that the transformer extreme switches the electrode; The sensor transmitter senses and determines the current size in the first loop, and transmits a radio frequency signal to the outside.

3. The rock and soil internal deformation measuring device for geotechnical model test according to claim 2 is characterized by: The forward coil power supply and the reverse coil power supply are respectively connected to the coil via wires to supply power.

4. The rock and soil internal deformation measuring device for geotechnical model test according to claim 3 is characterized by: The coil is wound around the outer periphery of the iron core, and the iron core is arranged at the center of the arc top of the second end. The lower end surface of the iron core and the center of the arc top of the second end are coplanar and do not move outward.

5. The rock and soil internal deformation measuring device for geotechnical model test according to claim 4, characterized in that: The side wall is provided with an opening, and the output pin passes through the opening to be connected with the sensor transmitter.

6. The rock and soil internal deformation measuring device for geotechnical model test according to claim 5, characterized in that: The first end and the second end are both connected to the shell through threads.

7. A method for measuring the internal deformation of a rock and soil body for geotechnical model testing using a device for measuring the internal deformation of a rock and soil body for geotechnical model testing as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1: According to the measurement requirements and the thickness of the soil layer of the slope model, a certain number of capsule units are selected, and the capsule units are assembled in the order of connecting the variable extreme point and the constant extreme point to form a multi-section capsule unit; Step S2: Before filling the slope model, the multi-section capsule units are placed in a direction perpendicular to the preset slope surface, and the soil is covered and compacted in layers according to the test design requirements until the compacted surface of the soil reaches the preset slope surface, and the buried direction and position of the multi-section capsule units are marked on the side wall of the slope model box; Step S3: demodulating the radio frequency signal emitted by the sensor transmitter, setting the pressure data obtained after demodulation to zero, and the obtained position of the multi-section capsule unit is the initial position; Step S4: performing a slope model destruction test, obtaining and recording the position and pressure changes of the multi-section capsule unit during the destruction process; Step S5: After the test is completed, the soil deformation and displacement conditions before and after the soil deformation are compared to obtain the final soil deformation and displacement data in the slope model test.

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