Integrated device for preparing dynamic resilient modulus soil samples and performing wet-dry cycles and its usage method

Abstract

The present invention discloses an integrated device and method for preparing dynamic resilient modulus soil samples and performing wet-dry cycles. The device includes an enclosed box body, in which multiple sample preparation molds made of metal are installed. The sample preparation molds are installed on a lower compaction plate made of permanent magnets. Above the sample preparation molds, there is an adjustable-position spray head, which is connected to an atomization device through a telescopic pipe. A magnetizer is installed on the water inlet pipe of the atomization device; a coil is sleeved on the outer side wall of the sample preparation mold, and the coil is connected to an electromagnetic heater; corresponding signals are collected through a temperature sensor, a mass sensor, and a meter, and then the drying temperature, wetting time, and number of wet-dry cycles of the sample are controlled through corresponding controllers. The present invention reduces human disturbance, can directly obtain the required wet-dry cycle samples, the samples are uniformly compacted, the compaction degree is controllable, can effectively improve the efficiency and effect of wet-dry cycles, and improve the accuracy of test results.

Description

Technical Field

[0001] The present invention belongs to the technical field of geotechnical tests, and relates to a device for preparing dynamic resilient modulus soil samples and integrated wet-dry cycling, as well as a usage method thereof. The device can realize the compaction and shaping of sample preparation and integrated wet-dry cycling. Background Art

[0002] Geotechnical tests are the main methods for studying the basic performance indexes of soil masses. At present, the processes of sample preparation, sample drying, and sample humidification are all independent, and there is no supporting wet-dry cycling device for some of the samples required for tests. In addition, the following defects also exist in the test process:

[0003] 1. Traditional humidification usually adopts methods such as soaking humidification or dripping humidification, which have problems such as poor control of humidification degree, low humidification efficiency, large disturbance to the sample, and particle shedding of the sample.

[0004] 2. Traditional drying methods mostly adopt resistance oven heating for drying, which has high energy consumption, low efficiency, and is not easy to control the drying degree.

[0005] 3. Traditional wet-dry cycling instruments are mainly manually operated, with low automation. And the wet-dry cycling test takes a long time. The processes of humidification and drying must be watched by a special person, with a large labor volume, low efficiency, high cost, and manual operation has a great interference to the test, resulting in large errors in the test results.

[0006] The existing equipment for soil sample preparation, humidification, and drying has a single function. The equipment usually has no external interface and can often only perform a certain job. The previous improvements were just simple assembly of each equipment, without reflecting the advantages of integration. The various functions of the equipment cannot operate coordinately, and there is not much improvement in terms of functionality, etc., making it difficult to meet the actual needs. Summary of the Invention

[0007] In order to solve the above problems, the present invention provides a device for preparing dynamic resilient modulus soil samples and integrated wet-dry cycling, which reduces human disturbance, can directly obtain the required wet-dry cycling samples, the samples are evenly compacted, the compaction degree is controllable, can effectively improve the efficiency and effect of wet-dry cycling, and improve the accuracy of test results.

[0008] Another object of the present invention is to provide a usage method of the device for preparing dynamic resilient modulus soil samples and integrated wet-dry cycling.

[0009] The technical solution adopted by the present invention is that a device for preparing dynamic resilient modulus soil samples and integrated wet-dry cycling includes:

[0010] Sample preparation and wet-dry cycling system, the sample preparation and wet-dry cycling system includes a closed box body, inside which there are installed multiple sample preparation molds made of metal. The sample preparation molds are installed on a lower compaction plate made of permanent magnet. The bottom of the lower compaction plate is connected to the telescopic end of a jack. A dial indicator is installed between the compaction device at the top of the sample preparation mold and the top of the box body; Above the sample preparation mold, there is an adjustable-position nozzle installed. The nozzle is connected to an atomization device through a telescopic pipe, and a magnetizer is installed on the water inlet pipe of the atomization device; A coil is sleeved on the outer side wall of the sample preparation mold, and the coil is connected to an electromagnetic heater;

[0011] Digital control system, which is used to collect corresponding signals through a temperature sensor, a mass sensor, and a meter, and then control the drying temperature, wetting time, and wet-dry cycling times of the sample through corresponding controllers.

[0012] Further, the temperature sensor is installed on the sample preparation mold. The temperature sensor is connected to a temperature controller through a signal transmission line, and the temperature controller is connected to the electromagnetic heater through a signal transmission line to control the temperature of the sample preparation mold in real time, so as to adjust the drying temperature of the sample;

[0013] The mass sensor is installed between the base of the jack and the bottom of the box body, and is used to monitor the mass change of the sample during wetting and drying; The mass sensor is connected to a mass controller through a signal transmission line, and the mass controller is connected to the electromagnetic heater and the atomization device, and then controls whether to humidify the sample; The meter is installed at the nozzle;

[0014] The controller in the digital control system further includes a time controller. The time controller is connected to the temperature controller and the mass controller at the same time, and is used to control the standing time of the sample after drying and wetting and the wet-dry cycling times.

[0015] Further, the coil is spaced 10 - 15 mm from the sample preparation mold.

[0016] Further, a fixed bracket is installed on the lower compaction plate for fixing the sample preparation mold.

[0017] Further, the dial indicator is fixed to the top of the box body. A compaction table is installed at the bottom of the dial indicator. An upper compaction plate is placed on the top of the sample preparation mold, and the top of the upper compaction plate is in contact with the compaction table.

[0018] Further, a horizontal iron frame is provided above the sample preparation mold. The iron frame can move up and down, and the plane where the iron frame moves does not intersect with the plane where the compaction plate and the compaction table are located. A telescopic tube is installed on the iron frame. One end of the telescopic tube is equipped with a nozzle, and the other end of the telescopic tube is connected to an atomization device. The atomization device is connected to the water inlet through a pipeline, and a magnetizer and a first valve are installed on the pipeline. A piston is installed inside the atomization device. The piston is hermetically connected to the sliding wall inside the atomization device. One side of the piston away from the telescopic tube is connected to the telescopic rod of a pneumatic top. A light spring is provided on the other side of the piston. The pneumatic top is connected to a gas cylinder through a pipeline, and a high-pressure processor and a second valve are installed on the pipeline. The high-pressure processor pressurizes the water inside the atomization device to form atomized water.

[0019] Further, the high-pressure processor and the second valve are respectively connected to a quality controller. The quality controller controls the working states of the high-pressure processor and the second valve, and through the information feedback of a quality sensor and a flowmeter, it can control the water content of the sample in real time.

[0020] A method for using an integrated device for preparing dynamic resilient modulus soil samples and performing wet-dry cycles includes the following steps:

[0021] S1: Install the sample preparation mold on the lower compaction plate;

[0022] S2: Screw the compaction table into the bottom end of the circular bracket of the dial gauge. Confirm that the reading of the dial gauge is zero. Add the pre-weighed soil sample along the inner wall of the sample preparation mold into the sample preparation mold. An upper compaction plate is placed on the top of the soil sample. Control the jack to lift the sample preparation mold upward so that the soil sample is compacted under the reaction force. Compact it layer by layer, and keep the reading change of the dial gauge consistent for each layer of compaction. After each layer of compaction, use a soil scraper to scrape and polish to obtain the sample.

[0023] S3: After the sample preparation is completed, relieve the pressure of the jack, remove the upper compaction plate, place a permeable stone on the sample, align the nozzle with the top of the sample, and the time controller controls the wetting, drying time and the number of cycles of the sample; the temperature controller controls the working state of the electromagnetic heater, and the electromagnetic heater controls the working state of the coil; the quality controller controls the working state of the atomization equipment, and through the information feedback of the quality sensor and the flowmeter, it can control the water content of the sample in real time, forming coordinated work of each component and automatically controlling the wet-dry cycle process of the sample.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. The present invention integrates sample preparation and wet-dry cycles in one device, shortening the sample preparation time and realizing the integration of compaction and shaping of sample preparation and wet-dry cycles; through the dial gauge, the compaction deformation of the soil sample can be accurately controlled, and the digital control system can accurately control the wet-dry cycles of the sample, reducing human disturbance, and directly obtaining the required wet-dry cycle samples, reducing the time and energy required for the experimenter.

[0026] 2. The present invention uses electromagnetic heating to dry the specimen, and at the same time, a magnetic field generated by a samarium-cobalt magnet is used to accelerate the seepage of atomized magnetized water, greatly improving the efficiency and effect of the wet-dry cycle.

[0027] 3. When preparing the specimen in the present invention, the dial indicator reading and the graduated indenter are used to determine whether the compaction is qualified, which is simple and reliable. During humidification, the mass information fed back by the mass sensor is used to determine whether the humidification system works; during drying, the temperature sensor is used to control the drying temperature, and the mass sensor is used to determine whether the specimen is completely dried, and the information is transmitted to the mass controller through the signal transmission line, and the mass controller controls the operation of the electromagnetic heater. This makes the structure scientific and reasonable, the systems work in coordination with each other, and the degree of automation is high, optimizing the specimen preparation and wet-dry cycle process to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 is the overall structure schematic diagram of the embodiment of the present invention.

[0030] Figure 2 is the structure schematic diagram of the specimen preparation device in the embodiment of the present invention.

[0031] Figure 3 is the structure schematic diagram of the fixed bracket in the embodiment of the present invention.

[0032] Figure 4 is the structure schematic diagram of the specimen and weighing system in the embodiment of the present invention.

[0033] Figure 5 is the structure schematic diagram of the graduated compaction plate and indenter in the embodiment of the present invention.

[0034] Figure 6 is the magnetic field distribution diagram of the lower compaction plate made of samarium-cobalt magnet and magnetized water.

[0035] In the figure, 1. Ring-shaped bracket, 2. Micrometer, 3. Compaction table, 4. Upper compaction disc (including indenter with scale), 5. Temperature sensor, 6. Specimen preparation mold, 7. Coil, 8. Tightening screw, 9. Fixed bracket, 10. Lower compaction disc, 11. Jack, 12. Foot support, 13. Mass sensor, 14. Specimen, 15. PPS plastic pipe, 16. High-pressure gas processor, 17. Gas cylinder, 18. Base, 19. Electromagnetic heater, 20. Piston, 21. Second valve, 22. Pneumatic top, 23. Lightweight spring, 24. Flowmeter, 25. Telescopic tube, 26. Iron frame, 27. Magnetizer, 28. Working chamber, 29. Box body, 30. Time controller, 31. Temperature controller, 32. Mass controller, 33. Power switch. Detailed implementation mode

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0037] Embodiment 1

[0038] A device for preparing dynamic resilient modulus soil samples and integrating wet and dry cycles, as Figure 1 shown, includes a specimen preparation and wet-dry cycle system and a digital control system.

[0039] The specimen preparation and wet-dry cycle system includes a closed box body 29, and a plurality of specimen preparation molds 6 are installed in the box body 29. As Figures 2 - 4 shown, the bottom of the specimen preparation mold 6 is placed on the lower compaction disc 10, and a fixed bracket 9 is installed on the lower compaction disc 10 for fixing the specimen preparation mold 6; the bottom of the lower compaction disc 10 is connected to the telescopic end of the jack 11, and a mass sensor 13 is provided at the bottom of the base of the jack 11, and the mass sensor 13 is installed at the bottom of the box body 29; a micrometer 2 is installed directly above the specimen preparation mold 6, the micrometer 2 is fixed to the top of the box body 29, and a compaction table 3 is installed at the bottom of the micrometer 2, and an upper compaction disc 4 is placed on the top of the specimen preparation mold 6, and the top of the upper compaction disc 4 is in contact with the compaction table 3.

[0040] A coil 7 is sleeved on the outer side wall of the specimen preparation mold 6, and the coil 7 is spaced 15 mm from the specimen preparation mold 6. The coil 7 is connected to an electromagnetic heater 19 for heating the soil sample. The electromagnetic heater 19 is connected to the temperature controller 31 through a signal transmission line. The coil 7 is made of copper with a cross-sectional area of 25 mm 2 and is matched with an 8 kw electromagnetic heater 19, and the maximum heating temperature exceeds 300 °C.

[0041] Above the sample preparation mold 6, there is a horizontal iron frame 26 which can move up and down. An extensible tube 25 is installed on the iron frame 26, and a nozzle is installed at one end of the extensible tube 25. When the iron frame 26 moves to a suitable height, it is only necessary to adjust the extensible hose 25 above the sample 14. The plane where the iron frame 26 moves will not intersect with the plane where the compaction plate 4 and the compaction table 3 are located, avoiding mutual interference. The other end of the extensible tube 25 is connected to an atomizing device, and the atomizing device is connected to the water inlet 28 through a pipeline. A magnetizer 27 and a first valve are installed on the pipeline. A piston 20 is installed inside the atomizing device. The piston 20 is hermetically connected to the sliding wall inside the atomizing device. The telescopic rod of a pneumatic jack 22 is connected to the side of the piston 20 away from the extensible tube 25. A light spring 23 is provided on the other side of the piston 20. The pneumatic jack 22 is connected to a gas cylinder 17 through a pipeline (PPS plastic pipe 15). A high-pressure processor 16 and a second valve 21 are installed on the pipeline.

[0042] The injected water is magnetized by the magnetizer 27 and has magnetism. The paper "Pang X F, Deng B. The changes of macroscopic features and microscopic structures of water under influence of magnetic field. Physica B: Physics of Condensed Matter, 2008, 403(19)" points out that after the water added with nano-Fe3O4 is magnetized, its X-ray diffraction spectrum shifts towards a higher angle compared with that before magnetization, indicating that there is a magnetic interaction between nano-Fe3O4 and magnetized water, that is, it proves that magnetized water has certain magnetism. When the sample preparation is completed, remove the upper compaction plate 4, adjust the extensible tube 25 above the sample 14 by moving the iron frame 26. Then, turn on the gas cylinder 17, the high-pressure processor 16, and the second valve 21 in sequence. Use the pneumatic jack 22 to push the piston 20 to pressurize the magnetized water, so that the magnetized water is atomized. After opening the valve, the atomized water is sprayed out from the nozzle of the extensible tube 25 to humidify the sample 14. The flowmeter 24 can control the water injection volume of the nozzle. At the same time, under the magnetic force of the lower compaction plate 10 made of samarium-cobalt magnet, the water seepage is effectively accelerated, and the humidification process is completed faster.

[0043] The digital control system includes a time controller 30, a temperature controller 31, and a quality controller 32. The power switch 33 is connected to the time controller 30. The time controller 30 is simultaneously connected to the temperature controller 31 and the quality controller 32. The temperature controller 31 is respectively connected to the temperature sensor 5 and the electromagnetic heater 19. The quality controller 32 is respectively connected to the quality sensor 13, the high-pressure processor 16, the electromagnetic heater 19, etc. The high-pressure processor 16 pressurizes the water in the atomization device to form atomized water. The quality controller 32 determines whether the specimen 14 is humidified by monitoring the quality of the specimen 14. If the specimen 14 is humidified, the quality controller 32 controls the high-pressure processor 16 to stop working and no longer pressurize the atomization device.

[0044] The temperature sensor 5 is arranged on the upper side of the sample preparation mold 6 and is connected to the temperature controller 31 through a signal transmission line. The temperature controller 31 is integrated by a data processor, a display, and a control panel, and is used to collect and process the data of the temperature sensor 5. At the same time, the temperature controller 31 is connected to the electromagnetic heater 19 through a signal transmission line, and then controls the coil 7 to control the temperature state of the sample preparation mold 6 in real time, so as to adjust the drying temperature of the specimen 14. The temperature sensor 5 is a platinum resistance temperature sensor with a maximum range of 800 °C and an accuracy of ±1 °C.

[0045] The quality controller 32, the high-pressure processor 16, and the quality sensor 13 form a moisture content detection system. The quality sensor 13 is connected to the quality controller 32 through a signal transmission line. The quality controller 32 is integrated by a data processor, a display, and a control panel, collects and processes the data of the quality sensor 13, and can display and monitor the moisture content information of the specimen in real time, and control the opening and closing state of the second valve 21, so as to control whether to humidify the specimen 14.

[0046] The quality sensor 13 is a DYHW-108 high-precision quality sensor with a range of 0-100 kg. The time controller 30 is model KG316T and is used to control the static time of the specimen 14 after drying and humidification and the number of dry-wet cycles. The temperature controller 31 is model XYWK-1 and is used to control the drying temperature of the specimen 14. The electromagnetic heater 19 is model L02-110-65 and is used to control the operation of the electromagnetic heater 19. The quality controller 32 is model HZC-H1 and is used to monitor the quality change of the specimen 14 during humidification and drying. The high-pressure processor 16 is model VBA40A and can pressurize the gas in the gas cylinder 17 to generate atomized water.

[0047] The sample preparation mold 6 is made of heat-resistant steel, with high heat resistance and strength, capable of withstanding the high temperature during drying and the pressure during sample preparation. The external material of the box body 29 is ordinary stainless steel plate, and the working chamber 28 (the space inside the whole device) is made of hot-dip galvanized steel plate. A double-door is provided on the front of the box body 29, and four foot supports 12 are provided at the bottom of the base 18.

[0048] Example 2,

[0049] The usage method of the integrated device for preparing dynamic resilient modulus soil samples and wet-dry cycling and its usage method are specifically carried out according to the following steps:

[0050] S1: Place the sample preparation mold 6 on the lower compaction plate 10, and adjust the distance between the two fixed brackets 9 through the tightening and loosening screws 8 to fix the sample preparation mold 6;

[0051] S2: Thread the compaction table 3 into the bottom end of the annular bracket 1, confirm that the reading of the dial gauge 2 is zero, slowly add the pre-weighed soil sample along the inner wall of the sample preparation mold 6 into the sample preparation mold 6, and mobilize the sample preparation jack 11 to compact the soil sample under the reaction force of the compaction table 3. Add and compact in five layers, and determine the penetration depth each time according to the scale on the ram head. As Figure 5 shown, keep the reading change of the dial gauge 2 consistent for each layer of compaction, so that the compaction degree of each layer of soil sample is consistent. After each layer of compaction, use a soil scraper to scrape and polish to improve the uniformity of the compaction of the specimen 14.

[0052] S3: After the specimen 14 is prepared, adjust the jack 11 to relieve pressure, remove the upper compaction plate 4, place a permeable stone on the specimen 14, move the iron frame 26 to align the telescopic tube 25 with the top of the specimen 14, and turn on the power switch 33. The power switch 33 overall controls the power supply status of the time controller 30, temperature controller 31, mass controller 32, and high-pressure gas processor 16. The time controller 30 controls the wetting, drying time, and number of cycles of the specimen 14; the temperature controller 31 controls the working status of the electromagnetic heater 19, and the electromagnetic heater 19 controls the working status of the coil 7; the mass controller 32 controls the working status of the high-pressure gas processor 16, the second valve 21, etc., and through the information feedback of the mass sensor 13 and the flowmeter 24, the water content of the specimen 14 is controlled in real time, forming the coordinated work of each component and automatically controlling the wet-dry cycling process of the specimen 14.

[0053] Input the humidification standing time, drying standing time, and number of cycles into the time controller 30, set the maximum drying temperature in the temperature controller 31, and input parameters such as the initial state of the specimen 14, the total mass of the jack 11, sample preparation mold 6, upper compaction plate 4, etc., and the predetermined humidification mass into the mass controller 32.

[0054] After setting the corresponding data on the time controller 30, temperature controller 31, and mass controller 32, the wet-dry cycling device starts to work. First, water is injected into the water tank from the water injection port 28 through the magnetizer 27. The gas cylinder 17 is opened, the high-pressure gas processor 16 and the second valve 21 are turned on, so that the air pressure top 22 pushes the piston 20 to pressurize the magnetized water. The water injection valve is opened, and the magnetized high-pressure water is sprayed atomized through the nozzle of the telescopic tube 25. Under the magnetic force of the lower compaction plate 10 made of samarium-cobalt magnet at the bottom, the atomized magnetized water seeps in the test piece 14 at a certain speed. The mass sensor 13 monitors the weight of the test piece 14 in real time. When the total weight of the test piece 14 reaches the set value, the mass controller 32 issues commands to close the water injection valve, close the gas cylinder 17, etc., and stop humidification.

[0055] After the water injection valve is closed, the test piece 14 is left stationary for a period of time to allow it to fully absorb the water. The time controller 30 calculates the standing time after humidification. The humidification process of the test uses the natural water absorption method, which can restore the wet-dry cycling process of soil in actual engineering to the greatest extent.

[0056] When the set standing time is reached, the time controller 30 issues a heating command to the temperature controller 31, and the electromagnetic heater 19 starts to work. The temperature sensor 5 monitors the temperature of the test piece mold 6 in real time, and feeds the temperature information back to the temperature controller 31 for processing and display. The temperature controller 31 dynamically adjusts the working state of the electromagnetic heater 19 according to the difference between the working temperature and the real-time temperature, so as to dynamically monitor and display the temperature change of the test piece mold 6 during the wet-dry cycling process, and dynamically adjust the temperature of the test piece mold 6.

[0057] When the weight of the test piece 14 reaches the set value, the mass controller 32 issues a command to the temperature controller 31, and the electromagnetic heater 19 stops working. The test piece 14 cools naturally, and the time controller 30 starts to calculate the drying standing time. When the set standing time is reached, the time controller 30 issues a command to the mass controller 32 again, opens the water injection valve and the gas cylinder 17, etc., and then conducts the next cycle test until the entire cycle test ends. During the entire wet-dry cycling process, the mass controller 32 dynamically monitors the water content change of the test piece 14, and displays and processes and utilizes the moisture content information in real time, realizing the wet-dry cycling working state automatically controlled by the water content change state of the test piece 14.

[0058] The present invention globally adjusts the wetting and drying cycling state and the number of cycles of the test piece 14 during the test process through the time controller 30, dynamically adjusts the thermal system in combination with the temperature controller 31, and dynamically adjusts the water content of the test piece 14 by the mass controller 32, realizing the automatic control of the wet-dry cycling process of the test piece 14. At the same time, the test piece 14 is made and the wet-dry cycling process are carried out in one device. Most of the procedures in the whole process are automatically controlled by the machine, which largely reduces the interference to the test piece 14 and improves the test efficiency and accuracy.

[0059] The embodiments of the present invention include functions such as sample preparation, drying, and humidification. In the traditional sample preparation, drying, and humidification processes, they are carried out in multiple devices. Inevitably, the samples need to be transported, resulting in problems such as the loss of sample particles. The integration is difficult, and it is hard to coordinate and cooperate different functional devices with each other. In addition, the traditional drying and humidification methods have problems such as low efficiency, large disturbance to the samples, and high labor costs. For carbonaceous mudstone samples, when performing 6 wet-dry cycles, if the methods of soaking in water for humidification and drying in an oven are used, it is necessary for the test personnel to regularly weigh the mass of the samples to determine whether the samples are dried or humidified, which is time-consuming and laborious. 12 times of transportation and operations such as soaking in the water tank result in the damage of the sample structure, and about 15% of the soil particles are lost on average. Even if great attention is paid during the operation, there will still be about 10% of the particles lost. Such samples can no longer obtain accurate test results.

[0060] The embodiments of the present invention use the method of electromagnetic heating to dry the samples, and at the same time utilize the magnetic field to accelerate the seepage of water, greatly improving the efficiency of the wet-dry cycle. The wet-dry cycle state of the samples is monitored in real time through sensors, controllers, etc., and it is decided whether to dry or humidify the samples, so that the samples do not need to be moved during the whole process from preparation to the completion of the wet-dry cycle, ensuring the effect of the wet-dry cycle to the greatest extent.

[0061] As Figure 6 shown, the material of the lower compaction plate 10 is samarium-cobalt magnet, which can generate a magnetic field. Under the action of the magnetic field generated by the lower compaction plate 10, the magnetized water can seep more quickly and evenly inside the sample, thereby improving the efficiency and quality of sample humidification. It can greatly improve the efficiency and effect of the wet-dry cycle of the samples, and the high degree of automation can save the energy and time of the test personnel. If the magnetized water enters the magnetic field with the magnetic pole repelling the magnetic field generated by the compaction plate 10, then the lower part of the magnetized water is repelled and the upper part is attracted. Under the action of these two forces, the magnetic pole direction of the magnetized water changes until their magnetic pole directions are opposite and reach the state of mutual attraction. Therefore, there is no need to manually control the magnetic field direction of the magnetized water.

[0062] The magnetizer 27 is essentially a device capable of generating a magnetic field. When water passes through the magnetizer 27 at a certain speed, the water flow cuts the magnetic induction lines, generating electromagnetic induction and turning the water into magnetized water, which then has magnetism at this time. With the combined action of pressurized atomization and the magnetic field generated by the lower compaction plate 10 made of samarium-cobalt magnets, the magnetized water particles are smaller and are affected by the downward magnetic force, further accelerating the seepage of water. The paper "Miroslav Colic, Dwain Morse. The elusive mechanism of the magnetic'memory' of water. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1999, 154(1)." points out that various effects of magnetized water will still remain for several hours to several days after the water leaves the magnetic field, which is sufficient to complete the wetting of the specimen.

[0063] The seepage velocity formula of magnetized water in porous media:

[0064]

[0065] In the formula, C is a function related to saturation, porosity, and capillary diameter (known in this field); E is the internal energy of water; R is the molar gas constant; T is the temperature; p is the pressure; x is the water seepage direction, The meaning of is the rate of change of pressure along the water seepage direction.

[0066] It can be seen from Equation (1) that when the pressure gradient and C are constant, the seepage velocity of water is determined by the absolute value of its internal energy. If the absolute value of the internal energy of water decreases after magnetization, its seepage velocity will increase. We set the magnetic field strength to 0.2T, the internal energy of magnetized water is -8.76756 kcal·mol -1 , and the internal energy of non-magnetized water is -8.84623 kcal·mol -1 , and the temperature is 300K. Substituting these values into Equation (1), it can be seen that the seepage velocity of magnetized water is 15.14% faster than that of non-magnetized water. This is the result of the effect of magnetized water itself under the condition of no magnetic field.

[0067] If the magnetic field of the lower compaction plate 10 is added, the seepage velocity will be further accelerated. Taking a carbonaceous mudstone specimen with dimensions of 100×200 mm and a compaction degree of 96% as an example, the wetting time of the specimen under different conditions in actual tests is shown in Table 1.

[0068] Table 1 Wetting time of the specimen under different conditions

[0069] Test conditions Ordinary water Ordinary water + magnetic field Magnetized water Magnetized water + magnetic field 1 9:36 9:43 8:51 6:36 2 9:58 9:16 8:24 6:13 3 9:27 9:27 8:27 5:52 Average humidification time / h 9:40 9:29 8:34 6:14

[0070] If only considering the magnetic strength of the magnetized water generated, the higher the magnetic field strength of the magnetizer 27, the better. However, considering economic reasons and actual situations, it is best to control the magnetic field strength generated by the magnetizer 27 between 0.18T and 0.22T. Exceeding this range will not only increase the production cost but also increase the viscosity of the magnetized water, thereby reducing the seepage velocity of the water. Theoretically, the higher the magnetic field strength of the lower compaction plate 10, the better, the greater the magnetic force generated, and the faster the seepage velocity of the magnetized water. However, also considering cost issues and the personal safety of experimental personnel, etc., the magnetic field strength of the lower compaction plate 10 is controlled between 0.15T and 0.2T.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are all included in the protection scope of the present invention.

Claims

1. An integrated device for preparing dynamic resilient modulus soil samples and performing wet-dry cycles, characterized in that, Comprising: A sample preparation and wet-dry cycling system, the sample preparation and wet-dry cycling system includes a closed box body (29), and a plurality of sample preparation molds (6) made of metal are installed inside the box body (29). The sample preparation molds (6) are installed on a lower compaction plate (10) made of permanent magnet. The bottom of the lower compaction plate (10) is connected to the telescopic end of a jack (11). A dial indicator (2) is installed between the compaction device at the top of the sample preparation mold (6) and the top of the box body (29); An adjustable-position nozzle is installed above the sample preparation mold (6). The nozzle is connected to an atomization device through a telescopic tube (25), and a magnetizer (27) is installed on the water inlet pipeline of the atomization device; A coil (7) is sleeved on the outer side wall of the sample preparation mold (6), and the coil (7) is connected to an electromagnetic heater (19); A digital control system, which is used to collect corresponding signals through a temperature sensor (5), a mass sensor (13), and a flow meter (24), and then control the drying temperature, wetting time, and wet-dry cycling times of the sample through corresponding controllers; The temperature sensor (5) is installed on the sample preparation mold (6). The temperature sensor (5) is connected to a temperature controller (31) through a signal transmission line. The temperature controller (31) is connected to the electromagnetic heater (19) through a signal transmission line to control the temperature of the sample preparation mold (6) in real time, thereby adjusting the drying temperature of the sample (14); The mass sensor (13) is installed between the base of the jack (11) and the bottom of the box body (29) to monitor the mass change of the sample (14) during wetting and drying. The mass sensor (13) is connected to a mass controller (32) through a signal transmission line. The mass controller (32) is connected to the electromagnetic heater (19) and the atomization device to further control whether to humidify the sample (14); The flow meter (24) is installed at the nozzle; The controller in the digital control system further includes a time controller (30). The time controller (30) is connected to the temperature controller (31) and the mass controller (32) at the same time, and is used to control the standing time of the sample after drying and wetting and the number of wet-dry cycles; The dial indicator (2) is fixed to the top of the box body (29). A compaction table (3) is installed at the bottom of the dial indicator (2). The compaction table (3) is located at the bottom end of an annular bracket (1). An upper compaction plate (4) is placed on the top of the sample preparation mold (6), and the top of the upper compaction plate (4) is in contact with the compaction table (3); Above the sample preparation mold (6), there is a horizontal iron frame (26), which can move up and down. The plane where the iron frame (26) moves will not intersect with the plane where the upper compaction plate (4) and the compaction table (3) are located. An extensible tube (25) is installed on the iron frame (26). One end of the extensible tube (25) is installed with a nozzle, and the other end of the extensible tube (25) is connected to an atomizing device. The atomizing device is connected to a water inlet (28) through a pipeline, and a magnetizer (27) and a first valve are installed on the pipeline. A piston (20) is installed in the atomizing device. The piston (20) is hermetically connected to the sliding wall in the atomizing device. The side of the piston (20) far from the extensible tube (25) is connected to the telescopic rod of a pneumatic jack (22), and a light spring (23) is provided on the other side of the piston (20). The pneumatic jack (22) is connected to a gas cylinder (17) through a pipeline, and a high-pressure processor (16) and a second valve (21) are installed on the pipeline. The high-pressure processor (16) pressurizes the water in the atomizing device to form atomized water.

2. The integrated device for preparing dynamic resilient modulus soil samples and wet-dry cycling according to claim 1, characterized in that, The coil (7) is spaced 10 - 15 mm from the sample preparation mold (6).

3. The integrated device for preparing dynamic resilient modulus soil samples and wet-dry cycling according to claim 1, wherein A fixed bracket (9) is installed on the lower compaction plate (10) for fixing the sample preparation mold (6).

4. The integrated device for preparing dynamic resilient modulus soil samples and performing wet-dry cycles according to claim 1, wherein The high-pressure processor (16) and the second valve (21) are respectively connected to a quality controller (32). The quality controller (32) controls the working states of the high-pressure processor (16) and the second valve (21), and through the information feedback of a quality sensor (13) and a flowmeter (24), it controls the water content of the sample (14) in real time.

5. The method for using an integrated device for preparing dynamic resilient modulus soil samples and performing dry-wet cycles according to claim 1, characterized in that It includes the following steps: S1: Install the sample preparation mold (6) on the lower compaction plate (10); S2: Thread the compaction table (3) into the bottom end of the annular bracket (1) of the dial gauge (2). Confirm that the reading of the dial gauge (2) is zero. Add the pre-weighed soil sample along the inner wall of the sample preparation mold (6) into the sample preparation mold (6). An upper compaction plate (4) is placed on the top of the soil sample. Control the jack (11) to lift the sample preparation mold (6) upward, so that the soil sample is compacted under the reaction force, and it is compacted layer by layer. The reading change of the dial gauge (2) remains the same for each layer of compaction. After each layer of compaction, use a soil scraper to scrape and polish to obtain the sample (14); S3: After the sample preparation is completed, the jack (11) is depressurized, and the upper compaction plate (4) is removed. Place a permeable stone on the sample (14), align the nozzle with the top of the sample (14). The time controller (30) controls the wetting, drying time and the number of cycles of the sample (14); the temperature controller (31) controls the working state of the electromagnetic heater (19), and the electromagnetic heater (19) controls the working state of the coil (7); the quality controller (32) controls the working state of the atomizing device, and through the information feedback of the quality sensor (13) and the flowmeter (24), it controls the water content of the sample (14) in real time, forming the coordinated work of each component and automatically controlling the dry-wet cycling process of the sample.

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