Non-contact distance measurement frost heaving instrument

Abstract

The utility model discloses a non-contact distance measurement frost heaving instrument. The instrument comprises a see-through sample cylinder; the temperature control system comprises a first temperature control part and a second temperature control part, the first temperature control part is arranged at the lower part of the sample cylinder and forms the bottom of the sample cylinder, the second temperature control part can enter the sample cylinder, and the temperature of the first temperature control part and the temperature of the second temperature control part can be adjusted; the temperature acquisition system is used for measuring temperature data of different positions in the sample cylinder in the axial direction; the water replenishing system is arranged at the bottom of the sample cylinder; and the displacement acquisition system is erected above the second temperature control part, and the displacement acquisition system measures the displacement amount of different positions of the second temperature control part in a non-contact mode. Compared with the prior art, original contact type displacement measurement is changed into non-contact type displacement measurement, frost heaving displacement data in the frost heaving test can be obtained more comprehensively, accurately and completely, a traditional contact type dial indicator is replaced with the non-contact type measurement means, and displacement is collected more accurately while errors are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geological observation, in particular to a non-contact distance measuring frost heaving instrument. BACKGROUND

[0002] In cold region engineering, the frequent and periodic changes in water and heat in the seasonal frozen region will cause various engineering diseases, among which frost heaving and thawing settlement are the most common and the most difficult to handle. The volume change of soil during the freezing process and the freezing-thawing cycle is a key basic problem in frozen soil engineering. To investigate the frost heaving problem of soil, researchers have conducted various tests. From the development of frost heaving, it is mainly divided into three-dimensional and one-dimensional frost heaving. One-dimensional frost heaving test has the advantages of simple instrument setting, easy temperature control, and obvious frost heaving deformation, so it is adopted by a large number of researchers. Based on this, many one-dimensional frost heaving instruments with different designs have been developed. One-dimensional frost heaving test has two important data collection: temperature and displacement. The collection of temperature is realized by temperature sensor and data acquisition instrument, and the collection of displacement is mainly recorded by dial gauge or displacement meter. However, this traditional contact displacement collection method has obvious shortcomings: it can only measure the displacement of one point and cannot accurately reflect the frost heaving displacement on the entire frost heaving surface; and the displacement meter (dial gauge) is easily affected by temperature, which causes the collected data curve to have unexplained mutations due to poor contact and increased mechanical friction under negative temperature.

[0003] Researchers have also used methods such as thickening the top plate and fixing the displacement meter to try to solve the above problems. However, with the increase in the thickness of the top plate, the self-weight increases, which will affect the frost heaving of the sample, resulting in a smaller measured frost heaving displacement. This is different from the actual value of the test, and the thickening of the top plate also brings new problems of inaccurate temperature control, which increases the test error. Therefore, the effect of this method is limited and is suitable for tests of high water content and frost heaving sensitive soil samples, but it cannot be used for frost heaving displacement measurement of various test soil bodies.

[0004] The displacement collection in the existing one-dimensional frost heaving instrument is mainly realized by using a contact displacement meter. However, this method is not comprehensive enough for displacement collection and cannot accurately reflect the displacement of the top plate surface. Practical new type content

[0005] The present application aims to solve one of the above technical problems in the prior art. To this end, the present application provides a non-contact distance measuring frost heaving instrument

[0006] According to the embodiments of the present application, a non-contact distance measuring frost heaving instrument is provided, which includes a transparent sample cylinder.

[0007] The temperature control system comprises a first temperature control part and a second temperature control part, the first temperature control part is arranged at the lower part of the sample cylinder and forms the bottom of the sample cylinder, the second temperature control part can enter the sample cylinder, and the temperatures of the first temperature control part and the second temperature control part are adjustable;

[0008] The temperature acquisition system is used for measuring temperature data at different positions in the axial direction of the sample cylinder.

[0009] The water supplement system is arranged at the bottom of the sample cylinder.

[0010] The displacement acquisition system is arranged above the second temperature control part, and the displacement acquisition system measures the displacement of the second temperature control part at different positions in a non-contact manner.

[0011] The non-contact distance measuring frost heaving instrument has at least the following beneficial effects: during the frost heaving experiment, the soil sample is placed in the sample cylinder and compacted, the second temperature control part is placed on the upper part of the compacted soil sample, the distance between the temperature acquisition system and the second temperature control part is adjusted, the displacement acquisition system acquires the displacement changes of the second temperature control part at at least three positions, after the arrangement of each system is completed, the sample cylinder of the application is placed in a constant temperature and humidity box, when the internal temperature of the sample and the environmental temperature are the same and stable, the temperatures of the first temperature control part and the second temperature control part are adjusted, a temperature difference is formed between the second temperature control part and the first temperature control part, the soil sample is subjected to one-way freezing from top to bottom, after a period of freezing, the temperature data of the displacement acquisition system, the frost heaving displacement data of the displacement acquisition system from the second temperature control part, and the volume data of the water reduced by the water supplement system are collected as the frost heaving test data. Compared with the prior art, the original contact displacement measurement is changed to non-contact displacement measurement, the frost heaving displacement data in the frost heaving test can be more comprehensively, accurately and completely obtained, the non-contact measurement method is used to replace the traditional contact dial gauge, the displacement is more accurately collected while the error is reduced, the soil frost heaving test can be more comprehensively analyzed, and the test result can be more truly reflected.

[0012] According to the non-contact distance measuring frost heaving instrument, the displacement acquisition system comprises at least three laser displacement sensors, and the laser displacement sensors are distributed in a circumferential array around the central axis of the sample cylinder.

[0013] According to the non-contact distance measuring frost heaving instrument, the displacement acquisition system further comprises an adjusting assembly, and the adjusting assembly can adjust the distance between the laser displacement sensors and the second temperature control part.

[0014] The non-contact distance measuring frost heaving instrument according to the embodiment of the present application, the adjusting assembly comprises a first adjusting member and a second adjusting member, the first adjusting member extends above the sample cylinder, the second adjusting member is adjustably arranged on the first adjusting member, and the second adjusting member can adjust the depth into the sample cylinder, and the laser displacement sensor is arranged at the end of the second adjusting member into the sample cylinder.

[0015] The non-contact distance measuring frost heaving instrument according to the embodiment of the present application, the adjusting assembly further comprises a third adjusting member, the third adjusting member can be adjusted by rotating around the central axis thereof, the first adjusting member is adjustably arranged on the third adjusting member, and the first adjusting member can adjust the horizontal position of the end extending above the sample cylinder.

[0016] The non-contact distance measuring frost heaving instrument according to the embodiment of the present application, the end of the first adjusting member is provided with a first fastener and a first mounting hole for inserting the second adjusting member, the first fastener can press against the second adjusting member into the first mounting hole to limit the movement of the second adjusting member.

[0017] The non-contact distance measuring frost heaving instrument according to the embodiment of the present application, the end of the third adjusting member is provided with a second fastener and a second mounting hole for inserting the first adjusting member, the second fastener can press against the first adjusting member into the second mounting hole.

[0018] The non-contact distance measuring frost heaving instrument according to the embodiment of the present application, the first temperature control part comprises a first flow guide groove, a first liquid inlet and a first liquid outlet, the first flow guide groove is annularly arranged inside the first temperature control part, and the first liquid inlet and the first liquid outlet arranged outside the first temperature control part are respectively connected to both ends of the first flow guide groove.

[0019] The non-contact distance measuring frost heaving instrument according to the embodiment of the present application, the water replenishing system comprises a second flow guide groove and a second liquid inlet, the second flow guide groove is arranged inside the first temperature control part, one end of the second flow guide groove is connected to the second liquid inlet arranged outside the first temperature control part, and the other end of the flow guide groove is arranged at the center of the side of the first temperature control part facing the second temperature control part and serves as a second liquid outlet.

[0020] The non-contact distance measuring frost heaving instrument according to the embodiment of the present application, the inside of the second temperature control part is provided with a cavity, and the side of the second temperature control part away from the first temperature control part is provided with a third liquid inlet and a third liquid outlet communicating with the cavity.

[0021] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0022] The application will be further described below in conjunction with the drawings and embodiments.

[0023] Figure 1 is a structural schematic of a non-contact distance measuring frost heaving instrument of an embodiment of the application Figure 1 ;

[0024] Figure 2 is a structural schematic of a non-contact distance measuring frost heaving instrument of an embodiment of the application Figure 2 ;

[0025] Figure 3 is a structural schematic of a second temperature control part in an embodiment of the application

[0026] Figure 4 is a structural schematic of a first temperature control part in an embodiment of the application

[0027] Figure 5 is a structural schematic of a displacement acquisition system in an embodiment of the application.

[0028] Reference signs: 1, mounting plate; 2, sample cylinder; 3, connecting rod; 4, first temperature control part; 5, third liquid inlet; 6, third liquid outlet; 7, second temperature control part; 8, sealing ring; 9, second liquid outlet; 10, brass plate; 11, first liquid inlet; 12, second liquid inlet; 13, first liquid outlet; 14, second adjusting member; 15, first adjusting member; 16, third adjusting member; 17, mounting member; 18, laser displacement sensor. DETAILED DESCRIPTION

[0029] This part will describe the specific embodiments of the application in detail, the preferred embodiments of the application are shown in the drawings, the role of the drawings is to supplement the description of the text part with figures, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the application, but it cannot be understood as a limitation on the protection scope of the application.

[0030] In the description of the application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the application.

[0031] In the description of the present application, the meaning of one or more is one or more, the meaning of multiple is more than two, greater than, less than, more than, etc. is understood as not including the number, above, below, etc. is understood as including the number. If it is described to the first, the second is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0032] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical scheme.

[0033] Referring to Figure 1 and Figure 2 The non-contact frost heaving instrument of the embodiment of the present application includes a perspectively sample cylinder 2, a temperature control system, a temperature acquisition system, a water supplement system and a displacement acquisition system.

[0034] Among them, the sample cylinder 2 is set to be perspectively, which can more intuitively observe the frost heaving process and water supplement process of the soil sample. In specific embodiments, the sample cylinder 2 can be made of acrylic.

[0035] The temperature control system includes a first temperature control part 4 and a second temperature control part 7. The first temperature control part 4 is arranged at the lower part of the sample cylinder 2 and formed as the bottom of the sample cylinder 2. The second temperature control part 7 can enter the sample cylinder 2. The temperatures of the first temperature control part 4 and the second temperature control part 7 can be adjusted. Among them, the first temperature control part 4 serves as the bottom of the sample cylinder 2 and adjusts the temperature from the bottom for the soil sample placed in the sample cylinder 2. The second temperature control part 7 is placed on the top of the soil sample after the soil sample is compacted in the sample cylinder 2, which facilitates the displacement acquisition system to measure the displacement. It should be noted that the second temperature control part 7 adjusts the temperature from the top of the soil sample.

[0036] In the embodiment of the present application, the temperature acquisition system is used to measure the temperature data of different positions in the axial direction of the sample cylinder 2. Specifically, the temperature acquisition system includes at least three temperature sensors. A plurality of placement holes for the temperature sensors to be inserted are arranged on the side wall of the sample cylinder 2 along the axial direction. The temperature data of different positions in the axial direction of the sample cylinder 2 is realized by the plurality of temperature sensors placed at different positions.

[0037] The water supplement system is arranged at the bottom of the sample cylinder 2. The water supplement system is used to supplement water to the compacted soil sample from the bottom of the sample cylinder 2.

[0038] The displacement acquisition system is erected above the second temperature control part 7. The displacement acquisition system measures the displacement of different positions of the second temperature control part 7 in a non-contact manner.

[0039] Specifically, during the frost heaving experiment, the soil sample is placed in the sample cylinder 2 and compacted, the second temperature control part 7 connected with the cold bath device is placed on the upper part of the compacted soil sample, the temperature collection system is adjusted, and the distance between the displacement collection system and the second temperature control part 7 is adjusted, the displacement changes of at least three positions of the second temperature control part 7 are collected by the displacement collection system, and the displacement collection system and the temperature collection system are connected with the controller.

[0040] It should be noted that during the soil compaction process, the soil is compacted in three layers. When placing the temperature sensor of the temperature collection system, a hole is drilled in the compacted soil sample from the placement hole by a drill bit, and the drilling is stopped when the center of the soil sample is reached. At this time, the temperature sensor can be placed in the hole. After the measurement points of the displacement collection system are set, the frost heaving experiment can be formally started.

[0041] After the arrangement of each system is completed, the sample cylinder 2 of the present application is placed in the constant temperature and humidity box, and when the internal temperature of the sample and the environmental temperature are the same and stable, the temperature of the first temperature control part 4 and the second temperature control part 7 is adjusted, so that a temperature difference is formed between the second temperature control part 7 and the first temperature control part 4, so that the soil sample is subjected to one-way freezing from top to bottom. After a period of freezing, the temperature data of the displacement collection system, the frost heaving displacement data of the displacement collection system from the second temperature control part 7, and the volume data of the water reduced by the water supplementing system are collected as the frost heaving test data.

[0042] Compared with the prior art, the present application changes the original contact displacement measurement to non-contact displacement measurement, which can more comprehensively, accurately and completely obtain the frost heaving displacement data in the frost heaving test. The non-contact measurement method replaces the traditional contact dial gauge, which can reduce errors and more accurately collect displacement, and can more comprehensively analyze the soil frost heaving test and more truly reflect the test results.

[0043] In some embodiments, the displacement collection system includes at least three laser displacement sensors 18, and the laser displacement sensors 18 are distributed in a circumferential array with the central axis of the sample cylinder 2 as the center. A complete measurement reference surface is formed by the measurement points of the at least three laser displacement sensors 18 (three points determine a plane), and the laser displacement sensors 18 are distributed in a circumferential array with the central axis of the sample cylinder 2 as the center, which can greatly improve the measurement accuracy and more accurately measure the displacement data of the second temperature control part 7.

[0044] In some embodiments, as shown in Figure 1 and Figure 5 The displacement collection system further includes an adjusting assembly, which adjusts the distance between the laser displacement sensors 18 and the second temperature control part 7, facilitates the frost heaving experiment of different amounts of soil samples, and facilitates the accurate adjustment of the distance between the laser displacement sensors 18 and the first temperature control part 4.

[0045] In some examples, the adjusting assembly includes a first adjusting member 15 extending above the sample cylinder 2 and a second adjusting member 14 adjustably arranged on the first adjusting member 15 and capable of adjusting the depth of the second adjusting member 14 into the sample cylinder 2. The laser displacement sensor 18 is arranged at the end of the second adjusting member 14 into the sample cylinder 2.

[0046] In some specific embodiments, the top of the sample cylinder 2 is provided with a mounting plate 1 abutting the top of the sample cylinder 2. The mounting plate 1 and the first temperature control part 4 are connected by a connecting rod 3 so that the first temperature control part 4 can be fixed to the bottom of the sample cylinder 2 and the mounting plate 1 can be fixed to the top of the sample cylinder 2. The connecting rod 3 is connected to the mounting plate 1 or the first temperature control part 4 by screwing.

[0047] The first adjusting member 15 is arranged on the mounting plate 1 and serves as the mounting base of the second adjusting member 14. The second adjusting member 14 is arranged to be adjustable in the vertical direction so as to better adjust the distance between the laser displacement sensor 18 fixed on the second adjusting member 14 and the second temperature control part 7. In the embodiments of the present application, the end of the second adjusting member 14 is further provided with a mounting member 17 for fixing the laser displacement sensor 18. The mounting member 17 has a clamping groove, and the laser displacement sensor 18 is arranged in the clamping groove and is pre-tightened by a bolt, so that the laser displacement sensor 18 is more convenient to disassemble and assemble.

[0048] In some embodiments, the adjusting assembly further includes a third adjusting member 16 capable of rotating adjustment around its central axis. The first adjusting member 15 is adjustably arranged on the third adjusting member 16, and the first adjusting member 15 is capable of adjusting the horizontal position of the end extending above the sample cylinder 2.

[0049] In specific embodiments, the third adjusting member 16 is rotatably arranged on the mounting plate 1, and the mounting plate 1 is provided with an adjusting screw for limiting the rotation of the third adjusting member 16. The third adjusting member 16 serves as the mounting base of the first adjusting member 15, and the first adjusting member 15 is arranged to be adjustable in the horizontal direction. In combination with the rotational arrangement of the third adjusting member 16, the measuring point of the laser displacement sensor 18 can be adjusted to any position of the second temperature control part 7, so that the laser displacement sensor 18 is more convenient to adjust.

[0050] In some specific embodiments, the end of the first adjusting member 15 is provided with a first fastener and a first mounting hole for inserting the second adjusting member 14, the first fastener can press against the second adjusting member 14 into the first mounting hole to limit the movement of the second adjusting member 14. When the laser displacement sensor 18 needs to be adjusted in the vertical direction, the first fastener is loosened so that the second adjusting member 14 can move in the vertical direction, and when the laser displacement sensor 18 is adjusted to the desired height position, the first fastener is pressed into the first mounting hole to pre-press the second adjusting member 14, thereby fixing the position of the laser displacement sensor 18. In the embodiments of the application, the first fastener is a screw.

[0051] In some embodiments, the end of the third adjusting member 16 is provided with a second fastener and a second mounting hole for inserting the first adjusting member 15, the second fastener can press against the first adjusting member 15 into the second mounting hole. When the laser displacement sensor 18 needs to be adjusted in the horizontal direction, the second fastener is loosened so that the first adjusting member 15 can move in the horizontal direction, and when the laser displacement sensor 18 is adjusted to the desired horizontal position, the second fastener is pressed into the second mounting hole to pre-press the first adjusting member 15, thereby fixing the position of the laser displacement sensor 18. In the embodiments of the application, the second fastener is a screw.

[0052] In some embodiments, the temperature control system further comprises a constant temperature and humidity chamber, a low-temperature constant temperature tank, a cold bath liquid, and a flow guide pipe. The low-temperature constant temperature tank has two tanks, which are connected to the first temperature control part 4 and the second temperature control part 7 through the flow guide pipe. The cold bath liquid is circulated into the first temperature control part 4 and the second temperature control part 7 by starting the low-temperature constant temperature tank, and the temperature of the first temperature control part 4 and the second temperature control part 7 is controlled respectively. The first temperature control part 4 and the second temperature control part 7 can be set to the same temperature at the same time, and can also be set to different temperature differences according to the test scheme. During the test, the entire test sample cylinder 2 is placed in the constant temperature and humidity chamber, and the constant temperature and humidity chamber and the two low-temperature constant temperature tanks are set to the same temperature. After a certain period of time, the two low-temperature constant temperature tanks are set to different temperature differences.

[0053] In some embodiments, as shown in Figure 4 The first temperature control part 4 includes a first flow guide groove (not shown in the figure), a first liquid inlet 11 and a first liquid outlet 13. The first flow guide groove is annularly arranged in the inside of the first temperature control part 4, and the first liquid inlet 11 and the first liquid outlet 13 arranged outside the first temperature control part 4 are respectively connected to the two ends of the first flow guide groove. In use, the first liquid inlet 11 and the first liquid outlet 13 are connected to the external cold bath equipment, and by circulating different temperature cooling medium into the first flow guide groove, the first temperature control part 4 can be adjusted to different temperatures.

[0054] In the embodiment of the present application, the first temperature control part 4 is made of metal, and specifically, the top of the first temperature control part 4 can be made of brass plate 10, and a sealing ring 8 is arranged at the connection between the first temperature control part 4 and the sample cylinder 2 to improve the sealing effect.

[0055] The cold bath liquid is controlled by the low-temperature constant-temperature tank to flow into the base through the first liquid inlet 11, and flows out through the first liquid outlet 13 along the first flow channel, and the temperature control of the first temperature control part 4 is realized by controlling the temperature of the cold bath liquid.

[0056] In some specific embodiments, the water supplementing system includes a second flow channel and a second liquid inlet 12, the second flow channel is arranged inside the first temperature control part 4, one end of the second flow channel is connected to the second liquid inlet 12 arranged outside the first temperature control part 4, and the other end of the flow channel is arranged at the center of the side of the first temperature control part 4 facing the second temperature control part 7 and serves as the second liquid outlet 9.

[0057] In some specific embodiments, the water supplementing system further includes a Mariotte bottle, a water-permeable stone, and a stop valve. The Mariotte bottle can maintain a constant hydraulic gradient, the water-permeable stone can uniformly distribute water on the surface of the soil column to uniformly supplement the sample, and the stop valve is responsible for recording the final water supplementing amount.

[0058] In some specific embodiments, the second liquid inlet 12 is connected to the second flow channel, the second flow channel for water supplementing is not communicated with the first flow channel for the cold bath liquid, the Mariotte bottle is used to supplement water to the base, water enters through the second liquid inlet 12 and flows out through the second liquid outlet 9, at this time, the soil column sample in the sample cylinder is supplemented from bottom to top, and the water flow enters the soil column from the lower surface after flowing out of the water outlet.

[0059] In some embodiments, as shown in Figure 3 The second temperature control part 7 is made of brass, which can improve the temperature conduction efficiency. In use, the cold bath liquid flows into the second temperature control part 7 through the third liquid inlet 5 and flows out through the third liquid outlet 6 after filling the cavity. The flow and temperature control of the cold bath liquid are controlled by the low-temperature constant-temperature tank, thereby realizing the function of controlling the temperature of the second temperature control part 7.

[0060] In some embodiments, the inner diameter of the sample cylinder is 100 mm, the outer diameter is 110 mm, the wall thickness is 5 mm, the height is 160 mm, holes with a diameter of 5 mm are drilled every 20 mm along the bottom, and a total of 5 placement holes are arranged.

[0061] In some embodiments, the controllable temperature range of the constant-temperature and constant-humidity box is -20 to 40 degrees Celsius, the temperature control is relatively rapid, and the temperature control effect is stable.

[0062] In some embodiments, the temperature range of the low-temperature thermostat is -15 to 30 degrees Celsius, the temperature control is rapid, and the temperature of the brass top plate and the metal base can be set according to the test scheme.

[0063] In some embodiments, the temperature sensor is platinum, and there are a total of 5 sensors, which are distributed every 20 mm along the reserved hole.

[0064] In some embodiments, the laser range finder monitoring range is 120-280 mm, the analog output is 4-20 Ma, and the fixed head is designed according to the length of 45 mm, the width of 35 mm, and the height of 25 mm.

[0065] In some embodiments, the water-permeable stone is placed on the second liquid outlet 9 of the first temperature control part, i.e., the inside of the sample cylinder.

[0066] The embodiments of the application are described in detail above in combination with the drawings, but the application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. A non-contact frost heave measuring instrument, characterized in that: include A transparent sample tube; The temperature control system includes a first temperature control unit and a second temperature control unit. The first temperature control unit is disposed at the lower part of the sample cylinder and forms the bottom of the sample cylinder. The second temperature control unit can enter the sample cylinder. The temperatures of both the first temperature control unit and the second temperature control unit are adjustable. A temperature acquisition system is used to measure temperature data at different locations in the axial direction inside the sample cylinder; A water replenishment system is located at the bottom of the sample cylinder; A displacement acquisition system is installed above the second temperature control unit. The displacement acquisition system measures the displacement of the second temperature control unit at different positions in a non-contact manner.

2. The non-contact frost heave measuring instrument according to claim 1, characterized in that: The displacement acquisition system includes at least three laser displacement sensors, which are arranged in a circular array around the central axis of the sample cylinder.

3. The non-contact frost heave measuring instrument according to claim 2, characterized in that: The displacement acquisition system also includes an adjustment component, which makes the distance between the laser displacement sensor and the second temperature control unit adjustable.

4. The non-contact frost heave measuring instrument according to claim 3, characterized in that: The adjustment assembly includes a first adjustment member and a second adjustment member. The first adjustment member extends above the sample cylinder, and the second adjustment member is adjustablely disposed on the first adjustment member. The second adjustment member can adjust the depth of its entry into the sample cylinder. The laser displacement sensor is disposed at the end of the second adjustment member that enters the sample cylinder.

5. The non-contact frost heave measuring instrument according to claim 4, characterized in that: The adjustment assembly further includes a third adjustment member, which is rotatable about its own central axis. The first adjustment member is adjustablely disposed on the third adjustment member and is adjustable to adjust the horizontal position of the end extending above the sample tube.

6. The non-contact frost heave measuring instrument according to claim 4, characterized in that: The first adjusting member has a first fastener and a first mounting hole for the second adjusting member to be inserted at its end. The first fastener can enter the first mounting hole and press against the second adjusting member to restrict the movement of the second adjusting member.

7. The non-contact frost heave measuring instrument according to claim 5, characterized in that: The end of the third adjusting member is provided with a second fastener and a second mounting hole for the first adjusting member to be inserted. The second fastener can enter the second mounting hole and press against the first adjusting member.

8. The non-contact distance measuring frost heave instrument according to claim 1, characterized in that: The first temperature control unit includes a first flow guide groove, a first liquid inlet and a first liquid outlet. The first flow guide groove is arranged in a ring inside the first temperature control unit. The first liquid inlet and the first liquid outlet, which are located on the outside of the first temperature control unit, are respectively connected to the two ends of the first flow guide groove.

9. The non-contact frost heave measuring instrument according to claim 2, characterized in that: The water replenishment system includes a second guide channel and a second liquid inlet. The second guide channel is disposed inside the first temperature control unit. One end of the second guide channel is connected to the second liquid inlet disposed outside the first temperature control unit. The other end of the guide channel is disposed at the center of the side of the first temperature control unit facing the second temperature control unit and serves as the second liquid outlet.

10. The non-contact frost heave measuring instrument according to claim 1, characterized in that: The second temperature control unit has an internal cavity, and a third liquid inlet and a third liquid outlet are provided on the side of the second temperature control unit away from the first temperature control unit, which are connected to the cavity.

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