A device for measuring the permeability coefficient of muddy water in porous cover plates for slope drainage ditches

Abstract

The present invention relates to a device for measuring the muddy water permeability coefficient of a porous cover plate for a slope drainage ditch, comprising a sewage supply and flow collection device, a porous cover plate placement device and a water seepage collection device, wherein the sewage supply and flow collection device is used to simulate natural rainfall, and the water seepage collection device comprises a drainage channel, a triangular weir installed in the drainage channel, and a triangular weir probe. The porous cover plate to be measured is placed in the porous cover plate placement device, and then simulated rainfall is carried out through the sewage supply and flow collection device, and the simulated sewage falls on the porous cover plate in the form of rain. The sewage passing through the porous cover plate flows into the drainage channel, and then the permeability coefficient η of the porous cover plate is measured. Finally, by fitting the relationship between different rainfall intensities and the permeability coefficient η, the permeability law of the porous cover plate under different working conditions can be obtained. Thereby, an effective selection is provided for the design of slope drainage ditch cover plates.

Description

Technical Field

[0001] The invention relates to the field of engineering hydraulics, in particular to a device for measuring muddy water permeability coefficient of a porous cover plate for a slope drainage ditch. Background Art

[0002] The slope drainage ditch cover is the basic component of the roadbed construction of water conservancy projects. The slope drainage ditch cover is mainly made of large-pore sandless concrete, which is used to protect the drainage outlet and intercept sewage infiltration. At the same time, it can also serve as an auxiliary road.

[0003] The water source of this type of slope drainage ditch cover is mainly natural rainfall from the slope, so it is mainly muddy water. For different water conservancy projects, natural precipitation varies under different climate conditions; muddy water also has different characteristics under different slope conditions.

[0004] At present, the design of slope drainage ditch covers is mainly based on experience and lacks effective selection basis. Therefore, it is necessary to develop a device for measuring the muddy water permeability coefficient of porous covers used in slope drainage ditches of water conservancy projects to improve the scientific nature of the selection of such slope drainage ditch covers. Summary of the invention

[0005] In order to provide effective selection for slope drainage ditch cover design,

[0006] The present invention provides a device for measuring the muddy water permeability coefficient of a porous cover plate for a slope drainage ditch, which adopts the following technical scheme:

[0007] A device for measuring the muddy water permeability coefficient of a porous cover plate for a slope drainage ditch comprises a sewage supply and flow collection device, a porous cover plate placement device and a water seepage collection and measurement device. The sewage supply and flow collection device is used to simulate natural rainfall, and the water seepage collection and measurement device comprises a drainage channel, a triangular weir installed in the drainage channel, and a triangular weir measuring needle.

[0008] By adopting the above technical solution, the porous cover plate to be measured is placed in the porous cover plate placement device, and then simulated rainfall is carried out through the sewage supply and confluence device, and the simulated sewage falls on the porous cover plate in the form of rain. The sewage passing through the porous cover plate flows into the drainage channel, and the measured water surface depth Δh=h2-h1, h2 is the height from the bottom of the triangular weir to the triangular weir probe, and h1 is the height from the water surface to the triangular weir probe. The seepage flow rate q=KΔh is calculated based on the water depth Δh measured by the triangular weir 2.47, where K can be obtained by querying relevant engineering specifications. The calculation formula for the permeability of porous cover plates is derived from the Darcy formula as η=V / I, where the seepage velocity V=q / A, A represents the area of ​​the porous cover plate, q is the seepage flow rate; the hydraulic gradient I is the thickness of the porous cover plate h. Finally, by fitting the relationship between different rainfall intensities and permeability coefficients η, the permeability law of the porous cover plate under different working conditions can be obtained. This provides an effective selection for the design of slope drainage ditch cover plates.

[0009] Preferably, the sewage supply and confluence device includes a mixing chamber, a clean water injection pipe for injecting clean water into the mixing chamber, a sand adding pipe for adding sand into the mixing chamber, a stirring mechanism for stirring the material in the mixing chamber, and a discharge chamber connected to the mixing chamber for discharging the material, and a plurality of muddy water jet outlet holes are provided on the discharge chamber.

[0010] By adopting the above technical solution, before the experiment, a certain amount of clean water and sand and gravel are measured first, and then the two are introduced into the mixing chamber. Under the stirring of the stirring mechanism, the two are mixed to form sewage, which flows into the discharge chamber, and flows out of the discharge chamber through the muddy water jet outlet hole and falls on the porous cover plate, completing the simulation of rainfall.

[0011] Preferably, the sand adding pipe is sleeved outside the clean water injection pipe, and the sand adding pipe is fixedly connected to the clean water injection pipe through a connecting piece, the stirring mechanism includes a stirring shaft rotatably connected to the mixing chamber and a stirring blade installed at one end of the stirring shaft, the stirring blade is provided with at least three along the axial direction of the stirring shaft, and the clean water injection pipe is located directly above the stirring blade.

[0012] By adopting the above technical solution, when clean water falls into the mixing chamber through the clean water injection pipe, the impact force of the clean water on the stirring blade can cause the stirring blade to drive the stirring shaft to rotate relative to the mixing chamber, thereby playing the role of mixing clean water and sand and gravel. No additional power source is needed, reducing material costs.

[0013] Preferably, the discharge chamber is located below the mixing chamber and the lower end of the discharge chamber is flared.

[0014] By adopting the above technical solution, real rain can be simulated as much as possible, thereby improving the accuracy of detection.

[0015] Preferably, the porous cover plate placement device includes a water tank with an upward opening and a cover for closing the water tank opening, the water tank is installed on the drainage channel, the sewage supply and confluence device is installed on the cover, and the mixing chamber passes through the cover, a drainage groove is opened at the bottom of the water tank, and the porous cover plate is placed in the water tank and covers the drainage groove.

[0016] By adopting the above technical solution, during the experiment, the cover can be opened, the porous cover plate can be placed on the bottom of the water tank to cover the drainage groove, and then the cover can be closed to cover the upper opening of the water tank. The operation is convenient and the structure is simple.

[0017] Preferably, a control chamber is provided outside the discharge chamber, the inner wall of the control chamber abuts against the outer wall of the discharge chamber and closes the muddy water jet outlet hole, the control chamber is rotatably connected to the mixing chamber and a drainage hole corresponding to the muddy water jet outlet hole is opened on the control chamber.

[0018] By adopting the above technical solution, when it is necessary to clean the muddy water jet outlet hole on the discharge chamber, the control chamber can be rotated relative to the mixing chamber so that the control chamber closes the muddy water jet outlet hole. Then, clean water is injected into the mixing chamber and the discharge chamber, and the clean water is poured out by shaking. When it is necessary to use the sewage supply and confluence device to simulate rainfall, the discharge chamber is rotated relative to the mixing chamber so that the drainage hole is aligned with the muddy water jet outlet hole.

[0019] Preferably, the control chamber is fixedly connected to the sealing cover, the mixing chamber is rotatably connected to the sealing cover, and the sealing cover is provided with a locking member for fixing the mixing chamber.

[0020] By adopting the above technical solution, when it is necessary to rotate the control chamber relative to the mixing chamber, the sealing cover can be directly held by hand to rotate the mixing chamber relative to the control chamber, which is convenient to operate.

[0021] Preferably, a water stabilizing plate is installed in the water tank, a muddy water overflow port is opened on the water tank, and the muddy water overflow port is located above the water stabilizing plate.

[0022] By adopting the above technical solution, the water stabilizing plate and the muddy water overflow port are combined to keep the water level in the mixing chamber at a certain height, thereby simulating the rainfall intensity under different working conditions. Finally, by fitting the relationship between different rainfall intensities and the permeability coefficient η, the permeability law of the porous cover plate under different working conditions can be obtained.

[0023] Preferably, the muddy water overflow port is connected to a drainage culvert, the drainage culvert is connected to a drainage channel, and the discharge end of the drainage culvert is located at the discharge end of the triangular weir.

[0024] By adopting the above technical solution, sewage is discharged into the drainage channel through the drainage culvert, so that the sewage can be recycled.

[0025] Preferably, a sealing ring is provided on the inner bottom surface of the water tank, and the porous cover plate is placed on the sealing ring.

[0026] By adopting the above technical solution, the sealing between the porous cover plate and the bottom surface of the water tank is improved, ensuring that sewage flows through the porous cover plate and then falls into the drainage channel.

[0027] In summary, the present invention includes at least one of the following beneficial technical effects:

[0028] 1. The permeability law of porous cover plates under different working conditions can be obtained, providing an effective reference and selection for the selection of porous cover plates;

[0029] 2. Simple structure and low production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural diagram of embodiment 1.

[0031] Figure 2 It is a cross-sectional view of the first embodiment.

[0032] Figure 3 It is a structural schematic diagram of the cover plate and the sewage supply and confluence device in the first embodiment.

[0033] Figure 4 yes Figure 2 Enlarged view of point A in the middle.

[0034] Figure 5 It is a cross-sectional view of the water seepage measurement device in Example 1.

[0035] Figure 6 It is a schematic diagram of the structure of the cover plate and the sewage supply and confluence device in the second embodiment.

[0036] Explanation of the reference numerals in the accompanying drawings: 1. Sewage supply and confluence device; 2. Multi-porous cover plate placement device; 3. Seepage volume collection and measurement device; 4. Multi-porous cover plate; 5. Mixing chamber; 6. Clean water injection pipe; 7. Sand adding pipe; 8. Stirring mechanism; 9. Discharge chamber; 10. Connecting piece; 11. Muddy water jet outlet; 12. Stirring shaft; 13. Stirring blade; 14. Cover; 15. Drainage channel; 16. Triangular weir; 17. Triangular weir measuring needle; 18. Drainage trough; 19. Sealing ring; 20. Water stabilizing plate; 21. Drainage culvert; 22. Control room; 23. Drainage hole; 24. Locking piece; 25. Threaded hole; 26. Water tank; 27. Self-recording water level gauge. DETAILED DESCRIPTION

[0037] The following is combined with Figure 1-6 The present invention is described in further detail.

[0038] Embodiment 1:

[0039] The embodiment of the present invention discloses a device for measuring the permeability coefficient of muddy water in a porous cover plate for a slope drainage ditch. Figure 1 and Figure 2 A device for measuring the muddy water permeability coefficient of a porous cover plate for a slope drainage ditch comprises a sewage supply and confluence device 1, a porous cover plate placement device 2 and a seepage volume collection and measurement device 3.

[0040] The porous cover plate 4 is placed in the porous cover plate placement device 2. The sewage supply and confluence device 1 simulates rainfall, and the simulated rainfall falls into the porous cover plate placement device 2, and flows into the seepage measurement device 3 after passing through the porous cover plate 4 to test the seepage amount. Finally, the relationship between the rainfall intensity and the permeability coefficient of the porous cover plate 4 is obtained. It provides an effective reference for the selection of slope drainage ditch cover plates.

[0041] Specifically, refer to Figure 3 The sewage supply and confluence device 1 includes a mixing chamber 5, a clean water injection pipe 6 for injecting clean water into the mixing chamber 5, a sand adding pipe 7 for adding sand into the mixing chamber 5, a stirring mechanism 8 for stirring the material in the mixing chamber 5, and a discharge chamber 9 connected to the mixing chamber 5 for discharging the material.

[0042] Reference Figure 3 , the sand adding pipe 7 is sleeved outside the clean water injection pipe 6, and the sand adding pipe 7 is fixedly connected to the clean water injection pipe 6 through a connector 10. The clean water injection pipe 6 can be a PVC corrugated pipe. The mixing chamber 5 is coaxially fixedly connected to the lower end of the sand adding pipe 7, and the projection of the discharge port of the sand adding pipe along the vertical direction falls into the mixing chamber 5. The discharge chamber 9 is located below the mixing chamber 5 and is coaxially fixedly connected to the mixing chamber 5. And the projection of the mixing chamber 5 along the vertical direction falls into the discharge chamber 9. The lower end of the discharge chamber 9 is expanded. A plurality of muddy water jet outlet holes 11 are opened on the discharge chamber 9. The diameter of the muddy water jet outlet hole 11 is preferably about 1 cm to meet the water jet.

[0043] Reference Figure 3 The stirring mechanism 8 includes a stirring shaft 12 rotatably connected to the mixing chamber 5 and a stirring blade 13 installed at the upper end of the stirring shaft 12. Three stirring blades 13 are arranged along the axial direction of the stirring shaft 12. The stirring shaft 12 and the clean water injection pipe 6 are coaxially arranged. The lower end of the stirring shaft 12 is rotatably connected to the bottom surface of the discharge chamber 9 through a bearing seat.

[0044] When it is necessary to simulate rainfall, clean water is provided into the mixing chamber 5 through the clean water injection pipe 6, and sand is added into the mixing chamber 5 through the sand adding pipe 7 to simulate muddy water outflow. Sand can be artificial sand or model sand. When the clean water flows down to the stirring blade 13, the stirring shaft 12 can be driven to rotate relative to the mixing chamber 5, thereby stirring the water flow and mixing the clean water and sand and gravel together. Then the muddy water jet flows out of the discharge chamber 9 through the muddy water jet outlet 11 to complete the simulated rainfall. The sand content ρ of muddy water is expressed by the amount of sand added to the water per unit time, ρ=m1 / (m1+m2), m1 is the weight of sand and gravel, and m2 is the weight of water flow.

[0045] Reference Figure 2 and Figure 3The porous cover plate placement device 2 comprises a water tank 26 with an upward opening and a cover 14 for closing the opening of the water tank 26. The sewage supply and confluence device 1 is installed on the cover 14, and the mixing chamber 5 passes through the cover 14, and the mixing chamber 5 is fixedly connected to the cover 14.

[0046] Reference Figure 1 and Figure 2 The seepage measurement device 3 includes a drainage channel 15, a triangular weir 16 installed in the drainage channel 15, and a triangular weir measuring needle 17. The drainage channel 15 has a rectangular cross section. The water tank 26 is fixed to the drainage channel 15 by bolts. The water tank 26 can be made of pressure-resistant steel plate or organic glass material and can withstand a certain height of water pressure. Figure 2 A drainage groove 18 is provided at the bottom of the water tank 26, and the projection of the drainage groove 18 along the vertical direction falls into the drainage channel 15. The porous cover plate 4 is placed in the water tank 26 and covers the drainage groove 18. Figure 4 In order to improve the sealing between the porous cover plate 4 and the water tank 26 , a sealing ring 19 is provided on the inner bottom surface of the water tank 26 , and the porous cover plate 4 is placed on the sealing ring 19 and abuts against the sealing ring 19 .

[0047] Reference Figure 1 and Figure 2 In order to conveniently maintain the water level in the water tank 26, a water stabilizing plate 20 is installed in the water tank 26, and a muddy water overflow port is opened on the water tank 26, and the muddy water overflow port is located above the water stabilizing plate 20. A drainage culvert 21 is connected to the muddy water overflow port, and the drainage culvert 21 is connected to the drainage channel 15, and the discharge end of the drainage culvert 21 is located at the discharge end of the triangular weir 16. A self-recording water level gauge 27 is installed on the water tank 26.

[0048] When simulating rainfall intensities under different working conditions, the rainfall intensity is represented by the water surface height H after confluence, which can be read by the self-recording water level gauge 27 installed on the water tank 26. The self-recording water level gauge 27 is made of glass or organic glass material and engraved with water level scale. The overflow muddy water flows into the tail of the drainage channel 15 through the drainage culvert 21 and is finally discharged into the sedimentation tank for recycling.

[0049] Reference Figure 5 , the triangular weir 16 is a right-angled triangular weir 16. The triangular weir 16 is placed at a position five times the width of the drainage channel 15 to ensure a steady seepage flow. The triangular weir probe 17 is fixed on the drainage culvert 21. The right-angled triangular weir probe 17 can measure the water surface depth by the traditional scale reading method, or by ultrasonic or infrared sensing method. The measured water surface depth Δh=h2-h1, h2 is the height from the bottom of the right-angled triangular weir 16 to the center of the drainage culvert 21, and h1 is the height from the water surface to the center of the drainage culvert 21. The seepage flow rate q=KΔh2.47 is calculated based on the water depth Δh measured by the right-angled triangular weir 16, where K can be obtained by querying relevant engineering specifications.

[0050] The calculation formula of the permeability of the porous cover plate 4 is derived from the Darcy formula as η=V / I, where the permeability velocity V=q / A, A represents the area of ​​the porous cover plate 4, q is the seepage flow rate; the hydraulic gradient I is the thickness h of the porous cover plate 4. Finally, by fitting the relationship between different rainfall intensities H and permeability coefficients η, the permeability law of the porous cover plate 4 under different working conditions can be obtained. This provides an effective selection for the design of slope drainage ditch cover plates.

[0051] Embodiment 2:

[0052] The difference between the second embodiment and the first embodiment is that, referring to Figure 6 The discharge chamber 9 is provided with a control chamber 22, the inner wall of the control chamber 22 abuts against the outer wall of the discharge chamber 9 and closes the muddy water jet outlet hole 11, the control chamber 22 is rotatably connected to the mixing chamber 5, and the control chamber 22 is provided with a drainage hole 23 corresponding to the muddy water jet outlet hole 11. The control chamber 22 is fixedly connected to the cover 14, the mixing chamber 5 is rotatably connected to the cover 14, and the cover 14 is provided with a locking member 24 for fixing the mixing chamber 5. The locking member 24 is a bolt, and the mixing chamber 5 is provided with a threaded hole 25 for screwing the locking member 24. Two threaded holes 25 are provided along the circumference of the mixing chamber 5.

[0053] When it is necessary to clean the muddy water jet outlet hole 11 on the discharge chamber 9, the locking piece 24 can be screwed out from one of the threaded holes 25, and the control chamber 22 can be rotated relative to the mixing chamber 5 to close the muddy water jet outlet hole 11. Then, clean water is injected into the mixing chamber 5 and the discharge chamber 9, and the clean water is poured out by shaking. When it is necessary to use the sewage supply and confluence device 1 to simulate rainfall, the discharge chamber 9 is rotated relative to the mixing chamber 5 to align the drainage hole 23 with the muddy water jet outlet hole 11, and the locking piece 24 is screwed into the corresponding threaded hole 25.

[0054] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for measuring the permeability coefficient of muddy water in a porous cover plate for a slope drainage ditch, characterized in that: It comprises a sewage supply and confluence device (1), a porous cover plate placement device (2) and a water seepage measurement device (3), wherein the sewage supply and confluence device (1) is used to simulate natural rainfall, and the water seepage measurement device (3) comprises a drainage channel (15), a triangular weir (16) installed in the drainage channel (15) and a triangular weir measuring needle (17); The sewage supply and confluence device (1) comprises a mixing chamber (5), a clean water injection pipe (6) for injecting clean water into the mixing chamber (5), a sand adding pipe (7) for adding sand into the mixing chamber (5), a stirring mechanism (8) for stirring the material in the mixing chamber (5), and a discharge chamber (9) for discharging the material and communicating with the mixing chamber (5), wherein a plurality of muddy water jet outlet holes (11) are provided on the discharge chamber (9); The sand adding pipe (7) is sleeved outside the clean water injection pipe (6), and the sand adding pipe (7) is fixedly connected to the clean water injection pipe (6) through a connecting piece (10). The stirring mechanism (8) comprises a stirring shaft (12) rotatably connected to the mixing chamber (5) and a stirring blade (13) installed at one end of the stirring shaft (12). The stirring blade (13) is provided with at least three stirring blades along the axial direction of the stirring shaft (12), and the clean water injection pipe (6) is located directly above the stirring blade (13); The discharge chamber (9) is located below the mixing chamber (5) and the lower end of the discharge chamber (9) is flared; The porous cover plate placement device (2) comprises a water tank (26) with an opening facing upward and a cover (14) for closing the opening of the water tank (26); the water tank (26) is installed on a drainage channel (15); the sewage supply and confluence device (1) is installed on the cover (14), and the mixing chamber (5) passes through the cover (14); a drainage groove (18) is provided at the bottom of the water tank (26); and the porous cover plate (4) is placed in the water tank (26) and covers the drainage groove (18); The discharge chamber (9) is provided with a control chamber (22) on its outer wall, the inner wall of the control chamber (22) abuts against the outer wall of the discharge chamber (9) and closes the muddy water jet outlet hole (11), the control chamber (22) is rotatably connected to the mixing chamber (5) and a drainage hole (23) corresponding to the muddy water jet outlet hole (11) is opened on the control chamber (22).

2. The device for measuring the muddy water permeability coefficient of a porous cover plate for a slope drainage ditch according to claim 1, characterized in that: The control chamber (22) is fixedly connected to the sealing cover (14), the mixing chamber (5) is rotatably connected to the sealing cover (14), and a locking member (24) for fixing the mixing chamber (5) is provided on the sealing cover (14).

3. The device for measuring the muddy water permeability coefficient of a porous cover plate for a slope drainage ditch according to claim 1, characterized in that: A water stabilizing plate (20) is installed in the water tank (26), and a muddy water overflow port is provided on the water tank (26), and the muddy water overflow port is located above the water stabilizing plate (20).

4. The device for measuring the muddy water permeability coefficient of a porous cover plate for a slope drainage ditch according to claim 3, characterized in that: The muddy water overflow port is connected to a drainage culvert (21), the drainage culvert (21) is connected to the drainage channel (15), and the discharge end of the drainage culvert (21) is located at the discharge end of the triangular weir (16).

5. The device for measuring the muddy water permeability coefficient of a porous cover plate for a slope drainage ditch according to claim 1, characterized in that: The inner bottom surface of the water tank (26) is provided with a sealing ring (19), and the porous cover plate (4) is placed on the sealing ring (19).

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