A permeability test device for coarse grained soil samples

Abstract

This application provides a permeability testing device for easy loading and unloading of coarse-grained soil samples. The device includes an instrument cylinder, an upper permeable plate, a lower permeable plate, a base, an instrument support, an upper outlet, a lower inlet, a pressure measuring hole, a handle, an instrument cylinder base plate, hinges, and a fixing pin. The upper and lower permeable plates are installed inside the instrument cylinder, and soil or sediment samples can be filled between them. Three pressure measuring holes are provided on the side wall of the instrument cylinder. The handle is installed on the upper part of the instrument cylinder side wall. An upper outlet is located at the top of the instrument cylinder, and a lower inlet is located at the bottom. The instrument cylinder is fixed to the base by hinges and a fixing pin. An instrument support is installed at the bottom of the base. This device can be used to measure the permeability coefficient of coarse-grained sediment particles, and it facilitates the loading and unloading of sediment, significantly improving testing efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of soil mechanics testing devices, specifically relating to a permeability testing device that is easy to load and unload coarse-grained soil samples. Background Technology

[0002] The permeability coefficient is an important indicator reflecting the permeability of soil and one of the main parameters used in seepage calculations. Understanding soil permeability and measuring the permeability coefficients of different soil types are of significant practical importance in environmental engineering, geological engineering, water conservancy engineering, and civil engineering.

[0003] Currently, laboratory and field methods are commonly used to determine the permeability coefficient of soil samples. In laboratory settings, the constant head test is typically used to determine the permeability coefficient of coarse-grained soils. However, when determining the permeability coefficient of sediment in natural riverbeds, the high gravel content in most mountainous riverbeds, coupled with the small size of existing laboratory permeability measuring devices, limits their effectiveness in measuring the permeability coefficient of coarse-grained sediments, affecting the accuracy of the test data. Furthermore, the current method of using permeability measuring devices involves directly placing the obtained soil or sand sample inside the device for measurement. This method requires multiple loading and unloading of soil samples when measuring multiple samples, consuming a significant amount of time, hindering test repeatability, and significantly impacting test efficiency.

[0004] Based on the above, this utility model provides a permeability testing device that is easy to load and unload coarse-grained soil samples. This device can be used to measure the permeability coefficient of larger-diameter sediment particles, and it is convenient to fill the test device with sediment and unload it, which can significantly improve the test efficiency. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a permeability test device that is easy to load and unload coarse-grained soil samples. This device can be used to measure the permeability coefficient of larger-diameter sediment particles and has the characteristics of convenient loading and unloading of sediment samples.

[0006] A permeability testing device for easy loading and unloading of coarse-grained soil samples includes an instrument cylinder, an upper permeable plate, a lower permeable plate, a base, an instrument support, an upper outlet, a lower inlet, a pressure measuring hole, a handle, an instrument cylinder base plate, hinges, and a fixing pin. The upper and lower permeable plates are installed inside the instrument cylinder, and soil or silt samples can be filled between the upper and lower permeable plates. Three pressure measuring holes are provided on the side wall of the instrument cylinder. The handle is installed on the upper part of the side wall of the instrument cylinder. An upper outlet is opened at the upper part of the instrument cylinder, and a lower inlet is opened at the lower part of the instrument cylinder. The instrument cylinder is fixed to the base by hinges and fixing pins. An instrument support is installed at the lower part of the base.

[0007] Preferably, the inner diameter of the instrument cylinder can be determined according to the particle size of the soil or silt sample, wherein the ratio of the inner diameter of the cylinder to the maximum particle size of the sample should not be less than 5 (Standard for Geotechnical Testing Methods, GBT 20123-2019).

[0008] Preferably, the diameters of the upper and lower permeable plates are the same as the inner diameter of the instrument cylinder.

[0009] Preferably, the upper permeable plate and the lower permeable plate are provided with permeable holes, and the permeable holes of the upper permeable plate and the lower permeable plate have the same diameter, which is smaller than the minimum particle size of the sediment sample.

[0010] Preferably, the upper permeable plate is fixed to the instrument cylinder by upper permeable plate fixing bolts and is detachable.

[0011] Preferably, the lower permeable plate is fixed to the instrument cylinder by a permeable plate support ring and is detachable.

[0012] Preferably, the pressure measuring hole includes a first pressure measuring hole, a second pressure measuring hole, and a third pressure measuring hole.

[0013] Preferably, the first and second pressure measuring holes are located on the upper part of the instrument cylinder side wall, and the third pressure measuring hole is located on the side wall of the lower permeable plate.

[0014] Preferably, a filter screen is provided at the connection between the first pressure measuring hole, the second pressure measuring hole, the third pressure measuring hole and the instrument cylinder.

[0015] Preferably, the diameter of the upper outlet is larger than the diameter of the lower inlet.

[0016] Preferably, the hinge and the fixing pin have opening and closing functions, enabling the combination and separation of the instrument tube and the base.

[0017] Preferably, the instrument stand shown consists of three support legs.

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

[0019] The instrument can determine the cylinder size based on the maximum particle size of the sediment sample, enabling the measurement of the permeability coefficient of coarse-grained soil or sediment samples. Furthermore, the instrument cylinder and base are connected by hinges and fixing pins, allowing for quick separation and installation of the cylinder and base. This facilitates repeatable testing of soil or sediment samples, promotes rapid sample unloading, and significantly improves testing efficiency. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the elevation structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the upper and lower permeable panels of this utility model.

[0023] Figure 3 This is a schematic diagram of the hinge structure of this utility model;

[0024] Figure 4 This is a schematic diagram of the fixing pin structure of this utility model;

[0025] Figure 5 This is a schematic diagram of the elevation structure of an embodiment of this utility model.

[0026] The components are as follows: 1. Instrument tube; 2. Upper permeable plate; 201: Upper permeable plate fixing bolt; 3. Lower permeable plate; 301: Lower permeable plate support ring; 302: Permeable hole; 4. Base; 401: Base top cover; 5. Instrument bracket; 6. Upper outlet; 7. Lower inlet; 701: Lower inlet control valve; 801: First pressure measuring hole; 802: Second pressure measuring hole; 803: Third pressure measuring hole; 9: Handle; 10: Instrument tube bottom plate; 11: Hinge; 12: Fixing pin. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example:

[0030] Reference Figures 1 to 4As shown, this embodiment provides a permeability testing device for easy loading and unloading of coarse-grained soil samples, including an instrument cylinder 1, an upper permeable plate 2, a lower permeable plate 3, a base 4, an instrument support 5, an upper outlet 6, a lower inlet 7, a pressure measuring hole 8, a handle 9, an instrument cylinder base plate 10, a hinge 11, and a fixing pin 12. The upper permeable plate 2 and the lower permeable plate 3 are installed inside the instrument cylinder 1. Soil samples or silt samples can be filled between the upper permeable plate 2 and the lower permeable plate 3. The side wall of the instrument cylinder 1 is provided with a first pressure measuring hole 801, a second pressure measuring hole 802, and a third pressure measuring hole 803. The handle 9 is installed on the upper part of the side wall of the instrument cylinder 1. The upper part of the instrument cylinder 1 has an upper outlet 6, and the lower part of the instrument cylinder 1 has a lower inlet 7. The instrument cylinder 1 is fixed to the base 4 by the hinge 11 and the fixing pin 12. The instrument support 5 is installed on the lower part of the base 4.

[0031] Specifically, the mud and sand sample filling height of the instrument tube 1 is 30 cm.

[0032] Specifically, the inner diameter of the instrument cylinder 1 is 30 cm, and the maximum particle size that can be used to measure soil samples or sediment tests is 6 cm (Geotechnical Testing Methods Standard, GBT 20123-2019).

[0033] Specifically, the diameters of the upper permeable plate 2 and the lower permeable plate 3 are the same as the inner diameter of the instrument cylinder 1, both being 30 cm.

[0034] Specifically, the upper permeable plate 2 and the lower permeable plate 3 are provided with permeable holes 302. The permeable holes 302 of the upper permeable plate 2 and the lower permeable plate 3 have the same diameter, which is smaller than the minimum particle size of the sediment sample. In this embodiment, the diameter of the permeable holes 302 is 1 mm, that is, the particle size range of the sediment sample that can be measured in this embodiment is from 1 mm to 6 cm.

[0035] Specifically, the upper permeable plate 2 is fixed to the instrument cylinder 1 by the upper permeable plate fixing bolt 201 and is detachable.

[0036] Specifically, the lower permeable plate 3 is fixed to the instrument cylinder by a permeable plate support ring 301 and is detachable.

[0037] Specifically, the pressure measuring holes include a first pressure measuring hole 801, a second pressure measuring hole 802, and a third pressure measuring hole 803.

[0038] Specifically, the first pressure measuring hole 801 and the second pressure measuring hole 802 are located on the upper part of the side wall of the instrument cylinder 1, and the third pressure measuring hole 803 is located on the side wall of the lower permeable plate 3. In this embodiment, the first pressure measuring hole 801, the second pressure measuring hole 802 and the third pressure measuring hole 803 are spaced 10 cm apart.

[0039] Specifically, filters are provided at the connection points between the first pressure measuring hole 801, the second pressure measuring hole 802, the third pressure measuring hole 803 and the instrument cylinder 1 to prevent some mud and sand from entering the pressure measuring hole and causing blockage.

[0040] Specifically, the upper outlet 6 has a larger diameter than the lower inlet 7, which facilitates free outflow within the instrument cylinder 1 during the test.

[0041] Specifically, the hinge 11 and the fixing pin 12 have opening and closing functions. The fixing pin 12 can realize the combination and separation of the instrument tube 1 and the base 4, which facilitates the rapid unloading of soil or mud samples during repeatability tests.

[0042] Specifically, the instrument support 5 shown consists of three support legs, and the support 5 is welded and fixed to the bottom of the base 4.

[0043] This invention utilizes Darcy's law to measure the permeability coefficient of coarse-grained soil samples. The specific experimental steps are as follows: First, place the experimental device in a suitable position to ensure that it remains in a relatively stable working state during the test; close the fixing bolt 12 and fix the instrument tube 1 to the base 4; place the lower permeable plate 3 on the lower permeable plate support ring 301; fill the instrument tube with the mud and sand sample in layers and gently tamp it with a wooden hammer to reduce uneven filling; when the filling height reaches the height of the upper permeable plate 2, install the upper permeable plate 2 on the instrument tube 1 using the upper permeable plate fixing bolt 201; connect the lower inlet 7, the first pressure measuring hole 801, and the second pressure measuring hole 8... 02. Connect the third pressure measuring hole 803 to the corresponding device to start the test. During the test, open the water inlet valve 701 of the lower water inlet 7 to slowly fill the instrument from bottom to top, and let the water flow out from the upper water outlet 6. Close the water inlet valve 701, let it stand for a period of time, and check whether there is any blockage or leakage at the joints of the instrument. After confirming that the condition of each component of the instrument is normal, the test can be carried out. After the previous set of tests is completed, remove the upper permeable plate 2, open the fixing pin 12, pour out the mud and sand sample in the instrument cylinder 1, and carry out the next set of tests. After all tests are completed, remove the upper permeable plate 2 and the lower permeable plate 3, and clean the instrument cylinder 1.

[0044] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0045] 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 permeability test device for a coarse-grained soil sample that is easy to attach and detach, characterized by, Includes an instrument cylinder, upper permeable plate, lower permeable plate, base, instrument bracket, upper outlet, lower inlet, pressure measuring hole, handle, instrument cylinder base plate, hinge, and fixing pin. The instrument tube is equipped with an upper permeable plate and a lower permeable plate. Soil or silt samples are filled between the upper and lower permeable plates. The instrument tube has a pressure measuring hole on its side wall. The handle is installed on the upper part of the instrument tube's side wall. The upper part of the instrument tube has an upper water outlet, and the lower part of the instrument tube has a lower water inlet. The instrument tube is fixed to the base by hinges and fixing pins. An instrument support is installed on the lower part of the base.

2. The device for permeation test of coarse-grained soil sample according to claim 1, wherein, The diameters of the upper and lower permeable plates are the same as the inner diameter of the instrument cylinder, and the ratio of the inner diameter of the cylinder to the maximum particle size of the sample should not be less than 5.

3. The device for permeation test of coarse-grained soil sample according to claim 1, wherein, The upper and lower permeable plates are provided with permeable holes, and the permeable holes of the upper and lower permeable plates have the same diameter, which is smaller than the minimum particle size of the sediment sample.

4. The permeability testing device for easy loading and unloading of coarse-grained soil samples according to claim 1, characterized in that, The upper permeable plate is detachably fixed to the instrument cylinder by upper permeable plate fixing bolts; the lower permeable plate is detachably fixed to the instrument cylinder by permeable plate support rings.

5. The permeability testing device for easy loading and unloading of coarse-grained soil samples according to claim 1, characterized in that, The pressure measuring holes include a first pressure measuring hole, a second pressure measuring hole, and a third pressure measuring hole. The first and second pressure measuring holes are located on the upper part of the instrument cylinder side wall, and the third pressure measuring hole is located on the side wall of the lower permeable plate.

6. The permeability testing device for easy loading and unloading of coarse-grained soil samples according to claim 5, characterized in that, The first, second, and third pressure measuring holes are equipped with filters at the connection points with the instrument cylinder to prevent some mud and sand from entering the pressure measuring holes and causing blockage.

7. The permeability testing device for easy loading and unloading of coarse-grained soil samples according to claim 1, characterized in that, The diameter of the upper outlet is larger than the diameter of the lower inlet.

8. The permeability testing device for easy loading and unloading of coarse-grained soil samples according to claim 1, characterized in that, The hinge and the fixing pin have opening and closing functions, enabling the combination and separation of the instrument tube and the base.

9. The permeability testing device for easy loading and unloading of coarse-grained soil samples according to claim 1, characterized in that, The instrument stand shown consists of three support legs.

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