A soft foundation reinforcement vibroflotation test system

Abstract

The application discloses a soft foundation reinforcement vibroflotation test system and relates to the technical field of geotechnical engineering. The system comprises a lifting mechanism, a vibroflotation mechanism, a test box and a controller. The vibroflotation mechanism is installed on the moving plate of the lifting mechanism through a connecting plate. The vibroflotation mechanism has an upper rod and a lower rod which can rotate relative to each other and is integrated with an axial exciter, a radial vibrator and a rotary driving assembly, so that the axial, radial and rotary motions can be combined to excite. A plurality of sensors are arranged in the test box to monitor the change of soil parameters during the test. Meanwhile, the system is connected with an external air pump and a water pump through the air inlet and the water outlet on the rod to form a gas-water combined action mechanism of "high-pressure air pressure into - active negative pressure suction". The application can simulate the complex dynamic behavior in the actual vibroflotation construction in full scale and realize the synchronous and accurate monitoring of the construction parameters and the soil response through the sensor network, so that an efficient and reliable indoor test method is provided for the optimization and determination of the soft foundation reinforcement construction parameters.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, specifically to a vibratory compaction test system for soft soil foundation reinforcement. Background Technology

[0002] Vibro-compaction is greatly affected by engineering experience, water depth conditions, and construction parameters in actual construction. In soft soil foundation reinforcement, it often requires multiple tests and adjustments to determine suitable construction parameters. However, the marine environment is unique, engineering experience is limited, construction is difficult and costly, and construction risks are also high. At present, vibro-compaction tests are highly dependent on engineering experience and field experiments, and the perception of suitable parameters and changes in foundation parameters is not comprehensive, resulting in great blindness and uncertainty.

[0003] Therefore, it is necessary to propose a vibratory impact testing system for soft soil reinforcement to solve the above problems. Summary of the Invention

[0004] Technical problem to be solved: The purpose of this invention is to provide a vibratory compaction test system for soft foundation reinforcement, so as to solve the problems mentioned in the background art that the existing vibratory compaction test is highly dependent on engineering experience and field experiments, and has an incomplete perception of suitable parameters and changes in foundation parameters, resulting in great blindness and uncertainty.

[0005] Technical Solution: To achieve the above objectives, the present invention provides the following technical solution: A vibratory compaction test system for soft soil reinforcement, comprising a lifting mechanism, a vibratory compaction mechanism, a test chamber, a controller, an air pump, and a water pump. The lifting mechanism, the vibratory compaction mechanism, and the test chamber are all electrically connected to the controller. The vibratory compaction mechanism includes an upper rod fixedly mounted on the moving end of the lifting mechanism, a lower rod concentrically rotatably mounted on the lower end of the upper rod, and a drive assembly for driving the lower rod to rotate. Both the upper and lower rods have cavities inside, and the two cavities are interconnected. A cross-shaped upper wing plate is fixedly mounted on the periphery of the upper rod, and a cross-shaped lower wing plate is fixedly mounted on the periphery of the lower rod. Multiple first through holes are equidistantly spaced vertically along the upper wing plate, and multiple through holes communicating with the cavities are provided on both the upper and lower rods. The second through hole contains a filter screen; the upper end of the upper rod is fixedly installed with a vibrator, and the lower end of the lower rod is fixedly installed with a vibration component. The upper part of the upper rod is symmetrically provided with a drain port and an air inlet communicating with its interior. The air inlet is connected to the output end of the air pump, the outer end of the drain port is connected to the input end of the water pump, and the inner end of the drain port is connected to a water pipe and communicates with the cavity of the lower rod through the water pipe. The experimental box is located directly below the upper rod. The experimental box includes a box body with an opening at the top, a data acquisition component set inside the box body, a top plate fixedly installed at the opening at the top of the box body, a drainage channel opened in the top plate, a drainage plate fixedly installed at the bottom of the top plate, the lower end of the drainage plate extending to the bottom of the box body, and the upper end extending into the drainage channel. A drainage pipe communicating with the drainage channel is fixedly installed on the box body.

[0006] Preferably, the lifting mechanism includes a base plate, a U-shaped frame fixedly mounted on the base plate, a movable plate slidably mounted vertically within the U-shaped frame, and a first motor fixedly mounted on the top of the U-shaped frame. A first lead screw is threadedly fitted in the middle of the movable plate, the upper end of the first lead screw is fixedly connected to the output shaft of the first motor, and the lower end is rotatably connected to the base plate.

[0007] Preferably, the inner sides of both side plates of the U-shaped frame are provided with vertical grooves, and sliders are slidably installed in the grooves. Both sliders are fixedly connected to the movable plate, and a connecting plate is fixedly installed on one side of the movable plate.

[0008] Preferably, the drive assembly includes a second motor concentrically fixedly installed inside the upper rod, a fixed plate concentrically fixedly installed inside the lower rod, a second lead screw concentrically fixedly installed on the output shaft of the second motor, and the lower end of the second lead screw being fixedly connected to the fixed plate.

[0009] Preferably, the lower wing plate has a sliding hole communicating with the chamber of the lower rod. A telescopic filter screen is fixedly installed in the sliding hole. A connecting seat is threaded onto the second lead screw. The vibration assembly includes four first vibrators fixedly installed in a cross shape on the connecting seat, and two second vibrators fixedly installed concentrically in the chamber of the lower rod. The other end of each first vibrator passes through the corresponding telescopic filter screen and is fixedly installed with a first vibration plate. The lower end of each second vibrator passes through the lower end face of the lower rod and is fixedly installed with a second vibration plate.

[0010] Preferably, the data acquisition component includes multiple monitoring groups arranged on the front and rear inner side walls of the box and equidistantly along the left and right directions. Each monitoring group includes multiple sensors arranged equidistantly along the vertical direction. The multiple sensors include a pore water pressure sensor, a soil pressure cell, and an accelerometer.

[0011] Preferably, there are two top plates, which are arranged symmetrically along the longitudinal direction.

[0012] Beneficial Effects: Compared with existing technologies, this invention provides a vibro-compaction testing system for soft soil foundation reinforcement. This system features a unique structure and ease of use. By arranging multiple sensors within the test chamber, it can monitor changes in key parameters such as pore water pressure and soil pressure in real time and from multiple dimensions during the test. Combined with a controller that automatically records various operating parameters, it significantly reduces reliance on engineering experience and provides comprehensive and accurate data support for parameter optimization. This allows for the indoor simulation of complex marine environments and soft soil foundation conditions, avoiding the high costs, high risks, and uncontrollable factors associated with field testing. This provides a reliable and economical testing method for determining vibro-compaction parameters. In addition, through the synergistic action of the vibrator, rotary drive, and multiple vibrators, axial, radial, and rotary composite excitation is achieved, which can more realistically simulate the complex dynamic behavior in actual vibro-compaction construction, improving the realism of the test simulation and the adjustability of parameters. The combined action of high-pressure air injection and active negative pressure suction effectively promotes the rapid discharge of pore water in saturated soil and significantly accelerates the dissipation of excess pore water pressure, which can prevent soil liquefaction or the formation of "rubber soil" and improve the vibro-compaction efficiency. Attached Figure Description

[0013] Figure 1 This is a three-dimensional schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional schematic diagram of the structure of the present invention; Figure 3 This is a cross-sectional schematic diagram of the upper rod structure of the present invention; Figure 4 This is a cross-sectional schematic diagram of the lower rod structure of the present invention.

[0014] In the diagram: 1. Lifting mechanism; 11. Base plate; 12. U-shaped frame; 13. Moving plate; 14. Slide groove; 15. First motor; 16. Connecting plate; 17. First lead screw; 2. Vibration and impact mechanism; 21. Upper rod; 22. Upper wing plate; 23. First through hole; 24. Second through hole; 25. Drain outlet; 26. Air inlet; 27. Exciter; 28. Lower rod; 29. ​​Lower wing plate; 210. Second motor; 211. Second lead screw; 212. Fixed plate; 213. Connecting seat; 214. First vibrator; 215. First vibrating plate; 216. Second vibrator; 217. Second vibrating plate; 218. Telescopic filter; 3. Experimental chamber; 31. Chamber body; 32. Sensor; 33. Top plate; 34. Drainage plate; 35. Drainage pipe. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Example 1: This Example 1 provides a vibratory impact testing system for soft soil reinforcement. It is a direct improvement on existing soft soil reinforcement devices and has a unique structure. Please refer to [link / reference].Figures 1-4 As shown, the system includes a lifting mechanism 1, a vibratory impact mechanism 2, an experimental chamber 3, and a controller (not shown in the figure). The lifting mechanism 1, the vibratory impact mechanism 2, the water pump, the air pump, and the sensor 32 inside the experimental chamber 3 are all electrically connected to the controller, which enables automated control and data acquisition.

[0017] The lifting mechanism 1 includes a horizontal base plate 11. A U-shaped frame 12 with an upward opening is fixedly installed on the base plate 11. A movable plate 13 is connected to the sliding grooves 14 vertically opened on the inner side of the two side plates of the U-shaped frame 12 via sliders on both sides (not labeled in the figure) to achieve a vertical sliding connection. A first lead screw 17 is threadedly fitted in the middle of the movable plate 13. The upper end of the first lead screw 17 is fixedly connected to the output shaft of a first motor 15 fixedly installed on the top of the U-shaped frame 12 via a coupling, and the lower end is rotatably connected to the base plate 11 via a bearing. Therefore, when the controller starts the first motor 15, the first motor 15 drives the first lead screw 17 to rotate, thereby driving the movable plate 13, which is threadedly engaged with it, to rise or fall precisely along the sliding grooves 14. To facilitate the connection of the vibratory impact mechanism 2, a connecting plate 16 is fixedly installed on one side of the movable plate 13.

[0018] The vibratory compaction mechanism 2 is fixedly installed on the moving plate 13 of the lifting mechanism 1 via the connecting plate 16 and moves together with it. The vibratory compaction mechanism 2 includes an upper rod 21 and a lower rod 28. The upper end of the upper rod 21 is fixedly installed with an exciter 27 for generating high-frequency vibration along the axial (vertical) direction of the rod. Four upper wing plates 22 arranged in a cross shape are fixedly welded to the periphery of the upper rod 21 to enhance the lateral compaction and vibration transmission effect of the soil. Multiple first through holes 23 are equidistantly opened vertically on the upper wing plates 22. A cavity is opened axially inside the upper rod 21. Drainage outlets 25 and air inlets 26 communicating with the cavity are symmetrically opened on the upper side wall of the upper rod 21.

[0019] The lower rod 28 is concentrically mounted on the lower end of the upper rod 21 via bearings, allowing the lower rod 28 to rotate relative to the upper rod 21 around its axis. Four lower wing plates 29 arranged in a cross shape are also fixedly welded to the periphery of the lower rod 28. The lower rod 28 also has an internal cavity, which communicates with the internal cavity of the upper rod 21, forming a continuous channel. The air inlet 26 is connected to the output end of the air pump, and the outer end of the drain outlet 25 is connected to the input end of the water pump. The inner end of the drain outlet 25 is connected to a water pipe (not shown in the figure) and communicates with the cavity of the lower rod 28 through the water pipe. Multiple second through holes 24 communicating with their respective cavities are provided on the side walls of both the upper rod 21 and the lower rod 28. These second through holes 24 communicate with the internal cavities of the rod, allowing fluid (gas or water) to pass through. To prevent soil particles from entering the rod, all second through holes 24 are fitted with high-strength metal filters (not shown separately in the figure).

[0020] The drive assembly is used to drive the lower rod 28 to rotate relative to the upper rod 21. The drive assembly includes a second motor 210 concentrically fixed inside the cavity of the upper rod 21. The output shaft of the second motor 210 faces downward and a second lead screw 211 is concentrically fixed. A fixing plate 212 is concentrically fixed inside the cavity of the lower rod 28. The lower end of the second lead screw 211 is fixedly connected to the fixing plate 212. When the second motor 210 starts, it drives the second lead screw 211 to rotate. Since the second lead screw 211 is fixedly connected to the lower rod 28 through the fixing plate 212, and the lower rod 28 is mounted on the upper rod 21 through bearings, the lower rod 28 will rotate as a whole with the second lead screw 211, achieving the effect of "rotational vibration".

[0021] The vibration assembly is installed inside the lower rod 28 to provide radial excitation force. It includes a connecting seat 213 that is threaded onto the second lead screw 211. Inside each lower flange 29 of the lower rod 28, there is a radially open sliding hole communicating with the chamber of the lower rod 28. A telescopic filter 218 (such as a corrugated metal filter) is fixedly installed in each sliding hole, which allows the connector to pass through and extend while maintaining a seal against sand. Four first vibrators 214 are fixedly mounted on the connecting seat 213 in a cross shape. The vibration output end (actuator) of each first vibrator 214 passes through the corresponding telescopic filter 218 and extends to the outside of the lower wing plate 29. A first vibration plate 215 is fixedly mounted at the end. Therefore, when the connecting seat 213 moves up and down, the first vibration plate 215 can move accordingly. In addition, a second vibrator 216 is also concentrically fixedly mounted in the cavity of the lower rod 28. Its vibration output end passes downward through the lower end face of the lower rod 28 and a second vibration plate 217 is fixedly mounted thereon to provide the excitation force at the bottom.

[0022] The test chamber 3 is used to hold soil samples and monitor the reinforcement process. The test chamber 3 is located directly below the upper rod 21. The test chamber 3 includes a box 31 with an open top for filling the sand sample to be tested. On the front and rear inner side walls of the box 31, multiple monitoring groups are equidistantly arranged in the left and right directions. Each monitoring group includes multiple sensors 32 equidistantly arranged in the vertical direction. These sensors 32 include pore water pressure sensors, soil pressure cells and accelerometers, which are used to monitor the changes in the internal state of the soil in real time during the test.

[0023] Two top plates 33 are symmetrically fixed at the upper opening of the box 31. The top plates 33 have drainage channels (not shown in the figure) inside. A drainage plate 34 is fixedly installed at the bottom of the top plate 33. The lower end of the drainage plate 34 extends to the vicinity of the bottom of the box 31, and the upper end extends into the drainage channel of the top plate 33. A drainage pipe 35 is fixedly installed on the box 31. The drainage pipe 35 is connected to the drainage channel in the top plate 33 and is used to orderly drain the water discharged from the soil during the test.

[0024] Working principle: First, prepare for the test by filling the prepared saturated sand sample into the box 31 of the test chamber 3 in layers to simulate the actual foundation soil environment. Connect the drain port 25 of the vibratory compaction mechanism 2 to an external water pump (pumping mode) through a pipe, and connect the air inlet 26 to an external high-pressure air pump through a pipe. All sensors 32 are connected to the controller.

[0025] The controller starts the first motor 15 of the lifting mechanism 1. The first motor 15 drives the first lead screw 17 to rotate, which drives the moving plate 13 and the entire vibratory impact mechanism 2 to descend smoothly, so that the upper rod 21, the lower rod 28 and the upper wing plate 22 and the lower wing plate 29 are gradually inserted into the soil sample of the experimental box 3 until the predetermined depth is reached. The controller simultaneously starts the exciter 27, the second motor 210, the first vibrator 214 and the second vibrator 216. The exciter 27 generates axial (vertical) vibration, which is transmitted to the soil through the rod. The second motor 210 drives the second lead screw 211 to rotate, which drives the entire lower rod 28 and its lower wing plate 29 and the second vibrating plate 217 to rotate together, forming a "rotational vibratory impact".

[0026] Because the connecting seat 213 is threaded into the rotating second lead screw 211 and is constrained from rotating by the inner wall of the lower rod 28, when the second lead screw 211 rotates, the connecting seat 213 will generate relative motion along the axial direction (i.e., vertical) of the second lead screw 211, thereby driving the four first vibrators 214 and the first vibrating plate 215 to move up and down reciprocally within the sliding hole; at the same time, the first vibrators 214 themselves generate high-frequency vibration. This simulates the change in the horizontal vibration amplitude of the vibratory compactor during vibratory compaction.

[0027] The second vibrator 216 drives the second vibrating plate 217 to generate independent bottom vibration. The combination of the exciter 27, the first vibrator 214, the second vibrator 216 and the rotational motion together constitutes a multi-dimensional composite excitation of the soil, which can more realistically simulate the complex dynamic behavior of the vibratory compactor on site.

[0028] An external high-pressure air pump continuously injects high-pressure gas into the inner cavity connecting the upper and lower rods through the air inlet 26. The gas is injected into the surrounding soil through the second through hole 24 on the rod wall and the first through hole 23 on the upper wing plate 22 (both equipped with filters). The high-pressure gas forms channels and pressure in the soil pores, which on the one hand can push the pore water to move to the low-pressure area (such as the direction of the drainage board 34), and on the other hand can temporarily support the pores, reduce the friction between particles, and make the soil particles easier to rearrange under vibration.

[0029] An external water pump actively draws water from the inner cavity of the lower rod 28 through the drain port 25 and water pipe. This operation can promptly discharge the small amount of water that has seeped into the rod cavity and the pore water that has been discharged to the vicinity of the rod with the gas, forming a negative pressure suction effect and accelerating the discharge of pore water through the drain plate 34 and drain pipe 35 into the system.

[0030] This combined air-water action, integrating high-pressure air injection and active negative pressure suction, significantly accelerates the dissipation of excess pore water pressure in saturated soil, effectively preventing liquefaction or "rubber soil" phenomena. This allows soil particles to reach a denser state more quickly and effectively under multi-dimensional vibration. The filter effectively prevents sand particles from flowing back into the rod, protecting the vibration components and ensuring unobstructed airflow.

[0031] Throughout the test, multiple sets of sensors 32 arranged on the inner wall of the chamber 31 monitored changes in parameters such as pore water pressure and lateral earth pressure within the soil in real time. The controller recorded all operating parameters (such as vibration frequency, rotation speed, air pressure, water pressure, insertion depth, etc.) and response data. By analyzing this data, the reinforcement effect under different vibratory compaction parameters and combined air-water conditions can be accurately evaluated, providing a basis for optimized design in practical engineering.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vibration impact testing system for soft soil reinforcement, comprising a lifting mechanism (1), characterized in that: It also includes a vibratory impact mechanism (2), an experimental chamber (3), a controller, an air pump, and a water pump. The lifting mechanism (1), the vibratory impact mechanism (2), and the experimental chamber (3) are all electrically connected to the controller. The vibratory impact mechanism (2) includes an upper rod (21) fixedly installed on the moving end of the lifting mechanism (1), a lower rod (28) concentrically rotatably installed on the lower end of the upper rod (21), and a drive assembly that drives the lower rod (28) to rotate. Both the upper rod (21) and the lower rod (28) have cavities inside. The two cavities are interconnected; an upper wing plate (22) arranged in a cross shape is fixedly installed on the periphery of the upper rod (21), and a lower wing plate (29) arranged in a cross shape is fixedly installed on the periphery of the lower rod (28). Multiple first through holes (23) are equidistantly opened vertically on the upper wing plate (22), and multiple second through holes (24) communicating with the cavities are opened on both the upper rod (21) and the lower rod (28). A filter screen is provided in the second through hole (24); the upper end of the upper rod (21) is fixed A vibrator (27) is installed, and a vibration assembly is fixedly installed at the lower end of the lower rod (28). The upper part of the upper rod (21) is symmetrically provided with a drain port (25) and an air inlet (26) communicating with its interior. The air inlet (26) is connected to the output end of the air pump, the outer end of the drain port (25) is connected to the input end of the water pump, and the inner end of the drain port (25) is connected to a water pipe and communicates with the cavity of the lower rod (28) through the water pipe. The experimental box (3) is located directly below the upper rod (21). The experimental box (3) includes a box body (31) with an opening at the top, a data acquisition component set inside the box body (31), a top plate (33) fixedly installed at the opening at the top of the box body (31), a drainage channel is provided inside the top plate (33), a drainage plate (34) is fixedly installed at the bottom of the top plate (33), the lower end of the drainage plate (34) extends to the bottom of the box body (31), the upper end extends into the drainage channel, and a drainage pipe (35) connected to the drainage channel is fixedly installed on the box body (31).

2. The vibration impact testing system for soft soil reinforcement according to claim 1, characterized in that: The lifting mechanism (1) includes a base plate (11), a U-shaped frame (12) fixedly installed on the base plate (11), a movable plate (13) slidably installed in the U-shaped frame (12) along the vertical direction, and a first motor (15) fixedly installed on the top of the U-shaped frame (12). A first lead screw (17) is threadedly fitted in the middle of the movable plate (13). The upper end of the first lead screw (17) is fixedly connected to the output shaft of the first motor (15), and the lower end is rotatably connected to the base plate (11).

3. The vibration impact testing system for soft soil reinforcement according to claim 2, characterized in that: The inner sides of both side plates of the U-shaped frame (12) are provided with vertical grooves (14), and sliders are slidably installed in the grooves (14). Both sliders are fixedly connected to the moving plate (13), and a connecting plate (16) is fixedly installed on one side of the moving plate (13).

4. The vibration impact testing system for soft soil reinforcement according to claim 1, characterized in that: The drive assembly includes a second motor (210) concentrically fixed in the upper rod (21) and a fixing plate (212) concentrically fixed in the lower rod (28). A second lead screw (211) is concentrically fixed on the output shaft of the second motor (210), and the lower end of the second lead screw (211) is fixedly connected to the fixing plate (212).

5. The vibration impact testing system for soft soil reinforcement according to claim 4, characterized in that: The lower wing plate (29) has a sliding hole that communicates with the chamber of the lower rod (28). A telescopic filter (218) is fixedly installed in the sliding hole. A connecting seat (213) is threaded onto the second lead screw (211). The vibration assembly includes four first vibrators (214) fixedly installed in a cross shape on the connecting seat (213), and a second vibrator (216) fixedly installed concentrically in the chamber of the lower rod (28). The other end of each of the first vibrators (214) passes through the corresponding telescopic filter (218) and is fixedly installed with a first vibration plate (215). The lower end of the second vibrator (216) passes through the lower end face of the lower rod (28) and is fixedly installed with a second vibration plate (217).

6. The vibration impact testing system for soft soil reinforcement according to claim 1, characterized in that: The data acquisition component includes multiple monitoring groups arranged on the front and rear inner walls of the box (31) and equidistantly arranged in the left and right directions. The monitoring groups include multiple sensors (32) arranged equidistantly in the vertical direction. The multiple sensors (32) include pore water pressure sensors, soil pressure cells and accelerometers.

7. The vibration impact testing system for soft soil reinforcement according to claim 1, characterized in that: There are two top plates (33), which are arranged symmetrically along the longitudinal direction.

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