Experimental device and method for directly measuring permeability characteristics of frozen soil

Abstract

The invention belongs to the technical field of frozen soil measurement, particularly relates to an experimental device and method for directly measuring permeability characteristics of frozen soil, and provides the following scheme aiming at the problem that a measurement result of an existing experimental device for directly measuring the permeability characteristics of the frozen soil is deviated from an actual situation. A high-temperature temperature control coil pipe and a low-temperature temperature control coil pipe are arranged outside the sample cylinder, a heat preservation sleeve is arranged outside the high-temperature temperature control coil pipe and the low-temperature temperature control coil pipe, a sealing cover is arranged on the upper side of the sample cylinder, a round hole is formed in the bottom of the sample cylinder, an exudation pipe is fixedly connected into the round hole, and a scraping module is arranged on the exudation pipe. A receiving barrel is arranged below the seepage pipe, and a water storage barrel is arranged above the sample barrel. According to the experimental device and method for directly measuring the permeability characteristics of the frozen soil, the state of water for permeability measurement can be controlled to a great extent, so that the situation that water permeates into the frozen soil in reality is accurately simulated, and the measurement accuracy is improved.

Description

Technical Field

[0001] The invention relates to the technical field of frozen soil measurement, and in particular to an experimental device and method for directly measuring the permeability characteristics of frozen soil. Background Art

[0002] When saturated soil freezes, there will still be some unfrozen water in the soil. The presence of unfrozen water provides a flow channel for the infiltration of frozen soil to a certain extent. In cold areas, climate change can cause water and heat migration in frozen soil, which can cause great damage to roads paved with high-grade pavement or gravel pavement and its ancillary structures, tunnels, retaining walls, sidewalks and slopes. The permeability characteristics of frozen soil are the key factors in the water and heat migration of frozen soil.

[0003] Existing experimental devices for direct measurement of permeability characteristics of frozen soil are often used in laboratory environments when measuring permeability characteristics. When conducting water infiltration, they are often unable to accurately simulate the current water status in the actual environment, resulting in deviations between the measurement results and the actual situation, affecting the accuracy of the measurement results. Summary of the invention

[0004] The invention discloses a frozen soil permeability characteristic direct measurement experimental device and method, aiming to solve the technical problem in the background technology that the measurement results of the existing frozen soil permeability characteristic direct measurement experimental device deviate from the actual situation.

[0005] The present invention provides a direct measurement experimental device for permeability characteristics of frozen soil, comprising a sample tube, a high-temperature temperature control coil and a low-temperature temperature control coil are arranged on the outside of the sample tube, a heat preservation sleeve is arranged on the outside of the high-temperature temperature control coil and the low-temperature temperature control coil, and a closing cover is arranged on the upper side of the sample tube, a round hole is opened at the bottom of the sample tube, a seepage pipe is fixedly connected in the round hole, a scraping module is arranged on the seepage pipe, a receiving bucket is arranged below the seepage pipe, a water storage cylinder is arranged above the sample tube, a constant pressure water control module is arranged on the water storage cylinder, a fine hole is opened on the outside of the water storage cylinder, a water delivery pipe is fixedly connected in the fine hole, and one end of the water delivery pipe away from the water storage cylinder is connected to the upper side of the sample tube through a flange;

[0006] The constant pressure water control module includes a plug plate, an annular air bag and a heating wire;

[0007] The scraping module includes an annular airbag and a spherical balloon.

[0008] By providing a sample cylinder, a high-temperature temperature control coil, a low-temperature temperature control coil, an insulation sleeve, a water storage cylinder, a water pipe, a constant pressure water control module, a scraping module, a seepage pipe and a receiving bucket, the device can control the state of water used for infiltration measurement to a great extent using the constant pressure water control module, thereby accurately simulating the actual situation of water infiltrating into frozen soil and improving the accuracy of the measurement.

[0009] In a preferred embodiment, the outer part of the plug plate is slidably connected to the inner wall of the water storage cylinder. Two annular grooves are equidistantly distributed on the outer part of the plug plate. Sealing rings are fixedly connected in the annular grooves. The outer parts of the sealing rings are in contact with the inner wall of the water storage cylinder. The bottom of the first annular airbag is fixedly connected to the upper side of the plug plate. An injection pipe is arranged on the first annular airbag. And the bottom of the plug plate is fixedly connected with a second annular airbag. A round opening is formed in the plug plate. An inflation pipe is arranged in the round opening. One end of the inflation pipe close to the second annular airbag is fixedly connected with the second annular airbag. A support is fixedly connected to the outer part of the heat preservation sleeve; Four convex platforms are fixedly connected to the inner wall of the water storage cylinder at equal circumferential intervals. Guide rods are slidably connected to the inner walls of the convex platforms. The bottoms of the guide rods are fixedly connected to the upper side of the plug plate. A hole groove is formed in the plug plate. A supplementary pipe is fixedly connected in the hole groove. An electronic valve II is arranged on the supplementary pipe. And the bottom of the electric heating wire is fixedly connected to the bottom inner wall of the water storage cylinder; Two symmetrical vertical frames are arranged outside the water storage cylinder. The bottoms of the two vertical frames are fixedly connected to the same bearing platform. The upper sides of the two vertical frames are fixedly connected to the same connecting plate. One side of the connecting plate far away from the water storage cylinder is fixedly connected with an adapter plate. And sliding grooves are formed in the opposite sides of the two vertical frames; The same tray is slidably connected in the two sliding grooves. The upper side of the tray is attached to the bottom of the water storage cylinder. An electronic valve I is arranged on the outer part of the water delivery pipe. A hole groove is formed in the tray. A lead screw is rotationally connected in the hole groove through an external thread. A fixed frame is movably connected to the outer part of the lead screw. And the upper side of the lead screw is movably connected to the bottom of the adapter plate; A first gear is fixedly connected to the bottom of the lead screw. A rotating shaft is movably connected to the fixed frame. A second gear is fixedly connected to the outer part of the rotating shaft. The second gear meshes with the first gear. A short shaft is fixedly connected to one side of the rotating shaft. A handle is fixedly connected to the side of the short shaft far away from the rotating shaft. And a clamping tooth ring is fixedly connected to the outer part of the short shaft. A receiving frame is fixedly connected to the side of the fixed frame close to the clamping tooth ring. Two symmetrical first springs are fixedly connected to the top inner wall of the receiving frame. One end of the first spring close to the clamping tooth ring is fixedly connected to the same fastener. The outer part of the fastener is slidably connected to the inner wall of the receiving frame. The fastener is clamped with the clamping tooth ring.

[0010] By providing a constant pressure water control module, the constant pressure water control module can use the first annular airbag and the second annular airbag to accurately control the pressure applied by the plug plate to the water storage cylinder, thereby effectively controlling the water flow rate into the specimen cylinder, so as to effectively control the air pressure in the specimen cylinder and improve the controllability of the device.

[0011] In a preferred embodiment, a splint one is arranged inside the seepage pipe. A gas guide pipe is fixedly connected to the bottom of the splint one. One end of the gas guide pipe away from the splint one is located outside the seepage pipe, and one end of the gas guide pipe away from the splint one is fixedly connected to the inner wall of the balloon. A splint two is fixedly connected to the outside of the gas guide pipe. The inner wall of the annular airbag three is fixedly connected to the outside of the gas guide pipe. The annular airbag three is located between the splint one and the splint two. A plurality of air holes are arranged on the gas guide pipe at equal circumferential intervals. The air holes are all communicated with the annular airbag three. And two symmetrical grips are fixedly connected to one end of the gas guide pipe close to the balloon. A fixing seat is slidably connected to the outside of the gas guide pipe. The fixing seat is fixedly connected to the side opposite to the seepage pipe. A positioning piece is fixedly connected to the outside of the gas guide pipe. The positioning piece is located above the fixing seat. And a second spring is fixedly connected to the bottom of the positioning piece. One end of the second spring away from the positioning piece is fixedly connected to the upper side of the fixing seat.

[0012] By providing a scraping module, the scraping module can use the balloon and the annular airbag three to enable the device to scrape the water attached to the seepage pipe into the receiving bucket, thereby avoiding the deviation between the measurement result of the measurement experiment and the actual situation, ensuring the reliability of the measurement result, and improving the accuracy of the measurement experiment result.

[0013] A direct measurement experiment method for the seepage characteristics of frozen soil uses a direct measurement experiment device for the seepage characteristics of frozen soil as described above, and includes the following steps:

[0014] Step 1: Open the closing cover, put the sample drawing into the sample cylinder, close the closing cover, open and adjust the high-temperature temperature control coil and the low-temperature temperature control coil, so that the temperature of the sample drawing in the sample cylinder is close to the actual situation. Fill the water storage cylinder with water, use the constant pressure water control module to pressurize or depressurize the water storage cylinder and control the temperature, and inject the water in the water storage cylinder into the sample cylinder through the water delivery pipe, and wait for the water to seep out;

[0015] Step 2: The seeped water flows from the seepage pipe into the receiving bucket, record the amount of water flowing into the receiving bucket per unit time, and use the scraping module to scrape out the water attached to the inner wall of the seepage pipe.

[0016] As can be seen from the above, a direct measurement experiment device for the seepage characteristics of frozen soil provided by the present invention can greatly control the state of the water used for seepage measurement, thereby accurately simulating the situation of water seeping into frozen soil in reality, and improving the accuracy of the measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the overall structure of a direct measurement experiment device for the seepage characteristics of frozen soil proposed by the present invention;

[0018] Figure 2 is a schematic cross-sectional structure diagram of a direct measurement experiment device for the seepage characteristics of frozen soil proposed by the present invention;

[0019] Figure 3 Schematic diagram of the constant-pressure water control module structure of a direct measurement experimental device for the seepage characteristics of frozen soil proposed by the present invention;

[0020] Figure 4 Schematic diagram of the fixing frame structure of a direct measurement experimental device for the seepage characteristics of frozen soil proposed by the present invention;

[0021] Figure 5 Schematic diagram of the plug plate structure of a direct measurement experimental device for the seepage characteristics of frozen soil proposed by the present invention;

[0022] Figure 6 Schematic diagram of the scraping module structure of a direct measurement experimental device for the seepage characteristics of frozen soil proposed by the present invention;

[0023] Figure 7 Schematic diagram of the air guide pipe structure of a direct measurement experimental device for the seepage characteristics of frozen soil proposed by the present invention.

[0024] In the figure: 1, sample cylinder; 2, closed cover; 3, high-temperature temperature control coil; 4, low-temperature temperature control coil; 5, heat preservation sleeve; 6, water storage cylinder; 7, water delivery pipe; 8, constant-pressure water control module; 801, bearing platform; 802, vertical frame; 803, connecting plate; 804, connecting plate; 805, sliding groove; 806, supporting plate; 807, fixing frame; 808, solenoid valve I; 809, lead screw; 810, gear I; 811, rotating shaft; 812, gear II; 813, handle; 814, clamping tooth ring; 815, accommodating frame; 816, fastener; 817, spring I; 818, plug plate; 819, annular airbag I; 820, injection pipe; 821, sealing ring; 822, annular airbag II; 823, guide rod; 824, supplementary pipe; 825, solenoid valve II; 826, inflation pipe; 827, heating wire; 9, scraping module; 901, clamping plate I; 902, fixing seat; 903, air guide pipe; 904, clamping plate II; 905, annular airbag III; 906, air hole; 907, balloon; 908, grip; 909, positioning piece; 910, spring II; 10, seepage pipe; 11, receiving bucket; 12, support. Specific embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in 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.

[0026] A direct measurement experimental device for the seepage characteristics of frozen soil disclosed by the present invention is mainly applied to scenarios where there are deviations between the measurement results of existing direct measurement experimental devices for the seepage characteristics of frozen soil and the actual situation.

[0027] Refer toFigures 1 - 7 , a direct measurement experimental device for the permeability characteristics of frozen soil, comprising a sample cylinder 1. A high-temperature temperature control coil 3 and a low-temperature temperature control coil 4 are arranged outside the sample cylinder 1. A heat insulation sleeve 5 is arranged outside the high-temperature temperature control coil 3 and the low-temperature temperature control coil 4. A closed cover 2 is arranged on the upper side of the sample cylinder 1. A round hole is opened at the bottom of the sample cylinder 1. An exudation pipe 10 is connected to the round hole by bolts. A scraping module 9 is arranged on the exudation pipe 10. A receiving bucket 11 is arranged below the exudation pipe 10. A water storage cylinder 6 is arranged above the sample cylinder 1. A constant-pressure water control module 8 is arranged on the water storage cylinder 6. Fine holes are opened outside the water storage cylinder 6. A water delivery pipe 7 is connected to the fine holes by bolts. One end of the water delivery pipe 7 far from the water storage cylinder 6 is connected to the upper side of the sample cylinder 1 by a flange;

[0028] The constant-pressure water control module 8 comprises a plug plate 818, a first annular airbag 819 and a heating wire 827;

[0029] The scraping module 9 comprises a third annular airbag 905 and a balloon 907.

[0030] Specifically, open the closed cover 2, put the sample diagram into the sample cylinder 1, close the closed cover 2, open and adjust the high-temperature temperature control coil 3 and the low-temperature temperature control coil 4, so that the temperature of the sample diagram in the sample cylinder 1 is close to the actual situation. Inject water into the water storage cylinder 6. Use the constant-pressure water control module 8 to pressurize or depressurize the water storage cylinder 6 and control the temperature. Inject the water in the water storage cylinder 6 into the sample cylinder 1 through the water delivery pipe 7. Wait for the water to seep out. The seeped water flows into the receiving bucket 11 from the exudation pipe 10. Record the amount of water flowing into the receiving bucket 11 per unit time, and use the scraping module 9 to scrape out the water attached to the inner wall of the exudation pipe 10; The device can use the constant-pressure water control module 8 to greatly control the state of the water used for permeability measurement, so as to accurately simulate the situation of water seeping into frozen soil in reality and improve the accuracy of measurement.

[0031] Refer to Figure 3 、 Figure 4 and Figure 5, in a preferred embodiment, the outside of the plug plate 818 is slidably connected to the inner wall of the water storage cylinder 6. Two annular grooves are provided at equal distances on the outside of the plug plate 818. Sealing rings 821 are connected by bolts in the annular grooves. The outsides of the sealing rings 821 are in contact with the inner wall of the water storage cylinder 6. The bottom of the first annular airbag 819 is connected to the upper side of the plug plate 818 by bolts. An injection pipe 820 is provided on the first annular airbag 819. And the bottom of the plug plate 818 is connected to the second annular airbag 822 by bolts. A round opening is provided on the plug plate 818. An inflation pipe 826 is provided in the round opening. One end of the inflation pipe 826 close to the second annular airbag 822 is connected to the second annular airbag 822 by bolts. The outside of the heat preservation sleeve 5 is connected to a bracket 12 by bolts; Four convex platforms are connected to the inner wall of the water storage cylinder 6 by bolts and are equally distributed circumferentially. Guide rods 823 are slidably connected to the inner walls of the convex platforms. The bottoms of the guide rods 823 are connected to the upper side of the plug plate 818 by bolts. A hole groove is provided on the plug plate 818. A supplementary pipe 824 is fixedly connected in the hole groove. An electronic valve II 825 is provided on the supplementary pipe 824. And the bottom of the heating wire 827 is connected to the bottom inner wall of the water storage cylinder 6 by bolts; Two symmetrical vertical frames 802 are provided on the outside of the water storage cylinder 6. The bottoms of the two vertical frames 802 are connected to the same bearing platform 801 by bolts. The upper sides of the two vertical frames 802 are connected to the same connecting plate 803 by bolts. One side of the connecting plate 803 away from the water storage cylinder 6 is connected to an adapter plate 804 by bolts. And sliding grooves 805 are provided on the opposite sides of the two vertical frames 802; The same support plate 806 is slidably connected in the two sliding grooves 805. The upper side of the support plate 806 is in contact with the bottom of the water storage cylinder 6. An electronic valve I 808 is provided on the outside of the water delivery pipe 7. A hole groove is provided on the support plate 806. A lead screw 809 is rotationally connected in the hole groove through an external thread. The outside of the lead screw 809 is rotationally connected to a fixed frame 807 through a bearing. And the upper side of the lead screw 809 is rotationally connected to the bottom of the adapter plate 804 through a bearing; A first gear 810 is connected to the bottom of the lead screw 809 by bolts. A rotating shaft 811 is rotationally connected to the fixed frame 807 through a bearing. A second gear 812 is connected to the outside of the rotating shaft 811 by bolts. The second gear 812 meshes with the first gear 810. One side of the rotating shaft 811 is connected to a short shaft by bolts. The side of the short shaft away from the rotating shaft 811 is connected to a handle 813 by bolts. And a clamping tooth ring 814 is connected to the outside of the short shaft by bolts. A receiving frame 815 is connected to the side of the fixed frame 807 close to the clamping tooth ring 814 by bolts. Two symmetrical first springs 817 are connected to the top inner wall of the receiving frame 815 by bolts. One end of the first spring 817 close to the clamping tooth ring 814 is connected to the same fastener 816 by bolts. The outside of the fastener 816 is slidably connected to the inner wall of the receiving frame 815. The fastener 816 is clamped with the clamping tooth ring 814.

[0032] Specifically, when conducting a measurement experiment, the second electronic valve 825 is closed, and water is injected into the first annular airbag 819 through the injection pipe 820, causing the first annular airbag 819 to gain weight and expand. Under gravity, the plug plate 818 slides downward in the water storage cylinder 6, and the first electronic valve 808 is opened. The water in the water storage cylinder 6 is transported into the specimen cylinder 1 through the water delivery pipe 7, thereby occupying the cavity formed between the surface of the specimen soil in the specimen cylinder 1 and the specimen cylinder 1. Pressure is applied inside the specimen cylinder 1, causing the water to start permeating into the specimen soil. Air is injected into the second annular airbag 822 through the air filling pipe 826, causing the water to generate buoyancy on the second annular airbag 822, pushing open the fastener 816 and rotating the handle 813. The handle 813 drives the second gear 812 to rotate, causing the first gear 810 to drive the lead screw 809 to rotate, thereby adjusting the height of the water storage cylinder 6 on the support plate 806. Utilizing the buoyancy and height, the air pressure inside the specimen cylinder 1 is adjusted, making the internal environment of the specimen cylinder 1 closer to reality.

[0033] In a specific application scenario, the constant-pressure water control module 8 is mainly applicable to the constant-pressure water control link in the constant-pressure water control process, that is, the constant-pressure water control module 8 can use the first annular airbag 819 and the second annular airbag 822 to accurately control the pressure exerted by the plug plate 818 on the water storage cylinder 6, thereby effectively controlling the flow rate of water flowing into the specimen cylinder 1, so as to effectively control the air pressure inside the specimen cylinder 1 and improve the controllability of the device.

[0034] Refer to Figure 6 and Figure 7 In a preferred embodiment, a first clamping plate 901 is arranged inside the seepage pipe 10. The bottom of the first clamping plate 901 is bolted to a gas guide pipe 903. One end of the gas guide pipe 903 away from the first clamping plate 901 is located outside the seepage pipe 10, and one end of the gas guide pipe 903 away from the first clamping plate 901 is bolted to the inner wall of the balloon 907; a second clamping plate 904 is bolted to the outside of the gas guide pipe 903. The inner wall of the third annular airbag 905 is bolted to the outside of the gas guide pipe 903. The third annular airbag 905 is located between the first clamping plate 901 and the second clamping plate 904. A plurality of air holes 906 are arranged on the gas guide pipe 903 at equal circumferential intervals. The air holes 906 are all connected to the third annular airbag 905, and two symmetric grips 908 are bolted to one end of the gas guide pipe 903 close to the balloon 907; a fixing seat 902 is slidably connected to the outside of the gas guide pipe 903. One side of the fixing seat 902 opposite to the seepage pipe 10 is bolted. A positioning piece 909 is bolted to the outside of the gas guide pipe 903. The positioning piece 909 is located above the fixing seat 902, and a second spring 910 is bolted to the bottom of the positioning piece 909. One end of the second spring 910 away from the positioning piece 909 is bolted to the upper side of the fixing seat 902.

[0035] Specifically, after the water seeping out in the sample cylinder 1 flows into the receiving bucket 11 through the seepage pipe 10, record the amount of water flowing into the receiving bucket 11 per unit time. Grasp the grip 908 and squeeze the balloon 907 tightly, so that the air in the balloon 907 is pumped into the third annular airbag 905 through the air duct 903. The third annular airbag 905 expands around under the restraint of the first splint 901 and the second splint 904. The expanded third annular airbag 905 seals the seepage pipe 10, overcome the pulling force of the second spring 910 and pull down the grip 908, so that the air duct 903 drives the third annular airbag 905 to slide downward in the seepage pipe 10, scrape off the water adhering to the inner wall of the seepage pipe 10 and drip it into the receiving bucket 11, and record the data again.

[0036] In a specific application scenario, the scraping module 9 is mainly applicable to the scraping link during the scraping process, that is, the scraping module 9 can use the balloon 907 and the third annular airbag 905 to make the device scrape the water adhering to the seepage pipe 10 into the receiving bucket 11, thereby avoiding the deviation between the measurement result of the measurement experiment and the actual situation, ensuring the reliability of the measurement result, and improving the accuracy of the measurement experiment result.

[0037] A direct measurement experiment method for the permeability characteristics of frozen soil, using a direct measurement experiment device for the permeability characteristics of frozen soil as described above, includes the following steps:

[0038] Step 1: Open the closed cover 2, put the sample diagram into the sample cylinder 1, close the closed cover 2, open and adjust the high-temperature temperature control coil 3 and the low-temperature temperature control coil 4, so that the temperature of the sample diagram in the sample cylinder 1 is close to the actual situation. Fill the water storage cylinder 6 with water, use the constant pressure water control module 8 to pressurize or depressurize the water storage cylinder 6 and control the temperature, and inject the water in the water storage cylinder 6 into the sample cylinder 1 through the water delivery pipe 7, and wait for the water to seep out (when conducting the measurement experiment, close the second solenoid valve 825, inject water into the first annular airbag 819 through the injection pipe 820, so that the first annular airbag 819 gains weight and expands. Under gravity, the plug plate 818 slides downward in the water storage cylinder 6, open the first solenoid valve 808, and the water in the water storage cylinder 6 is transported into the sample cylinder 1 through the water delivery pipe 7, thus occupying the cavity formed between the surface of the sample soil in the sample cylinder 1 and the sample cylinder 1. The pressure starts to increase in the sample cylinder 1, so that the water starts to penetrate into the sample soil. Inject air into the second annular airbag 822 through the air filling pipe 826, so that the water generates buoyancy on the second annular airbag 822, push open the fastener 816 and rotate the handle 813. The handle 813 drives the second gear 812 to rotate, so that the first gear 810 drives the lead screw 809 to rotate, thereby adjusting the height of the water storage cylinder 6 on the support plate 806. Utilize the buoyancy and height to adjust the air pressure in the sample cylinder 1, so that the environment in the sample cylinder 1 is close to the actual situation);

[0039] Step 2: The seeping moisture flows from the seepage pipe 10 into the receiving bucket 11. Record the amount of water flowing into the receiving bucket 11 per unit time, and use the scraping module 9 to scrape off the moisture adhering to the inner wall of the seepage pipe 10. (After the water seeping out in the sample cylinder 1 flows into the receiving bucket 11 through the seepage pipe 10, record the amount of water flowing into the receiving bucket 11 per unit time. Grasp the handle 908 and squeeze the balloon 907 tightly, so that the air in the balloon 907 is pumped into the third annular airbag 905 through the air guide pipe 903, causing the third annular airbag 905 to expand around under the restraint of the first splint 901 and the second splint 904. The expanded third annular airbag 905 seals the seepage pipe 10. Pull down the handle 908 against the tension of the second spring 910, causing the air guide pipe 903 to drive the third annular airbag 905 to slide downward in the seepage pipe 10, scraping off the moisture adhering to the inner wall of the seepage pipe 10 and dripping it into the receiving bucket 11, and record the data again.)

[0040] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. An experimental device for directly measuring the permeability characteristics of frozen soil, comprising a sample tube (1), characterized in that: The sample tube (1) is provided with a high-temperature temperature control coil (3) and a low-temperature temperature control coil (4) on the outside, and a heat preservation sleeve (5) is provided on the outside of the high-temperature temperature control coil (3) and the low-temperature temperature control coil (4), and a sealing cover (2) is provided on the upper side of the sample tube (1). A circular hole is provided at the bottom of the sample tube (1), and a seepage tube (10) is fixedly connected in the circular hole. A scraping module (9) is provided on the seepage tube (10), and a receiving bucket (11) is provided below the seepage tube (10). A water storage tube (6) is provided above the sample tube (1), and a constant pressure water control module (8) is provided on the water storage tube (6). A fine hole is provided on the outside of the water storage tube (6), and a water delivery tube (7) is fixedly connected in the fine hole. The end of the water delivery tube (7) away from the water storage tube (6) is connected to the upper side of the sample tube (1) through a flange. The constant pressure water control module (8) comprises a plug plate (818), an annular air bag (819) and a heating wire (827); The scraping module (9) comprises an annular airbag (905) and a spherical balloon (907).

2. The direct measurement experimental device for permeability of frozen soil according to claim 1 is characterized in that: The outside of the plug plate (818) is slidably connected to the inner wall of the water storage cylinder (6), and two equidistantly distributed annular grooves are provided on the outside of the plug plate (818). A sealing ring (821) is fixedly connected in each of the annular grooves, and the outside of the sealing ring (821) is in contact with the inner wall of the water storage cylinder (6). The bottom of the annular airbag 1 (819) is fixedly connected to the upper side of the plug plate (818), an injection tube (820) is provided on the annular airbag 1 (819), and the bottom of the plug plate (818) is fixedly connected to the annular airbag 2 (822). The plug plate (818) is provided with a circular opening, and an inflation tube (826) is provided in the circular opening. The inflation tube (826) is fixedly connected to the annular airbag 2 (822) at one end thereof close to the annular airbag 2 (822), and the outside of the thermal insulation sleeve (5) is fixedly connected to a bracket (12).

3. The direct measurement experimental device for permeability of frozen soil according to claim 2 is characterized in that: The inner wall of the water storage cylinder (6) is fixedly connected with four bosses distributed equidistantly around the circumference, the inner walls of the bosses are slidably connected with guide rods (823), the bottoms of the guide rods (823) are fixedly connected with the upper side of the plug plate (818), the plug plate (818) is provided with a hole groove, a replenishing pipe (824) is fixedly connected in the hole groove, and an electronic valve 2 (825) is provided on the replenishing pipe (824). The bottom of the electric heating wire (827) is fixedly connected with the inner wall of the bottom of the water storage cylinder (6).

4. The direct measurement experimental device for permeability of frozen soil according to claim 3 is characterized in that: Two symmetrical vertical frames (802) are arranged outside the water storage cylinder (6); the bottoms of the two vertical frames (802) are fixedly connected to a common support platform (801); the upper sides of the two vertical frames (802) are fixedly connected to a common connecting plate (803); a connecting plate (804) is fixedly connected to a side of the connecting plate (803) away from the water storage cylinder (6); and sliding grooves (805) are provided on opposite sides of the two vertical frames (802).

5. The direct measurement experimental device for permeability of frozen soil according to claim 4 is characterized in that: The two slide grooves (805) are slidably connected with a support plate (806), the upper side of the support plate (806) is in contact with the bottom of the water storage cylinder (6), an electronic valve (808) is arranged outside the water delivery pipe (7), a hole groove is opened on the support plate (806), a screw rod (809) is rotatably connected in the hole groove through an external thread, the outside of the screw rod (809) is movably connected with a fixing frame (807), and the upper side of the screw rod (809) is movably connected to the bottom of the connecting plate (804).

6. The direct measurement experimental device for permeability of frozen soil according to claim 5 is characterized in that: The bottom of the screw rod (809) is fixedly connected to a gear 1 (810), the fixed frame (807) is movably connected to a rotating shaft (811), the outside of the rotating shaft (811) is fixedly connected to a gear 2 (812), the gear 2 (812) is meshed with the gear 1 (810), one side of the rotating shaft (811) is fixedly connected to a short shaft, the side of the short shaft away from the rotating shaft (811) is fixedly connected to a handle (813), and the outside of the short shaft is fixedly connected to a locking toothed ring (81 4), a side of the fixing frame (807) close to the locking toothed ring (814) is fixedly connected to a containing frame (815), and the top inner wall of the containing frame (815) is fixedly connected to two symmetrical springs (817), and one end of the spring (817) close to the locking toothed ring (814) is fixedly connected to the same fastener (816), the outer portion of the fastener (816) is slidably connected to the inner wall of the containing frame (815), and the fastener (816) is locked with the locking toothed ring (814).

7. The direct measurement experimental device for permeability of frozen soil according to claim 6 is characterized in that: The exudation tube (10) is provided with a splint one (901), the bottom of the splint one (901) is fixedly connected with an air guide tube (903), one end of the air guide tube (903) away from the splint one (901) is located outside the exudation tube (10), and one end of the air guide tube (903) away from the splint one (901) is fixedly connected to the inner wall of the balloon (907).

8. The direct measurement experimental device for permeability of frozen soil according to claim 7 is characterized in that: The outside of the air guide tube (903) is fixedly connected to the second splint (904), the inner wall of the third annular air bag (905) is fixedly connected to the outside of the air guide tube (903), the third annular air bag (905) is located between the first splint (901) and the second splint (904), a plurality of circumferentially equidistantly distributed air holes (906) are provided on the air guide tube (903), the air holes (906) are all connected to the third annular air bag (905), and one end of the air guide tube (903) close to the balloon (907) is fixedly connected to two symmetrical handles (908).

9. The experimental device for directly measuring the permeability characteristics of frozen soil according to claim 8, characterized in that: The outside of the air guide tube (903) is slidably connected to a fixed seat (902), and the fixed seat (902) is fixedly connected to the side opposite to the exudation tube (10). The outside of the air guide tube (903) is fixedly connected to a positioning piece (909), and the positioning piece (909) is located above the fixed seat (902). The bottom of the positioning piece (909) is fixedly connected to a spring 2 (910), and the end of the spring 2 (910) away from the positioning piece (909) is fixedly connected to the upper side of the fixed seat (902).

10. A method for directly measuring the permeability characteristics of frozen soil, using the device for directly measuring the permeability characteristics of frozen soil as claimed in claim 9, characterized in that: The steps include: Step 1: open the sealing cover (2), place the sample into the sample tube (1), close the sealing cover (2), open and adjust the high temperature temperature control coil (3) and the low temperature temperature control coil (4), so that the temperature of the sample in the sample tube (1) is close to the actual situation, fill water into the water storage tube (6), use the constant pressure water control module (8) to pressurize or reduce the pressure of the water storage tube (6) and control the temperature, inject the water in the water storage tube (6) into the sample tube (1) through the water pipe (7), and wait for the water to seep out; Step 2: The seeped water flows from the seepage pipe (10) into the receiving bucket (11), the amount of water flowing into the receiving bucket (11) per unit time is recorded, and the scraping module (9) is used to scrape out the water attached to the inner wall of the seepage pipe (10).

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