Anti-scouring test device and use method thereof

Abstract

The invention discloses an anti-scouring test device. The anti-scouring test device comprises a stirring assembly, a supporting frame, a scouring water tank, a sample mold, a filtering tank and a measuring assembly, the stirring assembly is erected above the flushing water tank through a supporting frame, and the stirring end of the stirring assembly extends into the flushing water tank; the sample mold is arranged below the washing water tank and is detachably connected and communicated with the bottom of the washing water tank; a water inlet and a water outlet of the filter tank are respectively connected with a flushing water tank pipeline, and a valve is arranged on the pipeline; the measuring end of the measuring assembly extends into the washing water tank to measure washing data. On one hand, water circulation of the scouring experiment is achieved, on the other hand, redundant sediment in water is filtered, impact of sediment damaged by scouring on the surface of a sample is reduced, and on the other hand, the amount of the filtered sediment can be used for evaluating the anti-scouring performance of the solidified soil after the test is finished.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulics, and in particular to an anti-scour test device and a method for using the same. Background Art

[0002] At present, the scouring problem of offshore wind power monopile foundation is the main reason for the high maintenance cost of wind power installation. The existing methods to measure the anti-scouring performance of soil are large-scale field tests or SSRT scouring tests. However, from an engineering perspective, the large-scale field test is complicated to operate and costly, and there are still certain defects in its use. The test accuracy of the SSRT scouring test is insufficient, and the influence of sediment and water temperature on the scouring effect of soil samples is relatively large. For example, the wave and current test flume used by Du Shuo and others in the study of local scouring characteristics and solidified soil protection of offshore wind power monopile foundations is 175m in length, 1.2m in width, and 1.6m in height. It occupies a large area and has high test costs. In order to ensure that the surface of the sample is flush with the bottom of the test flume, the lifting and lowering of the sample soil flume needs to be manually controlled. This will cause errors in the test during long-term experiments. Wang Qiusheng et al. used an erosion function measuring instrument to conduct scour measurement experiments in the start-up test research of reshaped clay and soil with different gravel contents. The instrument did not consider the scouring effect of soil particles eroded from the surface of the sample on the sample. At the same time, the experimental instrument only considered the early strength of the soil sample and failed to test the long-term serviceability of the test soil sample. Fan Qinglai et al. conducted a scour test on the local scour around the pile legs of an offshore platform and its influence on the bearing capacity of the foundation. The scour test device in the Journal of Disaster Prevention and Mitigation Engineering was 42m long and 3m wide. The experimental operation was difficult and costly, and the influence of water temperature on the scouring effect of the experimental soil sample was not considered during the test. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides an anti-scour test device and a method for using the same to solve the technical problems in the prior art of complex test process operation, insufficient test accuracy, and high test device cost.

[0004] The present invention provides an anti-scouring test device, comprising: a stirring component, a support frame, a scouring water tank, a sample mold, a filtering tank and a measuring component;

[0005] The stirring assembly is set above the flushing water tank through a support frame, and the stirring end of the stirring assembly extends into the flushing water tank; the sample mold is arranged under the flushing water tank and is detachably connected and communicated with the bottom of the flushing water tank; the water inlet and outlet of the filter tank are respectively connected to the flushing water tank pipeline, and a valve is provided on the pipeline; the measuring end of the measuring assembly extends into the flushing water tank to measure the flushing data.

[0006] Furthermore, the flushing sink includes: a barrel-shaped sink body, a round pancake-shaped cover body and a sealing ring; a through hole is axially opened at the bottom of the sink body for connection of the sample mold; the sealing ring is arranged at the top opening of the sink body; the cover body is covered on the sink body and is sealed and connected to the sink body through the sealing ring.

[0007] Furthermore, the sample mold is barrel-shaped; the top opening of the sample mold is connected to the through hole at the bottom of the flushing water tank, the sample mold and the flushing water tank are coaxially arranged, and the solidified soil sample to be tested is placed in the sample mold.

[0008] Furthermore, the diameter of the sample mold is smaller than the diameter of the flushing tank.

[0009] Furthermore, the stirring assembly includes: a motor, a frequency converter and a stirring blade; the motor is fixed on the top of the support frame; the motor is connected to the frequency converter; the output shaft of the frequency converter is connected to the shaft of the stirring blade; the motor, the frequency converter and the stirring blade are coaxially arranged.

[0010] Furthermore, the filter tank includes: a tank box, a sieve plate and a water pump; the sieve plate is horizontally arranged in the tank box, dividing the tank box into two upper and lower chambers; the upper chamber of the tank box is provided with a water inlet, and the lower chamber is provided with a water outlet; the water pump is arranged in the lower part of the tank box and connected to the water outlet.

[0011] Furthermore, the measuring component includes: a thermometer, a flowmeter, a sediment sensor and a collector; the thermometer, the flowmeter and the sediment sensor are all connected to the collector; the collecting ends of the thermometer, the flowmeter and the sediment sensor are all extended into the scouring water tank; the collector is arranged on the outer wall of the scouring water tank, and is used to collect the anti-scouring related data of the solidified soil sample to be tested through the thermometer, the flowmeter and the sediment sensor.

[0012] The present invention also provides a method for using the anti-scour test device, comprising the following steps:

[0013] Step 1: Prepare the solidified soil sample to be tested in a sample mold, and connect the sample mold to the flushing water tank;

[0014] Step 2: Pour clean water into the flushing tank and the filter tank, and close the valves at the water inlet and outlet of the filter tank;

[0015] Step 3: Start the stirring component to stir, open the valves at the water inlet and outlet of the filter tank, and filter the water in the flushing tank;

[0016] Step 4: Start the measurement component to measure the flow velocity and sediment volume, and conduct subsequent tests.

[0017] Furthermore, in step 3, when the stirring component is stirring, the critical flow rate is set according to the following formula:

[0018] V C =K*V

[0019]

[0020] Where V C is the critical velocity; K is the coefficient; V is the water velocity; ρ w is water density; C is sediment concentration; d is sediment particle size; T is temperature.

[0021] Furthermore, in step 3, when the sediment content in the flushing water tank exceeds a preset value, the valves at the water inlet and the water outlet of the filter tank are opened to filter the water in the flushing water tank.

[0022] Beneficial effects of the present invention:

[0023] The cover body is arranged on the upper part of the flushing water tank of the present invention, so that a closed space is formed inside the flushing water tank, which can effectively limit the size of the center of the flushing vortex and effectively increase the effective flushing area.

[0024] The inner diameter of the upper part of the scouring water tank of the present invention is larger than the inner diameter of the lower part connecting the sample mold, which effectively reduces the boundary effect caused by the friction between the scouring vortex and the scouring water tank barrier and increases the scientific nature of the test.

[0025] The present invention connects the water in the flushing water tank with the water in the filter tank, and transports the water in the filter tank to the flushing water tank through a pipeline by a water pump. The excess water in the flushing water tank will flow back to the filter tank from the pipeline connected to the water inlet of the filter tank. On the one hand, the water circulation of the flushing experiment is realized, and on the other hand, the excess sediment in the water is filtered to reduce the impact of the sediment destroyed by the flushing on the surface of the sample. On the other hand, the amount of filtered sediment can be used to evaluate the anti-scouring performance of the solidified soil after the test.

[0026] The present invention can transfer the high temperature generated by the long-term operation of the motor to the water in the flushing tank through the stirring end of the stirring component, and can cool the water in the flushing tank through water circulation, thereby reducing the influence of temperature on the sample and improving the scientific nature of the flushing test.

[0027] The present invention takes into account the influence of sediment and water temperature on the scouring effect, provides a setting formula for the critical flow velocity, and improves the setting accuracy of the critical flow velocity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0029] Figure 1 It is a three-dimensional view of a specific embodiment of the present invention;

[0030] Figure 2 It is a front view of a specific embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] The present invention is further illustrated below in conjunction with specific embodiments. Those skilled in the art should understand that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention, and modifications to various equivalent forms of the present invention fall within the scope defined by the appended claims of this application.

[0033] like Figure 1 , 2 As shown, the present invention provides an anti-scouring test device, including: a stirring component, a support frame 3, a scouring water tank, a sample mold 14, a filter tank and a measuring component;

[0034] The flushing water tank includes: a barrel-shaped water tank body 42, a round pancake-shaped cover 41 and a sealing ring; the sample mold 14 is barrel-shaped; the stirring assembly includes: a motor 1, a frequency converter 2 and a stirring blade 5; the filter tank includes: a tank box 9, a sieve plate 10 and a water pump 15; the measuring assembly includes: a temperature and flow meter 12, a sediment sensor 13 and a collector 11;

[0035] The motor 1, the frequency converter 2, the stirring blade 5, the flushing water tank and the sample mold 14 are coaxially arranged in sequence from top to bottom;

[0036] The motor 1 is fixed on the top of the support frame 3; the motor 1 is connected to the frequency converter 2; the stirring blade 5 is arranged in the water tank body 42, and the shaft passes through the water tank body 42 from the cover body 41; the output shaft of the frequency converter 2 is connected to the shaft of the stirring blade 5 through a threaded connecting rod 6; a through hole is axially provided at the bottom of the water tank body 42, and an internal thread is provided in the through hole for connection with the sample mold 14, and holes and water inlets and outlets are also provided on the side wall for insertion of other devices; a sealing ring is provided at the top opening of the water tank body 42; the cover body 41 covers the water tank body 42 and is sealed and connected to the water tank body 42 through a sealing ring; the diameter of the sample mold 14 is smaller than the diameter of the flushing water tank, and the top outer wall of the sample mold 14 is provided with an external thread, which is screwed into the through hole at the bottom of the water tank body 42 through the external thread, and the solidified soil sample to be tested is placed in the sample mold 14;

[0037] The sieve plate 10 is horizontally arranged in the trough box 9, dividing the trough box 9 into two upper and lower chambers; the upper chamber of the trough box 9 is provided with a water inlet, and the lower chamber is provided with a water outlet; the water pump 15 is arranged in the lower part of the trough box 9 and connected with the water outlet; the water outlet of the trough box 9 is connected to the water inlet of the water tank body 41 by a pipeline, and a valve body 8 for controlling the on-off of the pipeline is provided on the pipeline; the water inlet of the trough box 9 is connected to the water outlet of the water tank body 41 by a pipeline, and a valve body 7 for controlling the on-off of the pipeline is provided on the pipeline; the temperature and flow meter 12 and the sediment sensor 13 are both connected to the collector 11; the collecting ends of the temperature and flow meter 12 and the sediment sensor 13 are both extended into the scouring trough through the holes on the side wall of the water tank body 42; the collector 11 is arranged on the outer wall of the scouring trough, and is used to collect the anti-scouring related data of the solidified soil sample to be tested through the temperature and flow meter 12 and the sediment sensor 13.

[0038] The water tank body 42, the cover body 41, the sample mold 14 and the tank box 9 can be made of acrylic plastic; the holes, inlets and outlets on the water tank body 42 and the cover body 41 are sealed.

[0039] The present invention also provides a method for using the anti-scour test device, comprising the following steps:

[0040] Step 1: Place the solidified soil sample to be tested in a sample mold, ensure that the sample surface is flush with the top of the sample mold, and connect the sample mold to the flushing water tank;

[0041] Step 2: Pour clean water into the flushing tank and the filter tank. The amount of water in the filter tank can reach 1 cm below the sieve plate. Close the valves at the water inlet and outlet of the filter tank.

[0042] Step 3: Start the stirring component to stir and set the critical flow rate according to the following formula:

[0043] V C =K*V

[0044]

[0045] Where V C is the critical velocity; K is the coefficient; V is the water velocity; ρ w is water density; C is sediment concentration; d is sediment particle size; T is temperature,

[0046] Take the temperature as 18℃, the flow rate as 8.6m / s and the concentration as 10.0mg / L as an example.

[0047]

[0048] V C =K*V=0.83*8.6=7.138(m / s);

[0049] When the sediment content in the flushing tank exceeds a preset value, the valves at the water inlet and outlet of the filter tank are opened to filter the water in the flushing tank;

[0050] Step 4: Start the measurement component to measure the flow velocity and sediment volume, and conduct subsequent tests.

[0051] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An anti-scour test device, characterized in that: include: Stirring components, support frames, flushing tanks, sample molds, filter tanks, and measuring components; The stirring assembly is set above the flushing water tank through a support frame, and the stirring end of the stirring assembly extends into the flushing water tank; the sample mold is arranged under the flushing water tank and is detachably connected and communicated with the bottom of the flushing water tank; the water inlet and outlet of the filter tank are respectively connected to the flushing water tank pipeline, and a valve is provided on the pipeline; the measuring end of the measuring assembly extends into the flushing water tank to measure the flushing data.

2. The anti-scour test device according to claim 1, characterized in that: The flushing water tank comprises: a barrel-shaped water tank body, a round pancake-shaped cover body and a sealing ring; a through hole is axially opened at the bottom of the water tank body for connection of a sample mold; the sealing ring is arranged at the top opening of the water tank body; the cover body is covered on the water tank body and is sealed and connected to the water tank body through the sealing ring.

3. The anti-scour test device according to claim 1 or 2, characterized in that: The sample mold is barrel-shaped; the top opening of the sample mold is connected to the through hole at the bottom of the flushing water tank, the sample mold and the flushing water tank are coaxially arranged, and the solidified soil sample to be tested is placed in the sample mold.

4. The anti-scour test device according to claim 3, characterized in that: The diameter of the sample mold is smaller than the diameter of the flushing tank.

5. The anti-scour test device according to claim 1, characterized in that: The stirring assembly comprises: a motor, a frequency converter and a stirring blade; the motor is fixed on the top of the support frame; the motor is connected to the frequency converter; the output shaft of the frequency converter is connected to the shaft of the stirring blade; the motor, the frequency converter and the stirring blade are coaxially arranged.

6. The anti-scour test device according to claim 1, characterized in that: The filter tank includes: a tank box, a sieve plate and a water pump; the sieve plate is horizontally arranged in the tank box, dividing the tank box into an upper and lower chamber; the upper chamber of the tank box is provided with a water inlet, and the lower chamber is provided with a water outlet; the water pump is arranged in the lower part of the tank box and connected to the water outlet.

7. The anti-scour test device according to claim 1, characterized in that: The measuring assembly comprises: a thermometer, a flowmeter, a sediment sensor and a collector; the thermometer, the flowmeter and the sediment sensor are all connected to the collector; the collecting ends of the thermometer, the flowmeter and the sediment sensor are all extended into the scouring water tank; the collector is arranged on the outer wall of the scouring water tank, and is used to collect the anti-scouring related data of the solidified soil sample to be tested through the thermometer, the flowmeter and the sediment sensor.

8. A method for using an anti-scour test device, applicable to the anti-scour test device as claimed in any one of claims 1 to 7, characterized in that: The method comprises the following steps: Step 1: Prepare the solidified soil sample to be tested in a sample mold, and connect the sample mold to the flushing water tank; Step 2: Pour clean water into the flushing tank and the filter tank, and close the valves at the water inlet and outlet of the filter tank; Step 3: Start the stirring component to stir, open the valves at the water inlet and outlet of the filter tank, and filter the water in the flushing tank; Step 4: Start the measurement component to measure the flow velocity and sediment volume, and conduct subsequent tests.

9. The method for using the anti-scour test device according to claim 8, characterized in that: In step 3, when the stirring component is stirring, the critical flow rate is set according to the following formula: V C =K*V Where V C is the critical velocity; K is the coefficient; V is the water velocity; ρ w is water density; C is sediment concentration; d is sediment particle size; T is temperature.

10. The method for using the anti-scour test device according to claim 8 or 9, characterized in that: In step 3, when the sediment content in the flushing water tank exceeds a preset value, the valves at the water inlet and the water outlet of the filter tank are opened to filter the water in the flushing water tank.

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