CN102809641A - Undisturbed soil sample expansion force testing device capable of controlling saturation - Google Patents

Abstract

The invention discloses a test device for soil sample expansion force without disturbance and controllable saturation, which comprises a base support system, a lower plate is fixed on the base support system, a ring knife seat and a ring knife are installed on the lower plate, and the upper part of the ring knife seat is An upper cover is installed; a central circular groove and an annular groove are opened on the lower plate, an earth pressure sensor is placed in the central circular groove, an annular water seepage plate is placed in the annular groove, and a water immersion circular groove is opened on the annular water seepage plate. Permeable stones are placed in the circular grooves, and the bottom of the annular grooves is connected to the external water injection system through pipes; soil samples are placed between the lower plate and the ring knife, and a permeable plate seat with permeable plates and permeable holes is placed on the top of the soil samples ; The upper cover is provided with plunger, overflow equipment and vacuum equipment. The invention effectively overcomes the problems of relatively large disturbance to the soil sample structure, inability to effectively control the strict saturation state and long test time in test devices such as the expansion back pressure method, pressurization expansion method and balanced pressurization method.

Description

Undisturbed and controllable saturated soil swelling force testing device

technical field

The invention belongs to the technical field of soil sample physical quantity test equipment, and in particular relates to a soil sample expansion force test device which can control saturation without disturbance.

Background technique

Geotechnical test is one of the basic contents of soil mechanics research. Geotechnical test can reveal the unique mechanical properties of soil, determine various theoretical and engineering design parameters, and at the same time verify the correctness and practicability of various theories. Therefore, the geotechnical test plays an irreplaceable role in the theoretical research and engineering application of soil mechanics.

Because of the importance of the geotechnical test, the accuracy of the geotechnical test is valued. The accurate determination of soil sample parameters in soil engineering tests is more related to the correctness and feasibility of theoretical research. Therefore, the new test device developed is of great significance for the rapid and undisturbed parameter determination of soil samples. Especially for the mechanical properties of special soil, special test devices and test methods should be used to study its special mechanical properties. nature.

Expansive soil is a geological body with significant expansion and contraction characteristics formed in natural geological processes. The clay composition is mainly composed of strongly hydrophilic minerals montmorillonite and illite. Expansive soil has different engineering properties from normal consolidated clay, such as super-consolidation, fissures, significant swelling and softening after water absorption, and shrinkage and cracking due to water loss. It must slip, and a dike must collapse." Expansive soil has serious damage to buildings, especially light buildings, roadbeds, airports, slopes and dams, and this damage is often repeated and long-term latent. Expansive soil and its engineering problems are one of the worldwide technical problems that have not been properly resolved in the geotechnical field, and these series of problems are all caused by the expansive force of expansive soil. Therefore, how to measure and evaluate the swelling force of expansive soil has become one of the key issues in the study of the mechanical properties of expansive soil.

As a special mechanical property of expansive soil, swelling force has important research value. There are many test methods for the expansion force test, and the common ones are the expansion back pressure method, the pressurized expansion method and the balanced pressurization method.

Expansion back pressure method refers to make the soil sample fully absorb water and freely expand and stabilize, and then apply a load to make it return to the original volume. After the soil sample is expanded to the maximum in the test, it is loaded and compressed step by step until the soil sample returns to the original volume. The pressure required to be applied at this time is defined as the expansion force.

The pressure expansion method is to first compress the soil sample and then swell it in water. The expansion amount of the soil sample immersed in water under a certain pressure is equal to the compression amount generated under this pressure. The pressure is defined as the expansion force. During the test, a series of The load-expansion corresponding relationship curve is used to determine the expansion force value.

The balanced pressurization method refers to that when the soil sample absorbs water and begins to expand to a certain extent, the load is applied step by step to eliminate the expansion deformation, and the volume of the soil sample remains constant. The cumulative value of the final applied load is the expansion force.

It can be seen from the analysis that these expansion force test methods all have shortcomings in varying degrees:

1. The pressure measured by the expansion back pressure method is the "consolidation pressure" rather than the real "expansion pressure". The physical process of particles slipping, breaking, recombining, pore free water discharge and pore reduction; expansion is the process from physicochemical to mechanical that the intergranular and intergranular combined water film thickens and "wedges" the particles. It can be seen that the force measured by the expansion back pressure method is "consolidation pressure" rather than "expansion pressure". The test device is: the test is carried out with a ring knife and a consolidation instrument. The general process of the operation is to first prepare the sample with a 2cm-high ring knife, then connect the ring knife to the height, install it into the consolidation instrument, and adjust the pointer of the dial indicator to zero. , add water to allow the soil sample to fully expand and stabilize, then load in stages until the compression deformation with a volume smaller than the initial volume of the soil sample occurs. According to the test results, a "water immersion pressurization curve" is obtained, and the corresponding pressure at the intersection of the curve and the zero deformation line is the expansion force. Its disadvantages are: the force measured by this method is "consolidation pressure" rather than "expansion pressure", which is inconsistent with the physical meaning of expansion force; the test of maximum expansion force needs to be obtained by drawing a curve, and cannot be directly measured by experiment , which is inconvenient and cannot reflect the true value of the experiment. In addition, this test method cannot control the saturation state of the soil sample.

2. In the pressurized expansion method, when the maximum first-order load is applied, the soil undergoes compression deformation, which changes the dry density and original structure of the soil. Therefore, there is a difference between the test value and the actual value. The test device is: the test is carried out with a ring knife and a consolidation instrument. The general process of the operation is that in the test, multiple soil samples are used to compress and stabilize under different loads, adjust the pointer position of the dial indicator (considering the deformation of the instrument), add water to any The soil sample swells until it is stable, and the test results are sorted out to obtain a "expansion rate curve under different loads". The corresponding pressure at the intersection of the curve and the zero deformation line is the expansion force. Its disadvantages are: the soil sample is firstly compressed in the test, which produces soil disturbance and destroys the microstructure of the soil sample; it is necessary to obtain the expansion force indirectly by drawing a curve, which is more troublesome than the direct test of the expansion force; Using multiple soil samples for the test occupies multiple instruments, which affects the turnover of the equipment, and the test cannot control the saturation state of the soil samples.

3. The balanced pressurization method is the standard method of "Standards for Soil Engineering Test Methods" (GB/T 50123-1999), and its test results are more in line with the physical meaning of expansion force, but it needs multiple and frequent tests to control deformation during the test. The application of load will also cause damage and destruction of the undisturbed soil structure to a certain extent. The test device is: the balanced pressure method also needs to use the ring knife and the consolidation instrument for the test operation. The test process is to put the soil sample into the consolidation instrument, adjust the dial gauge so that the pointer points to zero or a certain initial reading, then add water to make the soil sample swell, when the dial gauge reading starts to increase, immediately add an appropriate amount The load keeps the dial indicator at the initial reading, and when the reading of the dial indicator increases again, it is pressed back again. Repeatedly so that the dial indicator always maintains the initial reading. When the reading remains unchanged for two hours, it can be regarded as stable. The load is the expansion force.

It is worth noting that although the balanced pressurization method has many advantages in testing expansion force, it also has great disadvantages: first, the test process is cumbersome, and loads need to be continuously applied to ensure that the pointer of the dial indicator returns to its original position. The amount of load cannot be known in advance, which puts forward higher requirements on the operating level of the test personnel; second, the soil sample continues to absorb water and expand to repeated pressure and finally tends to be stable, and the balanced pressure test cannot accurately determine the soil load. The final state of the sample cannot be strictly controlled and determined during the test whether the state of the soil sample is completely saturated under the loading conditions at all levels; thirdly, the soil sample cannot reach the saturation state in the strict sense under the negative pressure condition without vacuuming; Fourth, since the saturation state of the soil sample cannot be actively controlled in the test, it needs to be fully saturated by natural immersion, so the test will inevitably take a long time. It often takes several days or even ten days to do a test, and the period does not include The failure of the test, if it is necessary to do a large number of expansion force tests at one time, more personnel, more instruments, and more time are needed, which is uneconomical; fifth, the test process is complicated and requires manual labor. Record the data; Sixth, the test device cannot control the saturation state of the soil sample.

The above test methods and equipment have their own advantages and disadvantages. By comprehensively comparing the above three test methods, the main problems in the expansion force test can be summarized as follows: First, the expansion force usually refers to the expansion measured under the condition of keeping the soil volume constant. In the test, how to ensure that the expansion force of the test strictly conforms to the meaning of the expansion force in the physical sense; second, how to ensure that the soil structure is not disturbed during the test, so that the undisturbed soil sample and the reshaped soil sample can be avoided before and after the test. Structural disturbance and damage; third, how to ensure the saturation of the test soil sample for the maximum expansion force measured; fourth, how to save time-consuming expansive force testing by actively controlling the saturation process; fifth, how to avoid The disadvantages of traditional method testing are complex operation and frequent readings.

Aiming at the problems and deficiencies of the existing devices in the traditional expansion force test, we use advanced technology to invent and develop a set of new expansion force test devices that are non-disturbed, controllable saturation, less time-consuming, and easy to operate. It is of great significance to study the expansive mechanical properties of expansive soil.

Contents of the invention

The purpose of the present invention is to provide a soil sample expansion force testing device that can control saturation without disturbance, which effectively overcomes the large disturbance to the soil sample structure in the test devices such as the expansion back pressure method, the pressurized expansion method and the balanced pressurization method. It cannot effectively control the problems of strict saturation state and long test time.

The technical solution adopted in the present invention is a soil sample expansion force testing device that can control saturation without disturbance, and is characterized in that it includes a base support system, a horizontal lower plate is fixed on the base support system, and a bottom plate is installed on the lower plate. Cylindrical ring knife seat, a cylindrical ring knife is coaxially installed inside the cylindrical ring knife seat, an upper cover is installed on the upper part of the ring knife seat, and a closed space is formed between the ring knife seat and the upper cover;

There is a central circular groove on the lower plate and on the inner side of the ring knife, and an annular groove is formed around the central circular groove. An earth pressure sensor is placed in the central circular groove, and the wire for the earth pressure sensor is opened at the bottom of the central circular groove. In the hole drawn out, an annular seepage plate is placed in the annular groove, and a plurality of water-soaking circular grooves are evenly opened on the annular water-seepage plate, and permeable stones are placed in each water-soaking circular groove, and the bottom of the annular groove is connected with the external water injection system through a pipe. connect;

A soil sample is placed between the lower plate and the ring knife, the top of the soil sample is placed with a permeable plate seat, the bottom of the permeable plate seat is inlaid with a permeable plate, and the permeable plate seat is provided with a permeable hole communicating with the permeable plate;

There is a central hole opened downward on the upper cover, and a plunger is arranged in the central hole, the bottom of the plunger rests on the permeable plate seat, the top of the upper cover is provided with a screw that can be adjusted up and down, and the bottom of the screw is against the plunger , The upper cover is also connected with an overflow device and a vacuum device.

The base support system includes a movable frame on which a bottom plate is fixed, and a base for fixing the lower plate is installed on the bottom plate through hexagonal bolts.

The lower plate is provided with a protruding ring blade foot external support ring, the ring knife seat is fixed on the outer side of the ring blade foot external support ring through threads, and the ring knife is cooperatively placed on the inner side of the ring blade foot external support ring.

The external water injection system includes a water box bracket installed on the upper cover. A water box with a scale line is installed on the water box bracket. The upper end of the water box is connected to the atmosphere. The bottom of the water box is connected to a water injection conduit. Conduit valve, the other end of the water injection conduit is connected with the bottom of the annular groove through the pagoda joint installed on the lower plate.

A rubber pad ring is arranged between the ring knife and the lower disc.

Filter paper was placed on the upper and lower surfaces of the soil samples, and filter paper was placed on the permeable plate.

Two uprights are fixed on the top of the upper cover, and a horizontal crossbeam is fixed by the two uprights. The crossbeam is provided with a vertically downward threaded through hole, and the screw rod is arranged in the threaded through hole.

An overflow connector and a vacuum connector are opened downward on the upper cover, an overflow device is installed on the overflow connector, a vacuum pump conduit is connected to the vacuum connector, and a vacuum pump valve is installed on the vacuum pump conduit.

The beneficial effect of the non-disturbance controllable saturated soil sample swelling force testing device of the present invention is: the device of the present invention is suitable for the measurement of soil sample swelling force, especially suitable for the maximum swelling force of undisturbed expansive soil and remodeled expansive soil under saturated conditions test. Use in the measuring process of the present invention, the first, directly take the undisturbed expansive soil sample by ring cutter, or make expansive soil remodeling soil sample by compacting sample, collect expansion force data under rigid sidewall condition, kept The constant volume of the soil sample effectively reduces the disturbance to the soil sample structure during the test; secondly, the saturation state of the soil sample is actively controlled by vacuum equipment to ensure the saturation state under strict conditions, thus effectively The test time of the expansion force is reduced; thirdly, the expansion force data is collected through the high-precision, micro-strain earth pressure sensor, which effectively ensures the accuracy of the test; fourthly, due to the relatively large diameter and height of the soil sample, its end constraints The effect can be greatly reduced, and at the same time, the smooth inner wall of the ring cutter can also effectively reduce the friction between the ring cutter wall and the soil, thereby ensuring the reliability and accuracy of the measurement of the earth pressure sensor placed at the center of the bottom of the soil sample. In summary, this test device has the characteristics of no disturbance to soil samples, active control of saturation, less time-consuming testing, simple structure, convenient operation and reliable data.

Description of drawings

Fig. 1 is the structure schematic diagram of the soil sample expansion force testing device that can control saturation without disturbance of the present invention;

Fig. 2 is the structural representation of the upper cover of the device among the present invention;

Fig. 3 is the structural representation of the lower plate of the device among the present invention;

Among them, 1. Rack; 2. Bottom plate; 3. Base; 4. Hexagonal bolts; 5. Bottom plate; ; 10. Central circular groove; 11. Hole; 12. Earth pressure sensor; 13. Conductor; 14. Ring seepage plate; 15. Soaking circular groove; 16. Pagoda joint; 17. Water injection conduit; 18. Water box; 19. Rubber pad ring; 20. Water permeable plate; 21. Water permeable plate seat; 22. Water permeable hole; 23. Plunger; 24. Upper cover; 25. Overflower joint; 26. Vacuum joint; ;29. Hex nut; 30. Screw; 31. First screw; 32. Water box bracket; 33. Second screw; 34. Overflow device; 35. Hexagon socket screw; 36. Vacuum pump conduit; ; 38. Water injection conduit valve.

Detailed ways

As shown in FIG. 1 , the present invention is a non-disturbance controllable saturated soil sample expansion force testing device, which includes a base support system. The base support system plays an integral role in the test process. The base support system includes a movable frame 1, on which a base plate 2 is fixed, and a base 3 is installed on the base plate 2 through hexagonal bolts 4, and the base 3 is used to fix a horizontal lower plate 5. A cylindrical ring knife seat 6 and a cylindrical ring knife 9 are coaxially installed on the bottom plate 5. The specific installation method is: the bottom plate 5 is provided with a raised ring blade foot external support ring 7, and the ring knife edge foot external support ring The ring 7 can prevent the phenomenon of eversion of the blade and foot of the ring knife 9 caused by the expansion of the soil sample 8 during the test process, which can prevent the lateral expansion of the expansive soil volume and prevent the damage of the ring knife 9 parts. The ring knife seat 6 is fixed on the outside of the outer support ring 7 of the ring knife edge foot by threads, and the ring knife 9 is cooperatively placed on the inner side of the outer support ring 7 of the ring knife edge foot, and a rubber pad ring is arranged between the ring knife 9 and the lower plate 5 19. The rubber gasket ring 19 can play a role of sealing during the vacuuming process. The top of the ring knife seat 6 is equipped with an upper cover 24 by two hexagon socket head cap screws 35, and a closed space is formed between the ring knife seat 6 and the upper cover 24.

As shown in FIG. 3 , in the closed space formed by the ring knife holder 6 and the upper cover 24 , a central circular groove 10 is formed on the lower plate 5 and inside the ring knife 9 , and an annular groove is formed around the central circular groove 10 . An earth pressure sensor 12 is placed in the central circular groove 10 , and a hole 11 is opened at the bottom of the central circular groove 10 , and the hole 11 is used for leading out a wire 13 of the earth pressure sensor 12 . The wire 13 is drawn out through the hole 11 and then connected to an external data acquisition system. The data acquisition system is used for data acquisition during the test. The annular groove is used for arranging the water injection channel, and an annular water seepage plate 14 is placed in the annular groove, and the upper surface of the placed annular water seepage plate 14 is flush with the upper surface of the earth pressure sensor 12 . The annular seepage plate 14 is evenly provided with three water-soaking circular grooves 15 in the circumferential direction, so as to strengthen the uniformity of the water-soaked saturation of the soil sample 8 during the water-soaking process. Water-permeable stones are placed in each water-soaking circular groove 15, and the bottom of the annular groove is connected with an external water injection system through a pipeline. A soil sample 8 is placed between the lower wall 5 and the ring knife 9 . A permeable plate seat 21 is placed on the top of the soil sample 8, and a permeable plate 20 is inlaid on the bottom of the permeable plate seat 21. The lower surface of the permeable plate 20 is in close contact with the upper surface of the soil sample 8. Connected left and right two water permeable holes 22. The water permeable hole 22 can promote the beneficial discharge of the air around the water permeable plate 20 after the test water injection. Filter paper is placed on the upper and lower surfaces of the soil sample 8 , and filter paper is placed on the permeable plate 20 .

As shown in FIG. 2 , the upper cover 24 is opened downward and is provided with a central hole, and a plunger 23 is arranged in the central hole. The screw rod 30, the bottom of the screw rod 30 is against the plunger 23. The screw 30 can pre-apply a certain pressure, which fully ensures the close contact between the soil sample 8 and the two planes of the permeable plate 20 and the lower wall 5, so as to improve the test accuracy. Also be connected with overflow equipment and vacuumizing equipment on the upper cover 24. The top of the upper cover 24 is fixed with two columns 27, and the two columns 27 are fixed with a horizontal beam 28 by two hexagonal nuts 29. through hole. An overflow joint 25 and a vacuum joint 26 are opened downward on the upper cover 24, and an overflow 34 is installed on the overflow joint 25, and the overflow 34 is made of plexiglass. A vacuum pump conduit 36 is connected to the vacuum joint 26 , and a vacuum pump valve 37 is installed on the vacuum pump conduit 36 .

The external water injection system includes a water box support 32 installed on the upper cover 24 by two first screws 31, and a water box 18 with scale marks is installed on the water box support 32 by four second screws 33. The upper end of the water box 18 Connected with the atmosphere, the bottom of the water box 18 is connected with a water injection conduit 17, the water injection conduit 17 is equipped with a water injection conduit valve 38, and the other end of the water injection conduit 17 is connected to the bottom of the annular groove through the pagoda joint 16 installed on the lower plate 5 .

During the test, close the water injection conduit valve 38 of the water injection conduit 17, inject water in the water box 18, and record the scale mark of the water surface in the water box 18 at this moment. Open the vacuum pump conduit valve 37 to start the vacuuming equipment. After vacuuming is completed, the vacuum pump catheter valve 37 is closed, and the data is recorded for the first time through the data acquisition system. Open the water injection conduit valve 38 to allow water to flow out. Water enters the annular seepage plate 14 in the lower wall 5 through the water injection conduit 17 and contacts the soil sample 8, and the soil sample 8 begins to soak in water. When the water surface is seen through the overflow device 34, the water injection ends, and the water injection conduit valve 38 is closed, and the position of the water surface scale line in the water box 18 is recorded at this moment. Soil sample 8 began to swell after soaking in water. Observe the changes in the data in the external data acquisition system. After the data is stable, record the data for the second time.

The above test operations are applicable to the undisturbed soil sample of expansive soil and the remodeled soil sample of expansive soil, the difference between the two lies only in the preparation process of the soil sample. The undisturbed soil sample of expansive soil is directly taken at the scene with a large rigid ring knife 9, and the soil sample at both ends of the ring knife 9 is leveled with a soil cutter during the test, and the test operation can be carried out; the remodeling soil sample of expansive soil is sample preparation Firstly, crush the undisturbed air-dried expansive soil sample, sieve, and mix well, then add water with a sprayer according to the required water content and mix well, keep it moist for a whole day and night, and compact it layer by layer to the required density. The sample preparation errors of water volume and density were controlled within 1%.

The present invention is in carrying out soil sample expansion force test process:

1. By using the ring knife 9, the volume of the soil sample 8 can be strictly controlled and constant in the rigid side wall. Therefore, the expansion force tested by the present invention strictly conforms to the physical meaning of the maximum expansion force.

2. Both the undisturbed expansive soil sample and the remodeled expansive soil sample can be tested.

3. Through the cooperation of the screw rod 30 and the plunger 23, the preload is applied to the soil sample 8, which fully ensures the close contact between the soil sample 8 and the two planes of the permeable plate 20 and the lower wall 5 respectively.

4. The large-diameter ring cutter 9 is specially made, which can directly collect the undisturbed soil sample 8. During the test, the ring cutter 9 is directly put into the test device, which reduces the disturbance to the expansive soil sample during the two processes of sampling and test preparation.

5. There is no disturbance to the original expansive soil sample and the remodeled expansive soil sample during the expansive force test, which can ensure that the structure of the original expansive soil sample and the remodeled expansive soil sample is consistent with that before the test.

6. The expansive soil sample is finally fully saturated through vacuum equipment, which provides a technical means for determining the maximum expansion force and effectively reduces the time consumed by the test.

7. There is an annular seepage plate 14 on the lower wall 5, and a plurality of water-soaking circular grooves 15 are uniformly opened in the circumferential direction of the annular water-seepage plate 14, so that the uniformity of soaking and saturation of the soil sample 8 can be more strictly controlled during the vacuuming and saturation process. The saturation of the entire soil sample 8 is fully guaranteed, so that the soil sample 8 is always in a strictly saturated state.

8. The expansion force reading is tested by the earth pressure sensor 12, the signal is accurate and efficient, and the consumption of manpower, material resources, financial resources and time is reduced.

9. The soil pressure sensor 12 is placed at the center of the bottom of the soil sample 8. On the one hand, the smooth inner wall of the special ring cutter can effectively reduce the friction effect between the ring cutter wall and the soil during sampling and testing. On the other hand, due to the test soil The diameter and height of sample 8 are relatively large, and the restraint effect of its end can be greatly reduced.

10. The instrument is easy to operate, there is no higher technical and experience requirement for the test personnel, and the success rate of the test is guaranteed.

Claims (8)

1. An undisturbed and controllable saturated soil sample expansion force testing device, characterized in that it includes a base support system, and a horizontal lower wall (5) is fixed on the base support system, and the lower wall (5) A cylindrical ring knife seat (6) is installed on the top, a cylindrical ring knife (9) is coaxially installed inside the cylindrical ring knife seat (6), and an upper cover is installed on the upper part of the ring knife seat (6) (24), a closed space is formed between the ring knife seat (6) and the upper cover (24); A central circular groove (10) is formed on the lower plate (5) and on the inner side of the ring knife (9), and an annular groove is formed around the central circular groove (10). Inside the central circular groove (10) An earth pressure sensor (12) is placed, and a hole (11) is opened at the bottom of the central circular groove (10) for the lead wire (13) of the earth pressure sensor (12) to lead outward, and a hole (11) is placed in the annular groove An annular water seepage plate (14), the annular water seepage plate (14) is evenly opened with a plurality of water-soaking circular grooves (15), and water-permeable stones are placed in each of the water-soaking circular grooves (15), and the ring-shaped grooves The bottom is connected to the external water injection system through pipes; A soil sample (8) is placed between the lower wall (5) and the ring knife (9), and a permeable plate seat (21) is placed on the top of the soil sample (8), and the permeable plate seat (21) The bottom is inlaid with a permeable plate (20), and the permeable plate seat (21) is provided with a permeable hole (22) communicating with the permeable plate (20); The upper cover (24) is provided with a central hole opened downward, and a plunger (23) is arranged in the central hole, and the bottom of the plunger (23) is against the permeable plate seat (21), and the The top of the upper cover (24) is provided with a screw (30) that can be adjusted up and down, and the bottom of the screw (30) is against the plunger (23). The upper cover (24) is also connected with an overflow device and Vacuum equipment. 2. The non-disturbance controllable saturated soil sample swelling force testing device according to claim 1, characterized in that, the base support system includes a movable frame (1), and the frame (1) is fixed on There is a bottom plate (2), on which a base (3) for fixing the bottom plate (5) is installed through hexagonal bolts (4). 3. The non-disturbance controllable saturated soil sample expansion force testing device according to claim 1, characterized in that, the bottom wall (5) is provided with a raised ring blade foot external support ring (7), The ring knife seat (6) is fixed on the outer side of the ring blade foot outer support ring (7) through threads, and the ring knife (9) is matched and placed on the inner side of the ring knife edge foot outer support ring (7). 4. The non-disturbance controllable saturated soil sample expansion test device according to claim 1, characterized in that, the external water injection system includes a water box bracket (32) installed on the upper cover (24), and the A water box (18) with scale lines is installed on the water box bracket (32), the upper end of the water box (18) communicates with the atmosphere, and the bottom of the water box (18) communicates with a water injection conduit (17). A water injection conduit valve (38) is installed on the water injection conduit (17), and the other end of the water injection conduit (17) is connected to the bottom of the annular groove through a pagoda joint (16) installed on the lower wall (5). 5. The non-disturbance controllable saturated soil sample expansion test device according to claim 1, characterized in that a rubber pad ring (19) is arranged between the ring knife (9) and the lower plate (5). 6. The undisturbed and controllable saturated soil sample swelling force testing device according to claim 1, characterized in that filter paper is placed on the upper and lower surfaces of the soil sample (8), and the permeable plate (20) is placed on With filter paper. 7. The non-disturbance controllable saturated soil sample swelling force testing device according to claim 1, characterized in that, two uprights (27) are fixed on the top of the upper cover (24), through which two uprights (27) A horizontal crossbeam (28) is fixed, and a vertically downward threaded through hole is opened on the crossbeam (28), and the screw rod (30) is arranged in the threaded through hole. 8. The non-disturbance controllable saturated soil sample swelling force testing device according to claim 1, characterized in that, the upper cover (24) is opened up and down and provided with an overflow joint (25) and a vacuum joint (26), an overflow device (34) is installed on the overflow connector (25), a vacuum pump conduit (36) is connected to the vacuum pump connector (26), and a vacuum pump conduit (36) is installed on the vacuum pump conduit (36). Vacuum pump valve (37).

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