Coarse-grained saline soil salt frost heaving and water salt migration test device

Abstract

A kind of coarse salted soil salt frost heaving and water salt migration test device, outer cylinder is arranged between top plate and bottom plate, and top plate and bottom plate are connected and fixed by connecting rod and fastening nut, inner cylinder is concentrically arranged in outer cylinder, simulation device is arranged on the upper portion of inner cylinder, and the bottom of simulation device is connected with the inside of inner cylinder, and the top is provided with rubber hose;The device is designed by inner cylinder and outer cylinder, simulation device is arranged on the upper portion of inner cylinder, simulation device can be passed into water and frozen liquid simultaneously to simulate, realizes the real-time measurement of salt heaving and water salt migration of coarse salted soil in the process of test, with the advantages of free disassembly, assembly, easy to carry and reuse etc.

Description

Technical Field

[0001] This utility model belongs to the field of geotechnical testing technology, specifically relating to a test device for salt frost heave and water-salt migration in coarse-grained saline soil. Background Technology

[0002] Coarse-grained saline soils are widely distributed in Northwest my country, and their soil properties are significantly affected by water and salt migration and frost heave. These soils exhibit complex physical and chemical behaviors under extreme climatic conditions. Especially after water evaporation and salt accumulation, the migration and distribution of salts can alter soil structure, leading to engineering problems in airport buildings or other structures. Due to the existence of salt frost heave, alternating periods of cold and heat, as well as wet and dry conditions, have a significant impact on the stability and strength of coarse-grained saline soils, often resulting in potential risks in airport construction projects. Current research on the salt frost heave characteristics and water-salt migration of coarse-grained saline soils lacks systematic experimental equipment. Existing model test devices have limitations in controlling the water-salt environment and simulating freeze-thaw cycles, making it impossible to accurately obtain the response characteristics of saline soils under different water-salt conditions and temperature changes. Utilizing coarse-grained saline soils as fillers for roadbeds or other structural layers in airport construction in saline-alkali areas can greatly facilitate construction and reduce costs. However, using coarse-grained saline soils as fillers requires testing to determine if the filler meets the requirements. Existing test equipment mostly focuses on salt frost heave tests on small samples and small-volume water-salt migration tests, and due to size and functional limitations, it is largely unsuitable for coarse-grained saline soils. Therefore, developing a test device with precise control over water-salt migration and frost heave characteristics is particularly important for in-depth research on the behavioral patterns of coarse-grained saline soils and for providing reliable data support for engineering applications. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a coarse-grained saline soil salt frost heave and water-salt migration test device that is reasonably designed, simple in structure, easy to carry, and reusable.

[0004] The technical solution adopted to solve the above technical problems is: a test device for salt frost heave and water-salt migration of coarse-grained saline soil, wherein the outer cylinder is set between the top plate and the bottom plate, the top plate and the bottom plate are connected and fixed by connecting rods and fastening nuts, an inner cylinder is concentrically set inside the outer cylinder, a simulation device is set at the top of the inner cylinder, the bottom of the simulation device is connected to the inside of the inner cylinder, and a rubber hose is set at the top.

[0005] The simulation device of this utility model is as follows: the shell is a circular structure, a cover plate is provided on the top of the shell, four second through holes are machined on the cover plate, two of which are provided with connectors, a liquid pipe is horizontally arranged inside the shell, the two ends of the liquid pipe are connected to the connectors, and a rubber hose is provided outside the connectors.

[0006] The liquid tube of this invention is spirally coiled on the bottom plate of the shell.

[0007] The bottom plate of the shell of this utility model is provided with evenly distributed seepage holes.

[0008] The outer cylinder of this utility model has first rectangular holes spaced apart vertically on its side wall, and the inner cylinder has second rectangular holes corresponding to the first rectangular holes on its side wall. A rubber plug is disposed in the first rectangular holes and the second rectangular holes.

[0009] The rubber stopper of this invention has a through groove processed in the middle, and a glass stopper is placed in the through groove.

[0010] The top plate and bottom plate of this utility model have the same structure.

[0011] The top plate of this utility model is as follows: the top plate body is a circular structure, and a first groove and a second groove are concentrically machined on the contact surface between the top plate body and the outer cylinder and the inner cylinder. The depth of the first groove is greater than the depth of the second groove. Four first through holes are machined in the first groove. The inner diameter of the first groove is adapted to the outer diameter of the inner cylinder, and the inner diameter of the second groove is adapted to the outer diameter of the outer cylinder. At least two sets of connecting holes are evenly distributed within a 360° phase of the outer edge of the top plate body, and the connecting rod is inserted through the connecting holes.

[0012] The outer and inner cylinders of this utility model are made of plexiglass.

[0013] This utility model has thermal insulation material between the outer cylinder and the inner cylinder.

[0014] This invention has the following advantages over the prior art:

[0015] 1. This device, through the design of an inner and outer cylinder, has a simulation device set in the upper part of the inner cylinder. The simulation device can simultaneously introduce water and chilled liquid to simulate the process, realizing real-time measurement of salt swelling and water-salt migration of coarse-grained saline soil during the test.

[0016] 2. This device can perform freeze-thaw cycle model tests on coarse-grained saline soil under various working conditions.

[0017] 3. This device can be freely disassembled and assembled, making it easy to carry and reuse. Attached Figure Description

[0018] Figure 1 This is a structural schematic diagram of one embodiment of the present invention.

[0019] Figure 2 yes Figure 1 The main view.

[0020] Figure 3 yes Figure 1 A schematic diagram of the structure of the top plate 1.

[0021] Figure 4 yes Figure 1 A schematic diagram of the structure of the simulation device 2.

[0022] Figure 5 yes Figure 4 A sectional view.

[0023] Figure 6 yes Figure 4 Top view (with cover plate 2-1 removed).

[0024] Figure 7 yes Figure 1 A schematic diagram of the structure of the rubber stopper 3.

[0025] Figure 8 yes Figure 1 A schematic diagram of the structure of the inner and outer cylinder 5.

[0026] Figure 9 yes Figure 1 A schematic diagram of the inner cylinder 6.

[0027] In the diagram: 1. Top plate; 2. Simulation device; 3. Rubber stopper; 4. Connecting rod; 5. Outer cylinder; 6. Inner cylinder; 7. Bottom plate; 8. Fastening nut; 1-1. Top plate body; 1-2. First groove; 1-3. Second groove; 1-4. Connecting hole; 1-5. First through hole; 2-1. Shell; 2-2. Cover plate; 2-3. Second through hole; 2-4. Connector; 2-5. Liquid pipe; 2-6. Leakage hole; 3-1. Through groove; 5-1. First rectangular hole; 6-1. Second rectangular hole. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to these embodiments.

[0029] Example 1

[0030] exist Figures 1-3In sections 7 to 9, the coarse-grained saline soil salt frost heave and water-salt migration test device of this utility model is composed of a top plate 1, an outer cylinder 5, an inner cylinder 6, and a bottom plate 7 connected together. The outer cylinder 5 is installed between the top plate 1 and the bottom plate 7. The top plate 1 and the bottom plate 7 are made of stainless steel. The inner cylinder 6 is concentrically arranged inside the outer cylinder 5. The outer cylinder 5 and the inner cylinder 6 are made of plexiglass tubes to facilitate observation of the test progress. The inner cylinder 6 is filled with coarse-grained saline soil. In this embodiment, the top plate 1 and the bottom plate 7 have the same structure. The top plate 1 is composed of a top plate body 1-1, which is a circular structure. The top plate body 1-1 has a first groove 1-2 and a second groove 1-3 concentrically machined on the contact surface with the outer cylinder 5 and the inner cylinder 6. The depth of the first groove 1-2 is greater than the depth of the second groove 1-3. The inner diameter of the first groove 1-2 is adapted to the outer diameter of the inner cylinder 6, and the inner cylinder 6 is fitted inside the first groove 1-2. The inner diameter of the second groove 1-3 is adapted to the outer diameter of the outer cylinder 5, and the outer cylinder 5 is fitted inside the second groove 1-3. At least two sets of connecting holes 1-4 are evenly distributed within a 360° phase of the outer edge of the top plate body 1-1. The number of sets of connecting holes 1-4 is determined according to the size of the top plate. The connecting rod 4 is inserted through the connecting hole 1-4. The outer cylinder 5 and the inner cylinder 6 are fixed between the top plate 1 and the bottom plate 2 by the fastening nuts 8 at both ends of the connecting rod 4. The outer cylinder 5 and the inner cylinder 6 are fitted into the groove, which improves the sealing performance of the device and makes the connection more stable and less likely to fall off. The outer cylinder 5 and the inner cylinder 6 can be insulated with heat-insulating material according to the test requirements. Four first through holes 1-5 are machined in the first groove 1-2. Rubber plugs or water supply and drainage connectors are installed in the first through holes 1-5 according to the test requirements. The side wall of the outer cylinder 5 is vertically spaced with first rectangular holes 5-1. The side wall of the inner cylinder 6 is provided with second rectangular holes 6-1 corresponding to the first rectangular holes 5-1. The rubber plug 3 is installed in the first rectangular holes 5-1 and the second rectangular holes 6-1. The rubber plug 3 is machined with a through groove 3-1 in the middle. A glass plug is installed in the through groove 3-1. During the test, the glass plug can be removed to install the corresponding sensor.

[0031] A simulation device 2 is installed on the upper part of the inner cylinder 6, such as Figures 4-6As shown, the simulation device 2 is composed of a shell 2-1, a cover plate 2-2, a connector 2-4, and a liquid pipe 2-5. The shell 2-1 has a circular structure, and a cover plate 2-2 is installed on the top of the shell 2-1. Four second through holes 2-3 are machined on the cover plate 2-2, and connectors 2-4 are installed in two of the second through holes 2-3. The liquid pipe 2-5 is horizontally arranged inside the shell 2-1, and both ends of the liquid pipe 2-5 are connected to the connectors 2-4. A rubber hose is installed outside the connectors 2-4. The rubber hose passes through the first through hole 1-5 on the top plate 1 and is connected to an external liquid supply and circulation device. In this embodiment, the liquid pipe 2-5 is spirally coiled on the bottom plate of the shell 2-1. Drainage holes 2-6 are evenly distributed on the bottom plate of the shell 2-1. During the test, water can be supplied to the simulation device 2 through the remaining two second through holes 2-3. The water flows evenly into the coarse-grained saline soil inside the inner cylinder 6 through the drainage holes 2-6 to simulate rainfall.

[0032] The operation process of this utility model is as follows:

[0033] (1) As Figure 1 As shown, assemble the relevant components of the testing instrument in sequence;

[0034] (2) Adjust the fastening nut 8 to ensure that the outer cylinder 5 and inner cylinder 6 are vertical. Waterproof the contact points between the outer cylinder 5, inner cylinder 6 and the top plate 1 and bottom plate 7. Fill the space between the outer cylinder 5 and inner cylinder 6 with insulation material according to different test requirements. Replace the rubber plug in the through hole of the bottom plate 7 with a water supply or drainage device. Alternatively, it can be left unreplaced according to test requirements.

[0035] (3) Fill the inner cylinder 6 with coarse-grained saline soil, and replace the glass stopper in the side wall rubber stopper 3 with the corresponding sensor according to the test requirements.

[0036] (4) Place the simulation device 2 on top of the coarse-grained saline soil. The two rubber hoses on the top of the simulation device 2 pass through the two first through holes 1-5 of the top plate 1 and are connected to the external liquid supply device. During the test, the coolant is delivered to the set temperature through one rubber hose and output through the other rubber hose to realize the circulation of coolant in the simulation device 2. According to different test needs, rubber hoses can be set in the other two first through holes 1-5 to deliver water to the inside of the simulation device, so that it flows evenly into the coarse-grained saline soil through the seepage holes 2-6 to realize the simulation of rainfall.

[0037] (5) Other measuring sensors may be installed between the top plate 1 and the cover plate 2-2 as needed for the test.

Claims

1. A test apparatus for salt frost heave and water-salt migration in coarse-grained saline soil, characterized in that: The outer cylinder (5) is located between the top plate (1) and the bottom plate (7). The top plate (1) and the bottom plate (7) are connected and fixed by the connecting rod (4) and the fastening nut (8). The inner cylinder (6) is concentrically arranged inside the outer cylinder (5). The simulation device (2) is arranged on the upper part of the inner cylinder (6). The bottom of the simulation device (2) is connected to the inside of the inner cylinder (6), and the top is equipped with a rubber hose.

2. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 1, characterized in that... The simulation device (2) is as follows: the shell (2-1) is circular, the top of the shell (2-1) is provided with a cover plate (2-2), the cover plate (2-2) is machined with four second through holes (2-3), two of the second through holes (2-3) are provided with connectors (2-4), a liquid pipe (2-5) is horizontally arranged inside the shell (2-1), the two ends of the liquid pipe (2-5) are connected to the connectors (2-4), and a rubber hose is provided outside the connectors (2-4).

3. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 2, characterized in that: The liquid tube (2-5) is spirally coiled on the bottom plate of the shell (2-1).

4. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 2, characterized in that... The bottom plate of the shell (2-1) is provided with evenly distributed seepage holes (2-6).

5. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 1, characterized in that: The outer cylinder (5) has a first rectangular hole (5-1) spaced at intervals in the vertical direction on its side wall, and the inner cylinder (6) has a second rectangular hole (6-1) on its side wall corresponding to the first rectangular hole (5-1). The rubber plug (3) is disposed in the first rectangular hole (5-1) and the second rectangular hole (6-1).

6. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 5, characterized in that: The rubber stopper (3) has a through groove (3-1) in the middle, and a glass stopper is placed in the through groove (3-1).

7. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 1, characterized in that: The top plate (1) and bottom plate (7) have the same structure.

8. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 7, characterized in that... The top plate (1) is as follows: the top plate body (1-1) is a circular structure. The top plate body (1-1) has a first groove (1-2) and a second groove (1-3) concentrically machined on the contact surface with the outer cylinder (5) and the inner cylinder (6). The depth of the first groove (1-2) is greater than the depth of the second groove (1-3). Four first through holes (1-5) are machined in the first groove (1-2). The inner diameter of the first groove (1-2) is adapted to the outer diameter of the inner cylinder (6). The inner diameter of the second groove (1-3) is adapted to the outer diameter of the outer cylinder (5). At least two sets of connecting holes (1-4) are evenly distributed within the 360° phase of the outer edge of the top plate body (1-1). The connecting rod (4) is inserted through the connecting hole (1-4).

9. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 1, characterized in that: The outer cylinder (5) and inner cylinder (6) are made of plexiglass.

10. The apparatus for testing salt frost heave and water-salt migration in coarse-grained saline soil according to claim 1, characterized in that: Thermal insulation material is provided between the outer cylinder (5) and the inner cylinder (6).

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