Salinized soil deformation measuring device under freezing and thawing cycle condition

Abstract

The utility model discloses a device for measuring the deformation of salinized soil under a freezing and thawing cycle condition, which relates to the technical field of devices for measuring the deformation of soil samples with different layer heights in a freezing and thawing process, and comprises stainless steel wafers and a stainless steel solid round bar, and the stainless steel wafers are fixedly mounted at the upper end and the lower end of the stainless steel solid round bar; a capillary hollow aluminum pipe is sleeved on the peripheral surface of the middle part of the stainless steel solid round rod; the upper end and the lower end of the capillary hollow aluminum pipe are not propped against the stainless steel round sheets; a soil three-parameter sensor is inserted into a hole reserved in the side edge of the organic glass cylinder, the peripheral surface of the organic glass cylinder is coated with heat preservation cotton, an upper temperature conduction disc is installed at the upper end of the organic glass cylinder, a lower temperature conduction disc is installed at the lower end of the organic glass cylinder, and the bottom of the organic glass cylinder is communicated with the Markov bottle. The utility model relates to a saline soil deformation measuring device under a freezing and thawing cycle condition, which can reveal deformation behaviors of soil bodies with different depths or specific soil layers in freezing and thawing cycles.

Description

Technical Field

[0001] This utility model relates to the technical field of measuring devices for soil samples of different heights during freeze-thaw cycles, and particularly to a device for measuring the deformation of saline soil under freeze-thaw cycle conditions. Background Technology

[0002] Saline soil is widely distributed in Northwest China, and the number of engineering projects in saline soil areas is constantly increasing. Saline soil has special properties, and after multiple seasonal freeze-thaw cycles, it will have a negative impact on the structure and stability of the soil, especially in infrastructure construction, such as the foundations of roads, bridges and buildings.

[0003] During soil freezing, temperature changes cause phase changes in the soil's internal moisture. Especially when the soil contains salt, the salt precipitates and migrates during freezing, forming ice and salt crystals, leading to salt frost heave deformation. During thawing, the ice transforms into water, and the salt dissolves, causing thaw settlement deformation. Furthermore, these deformations can lead to uneven settlement of the subgrade or foundation, cracks on the soil surface, and affect the soil's stability and bearing capacity. In freeze-thaw cycles, salt frost heave and thaw settlement alternate, making the measurement of salt frost heave and thaw settlement in saline soils under freeze-thaw cycles particularly important.

[0004] Due to temperature changes, moisture and salt migrate within the soil. Different soil layers at different depths exhibit varying salt and moisture content. Layers with lower salt content show significant frost heave and thaw settlement during freeze-thaw cycles, with thaw settlement exceeding frost heave. Conversely, soils with higher salt content exhibit significant salt-frost heave during freezing, while thaw settlement is less pronounced or disappears during thawing. Therefore, the deformation behavior of each soil layer differs during freeze-thaw cycles. However, current methods for measuring the deformation of saline soil under freeze-thaw cycles primarily utilize dial gauges or displacement sensors placed on top of the soil sample to measure the overall deformation of the soil, neglecting the deformation behavior of each individual layer. Therefore, measuring the deformation of each soil layer at different heights separately becomes a key technology for revealing the salt-frost heave characteristics of saline soils.

[0005] How to develop a device for measuring the deformation of saline soil under freeze-thaw cycles is a technical problem that urgently needs to be solved by those skilled in the art. Currently, the devices for measuring the deformation of saline soil samples under freeze-thaw cycles mainly use dial gauges or displacement sensors to measure the overall deformation of the soil, ignoring the influence of the deformation of soil layers at different depths or a specific soil layer on the overall stability and bearing capacity of the soil sample. Utility Model Content

[0006] The purpose of this invention is to provide a device for measuring the deformation of saline soil under freeze-thaw cycles, thereby solving the problems listed in the background art.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] This utility model is a device for measuring the deformation of saline soil under freeze-thaw cycles, including a stainless steel disc and a stainless steel solid rod. The stainless steel disc is fixedly installed at the upper and lower ends of the stainless steel solid rod. A capillary hollow aluminum tube is sleeved on the outer circumference of the middle part of the stainless steel solid rod. The upper and lower ends of the capillary hollow aluminum tube do not abut against the stainless steel disc.

[0009] It also includes an acrylic glass tube, in which soil three-parameter sensors are inserted into holes at different heights on the side of the acrylic glass tube. The outer circumference of the acrylic glass tube is covered with heat-insulating cotton. An upper temperature-conducting plate is installed at the upper end of the acrylic glass tube, and a lower temperature-conducting plate is installed at the lower end of the acrylic glass tube. The bottom of the acrylic glass tube is connected to the Marshall bottle.

[0010] Preferably, the upper temperature guide plate has a plurality of through holes evenly distributed thereon, and the outer wall of the capillary hollow aluminum tube abuts against the through holes.

[0011] Preferably, the stainless steel disc located at the upper end of the solid stainless steel bar abuts against the probe of the dial indicator, the dial indicator is electrically connected to the input terminal of the data acquisition instrument, and the output terminal of the data acquisition instrument is electrically connected to the computer.

[0012] Preferably, it also includes a lower low-temperature constant temperature chamber and an upper low-temperature constant temperature chamber, wherein the lower low-temperature constant temperature chamber is connected to the lower temperature guide plate, and the upper low-temperature constant temperature chamber is connected to the upper temperature guide plate.

[0013] Preferably, the capillary hollow aluminum tube has an outer diameter of 3mm, a wall thickness of 0.9mm, and lengths of 45cm, 35cm, 25cm, 15cm, and 5cm, respectively.

[0014] Preferably, the solid stainless steel round bar has a diameter of 0.8 mm and lengths of 50 cm, 40 cm, 30 cm, 20 cm, and 10 cm.

[0015] Preferably, the inner diameter of the plexiglass tube is 15cm and the height is 50cm.

[0016] Preferably, the stainless steel disc has a diameter of 1 cm and a thickness of 1 mm.

[0017] Preferably, the interior of the plexiglass tube is filled with a test soil column, the lower surface of the upper temperature-conducting plate abuts against the upper surface of the test soil column, and the upper surface of the lower temperature-conducting plate abuts against the lower surface of the test soil column.

[0018] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0019] This invention relates to a novel device for measuring the deformation of saline soil under freeze-thaw cycles. By embedding a solid stainless steel rod, a stainless steel disc, and an outer capillary hollow aluminum tube in layers, the device ensures that the vertical expansion and contraction of the solid stainless steel rod within the test soil column is unaffected by the lateral constraints of the soil. This allows for the acquisition of more detailed information on soil deformation or deformation of specific soil layers, revealing the deformation behavior of soil layers at different depths during freeze-thaw cycles. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of a device for measuring the deformation of saline soil under freeze-thaw cycles according to the present invention.

[0022] Figure 2 This is a top view of the temperature-conducting plate with an opening at the top of this utility model;

[0023] Figure 3 This is a schematic diagram of the deformation measurement device of this utility model.

[0024] Explanation of reference numerals in the attached diagram: 1. Data acquisition instrument; 2. Dial gauge; 3. Stainless steel disc; 4. Soil three-parameter sensor; 5. Capillary hollow aluminum tube; 6. Stainless steel solid round bar; 7. Upper temperature guide plate; 8. Computer; 9. Acrylic glass cylinder; 10. Insulation cotton; 11. Marshall bottle; 12. Lower low-temperature constant temperature chamber; 13. Lower temperature guide plate; 14. Upper low-temperature constant temperature chamber; 15. Through hole. Detailed Implementation

[0025] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0026] like Figure 1-3 As shown, a device for measuring the deformation of saline soil under freeze-thaw cycles includes a stainless steel disc 3 and a stainless steel solid rod 6. The lower end of the stainless steel solid rod 6 is welded to the stainless steel disc 3, and the upper end of the stainless steel solid rod 6 is bonded to the stainless steel disc 3. A capillary hollow aluminum tube 5 is sleeved on the outer circumference of the middle part of the stainless steel solid rod 6. The upper and lower ends of the capillary hollow aluminum tube 5 do not abut against the stainless steel disc 3.

[0027] It also includes an acrylic glass tube 9, in which soil three-parameter sensors 4 are inserted into holes at different heights reserved on the side of the acrylic glass tube 9. The outer circumference of the acrylic glass tube 9 is covered with heat insulation cotton 10. An upper temperature guide plate 7 is installed at the upper end of the acrylic glass tube 9, and a lower temperature guide plate 13 is installed at the lower end of the acrylic glass tube 9. The bottom of the acrylic glass tube 9 is connected to a Marshall bottle 11, and water is replenished into the acrylic glass tube through the Marshall bottle.

[0028] The upper temperature guiding plate 7 has five through holes 15 with a diameter of 4 mm evenly distributed. The outer wall of the capillary hollow aluminum tube 5 abuts against the through holes 15. The solution in the upper temperature guiding plate 7 and the lower temperature guiding plate 13 is ethylene glycol-based antifreeze.

[0029] Specifically, the stainless steel disc 3 located at the upper end of the solid stainless steel bar 6 abuts against the probe of the dial indicator 2, and the dial indicator 2 is electrically connected to the input terminal of the data acquisition instrument 1; the output terminal of the data acquisition instrument 1 is electrically connected to the computer 8.

[0030] Specifically, it also includes a lower low-temperature constant temperature chamber 12 and an upper low-temperature constant temperature chamber 14. The lower low-temperature constant temperature chamber 12 is connected to the lower temperature guide plate 13, and the upper low-temperature constant temperature chamber 14 is connected to the upper temperature guide plate 7. The temperature at both ends of the test soil column is controlled by the upper and lower low-temperature constant temperature chambers.

[0031] Specifically, the capillary hollow aluminum tube 5 has an outer diameter of 3mm, a wall thickness of 0.9mm, and lengths of 45cm, 35cm, 25cm, 15cm, and 5cm, respectively. The stainless steel solid round rod 6 has a diameter of 0.8mm and lengths of 50cm, 40cm, 30cm, 20cm, and 10cm, respectively. The capillary hollow aluminum tube is 5cm shorter than the stainless steel solid rod. Placing the stainless steel solid rod and stainless steel disc assembly inside the capillary hollow aluminum tube allows the stainless steel solid rod and stainless steel disc assembly to expand and contract vertically in the test soil column without being affected by the lateral confinement of the soil, thus enabling the acquisition of deformation behavior of soil layers at different heights under freeze-thaw cycles.

[0032] Specifically, the inner diameter of the plexiglass tube 9 is 15cm and the height is 50cm.

[0033] Specifically, the stainless steel disc 3 has a diameter of 1 cm and a thickness of 1 mm.

[0034] Specifically, the interior of the plexiglass cylinder 9 is filled with a test soil column, the lower surface of the upper temperature-conducting plate 7 abuts against the upper surface of the test soil column, and the upper surface of the lower temperature-conducting plate 13 abuts against the lower surface of the test soil column.

[0035] In the experiment, the stainless steel disc 3, the stainless steel solid round bar 6, and the outer capillary hollow aluminum tube 5 of the deformation measuring equipment were first buried in layers at different heights of the test soil column. The upper temperature guiding plate 7 was aligned with the capillary hollow aluminum tube 5 and passed through. Then, the stainless steel disc 3 and the top of the stainless steel solid round bar 6 were bonded together.

[0036] The specific implementation method is as follows:

[0037] 1) Experimental preparation: Wrap a layer of insulation cotton around the outside of the plexiglass tube, and use a flexible tube wrapped with insulation cotton to connect the temperature conducting plate located at the top and bottom of the soil column to the low temperature constant temperature chamber to form a circuit. Turn on the instrument to test the cooling effect.

[0038] 2) Soil sample preparation: Determine the required soil sample mass for the soil column according to the sample control conditions, mix the soil sample thoroughly and seal it for 24 hours;

[0039] 3) Filling the soil sample: Use sealing clay to fill the reserved hole of the plexiglass where the soil three-parameter sensor is placed, apply Vaseline inside the plexiglass tube, and fill the plexiglass tube with soil sample in layers and compact it. Scrape the surface of each layer. During the compaction process, embed the soil three-parameter sensor and deformation measurement device. First, embed the bottom of the stainless steel disc 3 and the stainless steel solid rod 6 and the outer capillary hollow aluminum tube 5 of the deformation measurement device in layers at different heights of the test soil column. Then, align the upper temperature guide plate with the capillary hollow aluminum tube and pass it through. Firmly bond the stainless steel disc 3 and the top of the stainless steel solid rod 6. After the soil column is left to stand for 12 hours, conduct a cooling test.

[0040] 4) The soil three-parameter sensor collects temperature, moisture and electrical conductivity data, the dial gauge deformation measurement system collects soil sample deformation data, the low temperature constant temperature circulation device is turned on, the upper and lower temperature guide plates are controlled according to the set time, and the freeze-thaw cycle test is carried out.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A device for measuring the deformation of saline soil under freeze-thaw cycles, comprising a stainless steel disc (3) and a stainless steel solid rod (6), wherein the stainless steel disc (3) is fixedly installed at both the upper and lower ends of the stainless steel solid rod (6), characterized in that: A capillary hollow aluminum tube (5) is fitted on the outer circumference of the middle part of the solid stainless steel round bar (6), and the upper and lower ends of the capillary hollow aluminum tube (5) do not abut against the stainless steel round plate (3). It also includes an acrylic tube (9), in which soil three-parameter sensors (4) are inserted into holes at different heights reserved on the side of the acrylic tube (9), the outer circumference of the acrylic tube (9) is covered with heat insulation cotton (10), an upper temperature guide plate (7) is installed at the upper end of the acrylic tube (9), a lower temperature guide plate (13) is installed at the lower end of the acrylic tube (9), and the bottom of the acrylic tube (9) is connected to the Marshall bottle (11).

2. The device for measuring deformation of saline soil under freeze-thaw cycles according to claim 1, characterized in that: The upper temperature guide plate (7) is provided with a plurality of through holes (15) evenly distributed, and the outer wall of the capillary hollow aluminum tube (5) abuts against the through holes (15).

3. The device for measuring deformation of saline soil under freeze-thaw cycles according to claim 1, characterized in that: The stainless steel disc (3) located at the upper end of the solid stainless steel bar (6) abuts against the probe of the dial indicator (2), and the dial indicator (2) is electrically connected to the input end of the data acquisition instrument (1); the output end of the data acquisition instrument (1) is electrically connected to the computer (8).

4. The device for measuring deformation of saline soil under freeze-thaw cycles according to claim 1, characterized in that: It also includes a lower low temperature constant temperature chamber (12) and an upper low temperature constant temperature chamber (14), wherein the lower low temperature constant temperature chamber (12) is connected to the lower temperature guide plate (13) and the upper low temperature constant temperature chamber (14) is connected to the upper temperature guide plate (7).

5. The device for measuring deformation of saline soil under freeze-thaw cycles according to claim 1, characterized in that: The capillary hollow aluminum tube (5) has an outer diameter of 3 mm, a wall thickness of 0.9 mm, and lengths of 45 cm, 35 cm, 25 cm, 15 cm, and 5 cm, respectively.

6. The device for measuring deformation of saline soil under freeze-thaw cycles according to claim 1, characterized in that: The solid stainless steel round bar (6) has a diameter of 0.8 mm and lengths of 50 cm, 40 cm, 30 cm, 20 cm and 10 cm respectively.

7. The device for measuring deformation of saline soil under freeze-thaw cycles according to claim 1, characterized in that: The inner diameter of the plexiglass tube (9) is 15cm and the height is 50cm.

8. The device for measuring deformation of saline soil under freeze-thaw cycles according to claim 1, characterized in that: The stainless steel disc (3) has a diameter of 1 cm and a thickness of 1 mm.

9. The device for measuring deformation of saline soil under freeze-thaw cycles according to claim 1, characterized in that: The interior of the plexiglass tube (9) is filled with a test soil column. The lower surface of the upper temperature guide plate (7) abuts against the upper surface of the test soil column, and the upper surface of the lower temperature guide plate (13) abuts against the lower surface of the test soil column.

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