Vacuum preloading device for underwater soft soil base layer

Abstract

The utility model provides a vacuum preloading device of underwater soft soil base, including drainage body, underwater vacuum preloading device, first pipe body and vacuum pump, the bottom of underwater vacuum preloading device is provided with a plurality of mounting hole, and the mounting hole is used for the installation of drainage body, the drainage body is inserted into the mud surface, the top of underwater vacuum preloading device is provided with second pipe body, and the second pipe body is used for the installation of drainage body. The second pipe body is connected to a vacuum pump through the first pipe body, and the vacuum pump is arranged on a hull or a shore base. According to the vacuum preloading device for the underwater soft soil base layer, the underwater vacuum preloading device is a recyclable device, the construction cost can be reduced, the drainage body is of a prefabricated sleeve structure, people do not need to go down, a film does not need to be laid, negative pressure is formed on the upper portion of the foundation to be treated, pore water in the foundation flows out along a specially-made drainage channel, and the construction efficiency is improved. By adopting the assembly type design, a plurality of underwater vacuum preloading devices can be combined for application, the stability of the system in an underwater environment is improved, and the system is plug-and-play and is convenient to recycle and reuse.

Description

Technical Field

[0001] This utility model belongs to the field of underwater soft soil base construction, and in particular relates to a vacuum preloading device for underwater soft soil base. Background Technology

[0002] Marine soft soil not only possesses the general characteristics of soft soil, such as high water content, high compressibility, low strength, and poor permeability, but also exhibits the unique characteristics of the marine environment. This results in significant settlement, slow consolidation, and prolonged settlement duration in marine soft soil foundations. Furthermore, due to settlement and other factors, constructed buildings or structures are susceptible to a series of problems, including localized deformation and cracking, panel damage, and erosion from seawater contact, leading to a range of safety hazards. Therefore, it is essential to properly treat and reinforce marine soft soil foundations before constructing offshore wind turbine suction pile foundations, offshore airports, and industrial artificial islands.

[0003] Vacuum preloading is a method that involves laying a horizontal drainage sand cushion layer and a vertical drainage board on a soft clay foundation. A specific airtight sealing membrane is laid on top of the sand cushion layer. Through the drainage filter pipe at the bottom and the vacuum device, the pore water pressure of the lower soil layer is reduced, creating negative pressure. Atmospheric pressure is then used to reinforce the soil and increase the effective stress.

[0004] However, vacuum preloading is currently mostly used in land-based engineering projects, and there are very few cases of vacuum preloading projects that can be applied to underwater environments. Moreover, most of these projects are located in the intertidal zone. The application of this technology to a fully underwater environment is still a blank.

[0005] The biggest challenge with existing underwater vacuum preloading technology lies in underwater membrane laying. The successful installation of the sealing membrane is a crucial factor in determining the smooth operation of vacuum preloading. If this problem can be solved, underwater vacuum preloading will find widespread application in engineering projects. Utility Model Content

[0006] In view of this, the present invention aims to propose a vacuum preloading device for underwater soft soil base courses, so as to solve the problem that the existing technology makes it difficult to carry out vacuum preloading projects in underwater environments and the construction conditions are relatively limited.

[0007] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0008] A vacuum preloading device for underwater soft soil base includes a drainage body, an underwater vacuum preloading device, a first pipe, and a vacuum pump. The underwater vacuum preloading device has multiple mounting holes at its bottom, which are used to install the drainage body. The drainage body is inserted into the mud surface. A second pipe is installed at the top of the underwater vacuum preloading device. The second pipe is connected to the vacuum pump through the first pipe. The vacuum pump is installed on the hull of a ship or on a shore foundation. The water in the mud surface is discharged through the drainage body, the underwater vacuum preloading device, the second pipe, the first pipe, and the vacuum pump.

[0009] Furthermore, the underwater vacuum pre-compression device includes an upper shell and a lower shell. The bottom of the lower shell is provided with multiple mounting holes. The upper end of the lower shell is sealed to the lower end of the upper shell. The upper end of the upper shell is equipped with a first tube.

[0010] Furthermore, the upper housing is provided with a connecting pipe, and a solenoid valve is installed on the connecting pipe.

[0011] Furthermore, a water-gas separation chamber is installed on the first pipe body.

[0012] Furthermore, the lower end of the upper housing is provided with multiple alignment heads along the circumferential direction, and the upper end of the lower housing is provided with multiple alignment grooves along the axial direction. The alignment heads and alignment grooves correspond one-to-one. Each alignment head is inserted into an alignment groove to position the relative position of the lower housing and the upper housing. The cross-section of the inner circle contour of the alignment groove is a trapezoidal structure, and the outer contour of the alignment head is adapted to the inner circle contour of the alignment groove.

[0013] Furthermore, the upper end of the lower housing is provided with an abutment groove along the circumference, and the lower end of the upper housing is provided with an abutment platform along the circumference. The cross-section of the abutment platform's outer contour is a triangular structure, and the inner contour of the abutment groove is adapted to the abutment platform.

[0014] Furthermore, a rubber waterstop strip is provided inside the abutment groove.

[0015] Furthermore, the abutment platform is provided with a flow channel, the inlet end of which is equipped with a slurry delivery hose, and the outlet end of which is located at the tip of the abutment platform and connected to the abutment groove.

[0016] Furthermore, the drainage body includes bamboo, and a drainage board is fitted around the bamboo, and a protective sleeve is provided around the drainage board. A conical head is installed at the bottom of the bamboo, and the lower end of the protective sleeve abuts against the upper end of the conical head.

[0017] Compared with existing technologies, the underwater vacuum preloading device for soft soil base courses described in this utility model has the following advantages: the underwater vacuum preloading device is a recyclable device, which can reduce construction costs; the drainage body adopts a prefabricated sleeve structure, eliminating the need for personnel to go down or to lay membranes; it creates negative pressure on the upper part of the foundation to be treated, causing pore water in the foundation to flow out through a specially designed drainage channel; and it adopts an assembled design, allowing multiple underwater vacuum preloading devices to be used in combination, improving the stability of the system in the underwater environment; it is plug-and-play and easy to recycle and reuse. Attached Figure Description

[0018] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0019] Figure 1 This is a construction schematic diagram of a vacuum preloading device for an underwater soft soil base layer as described in an embodiment of this utility model;

[0020] Figure 2 This is a schematic diagram of the upper shell structure according to an embodiment of the present utility model;

[0021] Figure 3 This is a top view of the lower housing as described in an embodiment of the present invention;

[0022] Figure 4 This is a cross-sectional schematic diagram of the alignment head and alignment groove as described in an embodiment of the present utility model;

[0023] Figure 5 This is a cross-sectional schematic diagram showing the upper and lower shells of the present invention being sealed together by a rubber waterstop strip.

[0024] Figure 6 This is a cross-sectional schematic diagram of the upper and lower shells connected by grouting sealing according to an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the structure of bamboo and drainage board combined according to an embodiment of the present utility model;

[0026] Figure 8 This is a schematic diagram of the drainage body described in an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1-Drainage body; 11-Bamboo; 12-Drainage board; 13-Conical head; 14-Sheath; 2-Underwater vacuum pre-compression device; 21-Upper shell; 22-Lower shell; 23-Second pipe; 24-Mounting hole; 25-Connecting pipe; 26-Solenoid valve; 27-Alignment head; 28-Alignment groove; 29-Abutment groove; 210-Abutment platform; 211-Rubber waterstop strip; 212-Flow channel; 213-Slurry delivery hose; 3-First pipe; 4-Vacuum pump; 5-Mud surface; 6-Hull; 7-Water-air separation chamber. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0030] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] like Figures 1-8As shown, a vacuum preloading device for underwater soft soil base includes a drainage body 1, an underwater vacuum preloading device 2, a first pipe 3, and a vacuum pump 4. The underwater vacuum preloading device 2 has multiple mounting holes 24 at its bottom for installing the drainage body 1, which is inserted into the mud surface 5. A second pipe 23 is installed at the top of the underwater vacuum preloading device 2, and the second pipe 23 is connected to the vacuum pump 4 through the first pipe 3. The vacuum pump 4 is installed on a ship hull 6 or a shore foundation. Water in the mud surface 5 is discharged through the drainage body 1. The underwater vacuum preloading device 2, the second pipe body 23, the first pipe body 3, and the vacuum pump 4 are discharged. The underwater vacuum preloading device 2 is a recyclable device, which can reduce construction costs. The drainage body 1 adopts a prefabricated sleeve structure, which does not require personnel to go down or membrane to be laid. It forms a negative pressure on the foundation to be treated, so that the pore water in the foundation flows out through the specially designed drainage channel. It adopts a prefabricated design, and multiple underwater vacuum preloading devices 2 can be used together to improve the stability of the system in the underwater environment. It is plug-and-play and easy to recycle and reuse.

[0034] The underwater vacuum pre-compression device 2 includes an upper shell 21 and a lower shell 22. The bottom of the lower shell 22 is provided with multiple mounting holes 24. The upper end of the lower shell 22 is sealed to the lower end of the upper shell 21. The upper end of the upper shell 21 is equipped with a first tube 3. The upper shell 21 is provided with a connecting pipe 25. A solenoid valve 26 is installed on the connecting pipe 25. A water-air separation chamber 7 is installed on the first tube 3. The solenoid valve 26, the water-air separation chamber 7 and the vacuum pump 4 are existing technologies and will not be described in detail here.

[0035] The lower end of the upper housing 21 is provided with multiple alignment heads 27 circumferentially, and the upper end of the lower housing 22 is provided with multiple alignment grooves 28 axially. The alignment heads 27 and alignment grooves 28 correspond one-to-one, with each alignment head 27 inserted into a corresponding alignment groove 28 to position the relative positions of the lower housing 22 and the upper housing 21. The cross-section of the inner contour of the alignment groove 28 is trapezoidal, and the outer contour of the alignment head 27 is adapted to the inner contour of the alignment groove 28. In this embodiment, the upper housing 21 is a cubic box-shaped bottomless steel structure. This "steel box" has a side length of 10-20m, a height of 0.5-1m, and a steel plate thickness of 30-50mm. The top of the "steel box" is connected to a second pipe 23 and a solenoid valve 26, with reinforcing ribs at the connection point. The edge of the side wall of the steel box is provided with pointed alignment heads 27. The lower shell 22 is a cubic box-shaped bottomless steel structure. This "steel box" has a side length of 10-20m, a height of 2-4m, and a steel plate thickness of 30-50mm. The upper shell 21 is provided with a pointed end every 2m, and the lower shell 22 is provided with alignment grooves 28 at the corresponding positions.

[0036] The upper end of the lower housing 22 is provided with an abutment groove 29 along the circumferential direction, and the lower end of the upper housing 21 is provided with an abutment platform 210 along the circumferential direction. The cross-section of the abutment platform 210 is a triangular structure. The inner circle contour of the abutment groove 29 is adapted to the abutment platform 210. In order to achieve a sealed connection between the upper housing 21 and the lower housing 22, two embodiments are provided as follows:

[0037] Example 1:

[0038] A rubber waterstop strip 211 is installed in the abutment groove 29. The rubber waterstop strip 211 is used to achieve a sealed connection between the upper shell 21 and the lower shell 22. The rubber waterstop strip 211 is pre-installed.

[0039] Example 2:

[0040] The abutment platform 210 is provided with a flow channel 212. The inlet end of the flow channel 212 is equipped with a grout delivery hose 213. The outlet end of the flow channel 212 is located at the tip of the abutment platform 210 and is connected to the abutment groove 29. Through an external grouting device, water glass gelling agent and other sealant are injected into the space between the abutment platform 210 and the abutment groove 29 to achieve water-stop sealing.

[0041] The drainage body 1 includes bamboo 11, with a drainage board 12 surrounding the bamboo 11, and a protective sleeve 14 surrounding the drainage board 12. A conical head 13 is installed at the bottom of the bamboo 11, and the lower end of the protective sleeve 14 abuts against the upper end of the conical head 13. In this embodiment, the vertical drainage body 1 is composed of bamboo 11 and annular drainage board 12. The bamboo 11 serves as the main body, and the annular drainage board 12 is securely fitted along its long axis. The large contact area of ​​the annular drainage board 12 effectively improves drainage efficiency. The annular drainage board 12 is a prior art technology. Due to the constraint of the bamboo 11 in the middle, the drainage board 12 is not easily bent, resulting in better treatment effect than using the drainage board 12 alone. The inside of the bamboo 11 is hollowed out and filled with crushed construction waste. Using construction waste as the filling material inside the bamboo 11 is energy-saving and environmentally friendly, and can improve its rigidity. After vacuum preloading, cement grout can be injected into the bamboo 11, making the vertical drainage body 1 function as a micropile.

[0042] A construction process for vacuum preloading of an underwater soft soil base includes the following steps: S1, lowering the lower shell 22 to the area to be constructed; S2, passing one end of the drainage body 1 through the installation hole 24 and pressing it into the mud surface 5; S3, fastening the upper shell 21 to the upper end of the lower shell 22 and completely submerging the upper shell 21 below the water body; S4, starting the vacuum pump 4 to form a vacuum negative pressure and extracting the pore water below the mud surface 5; S5, after completing the preloading, unloading and recovering the vacuum preloading device.

[0043] Specifically, during construction, after the transport ship arrives at the designated location, the lower hull 22 is slowly lowered into the water. Because the lower hull 22 has a through mounting hole 24, the upper and lower parts of the lower hull 22 are connected, and the pressure is equal, allowing the lower hull 22 to smoothly reach the treatment area under the traction of a crane. After reaching the treatment area, vertical drainage bodies 1 need to be installed. During installation, the vertical drainage body 1 is first inserted into the iron sheath 14, and then the sheath 14 along with the vertical drainage body 1 is inserted into the pre-reserved holes in the top plate and slowly driven into the soil covered by the steel plate. During installation, the middle hole and the four corner holes are driven in first according to the positioning devices. Then, according to the layout of one hole every 2m, the remaining drainage boards 12 are driven in sequentially. After installation is completed, the sheath 14 is pulled out. At this time, the conical head 13 and the vertical drainage body 1 will remain in the soil.

[0044] After the drainage board 12 is installed, the signal transmitter, which was previously attached to the top plate of the lower device, will continuously transmit GPS signals on the seabed. These signals can be received by the corresponding signal receiver on the ship. After receiving the GPS signal, the ship's crane will slowly lower the upper shell 21 into the water. To facilitate the sinking of the upper shell 21, two connecting pipes 25 are installed at the top of the upper shell 21. The connectivity of the connecting pipes 25 is controlled by a solenoid valve 26. After the solenoid valve 26 is opened, the upper and lower parts of the upper shell 21 are connected, and the pressure is equal. The upper shell 21 can sink smoothly under the traction of the crane. Then, the solenoid valve 26 is closed, and a sealed cavity is formed inside the upper shell 21 and the lower shell 22. The vacuum pump 4 is started, and a negative pressure is formed inside the cavity. The pore water inside the soil to be treated will flow into the cavity along the drainage board 12. When the cavity is full of water, it will flow into the water-air separation chamber 7 along the first pipe 3. As the vacuuming continues, the pore water pressure of the soil to be treated will gradually decrease, thereby increasing the effective stress of the soil.

[0045] The number of vertical drainage bodies 1 to be installed will be determined based on the specific circumstances of the project. To reduce the soil squeezing effect during vacuuming, the arrangement of the vertical drainage bodies 1 needs to be specified: Starting from the center of the area, one drainage body 1 will be installed every 2 meters along both the horizontal and vertical axes. Each vertical drainage body 1 should extend approximately 530 cm above the mud surface to facilitate horizontal drainage.

[0046] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A vacuum preloading device for underwater soft soil base courses, characterized in that: The device includes a drainage body (1), an underwater vacuum pre-compression device (2), a first pipe (3), and a vacuum pump (4). The underwater vacuum pre-compression device (2) has multiple mounting holes (24) at its bottom, which are used to install the drainage body (1). The drainage body (1) is inserted into the mud surface (5). The underwater vacuum pre-compression device (2) has a second pipe (23) at its top. The second pipe (23) is connected to the vacuum pump (4) through the first pipe (3). The vacuum pump (4) is installed on the hull (6) or shore base. The water in the mud surface (5) is discharged through the drainage body (1), the underwater vacuum pre-compression device (2), the second pipe (23), the first pipe (3), and the vacuum pump (4).

2. The vacuum preloading device for underwater soft soil base course according to claim 1, characterized in that: The underwater vacuum preloading device (2) includes an upper shell (21) and a lower shell (22). The bottom of the lower shell (22) is provided with multiple mounting holes (24). The upper end of the lower shell (22) is sealed to the lower end of the upper shell (21). The upper end of the upper shell (21) is equipped with a first tube (3).

3. The vacuum preloading device for underwater soft soil base course according to claim 2, characterized in that: The upper housing (21) is provided with a connecting pipe (25), and a solenoid valve (26) is installed on the connecting pipe (25).

4. The vacuum preloading device for underwater soft soil base course according to claim 2, characterized in that: A water-air separation chamber (7) is installed on the first pipe body (3).

5. The vacuum preloading device for underwater soft soil base course according to claim 2, characterized in that: The lower end of the upper housing (21) is provided with multiple alignment heads (27) along the circumferential direction, and the upper end of the lower housing (22) is provided with multiple alignment grooves (28) along the axial direction. The alignment heads (27) and alignment grooves (28) correspond one to one. Each alignment head (27) is inserted into an alignment groove (28) to position the relative position of the lower housing (22) and the upper housing (21). The cross-section of the inner circle contour of the alignment groove (28) is a trapezoidal structure, and the outer contour of the alignment head (27) is adapted to the inner circle contour of the alignment groove (28).

6. The vacuum preloading device for underwater soft soil base course according to claim 5, characterized in that: The lower shell (22) has an abutment groove (29) along the circumferential direction at the upper end, and an abutment platform (210) is provided along the circumferential direction at the lower end of the upper shell (21). The cross-section of the outer contour of the abutment platform (210) is a triangular structure, and the inner contour of the abutment groove (29) is adapted to the abutment platform (210).

7. The vacuum preloading device for underwater soft soil base course according to claim 6, characterized in that: A rubber waterstop strip (211) is installed inside the abutment groove (29).

8. A vacuum preloading device for underwater soft soil base courses according to claim 6, characterized in that: The receiving platform (210) is provided with a flow channel (212), the inlet end of the flow channel (212) is equipped with a slurry delivery hose (213), and the outlet end of the flow channel (212) is located at the tip of the receiving platform (210) and connected to the receiving groove (29).

9. A vacuum preloading device for underwater soft soil base courses according to claim 1, characterized in that: The drainage body (1) includes bamboo (11), and a drainage board (12) is fitted around the bamboo (11), and a protective sleeve (14) is provided around the drainage board (12). A conical head (13) is installed at the bottom of the bamboo (11), and the lower end of the protective sleeve (14) abuts against the upper end of the conical head (13).

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