A simulation device and measurement method for local scour depth of complex structure bridge piers

Abstract

The present invention discloses a device for simulating the local scour depth of complex bridge piers, comprising a water body disposed within a pool; a plurality of wave-generating devices disposed at equal intervals on one side of the pool; a test pool disposed in the middle of the pool, the test pool including a wall, a moving bed test area disposed in the middle of the wall, a bridge pier model disposed at the top center of the moving bed test area, and a fixed bed test area, a sedimentation area, and an energy dissipation forepool area disposed on either side of the moving bed test area; two flow-generating devices disposed at the bottom of either side of the wall; and test devices disposed in the moving bed test area, the fixed bed test area, and the pool for data collection. The present invention improves the integrity of the physical model test for local scour of bridge piers and can intuitively and accurately display the results of the local scour test of bridge piers.

Description

Technical Field

[0001] The present invention relates to the technical field of water transport engineering hydrodynamic simulation test, in particular to a simulation device and a measurement method for the local scouring depth of a complex structure bridge pier. Background Art

[0002] With recent social development, the demand for bridge construction has steadily increased. Bridge construction has not only significantly contributed to the development of transportation but also boosted regional economic growth. Driven by the need for interaction and integration between my country's various economic zones, large bridges located in complex hydrodynamic conditions, such as rivers, estuaries, and seas, are being built continuously. The complex hydrodynamic conditions of these bridges, along with their pier foundation structures, make them susceptible to localized scouring, leading to pier instability and flood damage. Bridge safety has therefore become a matter of considerable concern. Research has shown that localized scouring of pier foundations is a major cause of most bridge flood damage. In the United States, pier scouring accounted for over half of all bridge damage between 1989 and 2000. In India, a combination of flooding and scouring accounted for 51.9% of bridge flood damage over the nearly 40 years from 1977 to 2017. Therefore, studying localized scouring of piers is of significant engineering significance for bridge safety and reliability.

[0003] Researchers at home and abroad have primarily used theoretical formula calculations, numerical simulations, and physical model tests to address the issue of hydrodynamic conditions and local scour at bridge piers. Currently, there are no purely theoretical formulas for local scour at bridge piers. Most formulas are based on field observations and laboratory test data, which limits their applicability. Numerical simulation methods are primarily based on the derivation of theoretical formulas. Although considerable research has been conducted on the numerical simulation of local scour at bridge piers, resulting in a number of different numerical calculation methods, the calculated results often differ from the actual values. This is due to the complex water flow around the piers. Therefore, using physical model tests to predict bridge pier scour is a more reliable experimental approach.

[0004] In traditional physical model tests, the local scour depth of bridge piers is mainly measured by manual measurement methods such as nail insertion and cross-sectional measurement. The manual measurement method consumes a huge amount of manpower and time, and there are errors in manual measurement. The cross-sectional measurement method measures the scour and siltation conditions on a section with equal spacing, which also has the problem of taking a long time and having errors after the results of each section are combined and interpolated.

[0005] Therefore, a simulation device and measurement method for the local scour depth of complex structure bridge piers are urgently needed to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a simulation device and a measurement method for the local scour depth of complex structure bridge piers, so as to solve the problems existing in the prior art.

[0007] To achieve the above-mentioned object, the present invention provides the following solution: The present invention provides a device for simulating the local scour depth of a complex structure bridge pier, comprising:

[0008] A pool body, wherein a water body is provided in the pool body;

[0009] A wave generating device, wherein a plurality of the wave generating devices are provided, and the plurality of the wave generating devices are arranged at equal intervals on one side of the pool body;

[0010] A test water pool, the test water pool is arranged in the middle of the pool body, the test water pool includes a wall, a moving bed test area is arranged in the middle of the wall, a pier model is arranged at the center of the top surface of the moving bed test area, and a fixed bed test area, a sedimentation area and an energy dissipation forepool area are arranged on both sides of the moving bed test area respectively;

[0011] A flow generating device, wherein two flow generating devices are provided, and the two flow generating devices are respectively arranged at the bottom of both sides of the wall;

[0012] A test device is provided in the moving bed test area, the fixed bed test area and the tank body for collecting data.

[0013] Preferably, the test device includes a water level monitor, an acoustic Doppler current meter, a wave height sensor, a probe-type underwater high-frequency ultrasonic ranging system and a three-dimensional laser scanner; two of the water level monitors are provided and are respectively arranged on the two fixed-bed test areas, several of the acoustic Doppler current meters, the probe-type underwater high-frequency ultrasonic ranging systems and the wave height sensors are provided and are all arranged on the moving bed test area, four of the three-dimensional laser scanners are provided, two of which are respectively arranged on the two fixed-bed test areas, and the other two three-dimensional laser scanners are respectively arranged in the pool body and on both sides of the moving bed test area, and the probe-type underwater high-frequency ultrasonic ranging system is arranged around the bottom of the pier model.

[0014] Preferably, the area outside the test water pool in the pool body is set as a water circulation area, the pool body is set as a rectangular structure, and the water volume in the water circulation area is larger than the water volume within the wall.

[0015] Preferably, solid water weir discharge partition walls are respectively provided on both sides of the enclosure, and one side of the solid water weir discharge partition wall and the enclosure form the energy dissipation front pool area, one side of one of the fixed bed test areas is set as an inclined surface, and one side of the other fixed bed test area is set as a vertical section, and the sedimentation area is respectively provided on one side of the two fixed bed test areas.

[0016] Preferably, a uniform porous flow stabilizing partition wall is provided on one side of the fixed bed test area which is set as an inclined surface, and one of the sedimentation areas is formed between the uniform porous flow stabilizing partition wall and one of the solid water weir discharge partition walls, and another sedimentation area is formed between the fixed bed test area which is set as a section on one side and the other solid water weir discharge partition wall.

[0017] Preferably, the uniform porous flow-stabilizing partition wall is configured as a brick structure, and a plurality of water holes are opened on the side of the uniform porous flow-stabilizing partition wall.

[0018] Preferably, the bottom elevation of the sedimentation area is much lower than the elevation of the moving bed test area.

[0019] Preferably, the fixed bed test area is a transition area where water moves evenly, the interior of the fixed bed test area is filled with sand and gravel, the upper surface of the fixed bed test area is provided with a cement mortar layer, and the surface layer of the cement mortar layer is provided as a roughened layer.

[0020] Preferably, a model sand layer is provided on the top surface of the moving bed test area, the pier model is located at the center of the moving bed test area, and the bottom of the pier model is embedded in the model sand layer, and the top surface of the model sand layer is flush with the top surface of the fixed bed test area.

[0021] A method for simulating the measurement of the local scour depth of a complex structure bridge pier comprises the following steps:

[0022] Step 1: assembling the wave generating device, the test water pool, the flow generating device and the test device in the pool body, and filling the pool body and the test water pool with water;

[0023] Step 2: Debugging the wave generating device, current generating device and test device;

[0024] Step 3: Turn on the wave-generating device and the flow-generating device to conduct a flushing test.

[0025] The scouring depth around the pier is monitored in real time using a probe-type underwater high-frequency ultrasonic ranging sensor. When the monitored bed elevation remains unchanged, it is considered that dynamic equilibrium has been reached, the test is stopped, and drainage is carried out.

[0026] Step 4: Use a 3D laser scanner to scan the moving bed test area in the front, back, left, and right directions to avoid the obstruction area below the pier model. The directions referred to here are generally relative to the geometric center of the upper surface of the pier model. After the scanning is completed, the 3D point cloud data in the four directions are spliced and processed using a 3D point cloud processing program.

[0027] Step 5: Use a visualization program to edit the final three-dimensional point cloud data to intuitively and accurately display the measurement results of the local scour depth of the complex structure bridge pier.

[0028] The present invention discloses the following technical advantages: The test pool comprises a water circulation area, an energy dissipation forebay area, a sedimentation area, a fixed bed test area, a moving bed test area, a wave generator, and a flow generator. It simulates the hydrodynamic and test environment of complex bridge pier models. The test device monitors the wave and flow dynamic conditions required for the test, performing real-time monitoring to determine the scour equilibrium time and final scour depth. It also performs four-dimensional scanning of the topographic changes in the local scour of the bridge pier before and after the test, generating detailed full-space three-dimensional point cloud data. The present invention is suitable for physical model testing of local scour of complex bridge piers under the action of different single waves, single currents, or combined wave and current conditions in oceans, estuaries, and inland rivers. Based on a simulated hydrodynamic test pool and complex bridge piers, the system is equipped with all the necessary test devices. This overcomes the drawbacks of traditional physical model testing of bridge pier scour, such as long manual measurement cycles and low measurement accuracy. It further improves the integrity of physical model testing of bridge pier local scour, enabling intuitive and accurate display of test results. The system is low-cost, easy to operate, low-risk, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 It is a structural schematic diagram of the present invention;

[0031] Figure 2 It is the front view of the present invention;

[0032] Among them, 1. Water circulation area; 2. Energy dissipation front pool area; 3. Sand settling area; 4. Fixed bed test area; 5. Moving bed test area; 6. Bridge pier model; 7. Wave generating device; 8. Flow generating device; 9. Water level monitor; 10. Acoustic Doppler current meter; 11. Wave height sensor; 12. Probe-type underwater high-frequency ultrasonic ranging system; 13. Three-dimensional laser scanner; 14. Pool body; 15. Wall; 16. Solid water weir discharge partition wall; 17. Uniform porous flow stabilization partition wall. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figure 1-2 The present invention provides a device for simulating the local scour depth of a complex structure bridge pier, which is characterized by comprising:

[0036] A pool body 14, wherein water is provided in the pool body 14;

[0037] Wave generating devices 7, there are a plurality of wave generating devices 7, and the wave generating devices 7 are evenly spaced and arranged on one side of the pool body 14;

[0038] The test water pool is arranged in the middle of the pool body 14 and includes a wall 15. A moving bed test area 5 is arranged in the middle of the wall 15. A bridge pier model 6 is arranged at the center of the top surface of the moving bed test area 5. A fixed bed test area 4, a sedimentation area 3 and an energy dissipation front pool area 2 are arranged on both sides of the moving bed test area 5 in sequence;

[0039] There are two flow generating devices 8, and the two flow generating devices 8 are respectively arranged at the bottom of both sides of the wall 15;

[0040] The test device is arranged in the moving bed test area 5, the fixed bed test area 4 and the pool body 14 for data collection.

[0041] The test pool of the present invention consists of a water circulation area 1, an energy dissipation forebay area 2, a sedimentation area 3, a fixed bed test area 4, a moving bed test area 5, a wave generator 7, and a flow generator 8. It simulates the hydrodynamic and test environment of a complex bridge pier model 6. The test equipment monitors the wave and flow dynamic conditions required for the test, performing real-time monitoring to determine the scour equilibrium time and final scour depth. It also performs four-dimensional scanning of the topographic changes in the local scour of the pier before and after the test to generate detailed, full-space three-dimensional point cloud data. The present invention is suitable for physical model testing of local scour of complex bridge piers under the action of different single waves, single currents, or combined wave and current conditions in oceans, estuaries, and inland rivers. Based on a simulated hydrodynamic test pool and complex bridge piers, it is equipped with all the necessary test equipment. This overcomes the shortcomings of traditional physical model testing of bridge pier scour, such as long manual measurement cycles and insufficient measurement accuracy. It further improves the integrity of physical model testing of bridge pier local scour, allowing for intuitive and accurate display of test results. The present invention is low-cost, easy to operate, low-risk, and has a wide range of applications.

[0042] To further optimize the plan, the test equipment includes a water level monitor 9, an acoustic Doppler current meter 10, a wave height sensor 11, a probe-type underwater high-frequency ultrasonic ranging system 12 and a three-dimensional laser scanner 13; two water level monitors 9 are provided and are respectively arranged on the two fixed-bed test areas 4, several acoustic Doppler current meters 10, probe-type underwater high-frequency ultrasonic ranging systems 12 and wave height sensors 11 are provided and are all arranged on the moving bed test area 5, four three-dimensional laser scanners 13 are provided, of which two three-dimensional laser scanners 13 are respectively arranged on the two fixed-bed test areas 4, and the other two three-dimensional laser scanners 13 are respectively arranged in the pool body 14 and on both sides of the moving bed test area 5, and the probe-type underwater high-frequency ultrasonic ranging system 12 is arranged around the bottom of the pier model 6.

[0043] The water level monitor 9, acoustic Doppler current meter 10 and wave height sensor 11 are used to monitor the wave and water flow dynamic conditions required for the test; the probe-type underwater high-frequency ultrasonic ranging system 12 consists of multiple probe-type underwater high-frequency ultrasonic ranging sensors rationally arranged around the bridge pier model 6, and determines the scour equilibrium time and final scour depth by real-time monitoring of the scour depth around the pier; the three-dimensional laser scanner 13 performs four-directional scanning of the topographic changes of the local scour of the bridge pier before and after the test to obtain detailed full-space three-dimensional point cloud data.

[0044] To further optimize the solution, the outer area of the test water pool within the pool body 14 is set as the water circulation area 1, the pool body 14 is set as a rectangular structure, and the water volume within the water circulation area 1 is larger than the water volume within the wall 15.

[0045] Tank 14 is the test tank for the Port and Coastal Engineering Laboratory. It is generally rectangular in shape, has a certain depth, and is equipped with inlet and outlet pipes and valves. Water circulation zone 1 is the area surrounding the test zone. This area holds a larger volume of water than the water within the test zone, ensuring a constant water level within the test zone and a uniform and stable flow within the test flow field.

[0046] To further optimize the solution, solid water weir discharge partition walls 16 are respectively set on both sides of the fence 15, and one side of the solid water weir discharge partition wall 16 and the fence 15 form an energy dissipation front pool area 2, one side of a fixed bed test area 4 is set as an inclined surface, and one side of the other fixed bed test area 4 is set as a vertical section, and a sedimentation area 3 is respectively set on one side of the two fixed bed test areas 4.

[0047] The wave-generating device 7 can generate waves in the water in the pool 14, so that the waves generated by the water can act on the pier model 6. The two flow-generating devices 8 are set. One close to the inclined surface is used to send water into the test pool to simulate the scouring of the pier model 6, and the other flow-generating device 8 is used to discharge the water in the test pool.

[0048] To further optimize the solution, a uniform porous flow stabilizing wall 17 is set on one side of the fixed bed test area 4 which is set as an inclined surface, and a sedimentation area 3 is formed between the uniform porous flow stabilizing wall 17 and one of the solid water weir discharge partition walls 16, and another sedimentation area 3 is formed between the fixed bed test area 4 which is set as a section on one side and another solid water weir discharge partition wall 16.

[0049] The solid water weir discharge partition wall 16 first buffers the impact of water flows from multiple water inlets, converts the impact kinetic energy of water flows from different water inlets into the falling potential energy of overflow at the weir top, and uniformly converts the water flow pattern containing multi-directional turbulence into a water flow pattern containing only the forward direction.

[0050] To further optimize the solution, the uniform porous flow stabilizing partition wall 17 is set to a brick structure, and a plurality of water holes are opened on the side of the uniform porous flow stabilizing partition wall 17.

[0051] The uniform porous flow stabilizing partition wall 17 utilizes its own uniform porous characteristics to further eliminate the flow velocity difference in the forward direction of the water flow pattern, and ultimately ensures that the water flow passing through the energy dissipation forebay area 2 is uniform and stable.

[0052] After further optimization, the bottom elevation of sedimentation area 3 is much lower than that of moving bed test area 5.

[0053] The drastic elevation difference causes the flow velocity of the highly sediment-laden water body carrying a large amount of sediment particles to decrease rapidly, causing the sediment particles in the water body to sink quickly and settle in the sedimentation area 3. On the one hand, this ensures the water quality of the influent water body, and on the other hand, it minimizes the loss rate of the model sand used in the test.

[0054] According to the further optimization scheme, the fixed bed test area 4 is a transition area for uniform movement of water, the interior of the fixed bed test area 4 is filled with sand and gravel, the fixed bed test area 4 is provided with a cement mortar layer, and the surface of the cement mortar layer is provided as a roughened layer.

[0055] The interior of the fixed bed test area 4 is filled with sand and gravel, the surface is smoothed with cement mortar, and the surface is roughened to ensure that the bottom surface roughness of the fixed bed test area 4 and the seabed roughness of the prototype sea area where the test object is located meet the test similarity criteria.

[0056] To further optimize the solution, a model sand layer is provided in the moving bed test area 5 , the pier model 6 is located at the center of the moving bed test area 5 , and the bottom of the pier model 6 is embedded in the model sand layer, and the top surface of the model sand layer is flush with the top surface of the fixed bed test area 4 .

[0057] Before the test, the pier model 6 was placed in the center of the moving bed test area 5 and evenly filled with model sand. After being fully soaked and compacted, the sand surface was scraped with a section plate until it was flush with the front and rear fixed bed test areas 4 to simulate the bed surface elevation before scouring.

[0058] A method for simulating the measurement of the local scour depth of a complex structure bridge pier comprises the following steps:

[0059] Step 1: Assemble the wave generating device 7, the test water pool, the flow generating device 8 and the test device in the pool body 14, and fill the pool body 14 and the test water pool with water;

[0060] Step 2: Debug the wave generating device 7, the current generating device 8 and the test device;

[0061] The hydrodynamic environment and test environment of the bridge pier are simulated using measuring devices such as a water level monitor 9, an acoustic Doppler current meter 10, and a wave height sensor 11;

[0062] Step 3: Start the wave-generating device 7 and the flow-generating device 8 to conduct a scouring test. Use a probe-type underwater high-frequency ultrasonic ranging sensor to monitor the scouring depth around the pier in real time. When the monitored bed surface elevation does not change, it is considered that the dynamic balance of scouring and silting has been achieved, the test is stopped, and drainage is carried out.

[0063] Step 4: Use a 3D laser scanner 13 to scan the moving bed test area 5 in the front, rear, left, and right directions to avoid the obstruction area below the pier model 6. The directions referred to here are generally relative to the geometric center of the upper surface of the pier model 6. After the scanning is completed, the 3D point cloud data in the four directions are spliced and processed using a 3D point cloud processing program.

[0064] Step 5: Use a visualization program to edit the final 3D point cloud data and intuitively and accurately display the measurement results of the local scour depth of complex structure bridge piers.

[0065] The 3D point cloud processing program is set up with existing technology. The data splicing and processing of the 3D point cloud processing program mainly unifies the coordinates of the point cloud data in four directions through translation, rotation, etc., and outputs the final 3D point cloud data. The following is a program example:

[0066] a=load('1a.dat'); %Read data in the first direction

[0067] b=load('2a.dat'); %Read data in the second direction

[0068] c=load('3a.dat'); %Read data in the third direction

[0069] d=load('4a.dat'); %Read data in the fourth direction

[0070] a(:,1)=a(:,1);

[0071] a(:,2)=a(:,2);

[0072] a(:,3)=((a(:,3)+1760) / 1000*15-1.925)*1;*Unified coordinate system (first direction)

[0073] b(:,1)=b(:,1)+100;

[0074] b(:,2)=b(:,2)+100;

[0075] b(:,3)=((b(:,3)+1760) / 1000*15-1.925)*1;*Unified coordinate system (second direction)

[0076] c(:,1)=c(:,1)+100;

[0077] c(:,2)=c(:,2)+100;

[0078] c(:,3)=((c(:,3)+1760) / 1000*15-1.925)*1; *Unified coordinate system (third direction)

[0079] d(:,1)=d(:,1)+100;

[0080] d(:,2)=d(:,2)+100;

[0081] d(:,3)=((d(:,3)+1760) / 1000*15-1.925)*1; *Unified coordinate system (fourth direction)

[0082] e_sum = [a; b; c; d]';

[0083] alpha=0*pi() / 180;

[0084] beta = 0*pi() / 180;

[0085] gamma = -13.7*pi() / 180;

[0086] J = zeros(3,3);

[0087] J(1,1)=cos(beta)*cos(gamma);

[0088] J(1,2)=-cos(beta)*sin(gamma);

[0089] J(1,3)=sin(beta);

[0090] J(2,1)=sin(alpha)*sin(beta)*cos(gamma)+cos(alpha)*sin(gamma);

[0091] J(2,2)=-sin(alpha)*sin(beta)*sin(gamma)+cos(alpha)*cos(gamma);

[0092] J(2,3)=-sin(alpha)*cos(beta);

[0093] J(3,1)=-cos(alpha)*sin(beta)*cos(gamma)+sin(alpha)*sin(gamma);

[0094] J(3,2)=cos(alpha)*sin(beta)*sin(gamma)+sin(alpha)*cos(gamma);

[0095] J(3,3)=cos(alpha)*cos(beta);

[0096] e=J*e_sum;%The above process is the rotation of the three-dimensional data angle in four directions

[0097] dlmwrite('result.dat',e'); % Output the final 3D point cloud data

[0098] The visualization program is an existing technology. It is used to edit the final 3D point cloud data and to intuitively and accurately display the measurement results of the local scour depth of pier model 6. The following is an example of the program and the results of the measurement method:

[0099]

[0100]

[0101]

[0102]

[0103] The wave-generating device 7 in the present invention is a wave-making machine in the prior art, which is a motor servo-driven push-plate absorption wave-making machine that can generate regular waves and irregular waves. Its wave-generating principle is as follows: during the wave-making test, the computer calculates the wave signal in front of the target wave based on the input wave-making parameters, and converts it into data equivalent to the speed and position of the wave-making plate according to a certain algorithm, and inputs it into the D / A converter. The D / A converter converts the digital signal into the analog voltage signal required by the servo driver. The servo driver outputs a pulse signal to control the speed and rotation angle of the servo motor, and drives the linear motion unit through the ball screw pair to drive the push-plate to move in the water according to the predetermined motion law, thereby achieving the desired wave; the servo driver directly processes the feedback signal of the motor encoder. The system samples the wave and forms an internal closed-loop speed control loop to improve control accuracy and speed stability, preventing motor step loss. Simultaneously, the control acquisition card receives feedback signals from the motor encoder to track the wave-making plate's position in real time, while an external closed-loop position control loop is established to improve the positioning accuracy of the wave-pushing plate. A wave height sensor 11 collects wave signals in front of the wave-making plate in real time, inputs them into a computer, and compares them with the target wave to extract and separate the reflected wave signal. This signal is then added to the control signal in anti-phase form, adding a displacement motion to the wave-making plate's motion that eliminates secondary reflected waves, achieving a wave-making function that absorbs secondary reflected waves. The wave-generating device 7 can simulate both regular and irregular wave spectrums in the sea area where the bridge pier structure is located. The maximum wave-generating depth is 0.7 m, the wave height range is 0-35 cm, and the wave period range is 0.5-5 s.

[0104] The flow-generating device 8 is a QSZ series submersible pump from the prior art, so a detailed description is unnecessary. It consists of a combination of axial-flow submersible pumps at the head and tail ends of the test tank, paired with a control distribution box. During testing, the flow-generating device 8 controls the flow rate within the test area by adjusting the number and flow rate of the combined axial-flow submersible pumps. The flow direction within the test area is controlled by adjusting the rotation direction of the axial blades of the combined axial-flow submersible pumps, allowing for either unidirectional or reciprocating circulation to achieve a flow field that meets the test's expectations.

[0105] The water level monitor 9 has a range of 0.05m-0.80m and an accuracy of ±1mm, and is used to automatically monitor and collect test water levels in real time. The acoustic Doppler current meter 10 has a flow range of 0.01m / s-4.00m / s and an accuracy of ±0.5%±1mm / s, and is used to measure the flow direction and flow distribution within the test area. The wave height sensor 11 consists of a digital capacitive wave height meter, an RS485 / RS232 converter, and a fixed bracket, with a range of 0.01m-0.40m and an accuracy of ±1mm. The data acquisition and analysis software for the wave height sensor 11 mainly includes sensor calibration, real-time Waveform display, data file storage and reading, wave spectrum analysis, statistical analysis, and analysis of incoming and reflected waves; a probe-type underwater high-frequency ultrasonic ranging system 12 is arranged vertically on the periphery of the pier model 6. The probe-type underwater high-frequency ultrasonic ranging system 12 has a measuring range of 30mm to 100mm and a measurement accuracy of ±0.1mm, and is used to monitor the distribution of scouring and silting on the bed surface around the pier in real time; a three-dimensional laser scanner 13 has an angle measurement accuracy of 0.5", a distance measurement accuracy of 1mm+1.5ppm, and a range of 1m to 500m, and is used to scan changes in bed surface topography at various locations within the moving bed test area 5.

[0106] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0107] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A device for simulating the local scour depth of complex structure bridge piers, characterized in that: include: A pool body (14), wherein water is provided in the pool body (14); A wave generating device (7), wherein a plurality of the wave generating devices (7) are provided, and the plurality of the wave generating devices (7) are arranged at equal intervals on one side of the pool body (14); A test water pool, the test water pool is arranged in the middle of the pool body (14), the test water pool includes a wall (15), a moving bed test area (5) is arranged in the middle of the wall (15), a pier model (6) is arranged at the center of the top surface of the moving bed test area (5), and a fixed bed test area (4), a sedimentation area (3) and an energy dissipation front pool area (2) are arranged on both sides of the moving bed test area (5) in sequence; A flow generating device (8), wherein two flow generating devices (8) are provided, and the two flow generating devices (8) are respectively provided at the bottom of both sides of the enclosure wall (15); A test device, the test device is arranged in the moving bed test area (5), the fixed bed test area (4) and the tank body (14) for collecting data; The area outside the test water pool in the pool body (14) is set as a water circulation area (1), the pool body (14) is set as a rectangular structure, and the water volume in the water circulation area (1) is greater than the water volume in the enclosure (15); Solid water weir discharge partition walls (16) are respectively provided on both sides of the enclosure (15), and one side of the solid water weir discharge partition wall (16) and the enclosure (15) form the energy dissipation front pool area (2), one side of the fixed bed test area (4) is set as an inclined surface, and one side of the other fixed bed test area (4) is set as a vertical section, and the sedimentation area (3) is respectively provided on one side of the two fixed bed test areas (4).

2. The device for simulating the local scour depth of a complex structure bridge pier according to claim 1, characterized in that: The test device includes a water level monitor (9), an acoustic Doppler current meter (10), a wave height sensor (11), a probe-type underwater high-frequency ultrasonic ranging system (12) and a three-dimensional laser scanner (13); two water level monitors (9) are provided and are respectively provided on the two fixed bed test areas (4); a plurality of acoustic Doppler current meters (10), a plurality of probe-type underwater high-frequency ultrasonic ranging systems (12) and a plurality of wave height sensors (11) are provided and are all provided on the moving bed test area (5); four three-dimensional laser scanners (13) are provided, two of which are respectively provided on the two fixed bed test areas (4); the other two three-dimensional laser scanners (13) are respectively provided in the pool body (14) and located on both sides of the moving bed test area (5); and the probe-type underwater high-frequency ultrasonic ranging system (12) is provided around the bottom of the pier model (6).

3. The device for simulating the local scour depth of a complex structure bridge pier according to claim 1, characterized in that: A uniform porous flow stabilizing partition wall (17) is provided on one side of the fixed bed test area (4) which is set as an inclined surface, and one of the sedimentation areas (3) is formed between the uniform porous flow stabilizing partition wall (17) and one of the solid water weir discharge partition walls (16), and another sedimentation area (3) is formed between the fixed bed test area (4) which is set as a section and another of the solid water weir discharge partition walls (16).

4. The device for simulating the local scour depth of a complex structure bridge pier according to claim 3, characterized in that: The uniform porous flow stabilizing partition wall (17) is configured as a brick structure, and a plurality of water holes are provided on the side surface of the uniform porous flow stabilizing partition wall (17).

5. The device for simulating local scour depth of complex structure bridge piers according to claim 1, characterized in that: The bottom elevation of the sedimentation area (3) is much lower than the elevation of the moving bed test area (5).

6. The device for simulating the local scour depth of a complex structure bridge pier according to claim 1, characterized in that: The fixed bed test area (4) is a transition area where water moves evenly. Sand and gravel are filled inside the fixed bed test area (4). A cement mortar layer is provided on the upper surface of the fixed bed test area (4). The surface of the cement mortar layer is provided as a roughened layer.

7. The device for simulating the local scour depth of a complex structure bridge pier according to claim 1, characterized in that: The moving bed test area (5) is provided with a model sand layer, the pier model (6) is located at the center of the moving bed test area (5), and the bottom of the pier model (6) is embedded in the model sand layer, and the top surface of the model sand layer is flush with the top surface of the fixed bed test area (4).

8. A method for simulating the measurement of the local scour depth of a complex structure bridge pier, according to the device for simulating the local scour depth of a complex structure bridge pier according to claim 1, characterized in that: The steps include: Step 1: assembling the wave-generating device (7), the test water pool, the flow-generating device (8) and the test device in the pool body (14), and filling the pool body (14) and the test water pool with water; Step 2: debugging the wave generating device (7), the flow generating device (8) and the test device; Step 3: Start the wave-generating device (7) and the flow-generating device (8) to conduct a scouring test, and use the test device to monitor the scouring depth around the pier in real time; when the monitored bed elevation does not change, it is considered that the dynamic balance of scouring and silting has been achieved, the test is stopped, and drainage is carried out; Step 4: Using the test device to scan the moving bed test area (5) in the front, back, left and right directions to avoid the obstruction area below the pier model (6); After scanning, the 3D point cloud data in four directions are spliced and processed using a 3D point cloud processing program; Step 5: Use a visualization program to edit the final three-dimensional point cloud data and display the measurement results of the local scour depth of the complex structure bridge pier intuitively and accurately.

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