A double plugging construction method in underwater grouting

Abstract

The application provides a double sealing construction method in underwater grouting, which comprises the following steps: upper sealing space construction: forming an upper sealing space between a steel pipe sleeve and a steel pipe pile by using a fixing plate, the upper sealing space is partially communicated with a grouting space above the upper sealing space, and a cross-sectional area of the communication part is smaller than that of a sealing part of the upper sealing space; upper sealing device assembly: assembling an upper sealing device in the upper sealing space, the upper sealing device is connected with an inflation hole, and the upper sealing device actively realizes sealing in a working state; lower sealing space assembly: arranging a bottom sealing supporting plate in a circumferential direction between the steel pipe sleeve and the steel pipe pile, and forming a lower sealing space between the bottom sealing supporting plate and a bottom of the upper sealing space; lower passive sealing device assembly: reversely pressing and fixing a lower passive sealing device on the bottom sealing supporting plate, and the passive sealing device is attached to an outer wall of the steel pipe pile.

Description

Technical Field

[0001] This invention relates to the technical fields of grouting and sealing construction, and in particular to a double sealing construction method for underwater grouting. Background Technology

[0002] In offshore grouting construction, the large grouting height leads to problems such as high organization difficulty and high cost. If grout leakage or mixing of grout with mud and seawater occurs, it may lead to major problems such as structural failure, economic loss, construction delay and safety risks.

[0003] Because the annular space between the steel casing and the steel pipe pile contains seawater and is very confined, direct dry sealing is not feasible. Furthermore, underwater grouting starting from the bottom of the annulus, followed by upward jacking to drain the water, presents significant technical challenges and risks due to the high grouting pressure and the difficulty of grouting to the top in a single operation. Any grout leakage would result in substantial losses. Therefore, developing a convenient, reliable, and economical grouting sealing method is essential. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-sealing construction method for underwater grouting. By sealing different locations in different sequences, the resulting sealing component includes both passive and active sealing. This allows seawater to be squeezed out under high pressure or high grouting intensity, thereby improving the operability of grouting and saving costs.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0006] A double-sealing construction method for underwater grouting includes the following steps:

[0007] Construction of the upper sealing space: A fixing plate is used to form an upper sealing space between the steel pipe sleeve and the steel pipe pile. The upper sealing space is partially connected with the grouting space above it, and the cross-sectional area of ​​the connection is smaller than the cross-sectional area of ​​the sealing part of the upper sealing space.

[0008] Assembly of the upper sealing device: An upper sealing device is assembled in the upper sealing space. The upper sealing device is connected to an air inlet, and the upper sealing device actively achieves sealing when in operation.

[0009] Assembly of the lower sealing space: A bottom sealing support plate is set in the circumferential direction between the steel pipe sleeve and the steel pipe pile, and the bottom sealing support plate and the bottom of the upper sealing space form the lower sealing space;

[0010] Assembly of the lower passive sealing device: The lower passive sealing device is fixed by counter-pressure on the bottom sealing plate, and the passive sealing device is in contact with the outer wall of the steel pipe pile.

[0011] In this invention, the upper layer is adjacent to the grouting construction location, so its sealing requirements are relatively strict. Therefore, an air inlet is added, and the sealing performance of the sealing space is improved by adjusting the air pressure, thereby achieving an adjustable seal and ensuring the pressure resistance during grouting.

[0012] In this invention, a passive sealing device is selected during the lower-level construction, which can directly achieve sealing without much intervention. At this time, the sealing is automatically generated and can be completed without any adjustment to block the outside world.

[0013] In this invention, the sealing location and sequence are fully considered during construction. Therefore, during long grouting, the upper sealing layer of this invention can be inflated with air. During sealing, air can be continuously inflated to increase the sealing performance and strength, thus achieving a reliable leak-proof effect.

[0014] As a further improvement of the present invention, in the construction of the upper sealing space, the fixing plate is an annular plate, the distance between the annular plate and the steel pipe pile is 30-70mm, and the side of the annular plate away from the steel pipe sleeve forms a smooth surface.

[0015] In this invention, a ring-shaped plate structure is selected to form a comprehensive enclosure and increase the connection distance, providing space for subsequent inflation and continuous adjustment of the upper sealing device. This allows for real-time changes in the sealing process, ensuring airtightness during grouting.

[0016] As a further improvement of the present invention, in the assembly of the upper sealing device in the above step, the upper sealing device is an airbag, and the airbag is connected to an air source through an inflation hole and an inflation pipe.

[0017] In this technical solution, an airbag is selected as the upper sealing device. The airbag has a certain pressure resistance, and as the air volume increases, its overall volume and pressure resistance will also change. Combined with the lower sealing device, the overall sealing performance is good and highly adjustable.

[0018] As a further improvement of the present invention, the airbag includes a working state and a non-working state. Under normal circumstances, it is in a non-working state and the airbag is in a deflated state. Before grouting, its working state is triggered, and the airbag is inflated to form an active sealing device that fills the space between the steel pipe sleeve and the steel pipe pile.

[0019] In this invention, the working mode of the airbag can be selected according to different states during construction. Especially before grouting, in order to facilitate the construction and installation of other components, the deflated state at this time occupies less volume, and there is more construction space when other components are constructed.

[0020] As a further improvement of the present invention, the working state is specifically as follows: the air source inflates the airbag through the air inflator and air inflator, and after the pressure reaches 1.5 times the grouting working pressure, the pressure is maintained for at least 30 minutes.

[0021] In this technical solution, there are certain limitations on the air pressure of the airbag. On the one hand, it is related to the grouting working pressure to ensure the sealing and pressure support resistance during grouting, thus ensuring smooth grouting. On the other hand, the pressure holding time and the corresponding pressure are set so that the pressure bearing range of the airbag can be warned in advance, ensuring the safety of the airbag during use.

[0022] As a further improvement of the present invention, in the working state, the airbag inflates and abuts against the steel pipe sleeve and the steel pipe pile.

[0023] In this technical solution, when in operation, the airbag inflates and presses against the outer periphery, filling the entire upper sealing space. This results in low cost and good sealing performance.

[0024] As a further improvement of the present invention, the lower passive sealing device is annular and fills the space between the steel pipe sleeve and the steel pipe pile to form a passive sealing device.

[0025] In this technical solution, the annular passive sealing device forms a filling layer between the steel pipe sleeve and the steel pipe pile along the bottom sealing plate. The resulting sealing structure has two layers, which provides better leakage prevention. The overall structure is simple and low in cost.

[0026] As a further improvement of the present invention, the passive sealing device forms a layered structure near the back pressure position and a ring-shaped structure with a closed space away from the back pressure position.

[0027] In this technical solution, the passive sealing device forms a layered structure, which has better compressive strength and sealing performance compared to a single layer. The ring-shaped structure formed on the side has a certain space while sealing, and it has a certain deformation during sealing to cooperate with the sealing.

[0028] As a further improvement of the present invention, the assembly of the lower-level passive sealing device in the step is specifically as follows:

[0029] Several counter-pressure bolts are fixedly connected along the circumference of the bottom support plate;

[0030] The mounting hole of the lower passive sealing device, which is composed of an annular sealing rubber ring, is inserted into the counter-pressure screw on the bottom plate, and the counter-pressure washer and counter-pressure nut are used to complete the fixed assembly on the counter-pressure screw.

[0031] In this technical solution, pressure gaskets are added to fix the side of the annular sealing rubber ring under pressure. Compared with bolt fixing alone, the assembly is more secure and the sealing effect is better. In conjunction with the subsequent fixing assembly, it ensures that it works with the upper sealing device to perform sealing.

[0032] As a further improvement of the present invention, the spacing between the plurality of the counter-pressure screws is 150-200mm, and the side of the bottom support plate facing the counter-pressure screws is a polished surface.

[0033] In this technical solution, a gap is formed between multiple counter-pressure screws, so that the entire lower sealing device forms a ring-shaped whole, thereby forming at least one continuous sealing layer along the entire sealing space, resulting in better performance. Attached Figure Description

[0034] Figure 1 A process flow diagram of a double-sealing construction method in underwater grouting provided by the present invention;

[0035] Figure 2 A schematic diagram of the passive blocking device provided by the present invention in its non-operating state;

[0036] Figure 3 This is a schematic diagram of the working state of the passive blocking device provided by the present invention;

[0037] In the picture:

[0038] 100. Sealing area; 110. Upper sealing space; 120. Lower sealing space; 200. Steel pipe pile; 300. Steel pipe sleeve; 400. Upper sealing device; 410. Inflation hole; 420. Inflation pipe; 430. Air source; 440. Fixing plate; 600. Bottom sealing support plate; 700. Passive sealing device; 710. Counter-pressure screw. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0040] First, let me give a general overview of the construction process of this invention.

[0041] See attached document Figure 1-3As shown, a double-sealing construction method for underwater grouting according to the present invention includes the following steps:

[0042] Construction of the upper sealing space: Between the steel pipe sleeve 300 and the steel pipe pile 100, the upper sealing space 110 is formed by using the fixing plate 440. The upper sealing space 110 is partially connected with the grouting space above it, and the cross-sectional area of ​​the connection is smaller than the cross-sectional area of ​​the sealing part of the upper sealing space 110.

[0043] Assembly of the upper sealing device 400: The upper sealing device 400 is assembled in the upper sealing space 110. The upper sealing device 400 is connected to an air inlet 410, and the upper sealing device 400 actively achieves sealing when in operation.

[0044] Assembly of the lower sealing space 120: A bottom sealing plate 600 is provided in the circumferential direction between the steel pipe sleeve 300 and the steel pipe pile 200. The lower sealing space 120 is formed between the bottom sealing plate 600 and the bottom of the upper sealing space 110.

[0045] Assembly of the lower passive sealing device: The lower passive sealing device 700 is fixed on the bottom sealing plate 600 by counter-pressure, and the passive sealing device 700 is in contact with the outer wall of the steel pipe pile 200.

[0046] In this invention, the upper layer is adjacent to the grouting construction location, so its sealing requirements are relatively strict. Therefore, an air inlet is added, and the sealing performance of the sealing space is improved by adjusting the air pressure, thereby achieving an adjustable seal and ensuring the pressure resistance during grouting.

[0047] In this invention, a passive sealing device is selected during the lower-level construction, which can directly achieve sealing without much intervention. At this time, the sealing is automatically generated and can be completed without any adjustment to block the outside world.

[0048] In this invention, the sealing location and sequence are fully considered during construction. Therefore, during long grouting, the upper sealing layer of this invention can be inflated with air. During sealing, air can be continuously inflated to increase the sealing performance and strength, thus achieving a reliable leak-proof effect.

[0049] In this invention, the construction method, compared to other existing methods, fully considers the compressive strength and effectiveness at different locations. Therefore, selective adjustments and choices of sealing components at different locations ensure the sealing of the steel casing and steel pipe pile. This not only accommodates a portion of seawater but also achieves bottom sealing within the confined space. Throughout the construction process, grouting begins underwater from the bottom of the annulus, upwards to drain the accumulated water within the annulus. The grouting pressure is high, allowing for a single, continuous grouting process to the top. The grouting seal is excellent, minimizing leakage and avoiding the risk of significant losses.

[0050] Secondly, the construction method of this invention will be described in detail.

[0051] 1) Targeting upper-level sealing

[0052] In this invention, the upper sealing layer is an active sealing component. During assembly, it is primarily assembled after the steel sleeve of the guide frame is processed. The specific process is as follows: First, the active sealing component (i.e., the upper sealing device 400) is fabricated and installed. Firstly, protective ring plates are fabricated. The steel plate (i.e., the fixing plate 440) is 16mm-18mm thick, made of Q345B or higher material. Each sleeve contains two protective ring plates (also part of the fixing plate 440). The inner edge of the ring plate should be smoothly ground without burrs, while the outer edge should have a welding bevel. The width of the protective ring plate (the entire fixing plate 440) is the width of the annular opening minus 50mm. After the protective ring plates are processed, the upper protective ring plate is welded and installed first, followed by the lower protective ring plate. The outer end of the protective ring plate is welded to the inner wall of the steel sleeve; the weld should be smoothly ground without burrs. The net distance between the upper and lower protective ring plates is 200mm.

[0053] In this invention, during construction, the upper sealing device is located in a space with two layers, namely, a fixing plate formed by two annular plates set close to the steel pipe sleeve along different height directions. The space between the two fixing plates is the upper sealing space. The distance between the annular plate and the steel pipe pile 200 is 30-70mm. The side of the annular plate away from the steel pipe sleeve 300 forms a smooth surface.

[0054] In this invention, a ring-shaped plate structure is selected to form a comprehensive enclosure and increase the connection distance, providing space for subsequent inflation and continuous adjustment of the upper sealing device. This allows for real-time adjustments during the sealing process, ensuring a tight seal during grouting. During construction, the assembly of the sealing components needs careful consideration. Therefore, the locations where the sealing device is laid on the fixing plate are treated to reduce sharp edges and prevent friction during assembly. The increased distance is 30-70mm. If the gap is too small, the filling area after the airbag inflates will be too small. The airbag, being elastic, provides a better sealing effect than the fixing plate. A gap smaller than 30mm prevents it from fully utilizing its function, while a gap larger than 70mm results in insufficient space on the fixing plate and a small bearing area. Even if the airbag inflates to form a large sealing space, the weak bottom support can easily cause the fixing plate to break during grouting.

[0055] In order to fully control the active blocking of the upper layer, in the assembly of the upper blocking device in the above step, the upper blocking device 400 is an airbag, and the airbag is connected to an air source 430 through an inflation hole 410 and an inflation pipe 420.

[0056] In this invention, an airbag is selected as the upper sealing device. The airbag has a certain pressure resistance, and as the air volume increases, its overall volume and pressure resistance will also change. Combined with the lower sealing device, the overall sealing performance is good and highly adjustable.

[0057] In actual use, the airbag has a working state and a non-working state. Under normal circumstances, it is in a non-working state and the airbag is in a deflated state. Before grouting, its working state is triggered, and the airbag is inflated to form an active sealing device that fills the space between the steel pipe sleeve and the steel pipe pile.

[0058] In this invention, the working mode of the airbag can be selected according to different states during construction. Especially before grouting, in order to facilitate the construction and installation of other components, the deflated state at this time occupies less volume, and there is more construction space when other components are constructed.

[0059] During control, the specific working state is as follows: the air source 430 inflates the airbag through the air inflator 420 and the air inflator 410, and after the pressure reaches 1.5 times the grouting working pressure, the pressure is maintained for at least 30 minutes.

[0060] In this invention, the air pressure of the airbag is subject to certain limitations. On the one hand, it is related to the grouting working pressure to ensure the sealing and pressure support resistance during grouting, thus ensuring smooth grouting. On the other hand, the pressure holding time and corresponding pressure are set so that the pressure bearing range of the airbag can be warned in advance, ensuring the safety of the airbag during use.

[0061] In order to achieve a good seal, in the working state, the airbag inflates and abuts against the steel pipe sleeve 300 and the steel pipe pile 200.

[0062] In this invention, when in operation, the inflated airbag abuts against the outer periphery, filling the entire upper sealing space. This results in low cost and excellent sealing performance. The airbag's abutment against the outer periphery effectively fills the space between the steel pipe pile and the steel pipe sleeve, forming a complete seal. There are no gaps or voids, preventing grout from leaking out.

[0063] 2) Introduction to the lower-level passive sealing device

[0064] Specifically, the lower passive sealing device 700 is annular and fills the space between the steel pipe sleeve 300 and the steel pipe pile 200 to form a passive sealing device.

[0065] In this embodiment, the annular passive sealing device forms a filling layer between the steel pipe sleeve and the steel pipe pile along the bottom sealing plate. The resulting sealing structure has two layers, which provides better leakage prevention, while the overall structure is simple and low in cost.

[0066] Furthermore, during assembly, the passive sealing device 700 forms a stacked structure near the back pressure position and a ring-shaped structure with a closed space away from the back pressure position.

[0067] In this invention, the passive sealing device forms a layered structure, which has better compressive strength and sealing performance compared to a single layer. The ring-shaped structure formed on the side has a certain space while sealing, and it has a certain deformation during sealing to cooperate with the sealing.

[0068] During construction, the assembly of the lower-level passive sealing device 700 in the aforementioned steps is specifically as follows:

[0069] Several counter-pressure screws 710 are fixedly connected along the circumference of the bottom support plate 600;

[0070] The mounting hole of the lower passive sealing device, which is composed of an annular sealing rubber ring, is fitted onto the counter-pressure screw 710 on the bottom sealing plate, and the counter-pressure washer and counter-pressure nut are used to complete the fixed assembly on the counter-pressure screw.

[0071] In this invention, pressure pads and the like are added so that the side of the annular sealing rubber ring is fixed by pressure. Compared with the fixation of bolts alone, the assembly is more secure and the sealing effect is better. In conjunction with the subsequent fixing assembly, it ensures that it works with the upper sealing device to perform the sealing.

[0072] To achieve integration, the spacing between the various counter-pressure screws is 150-200mm, and the side of the bottom support plate facing the counter-pressure screws is a polished surface.

[0073] In this invention, a gap is formed between multiple counter-pressure screws, so that the entire lower sealing device forms a ring-shaped whole, thereby forming at least one continuous sealing layer along the entire sealing space, resulting in better performance.

[0074] In this invention, during the assembly of the passive sealing device 700, the sequence is that the passive sealing device 700 is manufactured and installed after the active sealing device (i.e., the upper sealing device 400) is completed. First, the bottom sealing ring plate (i.e., the bottom sealing support plate 600) is manufactured. The steel plate thickness is 16mm-18mm, and the material is Q345B or higher. There is one protective ring plate in each sleeve. The inner edge of the bottom sealing ring plate should be polished smoothly without burrs, while the outer edge should be provided with a welding bevel. The bottom of the counter-pressure bolt 710 is welded to the upper surface of the bottom sealing ring plate, with a spacing of 150mm in the original circumferential direction. The width of the bottom sealing ring plate is the width of the annular opening minus 50mm. After the bottom sealing ring plate is processed, it is welded to the inner wall of the steel casing, with the bottom of the bottom sealing ring plate flush with the bottom of the steel casing; the weld should be ground smooth and free of burrs; the net distance between the bottom sealing ring plate and the lower protective ring plate of the upper sealing device 400 is 200mm; the bottom sealing support plate 600 should be treated with anti-corrosion measures.

[0075] Then install the sealing rubber ring; the sealing rubber ring is a hollow ring structure made of a 10mm thick and 400mm wide rubber sheet folded in half, which has a suitable deformation adaptability; the sealing rubber ring is installed above the bottom sealing ring plate, and the rubber ring is fixed to the bottom sealing ring plate by the counter-pressure bolt. The screw hole on the rubber ring is elliptical, so that the counter-pressure bolt and the rubber ring have an adjustment space of 20mm in the diameter direction.

[0076] Finally, a detailed description of the invention will be given using specific practical applications as examples.

[0077] After the main steel structure of the jacket or berthing component is completed, the installation of the plug and pipeline begins. In this invention, the entire plugging area 100 includes two spatial areas: the upper plugging space 110 and the lower plugging space 120.

[0078] The construction process is as follows: welding and installing the upper protective ring plate (i.e., the upper fixing plate 440) → opening holes in the steel sleeve wall → welding and installing the lower protective ring plate (i.e., the lower fixing plate 440) → welding the bottom support plate (i.e., the bottom sealing support plate 600) → installing the airbag (i.e., the upper sealing device 400) → installing the inflation pipe 420 (the air inlet, valve, and pipe are pre-assembled into one unit) → installing the sealing rubber ring (i.e., the passive sealing device 700) → inflation and debugging (the air needs to be released after debugging) → the substation jacket foundation is installed at sea → inserting the steel pipe piles from the top of the jacket into the sleeve of the jacket from top to bottom → driving the piles to the design elevation and completing temporary fixing → inflating the airbag to form a closed grouting space → grouting construction.

[0079] The specific steps described above are as follows:

[0080] (1) Weld the upper protective ring plate to the inner wall of the steel sleeve and complete the grinding and polishing process.

[0081] (2) A 22mm round hole is made on the steel sleeve 100mm below the upper protective ring plate, and the hole is ground and polished.

[0082] (3) Weld the lower protective ring plate to the inner wall of the steel sleeve and complete the grinding and polishing process.

[0083] (4) Weld and install counter-pressure screws evenly along the circumference of the bottom support plate at intervals of 150mm; weld and fix the bottom support plate to the inner wall of the steel sleeve, with the bottom of the support plate flush with the bottom of the steel sleeve, and complete the grinding and polishing process.

[0084] (5) Install the airbag, let the air delivery tube of the airbag pass through the round hole on the steel sleeve. After the airbag is installed in place, spot weld the air delivery tube and then use sealant to seal the gap between the air delivery tube and the round hole.

[0085] (6) Assemble the air nozzle, air stop valve, and inflation steel pipe to form an inflation pipeline and complete the airtightness test; the inflation pipe is fixed to the outer wall of the steel sleeve by steel supports, that is, one end of the steel support is welded to the outer wall of the steel sleeve, and the other end is provided with a guide pipe. The inflation pipe passes through the guide pipe to complete the sleeve fixation; the vertical spacing of the steel supports is 1.5m, and the diameter of the inflation pipe is 20mm. The lower end of the inflation pipe is threaded to the adapter valve at the end of the airbag delivery pipe, and an air stop rubber gasket is provided at the connection.

[0086] (7) Align the mounting hole on the annular sealing rubber ring with the counter-pressure screw on the bottom support plate and insert it. Then use the counter-pressure washer and counter-pressure nut to fix the sealing rubber ring.

[0087] (8) Connect the air compressor pipe to the air inlet at the top of the inflation pipe, open the air stop valve on the inflation pipe, and use the air compressor to inflate the airbag until the pressure reaches 4.5 MPa (the maximum working pressure for grouting is 3 MPa, and the coefficient is 1.5 times); maintain the pressure for 30 minutes, and if the air pressure does not drop, the airtightness of the surface inflation system is intact.

[0088] Specifically, the upper sealing device 400 also includes airbag installation and inflation testing: after the passive sealing device 700 is assembled, the airbag in the upper sealing device 400 is installed. The airbag consists of a rubber airbag, an inflation nozzle, an air supply pipe, and a conversion valve (custom-made). The airbag is installed between the upper and lower protective ring plates. The inflation nozzle is fixed to the airbag (similar to the principle of a tire). One end of the air supply pipe is connected to the inflation nozzle, and the other end is equipped with a conversion valve. The air supply pipe passes through a steel sleeve and connects to the external inflation pipe (threaded joint). The inflation pipe is led vertically upwards along the outer wall of the steel sleeve to a position approximately 2.5m above the designed high water level. A horizontal bend is installed at the top of the inflation pipe (20mm in diameter), with a stop valve on the horizontal bend and an air inlet at the end of the horizontal bend. After the airbag is installed, it should be inflated for an airtightness test, and a passive sealing rubber ring fit test should also be performed.

[0089] In this embodiment, the specific testing and debugging are as follows: After the sealing device is installed, a steel cylinder with the same diameter as the inserted steel pipe pile and a height of 1.5m is inserted into the steel sleeve of the guide frame for airtightness and fit tests. First, check the fit between the passive sealing rubber ring and the steel cylinder. If there are gaps, adjust the counter-pressure bolts appropriately, and then adjust the radial position of the rubber ring so that the rubber ring fits tightly against the steel cylinder. The second step is to conduct an airtightness test on the active sealing device; connect the air inlet to the air compressor, open the stop valve, and let the air compressor inflate the airbag through the inflation pipe. The inflation pressure should reach the design requirements; check the tightness between the airbag and the steel cylinder to ensure that it fits tightly against the steel cylinder; maintain the pressure for 30 minutes. If the pressure does not drop, it proves that the airtightness meets the requirements.

[0090] (9) Connect the air compressor hose to the air inlet at the top of the inflation pipe, open the air stop valve on the inflation pipe, and use the air compressor to inflate the airbag, pressing it tightly against the outer wall of the steel pipe pile until the pressure reaches 4.5 MPa (the maximum grouting working pressure is 3 MPa, with a coefficient of 1.5). The inflated airbag serves as the first sealing device at the bottom of the grouting area. Maintain the pressure for 30 minutes; if the air pressure does not drop, the surface inflation system is airtight. After passing the test, release the air from the airbag, allowing it to retract into the space between the upper and lower protective ring plates to prevent damage to the airbag when inserting the steel pipe pile.

[0091] (10) The foundation of the booster station jacket is installed in the sea using a crane vessel, with its bottom resting on the seabed and leveled. Steel pipe piles are inserted into the jacket casing from top to bottom, and then a hydraulic hammer is used to drive the steel pipe piles to the design elevation and temporarily fix them. The rubber ring of the lower passive sealing device will be tightly attached to the outer wall of the steel pipe pile, forming the first layer of sealing.

[0092] (11) Inflate the airbag to make it expand and fit tightly against the outer wall of the steel pipe pile; when the air pressure reaches 4.5 MPa, close the air stop valve to form a second seal, thereby forming a closed grouting space.

[0093] (12) Connect the grouting pipe to the grouting machine and carry out grouting construction. The grouting pressure shall not exceed 3 MPa.

[0094] In the early stages of my country's offshore wind power development, the sealing technology mainly relied on foreign passive sealing devices and technologies. Imported sealing devices were expensive and had long procurement cycles. Single-layer sealing also carried a certain risk of grout leakage, which could cause significant losses. The dual-sealing technology provided by this invention patent is suitable for grouting construction in deep water environments up to 50 meters deep. It has the advantages of simple manufacturing, convenient construction, dual protection, reliable leak prevention, and economic rationality.

[0095] This sealing technology can also be used in almost all underwater grouting projects, such as underwater grouting construction of berthing facilities for offshore wind power high-pile foundations and grouting construction of offshore oil and gas platform foundations, and has broad application prospects.

[0096] The beneficial effects of this invention are as follows:

[0097] 1. Dual sealing can reduce the risk of grout leakage. When the upper active sealing device leaks grout unexpectedly, the lower sealing device can also play a role in stopping the grout leakage.

[0098] 2. The main component of this patent that performs the grout-stopping function is the upper active plugging device, which is also the first device to perform the plugging action. The lower plugging device will only come into play when grout leakage occurs in the upper active plugging device; in other words, the lower plugging device is a backup plugging device.

[0099] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

[0100] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0101] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A double-sealing construction method for underwater grouting, characterized in that, Includes the following steps: Construction of the upper sealing space: A fixing plate is used to form an upper sealing space between the steel pipe sleeve and the steel pipe pile. The upper sealing space is partially connected with the grouting space above it, and the cross-sectional area of ​​the connection is smaller than the cross-sectional area of ​​the sealing part of the upper sealing space. Assembly of the upper sealing device: An upper sealing device is assembled in the upper sealing space. The upper sealing device is connected to an air inlet, and the upper sealing device actively achieves sealing when in operation. Assembly of the lower sealing space: A bottom sealing plate is set in the circumferential direction between the steel pipe sleeve and the steel pipe pile, and the bottom sealing plate and the bottom of the upper sealing space form the lower sealing space; Assembly of the lower passive sealing device: The lower passive sealing device is fixed by counter-pressure on the bottom sealing plate, and the passive sealing device is in contact with the outer wall of the steel pipe pile; During the construction of the upper sealing space, the fixing plate is an annular plate, the distance between the annular plate and the steel pipe pile is 30-70mm, and the side of the annular plate away from the steel pipe sleeve forms a smooth surface. In the assembly of the upper sealing device in the above step, the upper sealing device is an airbag, and the airbag is connected to an air source through an inflation hole and an inflation pipe. The airbag has a working state and a non-working state. Under normal circumstances, it is in a non-working state and the airbag is in a deflated state. Before grouting, its working state is triggered and the airbag is inflated to form an active sealing device that fills the space between the steel pipe sleeve and the steel pipe pile. The passive sealing device is annular and fills the space between the steel pipe sleeve and the steel pipe pile; The passive sealing device forms a layered structure near the back pressure position and a ring-shaped structure with a closed space away from the back pressure position. The assembly of the lower-level passive sealing device is specifically as follows: Several counter-pressure bolts are fixedly connected along the circumference of the bottom support plate; The mounting hole of the lower passive sealing device, which is composed of an annular sealing rubber ring, is inserted into the counter-pressure screw on the bottom plate, and the counter-pressure washer and counter-pressure nut are used to complete the fixed assembly on the counter-pressure screw.

2. The double-sealing construction method in underwater grouting according to claim 1, characterized in that, The specific working state is as follows: the air source inflates the airbag through the air inflator and air inflator, and after the pressure reaches 1.5 times the grouting working pressure, the pressure is maintained for at least 30 minutes.

3. The double-sealing construction method for underwater grouting according to claim 2, characterized in that, In the operating state, the airbag inflates and abuts against the steel pipe sleeve and the steel pipe pile.

4. The double-sealing construction method for underwater grouting according to claim 1, characterized in that, The spacing between the plurality of the counter-pressure screws is 150-200mm, and the side of the bottom support plate facing the counter-pressure screws is a polished surface.

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