Automatic water replenishing double-ring infiltration instrument for measuring hydraulic gradient

Abstract

The utility model provides an automatic water replenishing double-ring infiltration instrument for measuring hydraulic gradient. Comprising a water replenishing device and a double-ring infiltration instrument. The water replenishing device comprises a siphon, a flow meter, an airlock and a water tank with a ball valve. The double-ring infiltration instrument comprises an inner ring, an outer ring, a connecting hole, a fixed supporting rod and an L-shaped pressure measuring tube. The siphon is arranged between the water tank and the double-ring infiltration instrument; the flow meter is mounted on the siphon; the airlock is positioned on the siphon and is vertical to the water tank; the inner ring and the outer ring are combined through the fixed supporting rods to form an inner and outer integrated double-ring structure; the L-shaped piezometric tube is placed in a connecting hole of the inner and outer rings and the center of the inner ring. The device has the advantages of being reasonable in structure, convenient and fast to manufacture, low in cost, easy to use, high in applicability and capable of being widely applied to the fields of rock and soil testing, construction monitoring, scientific research and the like.

Description

Technical Field

[0001] This utility model relates to the field of measurement technology in geotechnical engineering, specifically to an automatic water replenishment double-ring infiltration meter for measuring hydraulic gradient. Background Technology

[0002] Permeability coefficient is one of the important physical properties of soil, reflecting its ability to allow water flow. This parameter is of great significance in agriculture, soil engineering, environmental science, and other fields, affecting irrigation management, soil moisture retention, and pollutant migration. Therefore, the scientific determination of permeability coefficient is crucial for accurately assessing and managing soil moisture characteristics. The dual-ring infiltration meter, as an advanced measurement tool, has become an important means of studying soil permeability by reducing boundary effects and improving measurement accuracy, providing a reliable data foundation for soil management and optimized water resource utilization.

[0003] While dual-ring infiltrators offer significant advantages in determining permeability coefficients, they also have some limitations. First, the accurate measurement of the hydraulic gradient is often affected by various factors, such as soil heterogeneity and variations in moisture properties. This makes it difficult to accurately obtain the hydraulic gradient in practical applications, thus affecting the calculation of the permeability coefficient. Second, maintaining the equilibrium of the liquid levels inside and outside the dual rings during experiments is challenging; any slight fluctuation or imbalance in the liquid level can lead to measurement errors. Furthermore, the accuracy of water supply recording can also be affected by human factors during operation and equipment performance, resulting in significant errors in water supply measurement, as illustrated by a device for accurately measuring the permeability coefficient of undisturbed soil disclosed in patent number 202122926221X. These limitations may restrict the accuracy of the measurement results under certain specific circumstances, necessitating a comprehensive analysis in conjunction with other measurement methods. Utility Model Content

[0004] To address the aforementioned technical problems, the purpose of this utility model is to provide an automatic water replenishment double-ring infiltration meter for measuring hydraulic gradients. This device has the advantages of simple operation, reasonable structure, low cost, safety and reliability, minimal disturbance to the soil, and accurate measurement results.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an automatic water replenishment double-ring infiltration instrument for measuring hydraulic gradient, comprising: an inner ring, an outer ring, an L-shaped pressure measuring tube, a flow meter, and a water tank and a pair of siphon tubes. A fixed support rod is provided between the outer wall of the inner ring and the inner wall of the outer ring to form an integral double-ring structure, and connecting holes with through holes are provided on the walls of the inner and outer rings. One end of each pair of siphon tubes is located inside the inner and outer rings respectively, and the other end is located inside the water tank outside the outer ring. The opening of the water tank is lower than the horizontal position of the outer ring, and a flow meter and an air lock are respectively provided on each pair of siphon tubes. The horizontal section of the L-shaped pressure measuring tube is inserted into the connecting hole between the outer and inner rings, and its end is located at the center of the inner ring. A float valve is provided on the wall of the water tank.

[0006] The inner and outer rings have several connection holes spaced 10cm apart from the bottom up, and the diameter of the connection holes is adapted to the diameter of the L-shaped pressure measuring tube.

[0007] The L-shaped pressure measuring tube has a long end of 70cm and short ends of 30cm, 35cm, and 40cm respectively. The diameter is adapted to the connecting hole, and there are 3 tubes in total. The long end of the L-shaped pressure measuring tube has a pressure gauge.

[0008] The flow meter is installed on the siphon pipe between the water tank and the double ring structure; the horizontal end of the siphon pipe is 70cm long, and the vertical end is adapted to the size of the water tank; an air lock is provided at the vertical end of the siphon pipe perpendicular to the water tank, and a water inlet hole is reserved on the air lock, and a cover is provided on the water hole.

[0009] The float valve is embedded in the center of the water tank wall, level with the liquid level controlled within the double-ring structure, and the external water pipe of the float valve is connected to the water source.

[0010] The beneficial effects of this invention are as follows: Compared with existing dual-ring infiltration meters, this invention can accurately measure the continuous hydraulic gradient of soil. It improves the accuracy of soil permeability coefficient determination; reduces the difficulty of maintaining the liquid level height of the inner and outer rings during the experiment, and enhances the accuracy of water supply when maintaining stable liquid levels in both rings, thus reducing experimental errors. Furthermore, it maintains a semi-automated experimental process, avoiding the influence of human factors on experimental accuracy. This device has a reasonable structure, is easy to manufacture, has low cost, is simple to use, and is highly applicable, making it suitable for a wide range of fields including geotechnical testing, construction monitoring, and scientific research. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of an automatic water replenishment double-ring infiltration instrument for measuring hydraulic gradient according to the present invention.

[0012] Figure 2 This is a top view schematic diagram of an automatic water replenishment double-ring infiltration instrument for measuring hydraulic gradient according to the present invention;

[0013] Figure 3This is a detailed schematic diagram of the water replenishment device of this utility model.

[0014] In the picture:

[0015] 1-Inner ring 2-Outer ring 3-Fixed support rod

[0016] 4-Siphon tube 5-Flow meter 6-Airlock

[0017] 7-Water tank 8-Float valve 9-L-type pressure testing pipe

[0018] 10-Connecting Hole Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0020] The design concept of this utility model is as follows: In the traditional double-ring method, the hydraulic gradient is directly set to 1 in the determination of soil permeability coefficient. This assumption has a great influence on the determination of permeability coefficient. In addition, the liquid level is required to remain constant during the double-ring test. However, the use of a Marshall bottle requires continuous water addition. There are many human factors in the whole process, which can easily produce errors and affect the test results.

[0021] like Figure 2 As shown, this utility model discloses an automatic water replenishment double-ring infiltration instrument for measuring hydraulic gradient, comprising an inner ring 1, an outer ring 2, a fixed support rod 3, an L-shaped pressure measuring tube 9, and a connecting hole 110 as the double-ring infiltration instrument, and a water replenishment device mainly consisting of a siphon tube 4, a flow meter 5, an air lock 6, a water tank 7, and a float valve 8. Figure 1 The diagram shows an overall schematic of an automatic water replenishment dual-ring infiltration meter for measuring hydraulic gradients, including an inner ring 1, an outer ring 2, a fixed support rod 3, an L-shaped pressure measuring tube 9, a connecting hole 10, a water tank 7, a float valve 8, a siphon tube 4, a flow meter 5, and an airlock 6. The inner ring 1 and outer ring 2 are combined by the fixed support rod 3 to form an integrated double-ring structure. The horizontal end of the L-shaped pressure measuring tube is placed at the center of the inner ring and is installed in the connecting hole between the outer and inner rings. The siphon tube, flow meter, and airlock are combined and placed between the water tank and the inner and outer rings. The float valve 8 is embedded in the water tank and is located at the center of the water tank 7.

[0022] The specific implementation steps of this utility model of an automatic water replenishment dual-ring infiltration instrument for measuring hydraulic gradient are as follows:

[0023] (1) Install the double-ring infiltration meter, embed the inner ring 1 and the outer ring 2 into the soil, and ensure that the double rings are horizontally embedded by fixing the support rod 3. Insert the L-shaped pressure measuring tubes 9 of different lengths into the connecting hole 10 in sequence.

[0024] (2) Install a water supply device, place the water tank 7 horizontally on one side of the double ring, make the float valve 8 level with the liquid level to be maintained, connect the external pipe of the float valve 8 directly to the water source, and place the siphon pipe 4 horizontally between the inner ring 1 and the outer ring 2 and the water tank 7 through the frame.

[0025] (3) Conduct data testing. Before opening the water source, seal the outlets at both ends of the siphon tube 4. Add water from the airlock 6 until all the air is expelled, and then seal it again. Open the external water source and inject water into the double ring to the designated position. After the water level has submerged the outlets at both ends of the siphon tube 4, unseal the outlets at both ends of the siphon tube 4 and start recording the change in the water level of the inner ring at different times, the amount of water injected to maintain the initial water level, the water head height of the L-shaped pressure measuring tube 9, and the water level of the inner ring.

[0026] (4) Change the water injection height of the inner and outer rings and take multiple measurements. Calculate the hydraulic gradient of the soil water by dividing the water head difference between the inner ring 1 and the L-shaped piezometer 9 by the soil height in the inner ring, i.e., i = Δh / l. Substitute the above calculation results into Darcy's law formula to calculate the undisturbed soil permeability coefficient, and take the average value as the soil permeability coefficient of the measurement area.

[0027] The specific implementation process of this utility model has been described above with reference to the accompanying drawings. However, this utility model is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Modifications, substitutions, improvements, etc., made by those skilled in the art under the guidance of this utility model without departing from the spirit and scope of protection of this utility model should all be included within the protection scope of this utility model.

Claims

1. An automated water-replenishing dual-ring infiltrometer for measuring hydraulic gradients, comprising: The inner ring (1), the outer ring (2), the L-shaped pressure measuring tube (9) and the flow meter (5) are characterized in that: further comprising a water tank (7) and a pair of siphon pipes (4), the fixed support rod (3) is arranged between the outer wall of the inner ring (1) and the inner wall of the outer ring (2) to form a double-ring structure of the inner and outer rings, and the connecting hole (10) with a through hole is arranged on the wall of the inner ring (1) and the outer ring (2); one end of the pair of siphon pipes (4) is located in the inner ring (1) and the outer ring (2) respectively, and the other end is located in the water tank (7) outside the outer ring (2), the water tank (7) is placed at a position with an opening lower than the horizontal position of the outer ring (2), and the pair of siphon pipes (4) are respectively provided with the flow meter (5) and the air lock (6); the horizontal section of the L-shaped pressure measuring tube (9) is inserted into the connecting hole (10) of the outer ring (2) and the inner ring (1), and the end is located at the center of the inner ring (1); the water tank (7) is provided with a float valve (8) on the wall.

2. The automatic water replenishable dual ring infiltrometer for measuring hydraulic gradient according to claim 1, wherein, The inner ring (1) and the outer ring (2) are provided with a plurality of connecting holes at intervals of 10 cm from the bottom, and the diameter of the connecting hole is matched with the diameter of the L-shaped pressure measuring tube (9).

3. The automatic water replenishable dual ring infiltrometer for measuring hydraulic gradient according to claim 2, wherein, The long end of the L-shaped pressure measuring tube (9) is 70 cm long, and the short ends are 30 cm, 35 cm and 40 cm long respectively, and the diameter is matched with the connecting hole, and there are three L-shaped pressure measuring tubes (9), and the long end of the L-shaped pressure measuring tube (9) has a pressure scale.

4. The automatic water replenishable dual ring infiltrometer for measuring hydraulic gradient according to claim 1, wherein, The flow meter is arranged on the siphon pipe (4) between the water tank (7) and the double-ring structure; the horizontal pipe end of the siphon pipe is 70 cm long, the vertical pipe end is matched with the size of the water tank (7); the vertical pipe end of the siphon pipe (4) is provided with an air lock (6) at the vertical position of the water tank (7), a water hole is reserved on the air lock (6), and a cover is arranged on the water hole.

5. The automatic water replenishable dual ring infiltrometer for measuring hydraulic gradient according to claim 1, wherein, The float valve (8) is embedded in the center of the water tank wall and is leveled with the liquid level controlled in the double-ring structure, and the external water pipe of the float valve (8) is connected with the water source.

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