Homogeneous soil layer soil column test system and method

Abstract

The invention relates to the technical field of geotechnical engineering test research equipment, and discloses a homogeneous soil layer soil column test system and method.The homogeneous soil layer soil column test system comprises a soil column cylinder, a water injection hole and a settlement monitoring unit are reserved at the top of the soil column cylinder, and the settlement monitoring unit comprises a settlement measuring instrument and an industrial camera; a water head adjusting device is arranged on the edge of the soil column cylinder and comprises a water tank, the water injection hole is connected with the water tank, and a transmission system for controlling the water tank to move up and down is arranged on the edge of the water tank; a buffer cavity is formed in the bottom of the soil column cylinder, a soil body containing cavity is formed in the buffer cavity, a permeable layer is arranged on the periphery of the soil body containing cavity, and a seepage flow measuring module is arranged on the edge of the buffer cavity. The underground water seepage flow and settlement measurement are integrated, synchronous and accurate measurement of the seepage-settlement combined process is achieved, operation is easy and convenient, and data are reliable. The device is suitable for permeation and settlement tests of different soil properties, and can provide an important experimental basis for stability analysis of underground water seepage flow and settlement prediction.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical engineering test and research equipment, and in particular to a homogeneous soil layer soil column test system and method. Background Art

[0002] In geotechnical engineering practice, accurate measurement of soil settlement and groundwater seepage is of great significance for assessing engineering stability, predicting geological disaster risks, and optimizing engineering design. Existing technologies have the following drawbacks: 1. Seepage measurement mostly uses manual readings, which makes it difficult to capture the transient seepage process; 2. Settlement measurement and seepage test are usually carried out separately, and it is impossible to obtain the seepage and settlement data simultaneously; 3. There is a lack of dedicated observation methods to investigate the mechanism of the impact of sudden water level changes on seepage and settlement in homogeneous soil layer experiments.

[0003] Therefore, those skilled in the art urgently need to develop a homogeneous soil layer soil column test system and method. Summary of the Invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a homogeneous soil column test system and method.

[0005] Based on one purpose of the present invention, the following technical solution is proposed: a homogeneous soil column test system, comprising a soil column tube, the top of the soil column tube is sealed, and a water injection hole is reserved at the seal, the side wall of the soil column tube is provided with a plurality of drainage holes, the soil column tube is provided with a settlement monitoring unit, the settlement monitoring unit includes a settlement measuring instrument arranged at the top of the soil column tube and an industrial camera arranged at the side of the soil column tube, and a light spot receiver is provided inside the soil column tube; A water head regulating device is provided on the side of the soil column, and the water head regulating device includes a water tank. The water injection hole and the water outlet of the water tank are connected by a first hose. A transmission system for controlling the up and down movement of the water tank is provided on the side of the water tank; A buffer cavity is provided at the bottom of the soil column, a soil accommodating cavity is provided inside the buffer cavity, a water-permeable layer is provided around the soil accommodating cavity, and a seepage measurement module is provided on the edge of the buffer cavity.

[0006] Preferably, the seepage flow measurement module includes a seepage flow electronic scale, the seepage flow electronic scale is provided with a measuring cup, the top of the measuring cup is provided with a third hose connected to the buffer cavity, and the outside of the seepage flow electronic scale is provided with an acrylic box.

[0007] Preferably, the permeable layer is composed of a 200-mesh stainless steel filter screen and permeable stone.

[0008] Preferably, the transmission system includes a water head regulating box, a vertical slide groove is opened on the front side of the water head regulating box, a support rod is slidably provided in the vertical slide groove, the support rod is located on one side of the water head regulating box and is connected to the lifting motor, and the side of the support rod away from the water head regulating box is connected to the working platform, the water tank is set on the working platform, and a control switch for driving the lifting motor is provided on the side of the water head regulating box.

[0009] Preferably, the upper and lower ends of the soil column and the upper end of the buffer cavity are connected with a frustum, the top of the soil column is provided with an upper cover plate, and the bottom of the buffer cavity is provided with a chassis. The upper cover plate, the soil column and the adjacent sides of the buffer cavity are connected by bolts, and a rubber pad is provided at the connection between the three, and the rubber pad is filled with silicone sealant.

[0010] Preferably, the water inlet of the water tank is connected to the water tank through a second hose, and the second hose is provided with a peristaltic pump.

[0011] Based on another object of the present invention, a soil column test method for a homogeneous soil layer is proposed, comprising the following steps: S1. Sampling: Obtain a number of representative samples through field surveys. Pre-treat the samples in the laboratory according to the experimental requirements and geotechnical test standards, and weigh sufficient samples. S2. Assembly: Align the screw holes corresponding to the soil column, the upper cover plate, and the top cone of the buffer cavity one by one, tighten the bolts, and add water to the soil column to check for leakage. If no leakage occurs, proceed to the next step. If leakage occurs, repair the leak. S3. Sample loading: Apply a layer of vaseline evenly on the inner wall of the soil column to prevent edge effect between the smooth inner wall and the soil; Soil samples were loaded in layers. To ensure that the degree of compaction and saturation of each section were as close as possible, about 10 cm of hot water was injected into the soil column each time. The hot water was slowly injected into the soil column, and then the sample was gradually added. Each injection was ensured to be saturated with water and the soil sample was allowed to stand for 20 minutes to allow the soil sample to absorb enough water. The process of injecting hot water and soil sample was repeated until the height of the soil sample reached 70 cm after filling. The sample was saturated with water for two consecutive days. Before the experiment, the bottom valve was ensured to be closed. S4. Test: Connect the assembled soil column to the water tank and the water inlet 24 above the soil column with a rubber hose. Start supplying water into the soil column through the water tank. Gradually adjust the water tank height and saturation time to fully saturate the soil sample. Raise the water level in the water tank from the bottom of the soil sample to the top, raising it 10 cm each time. The saturation time should be controlled to be more than 48 hours. After saturation, measure the permeability coefficient using the constant head method or the variable head method.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The system has a simple structure and is easy to operate, making it suitable for seepage analysis and settlement characteristics research in various soil types. This device integrates groundwater seepage and settlement measurements, enabling simultaneous and precise measurement of the seepage-settlement process. It is easy to operate and produces reliable data. This device is suitable for seepage settlement testing of different soil types and can provide an important experimental basis for groundwater seepage stability analysis and settlement prediction.

[0013] 2. The soil column test device is made of high-strength transparent organic glass, and the side wall is marked with scale lines to facilitate real-time observation of the settlement process of the soil sample. A settlement detection instrument is installed on the top, which uses a high-precision laser displacement sensor and an industrial camera (digital imaging technology) to monitor the settlement deformation of the soil sample surface in real time. Combined with the side wall scale, double verification can be performed.

[0014] 3. The test device, through a sophisticated hydraulic head adjustment mechanism, can accurately simulate various hydraulic head differentials within a range of 0-2 m and monitor the dynamic changes in groundwater seepage in real time. The device is equipped with a high-precision electronic scale with integrated data storage. Through a built-in USB interface, seepage data can be directly stored in real time to a mobile storage device. This enables continuous and accurate recording of seepage flow, effectively avoiding errors during data transmission and providing reliable, first-hand data for seepage analysis.

[0015] 4. The plexiglass cylinder is divided into two sections, connected by a frustum. A rubber gasket is added at the connection to maintain airtightness. The lower part of the test body is filled with a permeable layer (composed of a stainless steel filter and permeable stone). The side wall of the permeable layer is connected to the external water collection system through a water outlet hole (diameter 1 cm). A precision flow control valve (adjustment accuracy ±1%) is installed at the water outlet hole to achieve precise control of the seepage rate.

[0016] 5. The seepage control system includes a peristaltic pump. The seepage velocity can be controlled by adjusting a precision flow meter to simulate the effect of different seepage velocities on groundwater seepage. The water circulation system can maximize water conservation and reduce water consumption during the test. The water tank is filled with water and the peristaltic pump is used to inject water into the water inlet of the soil column. When the water level in the soil column rises above the water head height, the excess water flows from the overflow port through the rubber hose into the water tank. The peristaltic pump continues to inject water, forming a circulation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0018] 1-soil column; 2-drainage hole; 3-upper cover; 4-bolt; 5-rubber pad; 6-chassis; 7-scale line; 8-sedimentation measuring instrument; 9-spot receiver; 10-computer; 11-industrial camera; 12-buffer cavity; 13-third hose; 14-acrylic box; 15-seepage electronic scale; 16-peristaltic pump; 17-water trough; 18-water tank; 19-second hose; 20-head regulating box; 21-transmission system; 211-support rod; 212-vertical slide; 22-working platform; 23-control switch; 24-water injection hole; 25-first hose; 26-pressing plate. DETAILED DESCRIPTION

[0019] The present invention is described below in conjunction with the accompanying drawings and specific embodiments of the present invention. The description herein is only used to explain the present invention and is not intended to limit the present invention. Based on the embodiments of the present invention, any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art without creative work based on all other embodiments obtained in the present invention should be included in the scope of protection of the present invention.

[0020] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0022] Example 1 See also Figure 1The present invention provides a homogeneous soil column test system, comprising a soil column tube 1, the soil column tube 1 being 100 cm high, 20 cm inner diameter, 23 cm outer diameter, and 3 cm thick; the top of the soil column tube 1 being sealed, and a water injection hole 24 being reserved at the seal; a plurality of drainage holes 2 being provided on the side wall of the soil column tube 1, through which water in the soil column tube 1 can flow out, and which can also be used to cooperate with a water supply device to achieve a constant water head control function; a settlement monitoring unit being provided on the soil column tube 1, the settlement monitoring unit comprising a settlement measuring instrument 8 provided on the top of the soil column tube 1 and an industrial camera 11 provided on the side of the soil column tube 1; a light spot receiver 9 being provided inside the soil column tube 1; A water head regulating device is provided on the side of the soil column 1. The water head regulating device includes a water tank 18. The water injection hole 24 is connected to the water outlet of the water tank 18 by a first hose 25. A transmission system 21 for controlling the up and down movement of the water tank 18 is provided on the side of the water tank 18; the water inlet of the water tank 18 is connected to the water tank 17 by a second hose 19, and the second hose 19 is provided with a peristaltic pump 16 (0.1-1000mL / min); the water tank 18 has dimensions of 50cm×50cm×150cm and a thickness of 5cm, and the water tank 17 has dimensions of 50cm×50cm×150cm; A buffer cavity 12 is provided at the bottom of the soil column 1. A soil holding cavity is provided inside the buffer cavity 12. A permeable layer (3 cm) is provided around the soil holding cavity. The permeable layer is composed of a 200-mesh stainless steel filter screen and permeable stones. A seepage measurement module is provided on the edge of the buffer cavity 12.

[0023] The height of the water tank 18 is higher than the soil column tube 1, and it is connected to the soil column device through a hydraulic gradient and a hose to provide water.

[0024] The soil column 1 is used to fill homogeneous soil samples. The water head adjustment device realizes dynamic control of different water head heights through a precise adjustment device to simulate actual water head height conditions; the settlement meter 8 hits the laser on the light spot receiver 9, and then the settlement meter 8 transmits the data to the computer 10 in real time.

[0025] Furthermore, the seepage flow measurement module includes a seepage flow electronic scale 15, which is provided with a measuring cup. The top of the measuring cup is provided with a third hose 13 connected to the buffer cavity 12, and the third hose 13 is provided with a valve; the outside of the seepage flow electronic scale 15 is provided with an acrylic box 14, which prevents dust and the like from affecting the test results.

[0026] The seepage flow electronic scale 15 uses a high-precision sensor (Mettler-Toledo ME4002E) to monitor flow changes in real time; the settlement meter 8 uses a displacement sensor (KEYENCE LK-G500 series) and an industrial camera (Baslerace 2 acA2440-75um, 5 million pixels) to record the settlement under the action of water head.

[0027] The data of the transmission system 21, the settlement monitoring unit and the seepage flow measurement module are collected and recorded synchronously, and the data is monitored in real time. The seepage flow data can be directly stored in real time to a mobile storage device (computer 10) through the built-in USB interface.

[0028] The first hose, the second hose and the third hose are all rubber hoses with an inner diameter of 10 mm and an outer diameter of 12 mm.

[0029] Furthermore, the transmission system 21 includes a water head regulating box 20. A vertical chute 212 is defined on the front of the water head regulating box 20. A support rod 211 slides within the chute 212. The support rod 211 is located on one side of the water head regulating box 20 and is connected to the lifting motor. The side of the support rod 211 away from the water head regulating box 20 is connected to a work platform 22. The water tank 18 is positioned on the work platform 22. A control switch 23 for driving the lifting motor is located on the side of the water head regulating box 20. The water head height of the water head regulating box 20 is within a range of 0-20 cm.

[0030] The transmission system 21 adopts an electromechanical integration design, and the speed is adjusted by the control switch 23 to achieve smooth lifting and lowering of the water tank 18. The water tank 18 is placed on the working platform and moves vertically along the guide rail (vertical slide 212) to prevent the water tank 18 from swinging.

[0031] Furthermore, the soil column 1 (inner diameter 20 cm×height 100 cm) is made of high-strength transparent organic glass with a thickness of 3 cm. The side wall of the soil column 1 is symmetrically provided with scale lines 7 of 1.0 cm, 2.0 cm, 3.0 cm, 4.0 cm, etc., and the measuring range is 100 cm.

[0032] Transparent organic glass facilitates observation of the seepage state and soil sample state. The top of the soil column 1 is sealed, and a water injection hole 24 with a diameter of 1 cm is reserved for simulating groundwater recharge through a water tank 18 (20 L stainless steel water tank); a water outlet hole with a diameter of 1 cm is set on the side wall 10 cm away from the bottom. The water outlet hole is located in the buffer cavity 12 and is used to collect the seepage volume.

[0033] The seepage electronic scale 15 (0.01g accuracy range is 0-5 kg) records the seepage volume in real time. The transmission system 21 controls the up and down movement of the water tank 18, and the surface settlement and deformation of the soil sample are monitored in real time through high-precision sensors and industrial cameras 11.

[0034] Furthermore, the upper and lower ends of the soil column 1 and the upper end of the buffer cavity 12 are connected with a frustum, the top of the soil column 1 is provided with an upper cover plate 3, and the bottom of the buffer cavity 12 is provided with a chassis 6. The upper cover plate 3, the soil column 1 and the adjacent sides of the buffer cavity 12 are connected by bolts 4, and a rubber pad 5 is provided at the connection between the three. The rubber pad 5 is filled with silicone sealant to ensure the airtightness of the device.

[0035] The buffer cavity 12 is 6 cm high, the outer diameter of the chassis 6 is 28 cm, and the thickness is 3 cm, which plays a stabilizing supporting role, making the entire device more stable after placement; the outer diameter of the upper cover plate 3 is 28 cm, the width is 2.5 cm, and the thickness is 3 cm. It extends 0.5 cm into the tube within the width range, which plays a connecting and fixing role. Bolt holes 4 with a diameter of 1 cm are evenly arranged on the edge part, and the spacing between the bolt holes is equal.

[0036] Example 2 The present invention further provides a homogeneous soil layer column test method, comprising the homogeneous soil layer column test system of the above embodiment, and further comprising the following steps: S1. Sampling: Obtain a number of representative samples through field surveys. Pre-treat the samples in the laboratory according to the experimental requirements and geotechnical test standards, and weigh sufficient samples. S2, assembly; align the soil column 1 with the upper cover plate 3, the top of the buffer cavity 12 corresponding to the truncated cone screw holes one by one, tighten the bolts 4, add water to the soil column 1 to check for leaks, if not, proceed to the next step, if so, repair; S3. Sample loading: Apply a layer of vaseline evenly on the inner wall of the soil column 1 to prevent the smooth inner wall from having an edge effect with the soil; Soil samples were loaded in layers. To ensure that the degree of compaction and saturation of each section was as close as possible, about 10 cm of hot water was injected into the soil column 1 each time. The hot water was slowly injected into the soil column, and then the sample was gradually added. Each injection was ensured to be saturated with water and the sample was allowed to stand for 20 minutes to allow the soil sample to absorb enough water. The process of injecting hot water and soil sample was repeated until the height of the soil sample reached 70 cm after filling. The sample was saturated with water for two consecutive days. Before the experiment, the bottom valve was ensured to be closed. S4. Test: Connect the assembled soil column 1 to the water tank 18 and the water inlet 24 above the soil column 1 with a rubber hose, start supplying water to the soil column 1 through the water tank 18, and gradually adjust the height of the water tank 18 and the saturation time to fully saturate the soil sample. The water level of the water tank 18 is raised from the bottom of the soil sample to the top, each time by 10 cm. The saturation time should be controlled to be more than 48 hours. After saturation, measure the permeability coefficient using the constant head method or the variable head method.

[0037] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A homogeneous soil column test system, characterized by: The invention comprises a soil column tube (1), wherein the top of the soil column tube (1) is sealed, and a water injection hole (24) is reserved at the sealed position, a plurality of drainage holes (2) are provided on the side wall of the soil column tube (1), a settlement monitoring unit is provided on the soil column tube (1), and the settlement monitoring unit comprises a settlement measuring instrument (8) arranged at the top of the soil column tube (1) and an industrial camera (11) arranged at the side of the soil column tube (1), and a light spot receiver (9) is provided inside the soil column tube (1); A water head regulating device is provided on the side of the soil column (1), and the water head regulating device includes a water tank (18). The water injection hole (24) is connected to the water outlet of the water tank (18) via a first hose (25). A transmission system (21) for controlling the up and down movement of the water tank (18) is provided on the side of the water tank (18); A buffer cavity (12) is provided at the bottom of the soil column (1), a soil accommodating cavity is provided inside the buffer cavity (12), a water-permeable layer is provided around the soil accommodating cavity, and a seepage measurement module is provided on the edge of the buffer cavity (12).

2. A homogeneous soil column test system according to claim 1, characterized in that: The seepage flow measurement module comprises a seepage flow electronic scale (15), a measuring cup is provided on the seepage flow electronic scale (15), a third hose (13) connected to the buffer cavity (12) is provided on the top of the measuring cup, and an acrylic box (14) is provided on the outside of the seepage flow electronic scale (15).

3. The homogeneous soil column test system according to claim 1, characterized in that: The permeable layer is composed of a 200-mesh stainless steel filter and permeable stones.

4. The homogeneous soil column test system according to claim 1, characterized in that: The transmission system (21) includes a water head regulating box (20), a vertical slide groove (212) is provided on the front side of the water head regulating box (20), a support rod (211) is slidably provided in the vertical slide groove (212), the support rod (211) is located on one side of the water head regulating box (20) and is connected to the lifting motor, and the side of the support rod (211) away from the water head regulating box (20) is connected to the working platform (22), the water tank (18) is arranged on the working platform (22), and a control switch (23) for driving the lifting motor is provided on the side of the water head regulating box (20).

5. The homogeneous soil column test system according to claim 1, characterized in that: The soil column (1) is made of high-strength transparent organic glass, and the side walls of the soil column (1) are symmetrically provided with scale lines (7).

6. The homogeneous soil column test system according to claim 1, characterized in that: The upper and lower ends of the soil column (1) and the upper end of the buffer cavity (12) are connected with a truncated cone, the top of the soil column (1) is provided with an upper cover plate (3), the bottom of the buffer cavity (12) is provided with a chassis (6), the adjacent sides of the upper cover plate (3), the soil column (1) and the buffer cavity (12) are connected by bolts (4), and the connection between the three is provided with a rubber pad (5), and the area around the rubber pad (5) is filled with silicone sealant.

7. The homogeneous soil column test system according to claim 1, characterized in that: The water inlet of the water tank (18) is connected to the water tank (17) via a second hose (19), and a peristaltic pump (16) is provided on the second hose (19).

8. A soil column test method for a homogeneous soil layer, characterized by: The method uses the homogeneous soil column test system according to any one of claims 1 to 7, further comprising the following steps: S1. Sampling: Obtain a number of representative samples through field surveys. Pre-treat the samples in the laboratory according to the experimental requirements and geotechnical test standards, and weigh sufficient samples. S2, assembly; align the screw holes corresponding to the top cone of the soil column (1) with the upper cover (3) and the buffer cavity (12), tighten the bolts (4), add water to the soil column (1) to check for leakage, if not, proceed to the next step, if yes, repair; S3. Sample loading: Apply a layer of vaseline evenly on the inner wall of the soil column (1), slowly inject about 10 cm of hot water into the soil column (1) each time, then gradually add the sample, and repeat the process of injecting hot water and soil sample until the height of the soil sample reaches 70 cm after filling, and then keep it saturated with water for two consecutive days; S4. Test: Water is supplied to the soil column (1) through the water tank (18). The soil sample is fully saturated by gradually adjusting the height of the water tank (18) and the saturation time. The water level of the water tank (18) is raised from the bottom of the soil sample to the top, 10 cm each time. The saturation time should be controlled to be more than 48 hours. After the saturation is completed, the permeability coefficient is measured by the constant head method or the variable head method.

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