Karst corrosion speed testing system and method

Abstract

The invention discloses a karst corrosion speed testing system and method, and belongs to the technical field of karst geology and environmental engineering test.The karst corrosion speed testing system comprises a supporting platform, an upper water tank is arranged on the top face of the supporting platform, a lower water tank is arranged at the bottom of the supporting platform, a water circulation pipeline is communicated between the upper water tank and the lower water tank, and a testing mechanism is arranged between the upper water tank and the lower water tank; the testing mechanism comprises a plurality of channel pipes arranged between the upper water tank and the lower water tank side by side, rock samples are arranged in the channel pipes, and speed adjusting parts are arranged on the channel pipes. By arranging the rock samples with different upstream cross sectional areas and the channel pipes matched with the rock samples and combining the height-adjustable upper water tank and the water circulation pipeline, comparison simulation of karst corrosion behaviors under different flow velocity conditions is achieved, and then corrosion rate changes under different physical parameters are quantified.

Description

Technical Field

[0001] This invention belongs to the field of karst geology and environmental engineering testing technology, and particularly relates to a karst dissolution rate testing system and method. Background Technology

[0002] Karst landforms are widely distributed in carbonate rock areas, and chemical dissolution of rocks plays a central role in their formation and evolution. The rate of karst dissolution not only affects the evolution of groundwater dynamic systems but also directly impacts geological engineering safety, infrastructure stability, and the assessment of the regional hydrogeochemical environment. Therefore, quantitative research on rock dissolution processes has become an important research topic in fields such as geological engineering, environmental science, and hydrogeochemistry.

[0003] In existing technologies, methods for determining rock dissolution rates mainly include the following categories: 1. Field burial method, which involves burying pre-treated rock samples in a groundwater environment for an extended period and periodically measuring mass changes; 2. Static immersion method, which involves placing rock samples in a prepared simulated solution for static immersion and calculating the dissolution rate based on the mass difference before and after immersion; 3. Laboratory simulated flow reaction device, which uses a pumping system to circulate the solution across the surface of the rock sample. However, these methods have many limitations: on the one hand, field in-situ testing has a long cycle and uncontrollable environmental factors, resulting in poor experimental repeatability and difficulty in meeting the needs of high-precision research; on the other hand, traditional static or simple flow experimental devices are mostly intermittently operated, lacking real-time acquisition of water chemical parameters, failing to reflect the instantaneous reaction characteristics during karstification, and making it difficult to quantitatively describe the dynamic changes. In addition, most current experimental devices do not adequately control the geometric parameters of the samples, which is not conducive to analyzing the differences in dissolution behavior under different water-facing areas and different hydrodynamic conditions; at the same time, they generally lack a systematic flow rate control mechanism, making it difficult to unify experimental conditions and resulting in large dispersion of test results. Summary of the Invention

[0004] The purpose of this invention is to provide a karst dissolution rate testing system and method to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides a karst erosion rate testing system, including a support platform, an upper water tank on the top surface of the support platform, a lower water tank at the bottom of the support platform, a water circulation pipeline connecting the upper water tank and the lower water tank, a testing mechanism between the upper water tank and the lower water tank, the testing mechanism including multiple channel pipes arranged side by side between the upper water tank and the lower water tank, a rock sample inside the channel pipe, and a speed regulating part on the channel pipe; It also includes a data acquisition unit, which is used to obtain the initial mass and the mass after the experiment of the rock sample, and to calculate the rock dissolution rate.

[0006] Optionally, the speed regulating unit includes a drain valve connected to the channel pipe, the drain valve being located on the side of the channel pipe near the upper water tank, and a flow limiting orifice plate being provided inside the channel pipe, the flow limiting orifice plate being located on the side of the rock sample near the drain valve.

[0007] Optionally, the speed regulating unit may also include a replenishment pipe connected to the upper water tank.

[0008] Optionally, the channel tube is provided with a detachable clamping device for fixing the rock sample.

[0009] Optionally, the data acquisition unit includes an electronic balance for weighing the rock sample and a timer for recording the experimental cycle.

[0010] Optionally, the formula for calculating the rock dissolution rate is as follows: ; in The initial mass of the sample. ; The final mass of the sample test. ; The water-facing area of ​​the sample. ; For the experimental time, ; The rate of dissolution per unit area per unit time. .

[0011] Optionally, the channel tube is a transparent rigid pipe.

[0012] Optionally, the water circulation pipe route is made of corrosion-resistant flexible tubing.

[0013] Optionally, the water-facing cross-sectional areas of the rock samples located in the channel tube are different.

[0014] A method for testing the rate of karst dissolution includes the following steps: S1. Initial mass measurement of the rock sample, and fix the rock sample inside the channel tube; S2. Adjust the speed control unit and start the water circulation system to simulate the flow of karst solution through the rock sample, and record the experimental time; S3. After the test, measure the mass of the rock sample after the experiment, and calculate the dissolution rate using the formula for calculating the rock dissolution rate.

[0015] This invention discloses the following technical effects: By setting up rock samples with different water-facing cross-sectional areas and corresponding channel pipes, combined with a height-adjustable upper water tank and water circulation pipeline, this invention achieves comparative simulation of karst dissolution behavior under different flow rates, thereby quantifying the changes in dissolution rate under different physical parameters. This invention can effectively simulate karst dynamic conditions and has the advantages of simple structure, strong data controllability, and high test repeatability. It is suitable for standardized and quantitative research on karst dissolution processes in a laboratory environment. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the karst dissolution rate testing system of the present invention; Figure 2 This is a schematic diagram of the channel tube structure of the present invention; Figure 3 This is a schematic diagram of the clamping device of the present invention.

[0017] Figure label: 1. Upper water tank; 2. Lower water tank; 3. Support platform; 4. Channel pipe; 41. Slide groove; 5. Rock sample; 6. Water circulation pipeline; 7. Speed ​​regulating unit; 71. Liquid replenishment pipe; 72. Flow limiting orifice plate; 73. Drain valve; 9. Clamping device; 91. Slider; 92. Arc-shaped connecting plate; 93. Cavity; 94. Connecting rod; 95. Spring; 96. Limiting plate. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Reference Figures 1 to 3As shown, this embodiment provides a karst erosion rate testing system, including a support platform 3, an upper water tank 1 on the top surface of the support platform 3, a lower water tank 2 at the bottom of the support platform 3, a water circulation pipe 6 connecting the upper water tank 1 and the lower water tank 2, a testing mechanism between the upper water tank 1 and the lower water tank 2, the testing mechanism including multiple channel pipes 4 arranged side by side between the upper water tank 1 and the lower water tank 2, a rock sample 5 inside the channel pipe 4, and a speed regulating part 7 on the channel pipe 4; It also includes a data acquisition unit, which is used to obtain the initial mass and post-experimental mass of rock sample 5 and to calculate the rock dissolution rate.

[0021] This invention utilizes rock samples 5 with varying water-facing cross-sectional areas and corresponding channel pipes 4, combined with a height-adjustable upper water tank 1 and a water circulation pipeline 6, to comparatively simulate karst dissolution behavior under different flow rates, thereby quantifying the changes in dissolution rates under different physical parameters. This invention effectively simulates karst dynamic conditions and possesses advantages such as simple structure, strong data controllability, and high test repeatability, making it suitable for standardized and quantitative research on karst dissolution processes in a laboratory environment.

[0022] Further optimization of the scheme: the speed regulating unit 7 includes a drain valve 73 connected to the channel pipe 4. The drain valve 73 is located on the side of the channel pipe 4 near the upper water tank 1. The channel pipe 4 is provided with a flow limiting orifice plate 72, which is located on the side of the rock sample 5 near the drain valve 73.

[0023] To further optimize the design, the speed control unit 7 also includes a replenishment pipe 71 that is connected to the upper water tank 1.

[0024] The speed control unit 7 is used to control the flow rate of each channel to simulate different hydrodynamic environments. The replenishment pipe 71 is connected to an external water source to maintain a stable liquid level in the upper water tank 1; the drain valve 73 can be adjusted to create different head differences; the flow limiting orifice plate 72 is installed at the inlet of each channel pipe 4, and the local flow rate is controlled by setting different orifice diameters, thereby simulating the dissolution behavior under different hydrodynamic conditions.

[0025] To further optimize the design, a detachable clamping device 9 is installed inside the channel tube 4. The detachable clamping device 9 is used to fix the rock sample 5. The rock sample 5 is fixed in each channel tube 4 by the detachable clamping device 9, which facilitates the replacement of rock samples 5 of different materials or sizes.

[0026] The top and bottom of the channel tube 4 are symmetrically provided with sliding grooves 41. The clamping device 9 includes a slider 91 slidably connected in the sliding groove 41. The two sliders 91 are fixedly connected by symmetrically arranged arc-shaped connecting plates 92. A cavity 93 is provided on the side of the slider 91 away from the sliding groove 41. A connecting rod 94 is slidably connected in the cavity 93. A spring 95 is fixedly connected in the cavity 93. The spring 95 is fixedly connected to the connecting rod 94. One end of the connecting rod 94 is located outside the cavity 93 and is fixedly connected to a limiting plate 96. The limiting plate 96 is used to fix the rock sample 5.

[0027] Before the experiment, the rock sample 5 is placed between the two limiting plates 96 and clamped by the squeezing action of the spring 95. Then, the clamping device 9 is moved into the channel tube 4 along the slide 41 until it abuts against the side of the slide 41. After the experiment, the clamping device 9 is pushed out from the other side of the channel tube 4 and the rock sample 5 is taken out.

[0028] The scheme was further optimized, and the data acquisition unit included an electronic balance for weighing the rock sample 5 and a timer for recording the experimental cycle.

[0029] The data acquisition unit is used to measure the initial mass of rock sample 5, the experimental duration and the mass change after the experiment, and to calculate the rock dissolution rate per unit time and per unit area.

[0030] Further optimization of the scheme yields the following formula for calculating the rock dissolution rate: L: ; in The initial mass of the sample. ; The final mass of the sample test. ; The water-facing area of ​​the sample. ; For the experimental time, ; The rate of dissolution per unit area per unit time. .

[0031] The design was further optimized by making channel 4 a transparent rigid pipe, which facilitates observation of the solution flow and the karst dissolution process.

[0032] Further optimization of the design: the water circulation pipeline 6 is made of corrosion-resistant flexible hose and is connected between the upper water tank 1 and the lower water tank 2 through a sealed joint.

[0033] Further optimization of the design resulted in different water-facing cross-sectional areas for the rock samples 5 located in channel pipe 4. For example, each sample had a cross-sectional area of ​​5 cm². 2 10cm 2 and 15cm 2 This allows for a comparative analysis of the impact of different water-facing areas on the dissolution rate.

[0034] A method for testing the rate of karst dissolution includes the following steps: S1. Initial mass measurement of rock sample 5, and fix rock sample 5 inside channel tube 4; S2. Adjust the speed control unit 7 and start the water circulation system to simulate the flow of karst solution through the rock sample 5, and record the experimental time; S3. After the test, take out rock sample 5 and dry it to constant weight. Measure the mass of rock sample 5 after the test. Calculate the dissolution rate based on the mass difference, water-facing area, and test time using the formula for calculating rock dissolution rate.

[0035] The following is a typical experimental procedure for using this system to test the dissolution rate: After pretreatment of the rock sample 5 (e.g., polishing, drying), it is installed in the three channel tubes 4 and fixed with the detachable clamping device 9. The initial mass of each rock sample 5 was weighed using an electronic balance. ; Adjust the liquid level in the upper water tank 1, set the opening of the drain valve 73, and install flow limiting orifice plates 72 with different orifice diameters; Start the circulating water pump so that the simulated karst solution flows from the upper water tank 1 into each channel pipe 4, flows through the rock sample 5 and then enters the lower water tank 2; Maintain continuous system operation for a set time (e.g., 24 hours), the timer records the time; Shut down the system, remove each rock sample 5 and dry it to constant weight, then measure the final mass of rock sample 5 again using an electronic balance. ; Calculate the dissolution rate per unit time and per unit area for each sample. The calculation formula is as follows: in The initial mass of the sample. ; The final mass of the sample test. ; The water-facing area of ​​the sample. ; For the experimental time, ; The rate of dissolution per unit area per unit time. .

[0036] Based on the dissolution rate of rock sample 5 in different channel tubes 4 It can analyze the influence of changes in water-facing area and flow velocity on dissolution behavior.

[0037] Through the above structure and method, this system can simulate the hydrodynamic conditions in karst landforms in a controlled indoor environment, and realize comparative and quantitative testing of samples of different lithologies under various flow rate conditions. It solves the technical problems of poor repeatability, single control parameters, and difficulty in adjusting flow rate in existing testing methods, and is applicable to multiple fields such as geological engineering, hydrogeochemistry, and groundwater pollution simulation.

[0038] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "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, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0039] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A karst dissolution rate testing system, characterized in that: The system includes a support platform (3), an upper water tank (1) on the top surface of the support platform (3), a lower water tank (2) at the bottom of the support platform (3), a water circulation pipe (6) connecting the upper water tank (1) and the lower water tank (2), a testing mechanism between the upper water tank (1) and the lower water tank (2), the testing mechanism including multiple channel pipes (4) arranged side by side between the upper water tank (1) and the lower water tank (2), a rock sample (5) inside the channel pipe (4), and a speed regulating part (7) on the channel pipe (4); It also includes a data acquisition unit, which is used to obtain the initial mass and the mass after the experiment of the rock sample (5) and to calculate the rock dissolution rate.

2. The karst dissolution rate testing system according to claim 1, characterized in that: The speed regulating unit (7) includes a drain valve (73) connected to the channel pipe (4). The drain valve (73) is located on the side of the channel pipe (4) near the upper water tank (1). A flow limiting orifice plate (72) is provided inside the channel pipe (4). The flow limiting orifice plate (72) is located on the side of the rock sample (5) near the drain valve (73).

3. The karst dissolution rate testing system according to claim 1, characterized in that: The speed regulating unit (7) also includes a replenishment pipe (71) connected to the upper water tank (1).

4. The karst dissolution rate testing system according to claim 1, characterized in that: The channel tube (4) is provided with a detachable clamping device (9), which is used to fix the rock sample (5).

5. The karst dissolution rate testing system according to claim 1, characterized in that: The data acquisition unit includes an electronic balance for weighing the rock sample (5) and a timer for recording the experimental cycle.

6. The karst dissolution rate testing system according to claim 1, characterized in that: The formula for calculating the rock dissolution rate is as follows: ； in The initial mass of the sample. ; The final mass of the sample test. ; The water-facing area of ​​the sample. ; For the experimental time, ; The rate of dissolution per unit area per unit time. .

7. The karst dissolution rate testing system according to claim 1, characterized in that: The channel pipe (4) is a transparent rigid pipe.

8. The karst dissolution rate testing system according to claim 1, characterized in that: The water circulation pipeline (6) is made of corrosion-resistant flexible hose.

9. The karst dissolution rate testing system according to claim 1, characterized in that: The water-facing cross-sectional areas of the rock samples (5) located in the channel tube (4) are different.

10. A method for testing the rate of karst dissolution, based on the karst dissolution rate testing system according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Initial mass measurement of rock sample (5) and fixing rock sample (5) inside channel tube (4); S2. Adjust the speed control unit (7) and start the water circulation system to simulate the flow of karst solution through the rock sample (5), and record the experimental time; S3. After the test, measure the mass of the rock sample (5) after the test, and calculate the dissolution rate using the formula for calculating the rock dissolution rate.

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