Electromagnetic pulse loaded rock multiple saturation shear apparatus and method

Abstract

The present application provides a kind of electromagnetic pulse loaded rock multiple saturation shear device and method, by computer controller control electromagnetic induction system realizes high frequency electromagnetic pulse loading and unloading, can simulate the super low friction effect or high pressure water gas oil mixture superposition super low friction effect of structural plane under the load of earthquake or blasting (impact load) of high ground stress.Structure can be realized single rock sample multiple repeated shear by a set of adjustable pressure box device, and the test of rock sample dispersion is carried out.Loading end is composed of multiple loading heads, when high frequency electromagnetic pulse loading and unloading is carried out in horizontal direction, the shear failure of rock sample indefinite structural plane can be realized.High pressure reactor transparent visual side is equipped with high-speed photography DIC system, and the shear process structural plane damage real-time dynamic monitoring can be carried out.Rock-like material can be prepared by adding magnetic material, and rock-like test piece can be made, when surrounding electromagnetic pulse high frequency low amplitude loading is carried out, the test piece is subjected to the body force generated by surrounding magnetic field, and the saturation loading of rock sample is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to rock sample structural plane pulse shear, in particular to a kind of electromagnetic pulse loading rock multiple saturated shear device and method BACKGROUND

[0002] Rock sample structural plane is the medium that exists universally in mining engineering, tunnel engineering, and a large number of discontinuous structural planes in rock mass influence and determine the mechanical properties of rock mass, especially in shale gas (oil well), tunnel, underground cavern, when encountering earthquake or blasting (impact load) working condition, whether rock wall, surrounding rock deformation and destruction can continue to work stably is the key concern problem. Through electromagnetic pulse shear test, the mechanical properties and deformation characteristics of rock sample structural plane under instantaneous load can be understood, which can provide important basis for the design and construction of various rock mass engineering under earthquake or blasting (impact load) load.

[0003] At present, in the process of rock sample shear test, only one sample can be subjected to shear test. If shear c, φ value of a kind of rock is to be obtained, multiple samples need to be subjected to repeated shear test. How to carry out multiple repeated tests on one sample to obtain multiple test data, so as to reduce sample dispersion and obtain ultra-low friction coefficient, the traditional test device cannot meet the test requirements. Especially, under the working condition of simulating earthquake or blasting (impact load), how to repeatedly use limited samples to obtain multiple data has become a new engineering practice demand.

[0004] Traditional rock sample structural plane shear device is driven by hydraulic oil, although there is a servo machine for driving load, but it cannot realize instantaneous loading or high-frequency loading and unloading to simulate earthquake or blasting (impact load). Especially in the process of shale gas exploitation, the rock is wrapped by water, gas, oil and other substances, and the deep geothermal temperature is added to the seismic load. This kind of multiple coupling complex working condition needs a detachable autoclave sealing system to wrap the loading device inside, the sample can be immersed therein, and heating can be carried out, and oil, gas and water can be filled in any proportion to simulate the corresponding complex working condition. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a kind of electromagnetic pulse loading rock multiple saturated shear device and method, proposes to include the mixture of water, gas, oil and other mixtures, and can carry out instantaneous pulse shear device heating;It solves the problems that the existing test device in the prior art cannot carry out multiple repeated shear test on one sample, cannot realize instantaneous or high-frequency loading, and cannot simulate multiple coupling complex working conditions.

[0006] According to the embodiment of the present application, a rock multi-saturation shear device loaded by electromagnetic pulse comprises a frame system, a pressure cell system, an electromagnetic loading system, a sealing system, a high-speed photographic DIC system and a data acquisition system; the sealing system is arranged inside the frame system, the pressure cell system is arranged in the sealing system, the electromagnetic loading system comprises four electromagnetic loading modules arranged between the frame system and the pressure cell system, and the electromagnetic loading modules are signal connected to a control device; the electromagnetic loading modules are respectively arranged at the inner top, the inner bottom and the inner two sides of the frame system, the electromagnetic loading modules at the inner top and the inner bottom are oppositely arranged, the electromagnetic loading modules at the inner two sides are staggered in up and down directions, a fixed part and a movable part with magnetic field are arranged in the electromagnetic loading modules, the movable part can reciprocally move relative to the pressure cell system, and the magnetic pole direction in the fixed part can be continuously changed; the pressure cell system comprises fixed layers for wrapping the top end, the bottom end and the two sides of a rock sample containing magnetic substances, fractures are arranged at the two sides of the fixed layers, the positions of the fractures can be adjusted, and the fixed layers have magnetism; the sealing system is connected with input pipelines of oil, water and gas and a heater; the outer wall of one side of the sealing system is transparent, the electromagnetic loading modules at the inner two sides of the frame system are arranged at the two sides of the transparent outer wall, and the high-speed photographic DIC system is arranged at the outer wall; and the sensors in the data acquisition system are arranged on the fixed layers and are signal connected to an external computer controller.

[0007] Preferably, the frame system comprises a counterforce frame and loading channels for slidingly mounting the movable parts of the electromagnetic loading modules in the counterforce frame, and the sealing system is fixed and supported through the loading channels.

[0008] Preferably, the fixed part and the movable part of the electromagnetic loading module are respectively an electromagnetic induction system and a magnetic loading end, one end of the magnetic loading end is slidingly arranged in the loading channel, the other end is connected to the fixed layer, the electromagnetic induction system is arranged on the outer wall of the frame system and is connected to one end of the loading channel, a lubricating layer is arranged on the inner wall of the loading channel, the magnetic loading end is in T shape, the vertical section of the magnetic loading end is connected to the fixed layer, and the two horizontal sections are connected to the lubricating layer.

[0009] Preferably, the fixed layer comprises pressure plates and adjusting plates vertically and fixedly connected to the end portions of the pressure plates, the pressure plates are arranged at the top and the bottom of the rock sample, the adjusting plates are arranged at the two ends of the opposite walls of the two pressure plates, and the adjusting plates are stacked and arranged.

[0010] Preferably, vertical high-strength screws for stringing the adjusting plates are fixedly arranged at the end portions of the pressure plates, high-strength nuts are threadedly connected to the two ends of each high-strength screw, and the adjusting plates are locked on the high-strength screws through the high-strength nuts.

[0011] Preferably, multiple-end loading heads are connected in parallel to the magnetic loading ends through connecting devices, and the multiple-end loading heads correspond to the stacked adjusting plates one by one.

[0012] Preferably, the sealing system comprises an autoclave, an oil injection pipe and a water injection pipe are connected to the top of the autoclave, a gas injection pipe is connected to the side wall of the autoclave, a heater is connected to the bottom of the autoclave, and one side wall of the autoclave is transparent and visible.

[0013] Preferably, the data acquisition system comprises a computer controller and signal-connected pressure sensors, telescopic displacement sensors, temperature sensors and internal pressure sensors, the pressure sensors are arranged at the connecting end of the electromagnetic loading module and the fixed layer, the telescopic displacement sensors are arranged between the sealing system and the fixed layer, and the telescopic displacement sensors correspond to the electromagnetic loading module one by one and are arranged in parallel, and the temperature sensors and the internal pressure sensors are arranged at the inner bottom of the sealing system.

[0014] Preferably, the high-speed photography DIC system comprises a movable CCD high-speed camera, a control device and a light supplementing device, the movable CCD high-speed camera and the light supplementing device are movably arranged on the frame system and located at the transparent side wall of the sealing system, and the movable CCD high-speed camera and the light supplementing device are linked to the control device.

[0015] A shear method of a rock multiple saturation shear device loaded by electromagnetic pulses, comprising the following steps: S1, sample preparation: selecting a rock sample structural plane rock block on an engineering site, cutting the rock block into a hexahedral sample, selecting appropriate high-strength screws and adjusting plates according to the test needs, and assembling the sample, the high-strength screws, the adjusting plates, a pressing plate and a high-strength screw cap into a pressing box system with the sample; S1.1, the sample preparation can use rock samples with different rock sample heights, different structural plane thicknesses and different structural plane angles; S2, water, gas and oil injection: placing the pressing box system with the sample into a detachable autoclave, filling water, gas and oil at a certain ratio to simulate corresponding real geological conditions; the water, gas and oil three pipelines are externally connected to a water filling pump, an air compressor and an oil injection machine with metering equipment; S2.1, the water, gas and oil injection can be suitable for simulating working conditions such as shale gas, oil wells and well holes, and different types of gas, oil and water bodies can be injected according to different working conditions; S3, heating: controlling the heater to heat the inside of the autoclave through the controller, the temperature sensor feeds back the temperature of the mixture in the autoclave, and the temperature rising rate of the control family is controlled to reach the set temperature; S3.1, the heating temperature can be controlled at 0-250 DEG C; S4, applying a normal force: the top electromagnetic induction system is powered on, the top magnetic loading end applies a normal force to the upper disc rock block of the rock sample structural plane from top to bottom in its loading channel through a lubricating layer; the bottom electromagnetic induction system is powered on, the bottom magnetic loading end applies a reduced normal force to the lower disc rock block of the rock sample structural plane from bottom to top in its loading channel through a lubricating layer, the size of the normal force is controlled by a control device, the top magnetic loading end and the bottom magnetic loading end simultaneously apply force to a certain value, and then transmit to the rock sample; S4.1, the application of the normal force can change the magnetic pole direction of the electromagnetic induction system through the control device, the top and bottom magnetic loading ends make reciprocating motion to realize high-frequency vibration loading and unloading of the normal force, simulate the loading working condition of the up-down direction force of the earthquake, and realize the shear-dilation displacement instantaneous change of the upper and lower disc rock blocks of the rock sample structural plane; S5, applying a shear force: after the left electromagnetic induction system is powered on, the left magnetic loading end applies a shear force to the upper disc rock block of the rock sample structural plane from left to right in its loading channel through a lubricating layer, and after the right electromagnetic induction system is powered on, the right magnetic loading end applies a shear force to the lower disc rock block of the rock sample structural plane from right to left in the loading channel through a lubricating layer, the movement direction and running speed of the magnetic loading end can be realized by controlling the electromagnetic induction system, and fast reciprocating motion is realized.1、Shear force can be controlled by the control device to control the electromagnetic induction system to change the direction of the magnetic pole, the left and right side of the magnetic loading end to prevent the movement, to achieve high-frequency horizontal shear force loading and unloading, simulate the horizontal direction of the earthquake loading conditions, the instantaneous change of the loading shear displacement rate of the upper and lower disc rock mass on the rock sample structure surface; S6, high-speed photography DIC: according to the position of the sample structure surface, the position of the movable CCD high-speed camera is adjusted by the control equipment, the light supplementing equipment is opened to supplement the light source, the high-speed photography DIC system monitors the structure surface damage process in real time, and the key frame image is found through the control equipment, and the image processing is carried out later; S6.1, high-speed photography DIC can monitor the structure surface damage process in real time, and the key frame image is extracted through the DIC control equipment; S7, shear again: after the shear test, the sample is padded with a pad, and then fixed with a fixed layer, and then sheared again; S7.1, the pad for shearing can be made according to the test requirements to meet the assembly requirements of the adjustable pressure box system; S8, data acquisition and analysis: the normal force and shear force of the upper and lower disc rock mass on the sample structure surface are collected in real time through the pressure sensor, the normal shear dilation displacement of the upper and lower disc rock mass on the sample structure surface is collected in real time through the telescopic displacement sensor, the temperature in the autoclave is collected through the temperature sensor, the pressure value in the autoclave is collected through the internal pressure sensor, when the temperature value fed back by the temperature sensor is less than 60% of the program preset temperature value, the controller of the heater controls the rated power of the heater to heat, until the temperature value fed back by the temperature sensor is equal to 60% of the program preset temperature value, the controller controls the heater to heat at 30% of the rated power, until the temperature value fed back by the temperature sensor is equal to 80% of the program preset temperature value, the controller controls the heater to heat at 10% of the rated power, until the temperature value fed back by the temperature sensor is equal to 90% of the program preset temperature value, the controller controls the heater to heat at 1% of the rated power, until the temperature value fed back by the temperature sensor is equal to the program preset temperature value, when the pressure value in the autoclave fed back by the pressure sensor is less than the program preset pressure value, the controller starts the air pressure machine to work, until the pressure value in the autoclave fed back by the pressure sensor is equal to the program preset pressure value; S8.1, the telescopic displacement sensor is installed on the counterforce frame, which is telescoped through the control when needed, and the displacement data is collected.

[0016] The shear device has the following characteristics:

[0017] (1) The water, gas and oil pipes in the sealing system of the autoclave and the heating equipment can be separately injected with oil, gas and water and heated, or simultaneously injected and heated.

[0018] (2) The high-strength screw rod of the adjustable pressure box device can be assembled or not assembled according to the test situation.

[0019] (3) The shear pad can be made according to the test requirements to meet the assembly requirements of the adjustable pressure box device.

[0020] (4) The thickness of the adjusting plate can be customized according to the requirement of the high-strength steel plate with different thicknesses; the length specifications of the high-strength screw rod are various to meet different test requirements.

[0021] (5) The rock-like material containing magnetic substances can be made into a rock-like sample as a whole or a part (such as a gap, a bottom of the sample, etc.) to keep the authenticity of the sample; the magnetic substances can be magnetized in different directions in a magnetizer.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The present application can realize the following functions of the rock under the working conditions of the high-temperature complex environment containing water, gas, oil, etc. under the action of the earthquake or the blasting (impact load):

[0024] 1. Ultra-low friction effect simulation: the control device controls the electromagnetic loading module in the electromagnetic loading system to carry out high-frequency electromagnetic pulse loading and unloading, so as to simulate the ultra-low friction effect of the structural surface under the action of the earthquake or the blasting load.

[0025] 2. Superimposed ultra-low friction effect simulation: the rock sample is immersed in the sealed system, the sealed system can be filled with any proportion of oil, gas and water, the high-pressure water-gas-oil mixture formed can enter the structural surface of the rock sample, and the high-frequency electromagnetic pulse loading and unloading can be cooperated to simulate the superimposed ultra-low friction effect of the high-pressure water-gas-oil mixture.

[0026] 3. Multiple repeated shearing of a single rock sample: after a shearing test is carried out on the rock sample, the original height can be maintained by adding a pad, or the height can be reduced by adjusting the fracture position of the fixed layer in the pressing system, and then the shearing test is carried out again; after a diagonal shearing test is carried out, the rock sample is horizontally exchanged by 180°, and then the diagonal shearing test is carried out again to test the discreteness of the rock sample.

[0027] 4. Shearing failure of an indefinite structural surface of a rock sample: only the electromagnetic loading modules located on both sides of the frame system are used, the electromagnetic loading modules are staggered arranged, and when a plurality of loading heads are arranged at the end of the electromagnetic loading module, the high-frequency electromagnetic pulse loading is carried out in the horizontal direction.

[0028] 5. Real-time dynamic monitoring of the structural surface failure: the high-speed photography DIC system is used to capture the real-time failure mode of the transparent outer wall of the sealed system, the DIC digital image technology is used to monitor the stress and strain of the structural surface position and the strain field information in the whole test process, and the real-time dynamic monitoring of the structural surface failure in the shearing process is realized.

[0029] 6. Saturation loading of rock samples: When the rock sample is fixed using a magnetic pressure box system, the end of the electromagnetic loading module and the magnetic pressure box system attract each other during high-frequency, low-amplitude electromagnetic pulse loading. The electromagnetic loading module, which can slide relative to the pressure box system, performs high-frequency, low-amplitude loading to saturate the rock sample.

[0030] 7. Saturation loading of rock samples: Magnetic materials are added to prepare rock-like materials to obtain rock samples. When subjected to high-frequency, low-amplitude electromagnetic pulse loading, the rock samples are subjected to the surrounding magnetic field and generate body force, thus achieving saturation loading.

[0031] 8. Shear loading of different types of rock samples: Adjust the fixing layer according to the height, structural plane position and thickness of the rock sample to achieve shear loading of different types of rock samples.

[0032] 9. High-temperature working condition simulation of rock samples: The heating function can be realized through the heater in the sealed system. When used with a high-pressure water-gas-oil mixture, it can simulate the high-temperature working condition of rock samples.

[0033] In summary, this shearing device can simulate various coupled and complex working conditions. Through the continuous change of the magnetic poles of the fixed parts in the electromagnetic loading module, the moving parts move back and forth at high speed and load the pressure box system and the sample inside, enabling instantaneous and high-frequency loading. By adjusting the gap position of the pressure box system and adding pads inside, repeated shearing tests on the sample can be achieved. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a rock sample structural surface shearing device using electromagnetic pulse shearing.

[0035] Figure 2 This is a schematic diagram of the pressure box device with a sample height h1 and a structural surface thickness d1.

[0036] Figure 3 This is a schematic diagram of the pressure box device with a sample height h2 and a structural surface thickness d1.

[0037] Figure 4 This is a schematic diagram of the pressure box device with a sample height h1 and a structural surface thickness d2.

[0038] Figure 5 This is a schematic diagram of the pressure box device with sample height h1, structural surface thickness d1, and angle θ.

[0039] Figure 6 This is a schematic diagram of a structure with unclear structural planes (shear failure of rock sample with indeterminate structural planes) under multi-head loading.

[0040] Figure 7 This is a schematic diagram of a multi-stage direct shearing press box device with padding blocks.

[0041] Figure 8The structure diagram of the multiple oblique shear pressure box device with the cushion block.

[0042] In the above figure: 1, counterforce frame; 2, autoclave; 3, oil injection pipe; 4, water injection pipe; 5, gas injection pipe; 6, heater; 7, temperature sensor; 8, internal pressure sensor; 9, upper electromagnetic induction system; 10, upper magnetic loading end; 11, upper loading channel; 12, lubricating layer I; 13, first pressure sensor; 14, lower electromagnetic induction system; 15, lower magnetic loading end; 16, lower loading channel; 17, lubricating layer II; 18, second pressure sensor; 19, left electromagnetic induction system; 20, left magnetic loading end; 21, left loading channel; 22, lubricating layer III; 23, third pressure sensor; 24, right electromagnetic induction system; 25, right magnetic loading end; 26, right loading channel; 27, lubricating layer IV; 28, fourth pressure sensor; 29, upper disc rock block of rock sample structural surface; 30, lower disc rock block of rock sample structural surface; 31, rock sample structural surface; 32, computer controller; 33, control device; 34, extendable displacement sensor I; 35, extendable displacement sensor II; 36, extendable displacement sensor III; 37, extendable displacement sensor IV; 38, upper pressure box; 39, lower pressure box; 40, pressure plate; 41, adjusting plate; 42, high-strength screw; 43, high-strength nut; 44, movable CCD high-speed camera; 45, high-speed photography DIC control equipment; 46, light supplementing equipment; 47, multi-end loading head; 48, connecting device; 49, sample. DETAILED DESCRIPTION

[0043] The technical solutions in the present application will be further described below in combination with the drawings and examples.

[0044] As shown in the drawings, Figures 1-7 The present application proposes a rock multiple saturation shear device loaded by electromagnetic pulse, which comprises a frame system, a pressure box system, an electromagnetic loading system, a sealing system, a high-speed photography DIC system and a data acquisition system.

[0045] The frame system comprises a counterforce frame 1 and loading channels, and the upper loading channel 11, the lower loading channel 16, the left loading channel 21 and the right loading channel 26 are connected to the counterforce frame 1 as a whole.

[0046] The pressure box system comprises upper and lower pressure boxes and a rock sample structural surface sample. The rock sample structural surface 31 is used as a boundary to divide the rock sample structural surface into an upper disc rock block 29 and a lower disc rock block 30. The upper pressure box 38 and the lower pressure box 39 are respectively connected to the top of the upper disc rock block 29 and the bottom of the lower disc rock block 30.

[0047] Each pressure box is composed of a pressure plate 40, an adjusting plate 41, a high-strength screw 42 and a high-strength nut 43. The adjusting plate 41 is locked at both ends of the pressure plate 40 through the high-strength screw 42 and the high-strength nut 43.

[0048] The electromagnetic loading system comprises a bidirectional normal pressure loading device, a bidirectional shear force loading device and a control device 33.

[0049] The bidirectional normal pressure loading device comprises upper and lower normal pressure loading devices arranged oppositely.

[0050] The upper normal pressure loading device comprises an upper electromagnetic induction system 9, a lubricating layer I 12 and an upper magnetic loading end 10.

[0051] The lower normal pressure loading device comprises a lower electromagnetic induction system 14, a lubricating layer II 17 and a lower magnetic loading end 15.

[0052] The bidirectional shear force loading device comprises left and right shear force loading devices arranged oppositely.

[0053] The left shear force loading device comprises a left electromagnetic induction system 19, a lubricating layer III 22 and a left magnetic loading end 20.

[0054] The right shear force loading device comprises a right electromagnetic induction system 24, a lubricating layer IV 27 and a right magnetic loading end 25.

[0055] The magnetic loading end is connected in parallel with a multi-end loading head 47 through a connecting device 48, and the multi-end loading head 47 corresponds to the stacked adjusting plates 41 one by one.

[0056] The sealing system comprises an autoclave 2, connecting water, gas and oil 3 pipelines and heating equipment.

[0057] The high-speed photography DIC system comprises a movable CCD high-speed camera 44, a light supplementing device 46 and a high-speed photography DIC control device 45.

[0058] The data acquisition system comprises a computer controller 32 and first, second, third and fourth pressure sensors 13, 18, 23 and 28, and telescopic displacement sensors I, II, III and IV 34, 35, 36 and 37, and a temperature sensor 7 and an internal pressure sensor 8.

[0059] The first, second, third and fourth pressure sensors 13, 18, 23 and 28 are pressure application pressure sensors.

[0060] Application method of rock sample structural plane shearing device of electromagnetic pulse shearing

[0061] The rock sample structural plane shearing device of electromagnetic pulse shearing of the sample height h1 and the structural plane thickness d1 pressure box device is taken as an example for illustration. The device comprises the following steps: sample preparation, water and gas oil injection, heating, normal pressure application, shear force application, high-speed photography DIC, re-shearing, data acquisition and analysis.

[0062] (1) Sample preparation: select a rock sample structural plane rock block at an engineering site, cut the rock block into a parallelepiped sample, select a suitable high-strength screw rod 42 and an adjusting plate 41 according to the experimental requirements, assemble the sample 49, the high-strength screw rod 42, the adjusting plate 41, a pressure plate 40 and a high-strength screw cap 43 into a pressure box device with the sample.

[0063] (2) Water and gas oil injection: place the pressure box device with the sample 49 into a detachable autoclave 2, fill water, gas and oil in a certain proportion, simulate the corresponding real geological conditions, and externally connect the water filling pump, air compressor and oil injection machine with metering devices.

[0064] (3) Heating: use a heater 6 to heat the sample 49 in the autoclave 2, start the heater 6 through the computer controller 32, the temperature sensor 7 feeds back the temperature of the mixture in the autoclave 2, and the computer controller 32 controls the heating rate of the heater 6 to reach the set temperature.

[0065] (4) Apply normal force: After the upper electromagnetic induction system 9 is powered on, the upper magnetic loading end 10 applies normal pressure to the upper disc rock block 29 on the rock sample structure surface from top to bottom through the lubricating layer I 12 in the upper loading channel 11; after the lower electromagnetic induction system 14 is powered on, the lower magnetic loading end 15 applies shear normal pressure to the lower disc rock block 30 on the rock sample structure surface from bottom to top through the lubricating layer II 17 in the lower loading channel 16. The size of the normal force is controlled by the computer controller 32, and the upper and lower loading ends simultaneously apply force to a certain value, and then transmit it to the rock sample 49.

[0066] (5) Apply shear force: After the left electromagnetic induction system 19 is powered on, the left magnetic loading end 20 applies shear force to the upper disc rock block 29 on the rock sample structure surface from left to right through the lubricating layer III 22 in the left loading channel 21; after the right electromagnetic induction system 24 is powered on, the right magnetic loading end 25 applies shear force to the lower disc rock block 30 on the rock sample structure surface from right to left through the lubricating layer IV 27 in the right loading channel 26. Through the computer controller 32, the movement direction and speed of the magnetic loading end can be realized, and rapid reciprocating motion can be realized.

[0067] (6) High-speed photography DIC: According to the position of the rock sample structure surface 31, the position of the movable CCD high-speed camera 44 is adjusted by the high-speed photography DIC control device 45, and the light supplementing device 46 is turned on to supplement the light source. High-speed photography DIC real-time monitors the structure surface damage process, finds the key frame image of damage through the high-speed photography DIC control device 45, and performs post-image processing.

[0068] (7) Re-shearing: After one shearing experiment, the Figure 7 mode is used with a pad, and after being fixed with a pressure box, re-shearing is performed.

[0069] (8) Data acquisition and analysis: the normal force and shear force of the upper and lower rock blocks of the rock sample structure surface are collected in real time through the first pressure sensor 13, the second pressure sensor 18, the third pressure sensor 23, and the fourth pressure sensor 28; the normal shear dilation displacement of the upper and lower rock blocks of the rock sample structure surface is collected in real time through the telescopic displacement sensor I 34, the telescopic displacement sensor II 35, the telescopic displacement sensor III 36, and the telescopic displacement sensor IV 37; the temperature inside the autoclave 2 is collected in real time through the temperature sensor 7; and the pressure value inside the autoclave is collected in real time through the internal pressure sensor 8. When the temperature value fed back by the temperature sensor 7 is less than 60% of the program preset temperature value, the computer controller 32 instructs the heater 6 to heat at a rated power until the temperature value fed back by the temperature sensor 7 is equal to 60% of the program preset temperature value; the computer controller 32 instructs the heater 6 to heat at 30% of the rated power until the temperature value fed back by the temperature sensor 7 is equal to 80% of the program preset temperature value; the computer controller 32 instructs the heater 6 to heat at 10% of the rated power until the temperature value fed back by the temperature sensor 7 is equal to 90% of the program preset temperature value; the computer controller 32 instructs the heater 6 to heat at 1% of the rated power until the temperature value fed back by the temperature sensor 7 is equal to the program preset temperature value. When the pressure value inside the autoclave 2 fed back by the internal pressure sensor 8 is less than the program preset pressure value, the computer controller 32 instructs the air pressure machine to work until the pressure value inside the autoclave 2 fed back by the internal pressure sensor 8 is equal to the program preset pressure value.

[0070] The rock sample structure surface shearing method described above, the sample preparation of step (1) can be applied to rock samples of different rock sample heights, different structure surface thicknesses, and different structure surface angles.

[0071] The rock sample structure surface shearing method described above, the water, gas, and oil injection of step (2) can simulate working conditions such as shale gas, oil wells, and well holes, and different types of gas, oil, and water can be injected according to different working conditions.

[0072] The rock sample structure surface shearing method described above, the heating temperature of step (3) can be controlled at 0-250℃.

[0073] The rock sample structure surface shearing method described above, the normal force of step (4) can be controlled by the control system to change the magnetic pole direction of the electromagnetic induction system, and the upper and lower magnetic loading ends can be moved up and down to realize high-frequency vibration normal force loading and unloading, simulate the loading working condition in the upward and downward directions of the earthquake, and realize the instantaneous change of the shear dilation displacement of the upper and lower rock blocks of the rock sample structure surface.

[0074] The step (5) of applying shear force can change the magnetic pole direction by controlling the system to control the electromagnetic induction system, and the left and right magnetic loading ends make reciprocating motion, so that the high-frequency horizontal shear force can be loaded and unloaded, the loading working condition of the horizontal direction stress under the earthquake can be simulated, and the loading shear displacement rate of the upper and lower disc rock blocks of the rock sample structure surface can be changed instantaneously.

[0075] The step (6) of high-speed photography DIC can monitor the damage process of the structure surface in real time, and the DIC control equipment can extract the damage key frame image.

[0076] The step (7) of the shear pad block can be made according to the experimental requirements to meet the assembly requirements of the adjustable pressure box device.

[0077] The step (8) of the telescopic displacement sensor is installed on the counterforce frame 1, and the telescopic displacement sensor can be stretched and retracted through the computer controller 32 when needed, so that the displacement data can be collected.

[0078] The mixing ratio of the rock-like material is: quartz sand: barite powder: early strength cement: high-strength gypsum powder: Fe3O4 powder: water = 10: 5: 16: 4: 5: 10 (mass ratio).

Claims

1. A device for multiple saturation shearing of rock under electromagnetic pulse loading, characterized in that: The system includes a frame system, a pressure box system, an electromagnetic loading system, a sealing system, a high-speed photography DIC system, and a data acquisition system. The sealing system is located inside the frame system, and the pressure box system is located within the sealing system. The electromagnetic loading system includes four electromagnetic loading modules positioned between the frame system and the pressure box system, with each module connected to a control device. The electromagnetic loading modules are distributed at the inner top, inner bottom, and inner sides of the frame system. The modules at the inner top and inner bottom are arranged opposite each other, while the modules on the inner sides are arranged alternately. Each electromagnetic loading module contains a magnetically charged fixing component and a movable component. The movable parts can reciprocate relative to the pressure box system, and the magnetic pole direction inside the fixed parts can be continuously changed; the pressure box system includes a fixed layer for wrapping the top, bottom and sides of the rock sample (49) containing magnetic materials, with a break on both sides of the fixed layer and the position of the break is adjustable, and the fixed layer is magnetic; the sealing system is connected to the input pipes of oil, water and gas and the heater; one side of the outer wall of the sealing system is transparent, and the electromagnetic loading modules on both sides of the frame system are located on both sides of the transparent outer wall, and the high-speed photography DIC system is distributed on the outer wall; the sensors in the data acquisition system are arranged on the fixed layer and the signals are connected to the external computer controller; The frame system includes a reaction frame (1) and loading channels fixed inside the reaction frame (1) for sliding installation of the electromagnetic loading module. The sealing system is fixedly supported by the loading channels. The fixed part and the movable part of the electromagnetic loading module are respectively an electromagnetic induction system and a magnetic loading end. One end of the magnetic loading end is slidably disposed in the loading channel, and the other end is connected to the fixed layer. The electromagnetic induction system is disposed on the outer wall of the frame system and connected to one end of the loading channel. A lubricating layer is disposed on the inner wall of the loading channel. The magnetic loading end is T-shaped, with the vertical section of the magnetic loading end connected to the fixed layer and the two horizontal sections connected to the lubricating layer. The fixed layer includes a pressure plate (40) and an adjustment plate (41) vertically fixed to the end of the pressure plate (40). The pressure plate (40) is arranged at the top and bottom of the rock sample (49), and the adjustment plate (41) is distributed at both ends of the opposite walls of the two pressure plates (40). The adjustment plates (41) are stacked.

2. The electromagnetic pulse-loaded rock multiple saturation shearing device as described in claim 1, characterized in that: The end of the pressure plate (40) is vertically fixed with a high-strength screw (42) for connecting the adjustment plate (41) in series. Both ends of the high-strength screw (42) are threadedly connected with high-strength nuts (43). The adjustment plate (41) is locked onto the high-strength screw (42) by the high-strength nuts (43).

3. The electromagnetic pulse-loaded rock multiple saturation shearing device as described in claim 2, characterized in that: The magnetic loading end is connected in parallel with a multi-end loading head via a connecting device, and the multi-end loading head corresponds one-to-one with the stacked adjustment plate (41).

4. The electromagnetic pulse-loaded rock multiple saturation shearing device as described in claim 3, characterized in that: The sealing system includes a high pressure vessel (2), with an oil injection pipe (3) and a water injection pipe (4) connected to the top of the high pressure vessel (2), an air injection pipe (5) connected to the side wall of the high pressure vessel (2), a heater (6) at the bottom of the high pressure vessel (2), and one side wall of the high pressure vessel (2) being transparent and visible.

5. The electromagnetic pulse-loaded rock multiple saturation shearing device as described in claim 4, characterized in that: The data acquisition system includes a computer controller (32) and a pressure sensor, a retractable displacement sensor, a temperature sensor (7), and an internal pressure sensor (8) connected to it. The pressure sensor is located at the connection end between the electromagnetic loading module and the fixed layer. The retractable displacement sensor is located between the sealing system and the fixed layer. The retractable displacement sensor corresponds to the electromagnetic loading module one by one and is arranged in parallel. The temperature sensor (7) and the internal pressure sensor (8) are both located at the bottom of the sealing system.

6. The electromagnetic pulse-loaded rock multiple saturation shearing device as described in claim 5, characterized in that: The high-speed photography DIC system includes a movable CCD high-speed camera (44), a control device (45), and a lighting device (46). The movable CCD high-speed camera (44) and the lighting device (46) are movably mounted on the frame system and located at the transparent side wall of the sealed system. The movable CCD high-speed camera (44) and the lighting device (46) are connected to the control device (45).

7. The shearing method of a rock multiple saturation shearing device with electromagnetic pulse loading as described in claim 6, characterized in that... Includes the following steps: S1. Sample preparation: Prepare a rock sample (49) containing magnetic material. Select a suitable high-strength screw (42) and adjusting plate (41) according to the test requirements. Assemble the sample with the high-strength screw (42), adjusting plate (41), pressure plate (40) and high-strength nut (43) to form a pressure box system with the sample. S1.

1. Rock samples with different heights, thicknesses of structural surfaces, and angles of structural surfaces can be used for sample preparation; the mixing ratio of rock samples containing magnetic materials is: quartz sand: barite powder: early strength cement: high strength gypsum powder: Fe3O4 powder: water = 10:5:16:4:5:10 (mass percentage); S2, Water, Gas and Oil Injection: The pressure box system with the sample is placed into the detachable high pressure vessel (2), and water, gas and oil can be filled in a certain proportion to simulate the corresponding real geological conditions; the water, gas and oil pipelines are connected to a water pump, air compressor and oil injector with metering equipment. S2.1 Water-gas-oil injection can be used to simulate working conditions including shale gas, oil wells and wellbores, and can inject different types of gas, oil and water according to different working conditions; S3, Heating: The heater (6) is controlled by the computer controller (32) to heat the inside of the pressure vessel (2), and the temperature sensor (7) provides feedback on the temperature of the mixture inside the pressure vessel (2) to control the heating rate so that it reaches the set temperature; S3.1 The heating temperature can be controlled between 0-250℃; S4. Applying normal force: The top electromagnetic induction system is energized, and the top magnetic loading end applies normal pressure to the hanging wall rock block of the rock sample structure from top to bottom through the lubrication layer in its loading channel; the bottom electromagnetic induction system is energized, and the bottom magnetic loading end applies normal pressure to the hanging wall rock block of the rock sample structure from bottom to top through the lubrication layer in its loading channel. The magnitude of the normal pressure is controlled by the control device. The top magnetic loading end and the bottom magnetic loading end apply force to a certain value at the same time, and then transfer it to the rock sample. S4.1 Applying normal force can change the direction of the magnetic poles by controlling the electromagnetic induction system through the control device. The top and bottom magnetic loading ends make reciprocating motion to realize the loading and unloading of high-frequency vibration normal force, simulating the stress loading condition in the vertical direction of an earthquake, and the instantaneous changes of shear dilatation displacement of the rock blocks on the rock sample structure surface and the hanging wall. S5. Applying shear force: After the electromagnetic induction system on the left is energized, the magnetic loading end on the left applies shear force to the rock block on the surface of the rock sample from left to right through the lubrication layer in its loading channel. After the electromagnetic induction system on the right is energized, the magnetic loading end on the right applies shear force to the rock block on the lower surface of the rock sample from right to left through the lubrication layer in its loading channel. By controlling the electromagnetic induction system through the control device, the direction of movement and running speed of the magnetic loading end can be realized, and rapid reciprocating motion can be achieved. S5.

1. Applying shear force can be achieved by controlling the electromagnetic induction system to change the direction of the magnetic poles through the control device, and the left and right magnetic loading ends can perform anti-movement to realize the loading and unloading of high-frequency horizontal shear force, simulating the horizontal force loading condition of an earthquake, and the instantaneous change of the loading shear displacement rate of the rock block on the upper and lower sides of the rock sample structure. S6, High-speed photography DIC: Based on the location of the sample structure surface, the position of the movable CCD high-speed camera (44) is adjusted by the control device (45) and the supplementary lighting device (46) is turned on to supplement the light source. The high-speed photography DIC system monitors the structural surface damage process in real time, finds the damage key frame image by the control device (45), and performs post-image processing. S6.1 The high-speed photography DIC system can monitor the structural surface failure process in real time and extract key frame images of the failure through control equipment; S7. Second shear: After this shear test, the sample is padded with a pad, fixed with a fixing layer, and then sheared again. S7.1 The shearing pad can be manufactured according to the test requirements to meet the assembly requirements of the adjustable pressure box system; S8. Data Acquisition and Analysis: The normal force and shear force of the upper and lower rock blocks on the sample structure surface are collected in real time by the internal pressure sensor. The normal shear displacement of the upper and lower rock blocks on the sample structure surface is collected in real time by the retractable displacement sensor. The temperature inside the autoclave (2) is collected by the temperature sensor (7). The pressure inside the autoclave (2) is collected by the internal pressure sensor (8). When the temperature value fed back by the temperature sensor is less than 60% of the preset temperature value, the controller of the heater (6) controls the heater (6) to heat at the rated power until the temperature value fed back by the temperature sensor (7) is equal to 60% of the preset temperature value. Then the computer controller (32) controls the heater (6) to heat at 30% of the rated power. When the temperature value fed back by the temperature sensor (7) is equal to 80% of the preset temperature value, the computer controller (32) controls the heater (6) to heat at 10% of the rated power. When the temperature value fed back by the temperature sensor (7) is equal to 90% of the preset temperature value, the computer controller (32) controls the heater (6) to heat at 1% of the rated power. When the temperature value fed back by the temperature sensor (7) is equal to the preset temperature value, the computer controller (32) starts the air compressor to work until the pressure value fed back by the internal pressure sensor (8) is equal to the preset pressure value. S8.1 The retractable displacement sensor is installed on the reaction frame (1). When needed, it can be extended or retracted by control to collect displacement data.

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