Foundation pit soil layered permeation and seepage visualization indoor model test box

Abstract

The utility model discloses a kind of foundation pit soil layering permeation and seepage visualization indoor model test box, belong to geotechnical engineering test equipment technical field, comprising: test box main body, multiple layering partition plates are provided in test box main body;Test box main body has at least one transparent front wall;Multiple permeation channels are provided on each layering partition plate, and the channel mouth of permeation channel is provided with electric opening and closing valve;Fluorescent tracer injection system cooperates with the fluorescent tracer injection hole of being set on the side plate of test box main body;Ultraviolet developing module is set with the front wall of test box main body with inclination angle;High-speed camera recording system is set corresponding with the front wall of test box main body;Multi-channel independent water pressure control unit is located at the side of test box main body away from fluorescent tracer injection system;Data acquisition and analysis module is electrically connected with high-speed camera recording system.The utility model can directly reveal piping, seepage erosion and other seepage failure mechanism, provide scientific basis for seepage prevention design optimization.

Description

Technical Field

[0001] This utility model belongs to the technical field of geotechnical engineering testing equipment, specifically relating to a visual indoor model test chamber for layered permeability and seepage of foundation pit soil. Background Technology

[0002] Existing permeability testing devices (such as constant head permeameters and variable head permeameters) can only measure the permeability coefficient of a single layer of homogeneous soil samples, and cannot reflect the permeability differences and interlayer interactions of multi-layer soil in actual engineering.

[0003] In addition, traditional equipment lacks the ability to visualize seepage paths, making it difficult to observe the development process of seepage damage such as piping and contact scouring. This leads to seepage prevention designs relying on empirical formulas, resulting in significant uncertainty. Utility Model Content

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0005] A visualization indoor model test chamber for layered permeability and seepage in foundation pit soil includes:

[0006] The test chamber body has multiple detachable and connectable layered partitions arranged from top to bottom inside the test chamber body to divide the inner cavity of the test chamber body into multiple independent soil filling areas; the test chamber body has at least one transparent front wall;

[0007] Each of the layered partitions is provided with multiple permeation channels, and the inlet of each permeation channel is equipped with an electrically operated valve;

[0008] A fluorescent tracer injection system, which cooperates with a fluorescent tracer injection hole provided on the side plate of the main body of the test chamber to guide the fluorescent tracer into the target soil layer;

[0009] The ultraviolet developing module is set at an angle to the front wall of the main body of the test chamber to ensure that light uniformly covers the observation area;

[0010] A high-speed camera recording system is installed corresponding to the front wall of the test chamber body to collect the seepage trajectory of each soil layer inside the test chamber body;

[0011] A multi-channel independent water pressure control unit is located on the side of the test chamber body away from the fluorescent tracer injection system, and is used to inject permeable water with different water pressures into the corresponding fill layer;

[0012] A data acquisition and analysis module is electrically connected to the high-speed camera recording system and is used to generate a three-dimensional seepage field model.

[0013] Furthermore, the fluorescent tracer injection system includes a fluorescent tracer injection mechanism and a distributed injection pipeline, wherein the fluorescent tracer injection mechanism is connected to the fluorescent tracer injection port through the distributed injection pipeline.

[0014] Furthermore, the fluorescent tracer injection mechanism includes a storage tank and a micro peristaltic pump. The inlet end of the micro peristaltic pump is connected to the storage tank, and the outlet end of the micro peristaltic pump is connected to the main pipeline of the distributed injection pipeline.

[0015] Furthermore, the ultraviolet development module includes an ultraviolet lamp assembly and an adjustable bracket. The ultraviolet lamp assembly is set on the adjustable bracket with an adjustable irradiation angle, and the adjustable bracket is installed at the upper end of the test chamber body.

[0016] Furthermore, the wavelength of the ultraviolet lamp assembly is 365nm, the power is ≥30W, and the irradiation angle is adjustable from 0° to 45°.

[0017] Furthermore, the high-speed video recording system includes an industrial camera mounted on a tripod and a data acquisition computer connected to the industrial camera, wherein the center position of the lens of the industrial camera is set to correspond to the center position of the front wall.

[0018] Furthermore, the multi-channel independent water pressure control unit includes multiple micro servo water pumps, each of which has a maximum output pressure of 50 kPa and a control accuracy of ±1 kPa; each of the micro servo water pumps is independently connected to the water inlet of the corresponding backfill layer on the main body of the test chamber via a connecting water pipe.

[0019] Furthermore, the front wall is a 10mm thick high-strength transparent acrylic sheet.

[0020] The beneficial effects of this utility model are:

[0021] 1. This invention solves the problem that traditional permeameters cannot simulate stratified permeation and the seepage path is not visible. It can intuitively reveal the permeation damage mechanism such as piping and undercutting, and provide a scientific basis for the optimization of seepage prevention design.

[0022] 2. Layered Permeability Simulation: Removable partitions divide the test chamber into multiple independent zones, supporting the combined filling of different soil types such as clay, sand, and gravel. The electrically operated permeability channels precisely control the hydraulic connection between layers. Therefore, it has strong engineering applicability and can simulate complex geological structures containing interlayers and lenses. The test results directly guide the optimization of the cutoff wall depth.

[0023] 3. Visualization of seepage path: Fluorescent tracers are introduced into the target soil layer through distributed injection holes, ultraviolet lamps excite fluorescence development, and high-speed cameras record the entire trajectory of the seepage front expansion; therefore, the observation accuracy is high, the fluorescence tracer resolution reaches 0.1 mm, and the seepage velocity measurement error is ≤5%.

[0024] 4. Dynamic water pressure coupling: Multi-channel servo pumps provide independent water pressure for each soil layer, with a maximum simulated gradient of 50 kPa / m, which can reproduce complex seepage fields such as precipitation and tides.

[0025] 5. Intelligent Data Analysis: Based on machine vision-based seepage trajectory extraction algorithms and multi-sensor data fusion, it generates real-time permeability coefficient distribution cloud maps and risk warning reports. Therefore, operation is intelligent, supporting one-click execution of preset test procedures and reducing human intervention errors. Attached Figure Description

[0026] Figure 1 A schematic diagram of the structure of a visual indoor model test chamber for layered permeability and seepage of foundation pit soil provided by this utility model;

[0027] Figure 2 This is a cross-sectional structural diagram of the main body of the test chamber, the ultraviolet developing module, and the high-speed photography recording system.

[0028] Figure 3 This is a front view of the layered partition.

[0029] The components include: 1. Main body of the test chamber; 2. Layered partition; 3. Permeation channel; 4. Fluorescent tracer injection system; 4-1. Storage tank; 4-2. Miniature peristaltic pump; 4-3. Distributed injection pipeline; 4-4. Fluorescent tracer injection port; 5. Ultraviolet development module; 5-1. Ultraviolet lamp assembly; 5-2. Adjustable bracket; 6. High-speed photography recording system; 6-1. Industrial camera; 6-2. Data acquisition computer; 7. Multi-channel independent water pressure control unit; 7-1. Miniature servo water pump; 7-2. Water inlet; 8. Data acquisition and analysis module; 9. High-strength transparent acrylic sheet. Detailed Implementation

[0030] This invention provides a visualized indoor model test chamber for layered permeability and seepage in foundation pit soil. The technical solution of this invention will be described in detail below with reference to the accompanying drawings to facilitate understanding and mastery.

[0031] Example 1

[0032] refer to Figure 1-3 A visualization indoor model test chamber for layered permeability and seepage in foundation pit soil, comprising:

[0033] The test chamber body 1 has multiple detachable and connectable layered partitions 2 arranged from top to bottom inside the test chamber body 1 to divide the inner cavity of the test chamber body 1 into multiple independent soil filling areas; the test chamber body 1 has at least one transparent front wall;

[0034] Each layered partition 2 is provided with multiple permeation channels 3, and the inlet of the permeation channel 3 is equipped with an electrically operated valve.

[0035] Fluorescent tracer injection system 4, which is in conjunction with fluorescent tracer injection hole 4-4 on the side plate of the test chamber body 1, to guide the fluorescent tracer into the target soil layer;

[0036] The ultraviolet development module 5 is set at an angle to the front wall of the main body 1 of the test chamber to ensure that the light uniformly covers the observation area;

[0037] A high-speed camera recording system 6 is installed on the front wall of the test chamber body 1 to collect the seepage trajectory of each soil layer inside the test chamber body 1.

[0038] The multi-channel independent water pressure control unit 7 is located on the side of the test chamber body 1 away from the fluorescent tracer injection system 4, and is used to inject permeable water with different water pressures into the corresponding fill layer;

[0039] The data acquisition and analysis module 8 is electrically connected to the high-speed camera recording system 6 and is used to generate a three-dimensional seepage field model.

[0040] In this embodiment, the front wall of the test chamber body 1 is preferably made of a transparent material, preferably a 10mm thick high-strength transparent acrylic sheet 9.

[0041] In this embodiment, the layered partition 2 is made of 6061-T6 aluminum alloy and coated with polytetrafluoroethylene. Rubber sealing strips are provided on both sides of the layered partition 2, which are interference fit with the inner wall of the test chamber body 1, and the sealing pressure is ≥5kPa.

[0042] Preferably, the electric valve is driven by a stepper motor, with an opening and closing response time of ≤0.5s. The valve opening can be precisely adjusted by a PLC controller with an adjustment accuracy of ±0.1mm.

[0043] In this embodiment, the data acquisition and analysis module 8 integrates a pressure sensor, a flow meter, and a central data processor to calculate the permeability coefficient of each layer in real time and generate a three-dimensional seepage field model.

[0044] In this embodiment, the fluorescent tracer injection system 4 includes a fluorescent tracer injection mechanism and a distributed injection pipeline 4-3. The fluorescent tracer injection mechanism is connected to the fluorescent tracer injection port 4-4 through the distributed injection pipeline 4-3.

[0045] Specifically, the fluorescent tracer injection mechanism includes a storage tank 4-1 and a micro peristaltic pump 4-2. The inlet end of the micro peristaltic pump 4-2 is connected to the storage tank 4-1, and the outlet end of the micro peristaltic pump 4-2 is connected to the main pipeline of the distributed injection pipeline 4-3.

[0046] The fluorescent tracer injection system 4 includes a storage tank 4-1, a micro peristaltic pump 4-2, and a distributed injection pipeline 4-3. The injection flow rate is adjustable from 0.1 to 10 mL / min, and the concentration of the sodium fluorescein solution is 0.05% to 0.2%. Simultaneously, the fluorescent tracer injection port 4-4 on the side plate of the main body 1 is connected in series with the micro peristaltic pump 4-2 and the storage tank 4-1 via the distributed injection pipeline 4-3. Specifically, the sodium fluorescein solution in the storage tank 4-1 is pressurized by the peristaltic pump 4-2 and then distributed to the corresponding branch pipes on each floor through the main pipe of the distributed injection pipeline 4-3. The ends of the branch pipes are connected to the injection ports 4-4 on the side wall.

[0047] The pipeline interfaces use quick-release threaded joints to ensure sealing (pressure resistance ≥50kPa). It is important to note that fluorescent tracer injection holes 4-4 are evenly distributed along the side wall of the test chamber at each layer height to mark the seepage path, with a horizontal spacing ≤100mm and 3-5 holes per layer vertically (adjusted according to soil thickness). The holes are located in the center of each fill layer, with a diameter of 3mm and an embedded stainless steel guide tube (50mm in length) to prevent soil blockage.

[0048] In this embodiment, the main body 1 of the test chamber is a cuboid structure, and the interior is divided into 3 to 5 independent soil filling areas by a detachable layered partition 2. A permeation channel 3 with a diameter of 5 to 10 mm is opened at the bottom of each partition, with a channel spacing of ≤50 mm. An electric valve is installed at the channel opening. The front wall of the test chamber is made of 10 mm thick high-strength transparent acrylic plate 9, and fluorescent tracer injection holes 4-4 are evenly arranged along the height direction of each layer on the side wall, with a hole diameter of 3 mm and a hole spacing of ≤100 mm.

[0049] In this embodiment, the ultraviolet development module 5 includes an ultraviolet lamp group 5-1 and an adjustable bracket 5-2. The ultraviolet lamp group is set on the adjustable bracket 5-2 with an adjustable irradiation angle. The adjustable bracket 5-2 is installed on the upper end of the test chamber body 1.

[0050] Specifically, the wavelength of the UV lamp group 5-1 is 365nm, the power is ≥30W, and the irradiation angle is adjustable from 0° to 45°.

[0051] The UV lamp assembly 5-1 is mounted on an adjustable bracket 5-2 on the outer side of the top of the test chamber. The central axis of the lamp assembly is tilted at a 30° to 45° angle to the transparent acrylic plate 9 on the front wall of the test chamber to ensure uniform light coverage of the observation area. The adjustable bracket 5-2 is fixed to the top cover of the test chamber (made of aluminum alloy) with bolts. The power cord and control signal cord of the lamp assembly are embedded in the pre-embedded cable tray in the chamber and connected to an external controller, supporting remote adjustment of light intensity (30% to 100%) and on / off status.

[0052] In this embodiment, the high-speed video recording system 6 includes an industrial camera 6-1 mounted on a tripod and a data acquisition computer 6-2 connected to the industrial camera 6-1. The center position of the lens of the industrial camera 6-1 is set to correspond to the center position of the front wall.

[0053] Specifically, the high-speed video recording system 6 uses an industrial camera 6-1 with a frame rate of ≥60fps, which is mounted 1.5m in front of the test chamber and works with a data acquisition computer 6-2 equipped with image analysis software to extract the seepage trajectory.

[0054] In the high-speed photography recording system 6, the industrial camera 6-1 is preferably a high-speed camera, which is mounted on a tripod 1.5m from the front of the test chamber, with the center of the lens aligned with the center line of the transparent acrylic plate 9, and the vertical height aligned with the center of the test chamber (1.2m from the ground).

[0055] The industrial camera 6-1 is connected to the data acquisition computer 6-2 via an HDMI cable. Synchronization trigger signals are provided by the central data processor to ensure consistency between video recording timestamps and sensor data timestamps. The camera is equipped with a polarizing filter to eliminate glare interference from the acrylic panel. The image analysis software in the data acquisition computer 6-2, developed based on the OpenCV library, can automatically track seepage fronts, calculate flow velocity vector fields, and quantitatively analyze soil loss. Output results include seepage velocity distribution cloud maps and piping development time series.

[0056] In this embodiment, the multi-channel independent water pressure control unit 7 includes multiple micro servo water pumps 7-1, each with a maximum output pressure of 50 kPa and a control accuracy of ±1 kPa; each micro servo water pump 7-1 is independently connected to the water inlet 7-2 of the corresponding backfill layer on the main body 1 of the test chamber via a connecting water pipe.

[0057] Specifically, the miniature servo water pump 7-1 is centrally installed in an independent control cabinet on one side of the test chamber. The cabinet is connected to the test chamber via a waterproof cable and a pressure-resistant hose (pressure resistance ≥100kPa). A cooling fan (temperature ≤40℃) is installed inside the cabinet. Each layer's water inlet 7-2 is located 50mm from the top surface on the side wall of the test chamber, with one main water inlet (8mm diameter) per layer, connected to an external hose via a quick-connect fitting. A pressure buffer tank (500mL capacity) is installed at the pump output to reduce the impact of water pressure fluctuations on the soil.

[0058] Preferably, the multi-channel independent water pressure control unit 7 and the fluorescent tracer injection system 4 should be set on different sides of the test chamber to avoid the impact of water pressure fluctuations on the stability of fluorescent agent injection during stratified water pressure loading and permeation tests.

[0059] Preferably, the central data processor has a built-in dynamic calculation model for the penetration coefficient, and the formula is:

[0060]

[0061] In the above formula, K i Let L be the permeability coefficient of the i-th layer. i Let A be the seepage path length. i Let Δh be the cross-sectional area of ​​the water passage. i This is due to head difference.

[0062] This utility model provides a layered permeability and seepage visualization test chamber, the specific usage of which is as follows:

[0063] First, assemble the test chamber and fill the soil: insert the detachable layered partition 2 into the pre-set T-shaped groove on the inner wall of the test chamber, ensuring that the rubber sealing strip fits tightly against the chamber body; fill the soil in layers according to the design mix ratio. When filling the sand layer, a layered vibration compaction method should be used to prevent uneven density from causing preferential flow. It should be noted that the upper layer is silty clay with a compaction degree ≥90%, the middle layer is medium sand with a relative density Dr=70%, and the lower layer is gravel with a particle size of 5~10mm; after each layer is filled, use a handheld compactor to compact it to an energy of 0.45kJ / m³. 3 The material is compacted evenly, and the layer thickness is calibrated using a laser rangefinder, with the error controlled within ±2mm.

[0064] Further, perform fluorescent tracer injection and system debugging: Inject 0.1% sodium fluorescein solution into storage tank 4-1, start micro peristaltic pump 4-2, and set the injection flow rate to 2 mL / min; select the target injection layer, such as intermediate sand, through the fluorescent tracer injection and system control center, and the fluorescent agent is evenly infiltrated into the soil through distributed pipeline 4-3, with an injection time of 5 minutes; adjust the irradiation angle of UV lamp group 5-1 to 30°, turn on the light source and calibrate the white balance of industrial camera 6-1 to ensure the clarity of fluorescent development, and ensure that the continuous working time of UV lamps should not exceed 4 hours to avoid light source attenuation affecting the development effect.

[0065] Further, a layered water pressure loading and infiltration test was conducted: the multi-channel micro servo water pump 7-1 was started, and the water pressure was set to 10 kPa for the upper layer, 15 kPa for the middle layer, and 5 kPa for the lower layer. After stabilizing the pressure for 5 minutes, the initial flow rate was recorded. The infiltration channels 3 of each layer were opened sequentially by the PLC controller, from top to bottom, with a single opening interval of 2 minutes. The high-speed camera continuously filmed at a frame rate of 60 fps for 30 minutes, and the pressure and flow data of each layer were recorded simultaneously.

[0066] Further, data processing and result output are performed: image analysis software processes the video data frame by frame, extracts the coordinates of the seepage front, and calculates the average expansion velocity; the central data processor uses Darcy's formula to calculate the dynamic permeability coefficient of each layer, generating a three-dimensional seepage field model; when a sudden increase in the permeability coefficient of a certain layer is detected to be ≥20%, the system automatically triggers a piping warning signal. Finally, it is important to note that after the experiment, the fluorescent agent pipeline must be flushed with deionized water to prevent crystallization and blockage.

[0067] The technical solution of this utility model has been fully described above. It should be noted that the specific implementation of this utility model is not limited to the above description. All technical solutions formed by those skilled in the art based on the spirit of this utility model by adopting equivalent transformations or equivalent transformations in terms of structure, method or function shall fall within the protection scope of this utility model.

Claims

1. A visual indoor model test chamber for layered permeability and seepage of foundation pit soil, characterized in that, include: The test chamber body (1) has multiple detachable and connectable layered partitions (2) arranged from top to bottom inside the test chamber body (1) to divide the inner cavity of the test chamber body (1) into multiple independent soil filling areas; the test chamber body (1) has at least one transparent front wall; Each of the layered partitions (2) is provided with multiple permeation channels (3), and the inlet of each permeation channel (3) is provided with an electrically operated valve; A fluorescent tracer injection system (4) is provided, which is in conjunction with a fluorescent tracer injection hole (4-4) on the side plate of the test chamber body (1) to guide the fluorescent tracer into the target soil layer. The ultraviolet development module (5) is set at an angle to the front wall of the test chamber body (1) to ensure that the light uniformly covers the observation area; A high-speed camera recording system (6) is provided, which is correspondingly set to the front wall of the test chamber body (1) to collect the seepage trajectory of each soil layer in the test chamber body (1); A multi-channel independent water pressure control unit (7) is located on the side of the test chamber body (1) away from the fluorescent tracer injection system (4) and is used to inject permeable water with different water pressures into the corresponding fill layer; The data acquisition and analysis module (8) is electrically connected to the high-speed camera recording system (6) and is used to generate a three-dimensional seepage field model.

2. The indoor model test chamber for visualized seepage and permeability of foundation pit soil as described in claim 1, characterized in that, The fluorescent tracer injection system (4) includes a fluorescent tracer injection mechanism and a distributed injection pipeline (4-3). The fluorescent tracer injection mechanism is connected to the fluorescent tracer injection hole (4-4) through the distributed injection pipeline (4-3).

3. The indoor model test chamber for visualized seepage and permeability of foundation pit soil as described in claim 2, characterized in that, The fluorescent tracer injection mechanism includes a storage tank (4-1) and a micro peristaltic pump (4-2). The inlet end of the micro peristaltic pump (4-2) is connected to the storage tank (4-1), and the outlet end of the micro peristaltic pump (4-2) is connected to the main pipeline of the distributed injection pipeline (4-3).

4. The indoor model test chamber for visualized seepage and permeability of foundation pit soil as described in claim 1, characterized in that, The ultraviolet development module (5) includes an ultraviolet lamp group (5-1) and an adjustable bracket (5-2). The ultraviolet lamp group is set on the adjustable bracket (5-2) with an adjustable irradiation angle. The adjustable bracket (5-2) is installed on the upper end of the test chamber body (1).

5. The indoor model test chamber for visualized seepage and permeability of foundation pit soil as described in claim 4, characterized in that, The ultraviolet lamp assembly (5-1) has a wavelength of 365nm, a power of ≥30W, and an adjustable irradiation angle ranging from 0° to 45°.

6. The indoor model test chamber for visualized seepage and permeability of foundation pit soil as described in claim 1, characterized in that, The high-speed video recording system (6) includes an industrial camera (6-1) mounted on a tripod and a data acquisition computer (6-2) connected to the industrial camera (6-1). The center position of the lens of the industrial camera (6-1) is set to correspond to the center position of the front wall.

7. The indoor model test chamber for visualized seepage and permeability of foundation pit soil as described in claim 1, characterized in that, The multi-channel independent water pressure control unit (7) includes multiple micro servo water pumps (7-1), each of which has a maximum output pressure of 50 kPa and a control accuracy of ±1 kPa. Each of the micro servo water pumps (7-1) is independently connected to the water inlet (7-2) of the corresponding backfill layer on the main body (1) of the test chamber via a connecting water pipe.

8. The indoor model test chamber for visualized seepage and permeability of foundation pit soil as described in claim 1, characterized in that, The front wall is a 10mm thick high-strength transparent acrylic sheet.

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