Soil tension measuring device

Abstract

The utility model discloses a soil tension measuring device, which comprises a mounting component, a tension measuring component and a tension measuring component, and is characterized in that the mounting component comprises an inner sleeve and an outer sleeve, and the inner sleeve is arranged in the outer sleeve; the tension measuring equipment is arranged in the inner sleeve; once the outer sleeve is installed in a soil body, the outer sleeve is fixed in the soil body all the time, the effect of blocking surrounding soil pressure is achieved, and the inner sleeve is used for bearing the tension testing equipment, so that the tension testing equipment can be freely taken out of the outer sleeve when needing to be saturated again and does not need to be taken out by drilling holes again; the internal structure of the tension testing equipment cannot be damaged, and extra manpower and mechanical cost generated by re-drilling is also saved.

Description

Technical Field

[0001] The utility model relates to the field of soil suction measurement equipment, in particular to a soil tension measurement device. Background Art

[0002] Soil tension measurement, also known as soil suction measurement, is an important means of assessing soil moisture status and soil structural stability. This measurement method relies primarily on capillary action and surface tension phenomena in the soil. A soil tensiometer is a specialized instrument used to perform such measurements.

[0003] The soil matrix suction is usually measured on site using a tensiometer. However, due to the limited range of the tensiometer, when the suction value is too large (exceeding the tensiometer range), it often gasifies, causing the tensiometer suction measurement to be interrupted. At this time, the tensiometer can only be taken out of the soil and re-saturated before it can be inserted into the soil again to continue the suction measurement. Therefore, in order to facilitate the easy removal of the on-site tensiometer when it is gasified and easy installation after saturation, the development of on-site tensiometer installation and recovery devices is particularly important. The on-site installation of the tensiometer is an important step in accurately measuring the soil matrix suction. It is of great significance to reduce the disturbance to the surrounding soil during the installation and recovery of the tensiometer. At the same time, it is also necessary to ensure that the installation and recovery are simple and easy to operate. In short, the quality of the tensiometer installation directly affects the results of the soil matrix suction measurement.

[0004] There are two types of field soil tensiometers commonly used at present. One is to install a water-filled cap on the top of a plastic pipe, install a vacuum gauge on the upper side wall of the plastic pipe for reading, and install a porous ceramic head at the bottom of the plastic pipe for hydraulic transmission. The disadvantage of this type of soil tensiometer is that the plastic pipe is affected by the depth of the buried point. On the one hand, too much depth will reduce the ability of the water inside the pipe to transmit negative pressure. On the other hand, too much depth will make the plastic pipe itself prone to deformation or even long-term aging and fracture. The second type of field soil tensiometer adopts an integrated structure. The pressure sensor and the front porous ceramic head cap are integrated together. The front pressure sensing piece of the pressure sensor and the front ceramic head are connected through a small water cavity. The ceramic head is closely connected to the surrounding soil and transmits the soil suction to the small water cavity. Then the change in suction can be read by the pressure sensor. The second type is small in size and only needs to bury the entire sensor and ceramic head integration into the measurement point and then lead out a cable of the tensiometer, thus solving the problem that the first type of pipe tensiometer is affected by depth and the plastic pipe is easily aging and cracking due to environmental influences. Therefore, the second type of integrated tensiometer is more widely used and can be used for burial at any depth. This type of integrated tensiometer is currently mostly buried in the soil by pre-buried or drilled and then backfilled. However, once the integrated tensiometer is buried in the soil, it is difficult to take it out again for saturation or recovery after the monitoring process is completed once gasification occurs or the monitoring is completed. This is because if it is to be taken out of the soil, it is necessary to drill a hole again on the top surface of the tensiometer buried position, and then take out the tensiometer after drilling to the buried depth of the tensiometer. This operation has four disadvantages: First, the surrounding soil will be disturbed when drilling again, thereby affecting the accuracy of the tensiometer's suction measurement again. Second, because after the tensiometer is buried, its cable will be led out to the ground for data signal transmission, and the location of the second drilling is still the original hole position of the tensiometer, so the tensiometer or its cable may be damaged during the second drilling; Third, drilling again will incur additional manpower and mechanical costs, and once the tensiometer is vaporized again, it will need to be drilled again to remove it. Such repeated drilling will consume a lot of manpower and material resources; Fourth, after a long period of on-site suction monitoring, the soil at the original hole position of the tensiometer becomes more compact, the difficulty of drilling increases, and it becomes difficult to recycle and reuse the tensiometer.

[0005] In general, the existing soil tensiometer drilling, burying and removal schemes are time-consuming and labor-intensive, and there is a possibility of damaging the tensiometer and its cables, resulting in low efficiency in long-term on-site monitoring of soil suction. Utility Model Content

[0006] In order to overcome the shortcomings of the prior art that the soil tensiometer drilling, burying and removal schemes are time-consuming and labor-intensive, and there is a possibility of damaging the tensiometer and its cables, resulting in low efficiency in long-term on-site monitoring of soil suction, the utility model provides a soil tension measuring device, including: an installation component, including an inner sleeve and an outer sleeve, the inner sleeve is installed in the outer sleeve; a tension measuring device is installed in the inner sleeve.

[0007] Optionally, the mounting assembly further comprises a top cap, and the top cap is mounted on the outer sleeve.

[0008] Optionally, a through hole is provided on the top cap, a first sealing member is provided in the through hole, and a wire hole is provided on the first sealing member.

[0009] Optionally, the inner sleeve is longer than the outer sleeve.

[0010] Optionally, an outer thread is provided on the outer wall of the inner sleeve, and an inner thread is provided on the inner wall of the outer sleeve.

[0011] Optionally, the tension testing equipment comprises:

[0012] Tensiometer;

[0013] Soil contact piece, mounted on the tensiometer.

[0014] Optionally, the tension testing device further comprises a data acquisition box, and the tension meter is connected to the data acquisition box via a wire.

[0015] Optionally, the installation assembly further comprises a waterproof fixing structure, wherein the waterproof fixing structure is installed in the inner sleeve and connected to the soil contact piece.

[0016] Optionally, the waterproof fixing structure includes:

[0017] A connecting piece, mounted on the soil contact piece;

[0018] The bottom cap is installed in the inner sleeve and connected to the connecting piece. The bottom cap is provided with a mounting hole having the same size as the soil contact piece.

[0019] Optionally, a groove is provided on the bottom cap, a second sealing member is provided in the groove, and the second sealing member is located between the connecting member and the bottom cap.

[0020] The beneficial effects of the utility model are as follows: once the outer sleeve is installed in the soil, it is always fixed in the soil to block the surrounding soil pressure; the inner sleeve is used to carry the tension test equipment, so that the tension test equipment can be freely taken out from the outer sleeve when it needs to be re-saturated, without the need to drill holes again to take it out, and no damage will be caused to the internal structure of the tension test equipment, and the additional manpower and machinery costs caused by re-drilling will be saved; since the outer sleeve separates the surrounding soil, the surrounding soil will not be disturbed when the inner sleeve is taken out; in long-term operations, since the soil is separated by the outer sleeve and no drilling is required, the hardening of the surrounding soil will not affect the difficulty of the operation; therefore, the soil tension measuring device provided in this embodiment can also adapt to the development of long-term detection operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 is a schematic diagram of the structure of some embodiments;

[0023] Figure 2 is a front view of a bottom portion of a soil contact member in some embodiments;

[0024] Figure 3 is a front view of the top of the bottom cap in some embodiments;

[0025] Figure 4 is a cross-sectional view of a bottom cap in some embodiments.

[0026] Explanation of the reference numerals: 101, inner sleeve; 102, outer sleeve; 103, top cap; 104, first sealing member; 201, tensiometer; 202, soil contact member; 203, data acquisition box; 204, wire; 105, connector; 106, bottom cap; 107, groove; 108, second sealing member; 109, screw hole. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the concept, specific structure and technical effects of the utility model in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the utility model. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the formation of a better connection structure by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the creation of the utility model can be combined interchangeably without conflicting with each other.

[0028] This embodiment provides a soil tension measuring device, comprising: a mounting assembly, comprising an inner sleeve 101 and an outer sleeve 102, wherein the inner sleeve 101 is mounted in the outer sleeve 102; and a tension measuring device, mounted in the inner sleeve 101. The mounting assembly is used to install the main test device into the soil for testing, and the tension measuring device is used to measure soil tension.

[0029] During implementation, determine the soil area to be measured, select the measurement position in the area, drill a hole of a specified depth at the measurement position, then put the outer sleeve 102 into the drilled hole, install the saturated tension test equipment in the inner sleeve 101, and then install the inner sleeve 101 into the outer sleeve 102 in the hole. The tension measurement equipment contacts the soil at the bottom of the inner sleeve 101, thereby realizing the measurement of soil tension. When the on-site weather is dry and the soil suction exceeds the range of the tensiometer 201, the tensiometer 201 will be gasified and fail. At this time, you only need to pull the inner sleeve 101 out of the outer sleeve 102, and then re-saturate the tensiometer 201 and install it again. When the on-site test is completed, the inner sleeve 101 can be pulled out of the outer sleeve 102 and the outer sleeve 102 can be pulled out of the hole in the same way, and then the borehole can be backfilled with soil. During the measurement process, once the outer casing 102 is installed in the soil, it will be fixed in the soil to block the surrounding soil pressure. The inner casing 101 is used to carry the tension test equipment, so that the tension test equipment can be freely taken out from the outer casing 102 when it needs to be re-saturated. There is no need to drill holes again to take it out, which will not cause damage to the internal structure of the tension test equipment and save the extra manpower and machinery costs caused by re-drilling. Since the outer casing 102 separates the surrounding soil, the surrounding soil will not be disturbed when the inner casing 101 is taken out. In long-term operations, since the outer casing 102 separates the soil and no drilling is required, the hardening of the surrounding soil will not affect the difficulty of the operation. Therefore, the soil tension measurement device provided in this embodiment can also adapt to the development of long-term detection operations.

[0030] Specifically, the outer sleeve 102 and the inner sleeve 101 are both hollow cylindrical tubes. The materials of the outer sleeve 102 and the inner sleeve 101 can be PVC or metal. The inner diameter of the outer sleeve 102 is slightly larger than the outer diameter of the inner sleeve 101.

[0031] In some embodiments, the mounting assembly further includes a top cap 103 , which is mounted on the outer sleeve 102 .

[0032] During the measurement process, that is, when the inner sleeve 101 with the tension measuring device is installed in the outer sleeve 102, the top cap 103 is installed on the outer sleeve 102 and covers the top of the outer sleeve 102, so as to prevent external rainwater or dust from falling into the inner sleeve 101, thereby ensuring the accuracy of the measurement and protecting the tension measuring device in the inner sleeve 101 from being damaged by the external environment.

[0033] Specifically, the top cap 103 and the outer sleeve 102 are detachably connected. In this embodiment, an inner thread is provided in the top cap 103, and an outer thread is provided on the outer wall at the top end of the outer sleeve 102. The inner thread of the top cap 103 is matched with the outer thread on the outer wall at the top end of the outer sleeve 102, so that the top cap 103 can be stably mounted on the outer sleeve 102 and can also be easily disassembled. In other embodiments, the top cap 103 and the sleeve can also be connected by a snap-on connection, or a through hole can be provided on the top cap 103, and a screw hole can be provided on the top end of the outer sleeve 102, and the top cap 103 and the outer sleeve 102 are connected by bolts.

[0034] In some embodiments, the top cap 103 is provided with a through hole, a first sealing member 104 is provided in the through hole, and a wire hole is provided on the first sealing member 104. The wire hole is used for the wire 204 to pass through.

[0035] During implementation, the tension measuring device usually utilizes a wire 204 to transmit tension measurement information. The wire 204 can be led out from a wire hole on the first seal 104. The function of the first seal 104 is to seal and fix the wire 204 of the tension meter 201 to prevent external rain or dust from entering the inner casing through the gap between the wire 204 of the tension meter 201 and the top cap 103 of the outer casing.

[0036] In some embodiments, the inner sleeve 101 is longer than the outer sleeve 102 .

[0037] During implementation, the outer sleeve 102 is installed in the drilled hole, and the bottom end of the outer sleeve 102 contacts the bottom of the hole. When the inner sleeve 101 is installed in the outer sleeve 102, the bottom end of the inner sleeve 101 also contacts the bottom of the hole. Taking the bottom of the hole as a reference, the bottom end of the outer sleeve 102 is flush with the bottom end of the inner sleeve 101. Since the length of the inner sleeve 101 is greater than that of the outer sleeve 102, when the inner sleeve 101 is installed in the outer sleeve 102, the top end of the inner sleeve 101 is higher than the top end of the outer sleeve 102. When the operator needs to take out the inner sleeve 101, the inner sleeve 101 can be better grasped to take it out of the outer sleeve 102.

[0038] In some embodiments, an outer wall of the inner sleeve 101 is provided with an external thread, and an inner wall of the outer sleeve 102 is provided with an internal thread.

[0039] During implementation, the inner sleeve 101 is rotated in the outer sleeve 102 so that the outer thread on the inner sleeve 101 cooperates with the inner thread on the outer sleeve 102 to fix the inner sleeve 101 in the outer sleeve 102, thereby preventing the inner sleeve 101 from moving. At the same time, the inner sleeve 101 can be taken out by rotating it.

[0040] Specifically, the external thread on the inner sleeve 101 is arranged on the outer wall of the bottom of the inner sleeve 101, and the internal thread on the outer sleeve 102 is arranged on the inside of the bottom of the outer sleeve 102. The internal thread in the bottom area of ​​the outer sleeve and the external thread in the bottom area of ​​the inner sleeve are both provided with fixed pitch scales, so that the downward or upward movement distance of the inner sleeve in the outer sleeve can be accurately measured, thereby realizing accurate control of the position of the tensiometer 201 during removal or installation.

[0041] In some embodiments, the tension testing device includes: a tension meter 201; and a soil contact member 202 mounted on the tension meter 201.

[0042] During implementation, the soil contact member 202 contacts the soil, and the soil contact member 202 transmits the suction force of the soil to the tensiometer 201, and the tensiometer 201 calculates the tension of the soil.

[0043] Specifically, the soil contact piece 202 is connected to one end of the tensiometer 201 via threads.

[0044] In some embodiments, the tension testing device further includes a data acquisition box 203, and the tension meter 201 is connected to the data acquisition box 203 via a wire 204. The data acquisition box is used to collect data transmitted by the tension meter 201.

[0045] During implementation, after the soil contact piece 202 transmits the soil tension to the tension meter 201, the tension meter 201 is connected to the data acquisition box 203 through the wire 204. The soil contact piece 202 contacts the soil and transmits the soil tension to the tension meter 201. After the tension meter 201 calculates the tension data, it transmits the data to the data acquisition box 203, and the data acquisition box 203 saves the measured data.

[0046] Specifically, the tension meter 201 is installed inside the inner sleeve 101. The data acquisition box 203 is installed outside the inner sleeve 101. The tension meter 201 and the data acquisition box 203 are connected through a wire 204. The wire 204 passes through the wire hole in the first sealing member 104 on the top cap 103. The two ends of the wire 204 are respectively connected to the tension meter 201 inside the inner sleeve 101 and the data acquisition box 203 outside the inner sleeve 101.

[0047] In some embodiments, the installation assembly further includes a waterproof fixing structure, which is installed in the inner casing 101 and connected to the soil contact piece 202. The waterproof fixing structure is used to prevent moisture in the soil from entering the inner casing 101, and is also used to fix the soil contact piece 202.

[0048] During implementation, a waterproof fixing structure is installed in the inner casing 101 , and the waterproof fixing structure is connected to the soil contact piece 202 , which plays a role in fixing the soil contact piece 202 and preventing moisture in the soil from entering the inner casing 101 .

[0049] In some embodiments, the waterproof fixing structure includes: a connector 105 installed on the soil contact member 202; a bottom cap 106 installed in the inner sleeve 101 and connected to the connector 105, and a mounting hole of the same size as the soil contact member 202 is provided on the bottom cap 106.

[0050] During implementation, the connector 105 is installed on the soil contact member 202, and the bottom cap 106 is installed in the inner sleeve 101, and the bottom cap 106 is connected to the connector 105, and one end of the soil contact member 202 passes through the mounting hole on the bottom cap 106. The bottom cap 106 is connected to the connector 105 so that the soil contact member 202 is fixed in the inner sleeve 101. The bottom cap 106 is provided with a mounting hole of the same size as the soil contact member 202, so that one end of the soil contact member 202 can pass through the mounting hole to contact the soil. During the measurement process, only one end of the soil contact member 202 contacts the soil, and the outer shell of the tensiometer 201 is not in direct contact with the inner sleeve 101, and an air layer is sandwiched between the two. Other parts of the tensiometer 201 are not in contact with the soil, which avoids the reading of the tensiometer 201 being affected by the temperature and humidity of the surrounding soil, and also avoids the reading of the tensiometer 201 being affected by the stress change of the surrounding soil, thereby greatly reducing the error of soil suction monitoring.

[0051] Specifically, the soil contact piece 202 is cylindrical, the connecting piece 105 is annular, the connecting piece 105 is sleeved on the soil contact piece 202, further, the connecting piece 105 is welded on the soil contact piece 202, a plurality of through holes are provided on the connecting piece 105, and a pair of screw holes 109 are also provided on the bottom cap 106, the screw holes 109 on the connecting piece 105 correspond to the positions of the screw holes 109 on the bottom cap 106, and the bottom cap 106 and the soil connecting piece 105 can be fixed to each other by screwing bolts into the screw holes 109 during installation, the outer wall of the bottom cap 106 is provided with an external thread, and the inner wall of the inner sleeve 101 is provided with an internal thread, the external thread of the bottom cap 106 matches the internal thread of the inner sleeve 101, and when the bottom cap 106 is fixed in the inner sleeve 101, the bottom surface of the bottom cap 106 is flush with the lowest end of the inner sleeve 101.

[0052] In some embodiments, a groove 107 is provided on the bottom cap 106 , a second sealing member 108 is provided in the groove 107 , and the second sealing member 108 is located between the connecting member 105 and the bottom cap 106 .

[0053] During implementation, a second sealing member 108 is placed in the groove 107 of the bottom cap 106 , and the second sealing member 108 can prevent moisture in the soil from entering the inner casing 101 .

[0054] Specifically, the groove 107 on the bottom cap 106 is an annular groove 107, and the second sealing member 108 is an O-ring, which is placed in the annular groove 107. The above is a specific description of the preferred implementation of the utility model, but the invention of the utility model is not limited to the embodiments, and technicians familiar with the field can make various equivalent deformations or substitutions without violating the spirit of the utility model, and these equivalent deformations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A soil tension measuring device, characterized in that: include: The installation assembly comprises an inner sleeve and an outer sleeve, wherein the inner sleeve is installed in the outer sleeve, an outer thread is provided on the outer wall of the inner sleeve, and an inner thread is provided on the inner wall of the outer sleeve, wherein the outer thread on the inner sleeve cooperates with the inner thread on the outer sleeve, and the inner thread on the bottom area of ​​the outer sleeve and the outer thread on the bottom area of ​​the inner sleeve are both provided with fixed pitch scales; The tension measuring device is installed in the inner sleeve and includes: a tension meter; a soil contact piece installed on the tension meter, the installation assembly also includes a waterproof fixing structure, the waterproof fixing structure is installed in the inner sleeve and connected to the soil contact piece, the waterproof fixing structure includes: a connecting piece installed on the soil contact piece; a bottom cap is installed in the inner sleeve and connected to the connecting piece, and the bottom cap is provided with a mounting hole of the same size as the soil contact piece.

2. The soil tension measuring device according to claim 1, characterized in that: The mounting assembly also includes a top cap, which is mounted on the outer sleeve.

3. The soil tension measuring device according to claim 1, characterized in that: A through hole is arranged on the top cap, a first sealing member is arranged in the through hole, and a wire hole is arranged on the first sealing member.

4. The soil tension measuring device according to claim 1, characterized in that: The inner sleeve is longer than the outer sleeve.

5. The soil tension measuring device according to claim 1, characterized in that: The tension measuring device also includes a data acquisition box, and the tension meter is connected to the data acquisition box via a wire.

6. The soil tension measuring device according to claim 1, characterized in that: The bottom cap is provided with a groove, a second sealing member is provided in the groove, and the second sealing member is located between the connecting member and the bottom cap.

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