Indoor sampling model test device capable of being used for comparing disturbance degrees of soil samples

Abstract

The utility model provides an indoor sampling model test device capable of being used for comparing disturbance degrees of soil samples, which relates to the technical field of civil engineering and comprises a shell which comprises a test base and a model groove. The sampler is arranged in the shell; the injection system is arranged on the shell, is connected with the sampler and is used for driving the sampler to move up and down and rotate; the consolidation loading system comprises a consolidation upper cover, a counter-force frame and consolidation oil cylinders, the consolidation upper cover is arranged at the top of the model tank, the sampler penetrates through the consolidation upper cover, the two consolidation oil cylinders are arranged at the inner top of the counter-force frame, the output ends of the two consolidation oil cylinders are connected with the top of the consolidation upper cover, and the output ends of the two consolidation oil cylinders are connected with the top of the counter-force frame. And the model groove is arranged on the test base and is positioned in the reaction frame. According to the utility model, the injection system is used for injecting the sampler into the soil body, and the pressure volume controller can control the back pressure of the soil body so as to simulate marine environments with different water depths on one hand, and can monitor the volume change of the soil body in the consolidation process on the other hand, so that indoor sampling model tests of different types of samplers can be implemented.

Description

Technical Field

[0001] The utility model relates to the field of ocean drilling and soil sampling, in particular to an indoor sampling model test device which can be used for comparing the disturbance degree of soil samples. Background Art

[0002] Current marine drilling and soil sampling techniques still suffer from significant disturbance during sampling, necessitating the development of a sampler specifically designed for marine environments that minimizes soil disturbance. While the practicality of these samplers needs to be tested in practice, in-situ sampling and testing presents drawbacks such as uneven soil layers and high costs. Therefore, the most direct, simple, and effective approach is to use indoor model tests to control soil uniformity and simulate soil samples at different depths by controlling consolidation stress. Using different samplers to extract soil samples and compare the degree of disturbance is crucial.

[0003] For prior art, see CN114813207A, a simulated in-situ soil sampling disturbance device and disturbance evaluation method. This prior art utilizes a sampler to penetrate and evaluate the disturbance level, but only considers the disturbance caused by the sampler cutting, failing to evaluate the disturbance caused by the entire sampling process. Furthermore, because the sampler is slightly larger than the soil sample width, boundary effects occur during sampling, failing to truly simulate the actual soil sampling process. Utility Model Content

[0004] The utility model provides an indoor sampling model test device which can be used for comparing the disturbance degree of soil samples, and is used to solve the problems existing in the above-mentioned prior art.

[0005] To this end, the utility model adopts the following technical solutions:

[0006] The utility model provides an indoor sampling model test device which can be used to compare the disturbance degree of soil samples.

[0007] The invention comprises: a shell, wherein the shell comprises a test base and a model slot;

[0008] a sampler disposed inside the housing;

[0009] A penetration system is provided on the housing, the penetration system is connected to the sampler, and is used to drive the sampler to move up and down and rotate;

[0010] A consolidation loading system, comprising a consolidation upper cover, a reaction frame, and a consolidation oil cylinder. The consolidation upper cover is arranged on the top of the model tank, the sampler passes through the consolidation upper cover, two consolidation oil cylinders are provided, both arranged on the inner top of the reaction frame, and the output ends of the two consolidation oil cylinders are connected to the top of the consolidation upper cover. The model tank is arranged on the test base and located in the reaction frame.

[0011] The reaction frame is arranged on the top of the test base, and the model soil is arranged inside the model tank;

[0012] The penetration system is arranged on the top of the reaction frame, and the sampler is arranged on the inner top of the reaction frame.

[0013] Furthermore, a data acquisition system is connected to the top of the penetration system, a pore pressure sensor is provided on the inner wall of the model soil, a first bending element is provided at the bottom of the consolidation cover, the first bending element is connected to a bending element wave velocity emission and collection device, and a pressure volume controller is provided on the top of the test base.

[0014] Furthermore, a coarse sand layer is provided at the inner bottom of the model soil body, a second bending element is provided on the top of the coarse sand layer, and the second bending element is connected to a bending element wave velocity emission and collection device.

[0015] Furthermore, a slide rail is provided on one side of the reaction frame, the model groove is slidably connected to the slide rail, a push-pull oil cylinder is provided on the inner side of the slide rail, and the push-pull oil cylinder is connected to the model groove.

[0016] Furthermore, a water-stop rubber ring is provided on the side of the solidification upper cover.

[0017] Furthermore, it also includes a stirring unit for stirring the soil, the stirring unit includes a vacuum stirring box, an agitator arranged at the top of the vacuum stirring box and one end extending into the interior of the vacuum stirring box, a barometer arranged on one side of the top of the vacuum stirring box, a drainage pipe arranged at the bottom of the vacuum stirring box, and a vacuum pump, the output end of the vacuum pump is connected to an exhaust pipe, the free end of the exhaust pipe is connected to the top of the vacuum stirring box, and the top of the vacuum stirring box is provided with a fastening bolt.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The utility model has reasonable design, simple structure and convenient operation, and can be used to carry out indoor sampling model tests of different types of soil samplers and conduct disturbance evaluation;

[0020] Second, the push-pull cylinder applies thrust to the model tank, causing the sampler to slide on the slide rail to be located directly above the center of the sample. A pressure-volume controller is used to apply back pressure corresponding to a certain water depth to the mud to simulate the marine environment under the actual stratum. The penetration system can penetrate the sampler at a uniform speed, and can also rotate the sampler at a uniform speed to simulate different sampling processes. The inner diameter of the model tank is six times larger than the diameter of the sampler, thereby eliminating the influence of the boundary effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is a schematic diagram of the overall structure of the utility model;

[0022] Figure 2 This is a structural diagram of the slide rail and the push-pull cylinder in the utility model;

[0023] Figure 3 It is a schematic diagram of the internal structure of the stirring unit in the utility model.

[0024] The marks in the accompanying drawings are: 1. Penetration system; 2. Reaction frame; 3. Sampler; 4. Model soil; 5. Model trough; 6. Pore pressure sensor; 7. Coarse sand layer; 8. Consolidation cylinder; 9. Consolidation cover; 10. Test base; 11. Water-stop rubber ring; 12. First bending element; 13. Second bending element; 14. Bending element wave velocity emission and collection device; 15. Data acquisition system; 16. Pressure volume controller; 17. Slide rail; 18. Push-pull cylinder; 19. Agitator; 20. Barometer; 21. Fastening bolts; 22. Vacuum mixing box; 23. Drain pipe; 24. Exhaust pipe; 25. Vacuum pump. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0026] Reference Figure 1-3 As shown, an indoor sampling model test device for comparing the degree of disturbance of soil samples comprises: a shell; a sampler 3 arranged inside the shell; a penetration system 1 arranged on the shell, the penetration system 1 is connected to the sampler 3 and is used to drive the sampler 3 to move up and down and rotate; the shell comprises a test base 10 and a model tank 5; a consolidation loading system, the consolidation loading system comprises a consolidation cover 9, a reaction frame 2 and a consolidation cylinder 8, the consolidation cover 9 is arranged on the top of the model tank 5, and the sampler 3 penetrates the consolidation cover 9. Cover 9, two consolidation cylinders 8 are provided, both of which are arranged on the inner top of the reaction frame 2, and the output ends of the two consolidation cylinders 8 are connected to the top of the consolidation cover 9. The model tank 5 is arranged on the test base 10 and located inside the reaction frame 2; wherein the reaction frame 2 is arranged on the top of the test base 10, and the model soil 4 is arranged inside the model tank 5; the penetration system 1 is arranged on the top of the reaction frame 2, and the sampler 3 is arranged on the inner top of the reaction frame 2; the inner diameter of the model tank 5 is six times larger than the diameter of the sampler 3;

[0027] A data acquisition system 15 is connected to the top of the penetration system 1, a pore pressure sensor 6 is provided on the inner wall of the model soil body 4, a first bending element 12 is provided at the bottom of the consolidation cover 9, and the first bending element 12 is connected to the bending element wave velocity emission and collection device 14, a pressure volume controller 16 is provided on the top of the test base 10, a coarse sand layer 7 is provided at the inner bottom of the model soil body 4, and a second bending element 13 is provided on the top of the coarse sand layer 7, and the second bending element 13 is connected to the bending element wave velocity emission and collection device 14.

[0028] It also includes a stirring unit for stirring the soil; the stirring unit includes a vacuum stirring box 22, an agitator 19 arranged at the top of the vacuum stirring box 22 and one end extending into the interior of the vacuum stirring box 22, a barometer 20 arranged on one side of the top of the vacuum stirring box 22, a drainage pipe 23 arranged at the bottom of the vacuum stirring box 22, and a vacuum pump 25. The output end of the vacuum pump 25 is connected to the exhaust pipe 24, the free end of the exhaust pipe 24 is connected to the top of the vacuum stirring box 22, and the top of the vacuum stirring box 22 is provided with a fastening bolt 21.

[0029] A slide rail 17 is provided on one side of the reaction frame 2, and the model groove 5 is slidably connected to the slide rail 17. A push-pull cylinder 18 is provided on the inner side of the slide rail 17, and the push-pull cylinder 18 is connected to the model groove 5. A water-stop rubber ring 11 is provided on the side of the consolidation cover 9.

[0030] It also includes a stirring unit for stirring the soil, the stirring unit includes a vacuum stirring box 22, an agitator 19 arranged at the top of the vacuum stirring box 22 and one end extending into the interior of the vacuum stirring box 22, a barometer 20 arranged on one side of the top of the vacuum stirring box 22, a drainage pipe 23 arranged at the bottom of the vacuum stirring box 22, and a vacuum pump 25. The output end of the vacuum pump 25 is connected to the exhaust pipe 24, the free end of the exhaust pipe 24 is connected to the top of the vacuum stirring box 22, and the top of the vacuum stirring box 22 is provided with a fastening bolt 21.

[0031] The test method of the indoor sampling model test device for comparing the degree of disturbance of soil samples comprises the following steps:

[0032] 1. Prepare the slurry by pouring a certain amount of air-dried clay with a known initial moisture content into a vacuum mixing tank 22. Then, add a certain amount of distilled water. Simultaneously, use the agitator 19 and vacuum pump 25 to stir and evacuate the soil. Ensure that the mixture is evenly mixed and the vacuum level reaches above 98%. After vacuum stirring, transfer the slurry to the model tank 5. If the soil is sandy, mix the sand and water directly in the model tank.

[0033] 2. Pre-consolidation is performed. The push-pull cylinder 18 applies thrust to the model tank, causing the sampler to slide on the slide rail 17 to be located directly above the center of the sample. The pressure-volume controller 16 applies a back pressure corresponding to a certain water depth to the mud to simulate the marine environment under the actual stratum. The consolidation cylinder 8 pressurizes the mud at a certain consolidation pressure. At the same time, the pore pressure sensor 6 monitors the changes in the excess pore water pressure below the soil sample in real time. The consolidation cylinder 8 also monitors the consolidation displacement of the soil sample. When the consolidation degree of the soil sample reaches 95%, consolidation is completed.

[0034] 3. Measure the bending shear wave velocity v of the soil sample before sampling s1 The wave is transmitted from the bending element wave velocity transmitting and collecting device 14 through the first bending element 12, propagates through the soil and reaches the second bending element 13 to receive the wave. According to the distance from the first bending element 12 to the second bending element 13 and the time the shear wave passes, the bending element shear wave velocity v of the soil can be obtained. s1 ;

[0035] 4. Take samples with the sampler 3. Insert or rotate the sampler 3 into the soil sample at a certain speed. After the sampler 3 reaches the specified height, lift the sampling tube 3.

[0036] 5. Push out the soil sample taken from the sampling tube 3 and cut the soil sample to conduct triaxial k0 consolidation test, so that its consolidation pressure is equal to the consolidation pressure of the model test, and then measure its bending element wave velocity v s2 ;

[0037] 6. Use the bending element shear wave velocity to evaluate the disturbance degree of the soil sample according to the test results, and record the bending element shear wave velocity v when the soil sample is taken out by the tubular sampler. s2 and the bending element shear wave velocity v before sampling s1 , the disturbance degree of soil sampling is obtained through the changes in the shear wave velocity of the two times. The disturbance degree is expressed as:

[0038]

[0039] 7. According to the disturbance degree D of the soil sample obtained, when the disturbance degree D ≥ 10%, the soil sample is considered to be significantly disturbed; when the disturbance degree D < 10%, it is considered to be slightly disturbed.

[0040] The above embodiment is only a preferred technical solution of the present invention. Those skilled in the art should understand that the technical solutions or parameters in the embodiment can be modified or replaced without departing from the principle and essence of the present invention, and all should be included in the protection scope of the present invention.

Claims

1. An indoor sampling model test device that can be used to compare the degree of disturbance of soil samples, characterized in that: include: A housing, the housing comprising a test base (10) and a model tank (5); a sampler (3) arranged inside the housing; a penetration system (1) provided on the housing, the penetration system (1) being connected to the sampler (3) and being used to drive the sampler (3) to move up and down and rotate; A consolidation loading system, comprising a consolidation upper cover (9), a reaction frame (2) and a consolidation oil cylinder (8), wherein the consolidation upper cover (9) is arranged on the top of the model tank (5), the sampler (3) passes through the consolidation upper cover (9), two consolidation oil cylinders (8) are provided, both of which are arranged on the inner top of the reaction frame (2), and the output ends of the two consolidation oil cylinders (8) are connected to the top of the consolidation upper cover (9), and the model tank (5) is arranged on the test base (10) and located in the reaction frame (2); The reaction frame (2) is arranged on the top of the test base (10), and a model soil body (4) is arranged inside the model tank (5); The penetration system (1) is arranged on the top of the reaction frame (2), and the sampler (3) is arranged on the inner top of the reaction frame (2).

2. The indoor sampling model test device for comparing the degree of disturbance of soil samples according to claim 1, characterized in that: The top of the penetration system (1) is connected to a data acquisition system (15), a pore pressure sensor (6) is provided on the inner wall of the model soil (4), a first bending element (12) is provided at the bottom of the consolidation cover (9), the first bending element (12) is connected to a bending element wave velocity emission and acquisition device (14), and a pressure volume controller (16) is provided on the top of the test base (10).

3. The indoor sampling model test device for comparing the degree of disturbance of soil samples according to claim 2, characterized in that: A coarse sand layer (7) is provided at the inner bottom of the model soil body (4), a second bending element (13) is provided on the top of the coarse sand layer (7), and the second bending element (13) is connected to a bending element wave velocity emission and collection device (14).

4. The indoor sampling model test device for comparing the degree of disturbance of soil samples according to claim 1, characterized in that: A slide rail (17) is provided on one side of the reaction frame (2), the mold groove (5) is slidably connected to the slide rail (17), a push-pull oil cylinder (18) is provided on the inner side of the slide rail (17), and the push-pull oil cylinder (18) is connected to the mold groove (5).

5. The indoor sampling model test device for comparing the degree of disturbance of soil samples according to claim 1, characterized in that: A water-stop rubber ring (11) is provided on the side of the consolidation upper cover (9).

6. The indoor sampling model test device for comparing the degree of disturbance of soil samples according to claim 1, characterized in that: The utility model also comprises a stirring unit for stirring the soil.

7. The indoor sampling model test device for comparing the degree of disturbance of soil samples according to claim 6, characterized in that: The stirring unit includes a vacuum stirring box (22), an agitator (19) arranged at the top of the vacuum stirring box (22) and one end of which extends into the interior of the vacuum stirring box (22), a barometer (20) arranged on one side of the top of the vacuum stirring box (22), a drain pipe (23) arranged at the bottom of the vacuum stirring box (22), and a vacuum pump (25), wherein the output end of the vacuum pump (25) is connected to an exhaust pipe (24), the free end of the exhaust pipe (24) is communicated with the top of the vacuum stirring box (22), and a fastening bolt (21) is provided at the top of the vacuum stirring box (22).

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