Experimental device and method for underwater foundation scour development process and structural protection performance

Abstract

The present invention relates to an experimental device and method for studying the development process of underwater foundation scour and the protective performance of structures, comprising the following steps: connecting a flow channel to an experimental box, installing a combined wave-making gate on the flow channel; loading a foundation and marking dot arrays and grid lines in the experimental box, laying a scour protection structure on the foundation surface, and installing the foundation; opening the combined wave-making gate to create a wave effect; activating a vertical loading module to apply a load to the foundation; and recording the experimental process by photographing and videotaping. The present invention has the beneficial effects of being able to simulate the effects of water scour on the response of foundation structures under various working conditions, such as unprotected foundations being scoured by water, protected foundations being scoured by water, and scour protection structures of different shapes and structures; the alternating flow channel system is provided with a combined wave-making gate, which can simulate the multiple composite hydraulic environments at the foundation and the foundation.

Description

Technical Field

[0001] The present invention relates to an experimental device and method for the development process of underwater foundation scouring and the structural protection performance. The device and method can simultaneously apply scouring effects to the foundation and scouring protection structure, and load effects to the foundation for experiments. The device can also capture and analyze the deformation processes of the foundation, scouring protection structure and foundation. The device is suitable for experimental simulation and analysis of scenarios in which underwater foundations and other buildings are subjected to the coupled effects of water scouring effects, scouring protection effects and multi-dimensional load effects. Background Art

[0002] Underwater foundations located offshore or within rivers and lakes are subject to the effects of waves, tides, and currents. Surface particles surrounding the foundation are washed away by the currents, forming erosion pits of varying depth and shape. Depending on the size of the foundation, the fluid's Froude coefficient, the shear stress generated by the water, and the properties of the foundation, under extreme conditions, the depth of the erosion pits can sometimes be several times the width or diameter of the foundation, significantly reducing the bearing capacity of the foundation and easily leading to engineering accidents.

[0003] By laying scour protection structures on the foundation surface, the formation of erosion pits can be avoided, thereby effectively ensuring the design bearing capacity of the foundation. Similarly, backfilling scour protection materials in existing erosion pits to eliminate them can also restore the design bearing capacity of the foundation to a certain extent. The form of hydraulic scour, the material properties of the foundation and scour protection structures, the hydrodynamic strength, the nature of external loads, the wave form, frequency and duration, etc., will have different impacts on the foundations of buildings and structures built on rivers, lakes, and seashores. Experimental quantitative research on the scour development process of specific foundation materials and foundation forms in different fluid hydraulic environments, the working performance of different scour protection materials and protective structure forms in specific hydraulic environments, and the different changing trends of foundation bearing performance under unprotected scour and scour protection is an important part of foundation structure design. However, given that the foundation size in actual projects is too large, the installation, loading, measurement and extraction of the prototype foundation through prototype experiments are time-consuming and labor-intensive. In addition, the experimental results are easily affected by natural factors such as temperature, weather, hydrology, and human factors. The effect and mechanism of the change of a single parameter are difficult to clarify. Therefore, it is a difficult problem to carry out experimental research on prototype foundations in actual projects.

[0004] Therefore, there is an urgent need for an experimental device and method for the development process of underwater foundation scour and structural protection performance, which can capture and depict the development and changes of the foundation, scour protection structure morphology and fracture surface during the development of scour damage, as well as the migration process of particles inside the foundation and scour protection structure with high precision, and study the numerical simulation and mechanism explanation of scour damage and scour protection process. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide an experimental device and method for the development process of underwater foundation scouring and structural protection performance.

[0006] This experimental device for the development process of underwater foundation scour and structural protection performance includes: an alternating flow channel system, a foundation and scour protection system, a loading and measurement system, and a particle motion capture and video acquisition system;

[0007] The alternating flow channel system includes flow channels, four flow channels intersecting in the experimental box; a pad is provided at the junction of the flow channel and the experimental box; the fluid flows in the flow channel; a combined wave-making gate is provided in the flow channel;

[0008] The foundation and scour protection system includes an experimental box, a foundation, a scour protection structure, and a foundation. The experimental box is loaded with a foundation, and both the surface of the experimental box and the interior of the foundation are provided with marking dot matrix and grid lines; the foundation is doped with marking particles or tracer particles; the scour protection structure is laid within a certain range above the foundation; the foundation penetrates the scour protection structure and extends into the foundation;

[0009] The loading and measuring system is installed above the experimental box through a loading bracket. A horizontal motor is installed on the side of the loading bracket, and the horizontal motor is connected to the horizontal screw. A horizontal slide rail and a vertical motor are installed on the top surface of the loading bracket. The lower part of the vertical motor is connected to the vertical slide rail, the vertical screw and the loading arm to form a vertical loading module. When the horizontal screw rotates, the vertical loading module slides along the horizontal slide rail. The vertical loading module is connected to the top of the foundation through a connecting mechanism.

[0010] The particle motion capture and video acquisition system is installed on the side and top of the experimental box, and includes a laser scanner, a high-frequency camera and a video camera.

[0011] Preferably, in the alternating flow channel system, the cross section of the flow channel is rectangular or semicircular, the outside of the flow channel is connected to a fluid source, and a valve for controlling the flow and direction of the fluid is provided inside the flow channel, and the fluid is water or a viscous medium other than water.

[0012] Preferably, in the foundation and scour protection system, the foundation material is plastic particles, clay or fine sand, the scour protection structure includes stones, rubber cushions, semi-solid-solid cement and bionic water plants, and the experimental box is made of transparent material.

[0013] Preferably, a measuring device is also included, and the measuring system includes a three-axis dynamometer, a laser displacement meter and an accelerometer; the three-axis dynamometer is installed between the loading arm and the connecting mechanism, the laser displacement meter is installed on the loading bracket, and the accelerometer is built into the foundation.

[0014] As a preference, the shape and structure of the scour protection structure are determined according to experimental requirements, and the scour protection structure may not be provided.

[0015] The experimental method of the experimental device for the underwater foundation scour development process and structural protection performance includes the following steps:

[0016] S1. Connect the flow trough to the experimental box, install the combined wave-making gate on the flow trough, and place the pad at the junction of the flow trough and the experimental box;

[0017] S2. Load the foundation and mark the dot matrix and grid lines in the experimental box. Lay the scour protection structure on the foundation surface according to the experimental needs and install the foundation;

[0018] S3. Assemble the loading and measuring system, install the triaxial dynamometer on the loading arm, and connect the connecting mechanism to the foundation;

[0019] S4. Turn on the laser scanner, high-frequency camera, and video camera, and debug them to the operating state;

[0020] S5. Open the external valves to allow the fluid to flow in the flow channel and the experimental box according to the specified parameters, and open the combined wave-making gate to create a wave effect as required by the experiment; start the vertical loading module to apply load to the foundation;

[0021] S6. With the help of laser scanners, high-frequency cameras and video cameras, the experimental process is recorded by taking photos and videos, and the computer draws three-dimensional graphics and videos of the real-time evolution of the foundation and scour protection structure under the action of fluid scour.

[0022] Preferably, a laser scanner is used to illuminate and capture the movement trajectory of marker particles or tracer particles in the foundation, scour protection structure and fluid; a high-frequency camera is used in combination with the marker dot matrix and grid lines on the surface of the experimental box to record the deformation of the structure in the experimental box; and a camera is used to shoot and record the experimental steps and processes.

[0023] The beneficial effects of the present invention are:

[0024] 1) The experimental device for the development process of underwater foundation scouring and structural protection performance provided by the present invention can simulate the impact of water scouring on the response of foundation structures under various working conditions, such as unprotected foundations being scoured by water, protected foundations being scoured by water, and scour protection structures of different shapes and structures.

[0025] 2) The alternating flow channel system provided by the present invention is equipped with a combined wave-making gate, which can artificially simulate the generation of waves and water currents in the fluid, and can control the wavelength and height of the waves, the flow rate and direction of the water current, and simulate the multiple composite hydraulic environment at the foundation and base.

[0026] 3) The designed experimental box is made of transparent material. During the experiment, marker particles or tracer particles are used to mark the structure. With the help of cameras, high-frequency cameras, laser scanners and other equipment installed inside and outside the experimental box, the migration of particles inside the structure and the deformation trajectory of the structure can be recorded by shooting and scanning, which is convenient for studying and explaining the mode and internal mechanism of scouring damage to unprotected and protected structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A diagram of an experimental device for the development process of underwater foundation scour and structural protection performance provided by the present invention;

[0028] Among them: 1.1-flow channel; 1.2-combined wave-making gate; 1.3-fluid; 1.4-pad; 1.5-flow meter; 2.1-experimental box; 2.2-foundation; 2.3-marking dot matrix and grid lines; 2.4-scour protection structure; 2.5-foundation; 2.6-accelerometer; 3.1-loading bracket; 3.2-lateral motor; 3.3-lateral slide rail; 3.4-lateral screw; 3.5-vertical motor; 3.6-vertical slide rail; 3.7-vertical screw; 3.8-loading arm; 3.9-three-axis dynamometer; 3.10-connecting mechanism; 3.11-laser displacement meter; 4.1-laser scanner; 4.2-high-frequency camera; 4.3-camera. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the following examples. The following examples are provided only to facilitate understanding of the present invention. It should be noted that, without departing from the principles of the present invention, it is possible for a person skilled in the art to make various modifications to the present invention, and such improvements and modifications fall within the scope of the claims of the present invention.

[0030] Example 1

[0031] As an example, Figure 1 As shown, an experimental device for underwater foundation scour development process and structural protection performance includes: an alternating flow channel system, a foundation and scour protection system, a loading and measurement system, and a particle motion capture and video acquisition system;

[0032] The alternating flow channel system includes a flow channel 1.1, a combined wave-making gate 1.2, a fluid 1.3, a spacer 1.4, and a flow meter 1.5. Four mutually perpendicular flow channels 1.1, each pair connected to a test chamber 2.1, are used to transport the fluid 1.3 to the test chamber 2.1. The flow channel 1.1 is equipped with a vertically movable combined wave-making gate 1.2, which can be raised and lowered to change the flow velocity and flow pattern of the fluid 1.3, thereby creating waves within the test chamber 2.1. The wave-making effect on the fluid 1.3 is achieved by periodically raising and lowering the combined wave-making gate 1.2, thereby simulating the coupled effect of seawater flow and wave motion in real ocean conditions within the test chamber 2.1.

[0033] Spacer 1.4 is placed at the junction of flow channel 1.1 and experimental chamber 2.1 to modify the cross-sectional characteristics of the flow channel, allowing a smooth transition between the bottom of flow channel 1.4 and the surface of the foundation within the experimental chamber. Flow channel 1.1 has a rectangular or semicircular cross-section and is externally connected to a fluid source. A valve is provided within flow channel 1.1 to control the flow and direction of fluid 1.3. The valve can be opened and closed to allow four, three, or two of the fluids in flow channel 1.1 to operate in unison. Fluid 1.3 is water or a viscous medium other than water.

[0034] The foundation and scour protection system includes an experimental box 2.1, a foundation 2.2, a scour protection structure 2.4, and a base 2.5. The experimental box 2.1 is loaded with a foundation 2.2, and both the surface of the experimental box 2.1 and the interior of the foundation 2.2 are provided with a marking matrix and grid lines 2.3; the foundation 2.2 is mixed with marking particles or tracer particles; a scour protection structure 2.4 is laid within a certain range above the foundation 2.2; the shape and structure of the scour protection structure 2.4 are determined according to experimental needs, and the scour protection structure 2.4 can also be omitted. The foundation 2.2 is made of plastic particles, clay, or fine sand, and the scour protection structure 2.4 includes stones, rubber cushions, semi-solid-solid cement, and bionic water plants. The experimental box 2.1 is made of a transparent material. The base 2.5 penetrates the scour protection structure 2.4 and extends into the foundation 2.2; the base 2.5 has a built-in accelerometer 2.6.

[0035] The loading and measuring system includes a loading bracket 3.1, a transverse motor 3.2, a transverse slide 3.3, a transverse screw 3.4, a vertical motor 3.5, a vertical slide 3.6, a vertical screw 3.7, a loading arm 3.8, a three-axis dynamometer 3.9, a connecting mechanism 3.10 and a laser displacement meter 3.11. The loading and measuring system is installed above the experimental box 2.1 through the loading bracket 3.1. The transverse motor 3.2 is installed on the side of the loading bracket 3.1, and the transverse motor 3.2 is connected to the transverse screw 3.4; the transverse slide 3.3 and the vertical motor 3.5 are installed on the top surface of the loading bracket 3.1, and the vertical motor 3.5 is connected to the vertical slide 3.6, the vertical screw 3.7 and the loading arm 3.8 at the bottom to form a vertical loading module. The transverse motor 3.2 can drive the rotation of the transverse screw 3.4, and the transverse screw 3.4 rotates to vertically load The module slides horizontally along the transverse slide rail 3.3. A connecting mechanism 3.10 is installed at the bottom of the loading arm 3.8. The vertical loading module is connected to the top of the foundation 2.5 through the connecting mechanism 3.10. The vertical motor 3.5 can drive the loading arm 3.8 to move vertically along the vertical slide rail 3.6 by driving the rotation of the vertical screw 3.7. The loading and measurement system is a two-dimensional loading mechanism. By replacing different modules, static loads, dynamic loads, or pulse loads can be applied to the foundation 2.5 and other structures in the vertical and horizontal directions to complete the loading of the foundation 2.5 and other structures.

[0036] The loading and measuring system also includes a measuring device, which includes a three-dimensional dynamometer 3.9, a laser displacement meter 3.11, and an accelerometer 2.6. The three-dimensional dynamometer 3.9 is installed between the loading arm 3.8 and the connecting mechanism 3.10 to measure the load applied by the loading device to the foundation. The laser displacement meter 3.11 is installed on the loading bracket 3.1 to measure the displacement and deformation of the foundation.

[0037] The particle motion capture and video acquisition system, mounted on the sides and top of the experimental chamber 2.1, includes a laser scanner 4.1, a high-frequency camera 4.2, and a video camera 4.3. The laser scanner 4.1 illuminates and captures the motion trajectories of tracer particles within the foundation 2.2, the scour protection structure 2.4, and the fluid 1.3. The high-frequency camera 4.2 combines the marking dots and grid lines 2.3 on the chamber surface to record the deformation of the structures within the experimental chamber 2.1. The video camera 4.3 records the entire experimental process.

[0038] Example 2

[0039] As another implementation, in this embodiment, a method for conducting an experiment using the experimental device for the underwater foundation scour development process and structural protection performance in the first embodiment is proposed. The experimental method includes the following steps:

[0040] S1. Connect the flow channel 1.1 with the experimental box 2.1, install the combined wave-making gate 1.2 on the flow channel 1.1, and place the pad 1.4 at the connection between the flow channel 1.1 and the experimental box 2.1.

[0041] S2. Load foundation 2.2 and marking dots and grid lines 2.3 into experimental box 2.1. Lay scour protection structure 2.4 on the surface of foundation 2.2 and install foundation 2.5, depending on experimental needs. Foundation 2.5 can be installed first inside or on top of foundation 2.2, and then scour protection material can be laid around foundation 2.5. Alternatively, scour protection material can be laid on the surface of foundation 2.5 first, and then the foundation 2.5 structure can be installed.

[0042] S3. Assemble the loading and measuring system, install the three-axis dynamometer 3.9 on the loading arm 3.8, and connect the connecting mechanism 3.10 to the foundation 2.5.

[0043] S4. Turn on the laser scanner 4.1, the high-frequency camera 4.2 and the video camera 4.3, and debug them to the operating state.

[0044] S5. Open the external valve to allow fluid 1.3 to flow in flow channel 1.1 and experimental box 2.1 according to the specified parameters. Open the combined wave-making gate 1.2 to create a wave effect as required by the experiment. Start the vertical loading module to apply a load to foundation 2.5.

[0045] S6. With the help of laser scanner 4.1, high-frequency camera 4.2 and video camera 4.3, the experimental process is recorded by taking photos and videos. The laser scanner 4.1 is used to illuminate and capture the movement trajectory of the marked particles or tracer particles in the foundation 2.2, the scour protection structure 2.4 and the fluid 1.3; the high-frequency camera 4.2 is used in combination with the marked dot matrix and grid lines 2.3 on the surface of the experimental box 2.1 to record the deformation of the structure in the experimental box 2.1; the video camera 4.3 is used to shoot and record the experimental steps and processes, and a three-dimensional graphic and video of the real-time evolution process of the foundation 2.2 and the scour protection structure 2.4 under the scouring action of the fluid 1.3 are drawn by computer, and an in-depth analysis of the scour development process and the long-term working performance of the scour protection structure 2.4 is conducted.

Claims

1. An experimental device for underwater foundation scour development process and structural protection performance, characterized by: include: Alternating flow channel system, foundation and scour protection system, loading and measurement system, particle motion capture and video acquisition system; The alternating flow channel system comprises a flow channel (1.1), wherein four flow channels (1.1) intersect at an experimental box (2.1); a cushion block (1.4) is provided at the junction of the flow channel (1.1) and the experimental box (2.1); a fluid (1.3) flows in the flow channel (1.1); and a combined wave-making gate (1.2) is provided in the flow channel (1.1); The foundation and scour protection system comprises an experimental box (2.1), a foundation (2.2), a scour protection structure (2.4) and a base (2.5); the experimental box (2.1) is loaded with the foundation (2.2); the surface of the experimental box (2.1) and the interior of the foundation (2.2) are both provided with marking dot arrays and grid lines (2.3); the foundation (2.2) is doped with marking particles or tracer particles; the scour protection structure (2.4) is laid within a certain range above the foundation (2.2); and the base (2.5) penetrates the scour protection structure (2.4) and extends into the foundation (2.2); The loading and measuring system is installed above the experimental box (2.1) via a loading bracket (3.1); a horizontal motor (3.2) is installed on the side of the loading bracket (3.1); the horizontal motor (3.2) is connected to a horizontal screw (3.4); a horizontal slide rail (3.3) and a vertical motor (3.5) are installed on the top surface of the loading bracket (3.1); the lower part of the vertical motor (3.5) is connected to a vertical slide rail (3.6), a vertical screw (3.7) and a loading arm (3.8) to form a vertical loading module; when the horizontal screw (3.4) rotates, the vertical loading module slides along the horizontal slide rail (3.3); and the vertical loading module is connected to the top of the foundation (2.5) via a connecting mechanism (3.10); The particle motion capture and video acquisition system is installed on the side and upper part of the experimental box (2.1), including a laser scanner (4.1), a high-frequency camera (4.2) and a video camera (4.3); The loading and measuring system further includes a measuring device, which includes a three-dimensional dynamometer (3.9), a laser displacement meter (3.11), and an accelerometer (2.6); the three-dimensional dynamometer (3.9) is installed between the loading arm (3.8) and the connecting mechanism (3.10), the laser displacement meter (3.11) is installed on the loading bracket (3.1), and the base (2.5) has a built-in accelerometer (2.6); The experimental method of the experimental device for the development process of underwater foundation scour and structural protection performance includes the following steps: S1. Connect the flow trough (1.1) and the experimental box (2.1), install the combined wave-making gate (1.2) on the flow trough (1.1), and place the cushion block (1.4) at the junction of the flow trough (1.1) and the experimental box (2.1); S2. Load the foundation (2.2) and the marking dot matrix and grid lines (2.3) in the experimental box (2.1). Lay the scour protection structure (2.4) on the surface of the foundation (2.2) as required by the experiment, and install the foundation (2.5). S3. Assemble the loading and measuring system, install the three-axis dynamometer (3.9) on the loading arm (3.8), and connect the connecting mechanism (3.10) to the foundation (2.5); S4. Turn on the laser scanner (4.1), the high-frequency camera (4.2) and the video camera (4.3), and debug them to the operating state; S5. Open the external valve to allow the fluid (1.3) to flow in the flow channel (1.1) and the experimental box (2.1) according to the specified parameters, and open the combined wave-making gate (1.2) to create a wave effect as required by the experiment; start the vertical loading module to apply a load to the foundation (2.5); S6. With the aid of a laser scanner (4.1), a high-frequency camera (4.2), and a video camera (4.3), the experimental process is recorded by taking photos and videos. A computer is used to draw three-dimensional graphics and videos of the real-time evolution of the foundation (2.2) and the scour protection structure (2.4) under the scouring action of the fluid (1.3). The laser scanner (4.1) is used to illuminate and capture the movement trajectories of the marker particles or tracer particles in the foundation (2.2), the scour protection structure (2.4), and the fluid (1.3). The high-frequency camera (4.2) is used in combination with the marker dots and grid lines (2.3) on the surface of the experimental box (2.1) to record the deformation of the structure in the experimental box (2.1). The video camera (4.3) is used to photograph and record the experimental steps and process.

2. The experimental device for underwater foundation scour development and structural protection performance according to claim 1 is characterized by: In the alternating flow channel system, the cross section of the flow channel (1.1) is rectangular or semicircular, the flow channel (1.1) is externally connected to a fluid source, and a valve for controlling the flow and direction of a fluid (1.3) is provided inside the flow channel (1.1), wherein the fluid (1.3) is water or a viscous medium other than water.

3. The experimental device for underwater foundation scour development process and structural protection performance according to claim 1 is characterized by: In the foundation and scour protection system, the foundation (2.2) is made of plastic particles, clay or fine sand, the scour protection structure (2.4) includes stones, rubber cushions, semi-solid-solid cement and bionic water plants, and the experimental box (2.1) is made of transparent material.

Images