Installation method of bucket foundation structure submarine out-boarding anchor block

Abstract

This invention provides a method for installing anchor blocks on a submerged barge under a barrel-type foundation structure, belonging to the technical field of anchor block installation. The method includes: Step 1: Prefabricating the anchor blocks; Step 2: Excavating a foundation pit for the anchor blocks; Step 3: Lowering the anchor blocks onto the barge; Step 4: Installing the anchor blocks; Step 5: Backfilling. This method effectively avoids the shortcomings of existing technologies, such as difficulty in positioning the anchor blocks during installation and the difficulty in controlling the direction of the fixed climbing boom on the crane vessel to ensure the anchor rings on the anchor blocks align with the anchor chain direction.

Description

Technical Field

[0001] This invention belongs to the field of anchor block installation and construction technology, specifically relating to an installation and construction method for anchor blocks of a barrel foundation structure that is submerged. Background Technology

[0002] The breakwater of the container terminal and its supporting facilities in the deep-water port area is often arranged parallel to the front line of the wharf. It often adopts a barrel foundation structure. Each structural unit consists of a foundation barrel and an upper caisson. A total of several barrel foundation units are arranged. The bottom is protected by interlocking concrete blocks and riprap from both sides of the barrel.

[0003] During the installation of the barrel foundation structure, when the semi-submersible barge is submerged out of the barrel, the barge may drift due to the surface water flow velocity exceeding 2.48 m / s. To ensure a smooth submersion, anchor blocks are installed in the submersion area, with anchor chains and anchor floats on the anchor blocks. The anchor floats of the two rise anchors of the semi-submersible barge are made of steel wire ropes to resist the rising tide.

[0004] In the existing technology for the installation of anchor blocks, there are gravity anchor blocks for barge mooring that are easy to install, as mentioned in the technical solution with patent publication number "CN218617069U". However, it is not suitable for the installation of anchor blocks for barges submerged under barrel foundation structures, mainly due to the following drawbacks: 1. Neither the anchor block nor the crane vessel was equipped with GPS, making positioning difficult during anchor block installation; 2. The anchor ring on the anchor block should face the same direction as the anchor chain. However, since the crane vessel has a fixed boom, it is difficult to control the direction to ensure that the anchor ring on the anchor block faces the same direction as the anchor chain. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for installing anchor blocks on a submerged barge under a barrel-type foundation structure. This method effectively avoids the difficulties in positioning the anchor blocks during installation and the difficulty in controlling the direction of the crane vessel's fixed climbing rod to ensure that the anchor rings on the anchor blocks are aligned with the direction of the anchor chain.

[0006] The present invention employs the following technical solution.

[0007] A method for installing anchor blocks under a barrel foundation structure, comprising: Step 1: Prefabricate the anchor blocks; Step 2: Excavate the foundation pit for the anchor blocks; Step 3: Deploy the anchor blocks; Step 4: Install the anchor blocks; Step 5: Backfill.

[0008] Furthermore, in step 1: The precast anchor blocks are cast in one go; All the reinforcing bars for the hooks of the prefabricated anchor blocks are made of HPB235 steel; The corrosion protection range of the precast anchor block embedded parts is from 100mm into the concrete to all surfaces exposed outside the concrete; the corrosion protection treatment of the embedded parts is: after rust removal, a 40um thick zinc-rich primer is applied, followed by a 280um thick blue polyurethane topcoat, while the pull ring embedded parts are galvanized.

[0009] Furthermore, in step 2: After the grab vessel enters the construction area, the bow of the grab vessel faces east and the stern faces west. The grab vessel uses anchoring rods to deploy one anchor on the left bow and one on the right bow, which are deployed in a figure-eight pattern to achieve anchoring. After anchoring, the grab vessel is precisely positioned using the GPS system. The grab vessel's own anchor winch is used to raise and lower the cables to adjust the vessel's position, so that the grab vessel is on the excavation centerline and the grab is in the starting position, and then excavation begins. The undisturbed mud excavated during excavation is placed on both sides of the foundation pit for backfilling the foundation pit used for anchor blocks.

[0010] Furthermore, in step 3: The anchor blocks are transported to the semi-submersible barge using modular vehicles, and then transported to the construction site by the semi-submersible barge. The modular vehicle arrives at the dock before low tide. When the semi-submersible barge docks, the ship's ballast adjustment is completed simultaneously. The stern deck of the semi-submersible barge overlaps with the dock and is 5-10cm higher than the dock surface. The overlap between the stern deck and the dock is covered with a 2.5cm steel plate. The semi-submersible barge tilts its bow. The draft of the bow of the semi-submersible barge is 0.5m-1m greater than the draft of the stern. Once the semi-submersible barge is docked, the transport modular vehicles begin to drive onto it. Ballast is applied to the bow of the semi-submersible barge, and water is discharged from its stern. Based on the installation location of the anchor block, the anchor block is placed on the port side of the semi-submersible barge, that is, one side of the anchor block rests on the steel support pier of the original barrel foundation structure, and the other side of the anchor block rests on the concrete support pier. After the anchor blocks are lowered, they are secured with cables from the existing barrel-type foundation structure.

[0011] Furthermore, step 4 specifically includes: Step 4-1: Install the anchor chain; Step 4-2: Semi-submersible barge approach point; Step 4-3: Crane vessel enters the designated location; Step 4-4: Execute the hook; Steps 4-5: Measurement and positioning; Steps 4-6: Perform the installation.

[0012] Further, in step 4-1: The anchor chains were transported from the temporary dock to the semi-submersible barge via a transport barge at the steel reinforcement processing plant at the temporary dock. Before the anchor block is lowered, the semi-submersible barge crane is used in conjunction with the workers to install the anchor chain. One end of the anchor chain is tied to the anchor ring, and the other end of the anchor chain is connected to one end of a 52mm diameter steel wire rope with a buckle. The other end of the 52mm diameter steel wire rope is connected to the anchor float steel wire rope.

[0013] Furthermore, in step 4-2: The semi-submersible barge enters the submersion area with its bow facing east and its bow facing downstream. After arriving at the site, it is located at the submersion position under the guidance of the ship's GPS. First, the anchor boat drops one chain anchor, and then two main anchor cables are dropped.

[0014] Furthermore, in step 4-3: After the semi-submersible barge is in place, the crane vessel is then positioned. The crane vessel is arranged perpendicular to the semi-submersible barge on the upstream side. The front and rear side anchors of the crane vessel are both figure-eight anchors, and front and rear core-pulling cables are deployed.

[0015] Furthermore, in step 4-4: After the crane vessel is in position, the crane vessel's winch is moved to the semi-submersible barge. The crane vessel adjusts the boom angle and aligns the hook with the anchor block. Workers climb up the top of the anchor block using a ladder to first contact the reinforcing cable, and then connect the anchor block's lifting ring to the sling. At the same time, the other end of the anchor chain is connected to the crane vessel's auxiliary hook. The auxiliary hook of the crane vessel is raised first to raise the anchor chain, and then the lifting force of the main hook is increased to 2× (50~100t).

[0016] Furthermore, in steps 4-5: The surveyor, holding a handheld GPS, stood at the bow of the crane ship to indicate the direction for the crane ship to move its anchor. When there were still 50 meters left to the installation position, the transport ship took the surveyor to the anchor block surface for precise positioning.

[0017] Furthermore, in steps 4-6: Using a semi-submersible barge as a reference, the orientation of the anchor ring is controlled by adjusting the direction of the crane vessel; Once the anchor block position is set, the crane vessel simultaneously releases both hooks and strictly adjusts the angle according to the 5m interval between anchor blocks. When lowering the anchor block, the anchor winch controls the anchor chain, releasing the hooks and lowering the anchor chain simultaneously. Before entering the water, check whether the axis of the anchor ring is accurate. Finally, the float was attached, the anchor light was installed, and the markings were made to complete the installation. At low tide, the divers went underwater to untie the mooring line.

[0018] Furthermore, in step 5: The dredger re-enters the anchor block position based on the latitude and longitude of the excavation, and backfills the original mud from both sides of the pit to the elevation.

[0019] Furthermore, the anchor block is a frog-shaped reinforced concrete structure; one anchor ring and four hooks are pre-embedded in the anchor block, the exposed length of the anchor ring is 0.65m, the exposed part is coated with epoxy asphalt paint twice, the hooks are pre-embedded into the anchor block 3m, the exposed length is 0.695m; after the anchor block 1 is installed, it is backfilled with natural soil.

[0020] Furthermore, the anchor blocks are connected by anchor chains. One end of the anchor chain is connected to the anchor ring on the anchor block, and the other end of the anchor chain is connected to the wire rope. A section of wire rope with a float attached is attached to the outside of the wire rope. The anchor blocks are arranged in the same direction as the center line of the anchor chain wire rope of the floating vessel. When the anchor blocks are buried, the direction of the anchor ring is on the same straight line as the anchor chain.

[0021] The beneficial effects of the present invention are as follows, compared with the prior art: The surveyor first uses a handheld GPS to perform preliminary positioning at the bow of the crane vessel. Once near the installation area, the onboard surveyor precisely positions the anchor block structure. By dropping anchor, the orientation of the crane vessel's bow is controlled to ensure that the anchor ring's orientation is consistent with the anchor chain's direction. Attached Figure Description

[0022] Figure 1 This is a plan view of the anchor block in the installation and construction method of the anchor block of the submerged barge under the barrel foundation structure in this invention.

[0023] Figure 2 This is a schematic elevation view of the anchor block in the installation and construction method of the anchor block of the barrel foundation structure in this invention.

[0024] Figure 3 This is a flowchart of the installation and construction method of the anchor block that is submerged under the barrel foundation structure in this invention.

[0025] The reference numerals are: 1. Anchor block, 2. Anchor ring, 3. Hook. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0027] like Figures 1 to 3 As shown, a method for installing anchor blocks under a barrel foundation structure includes: The reinforced concrete anchor blocks of this invention are prefabricated at the offshore engineering base and transported to the construction site by a semi-submersible barge. Anchor block installation requires first excavating a foundation pit, then placing the anchor blocks on a crane vessel, and finally backfilling with natural mud to the required elevation to form an effective cover. The specific steps are as follows: Step 1: Prefabricate the anchor blocks; In a preferred but non-limiting embodiment of the present invention, in step 1: (1) The cement, sand, water, aggregates and admixtures used in the precast concrete for anchor blocks must meet the specific specifications. In addition to having a factory certificate, sampling inspections should be conducted based on the batch size upon arrival. Unqualified concrete and expired cement must not be used. All admixtures and their dosages shall be in accordance with the technical requirements and relevant regulations for concrete, and samples shall be taken for testing at any time. Unqualified materials must not be used.

[0028] (2) The fabrication of precast anchor blocks shall be carried out in strict accordance with the technical requirements of the relevant provisions of the current port engineering technical specifications.

[0029] (3) The precast anchor blocks should be poured in one go without construction joints. The concrete strength must meet the installation requirements and be accurately placed after inspection and approval. (4) All hook reinforcement bars in the prefabricated components of the prefabricated anchor blocks shall be made of HPB235 steel and shall not be cold-drawn steel bars. Cold bending shall not be used during the fabrication process. (5) The corrosion protection range of the precast anchor block embedded parts is from 100mm into the concrete to all surfaces exposed outside the concrete; the general corrosion protection treatment of embedded parts is: after rust removal, apply zinc-rich primer with a thickness of 40um and blue polyurethane topcoat with a thickness of 280um, while the pull ring embedded parts should be galvanized.

[0030] Step 2: Excavate the foundation pit for the anchor blocks; In a preferred but non-limiting embodiment of the present invention, in step 2: After the grab vessel enters the construction area, its bow faces east and its stern faces west. The grab vessel uses anchoring rods to deploy one anchor on the left bow and one on the right bow, arranged in a figure-eight pattern to achieve anchoring. The length of the anchor cable is determined according to the location of the construction area and the water depth.

[0031] After anchoring, the grab vessel is precisely positioned using the GPS system. The grab vessel's own anchor winch is used to raise and lower the cables to adjust the vessel's position, so that the grab vessel is on the excavation centerline and the grab is in the starting position, and then excavation begins. The undisturbed mud excavated during excavation is placed on both sides of the foundation pit for backfilling the foundation pit used for anchor blocks.

[0032] For example, if there are two anchor blocks, namely anchor block one and anchor block two, the foundation pit for anchor block one has a bottom width of 15m, a height of 5m, and a length of 15m; the foundation pit for anchor block two has a bottom width of 15m, a height of 6m, and a length of 15m. Both are excavated with slopes at a ratio of 1:2, and the total excavation volume is (3292m³ + 4662m³) = 7954m³.

[0033] Step 3: Deploy the anchor blocks; In a preferred but non-limiting embodiment of the present invention, in step 3: The anchor blocks are transported to the semi-submersible barge by modular vehicles, and then transported to the construction site by the semi-submersible barge. The semi-submersible barge is a Sanhanggong 5, with a length of 100m, a width of 40m, a depth of 7m, a design draft of 5m, and an empty draft of 3.3m. The modular vehicle, with a width of 2.43m, is used for transportation. The modular vehicle of this invention utilizes one power module unit (PPU).

[0034] The modular vehicle arrives at the dock before low tide. Ballast adjustments are completed simultaneously with the semi-submersible barge berthing. The stern deck of the semi-submersible barge overlaps with the dock and is 5-10cm higher than the dock surface. A 2.5cm steel plate covers the overlap between the stern deck and the dock to protect the modular vehicle tires and prevent the seams from widening. The semi-submersible barge is slightly bowed, and its bow draft is 0.5m-1m greater than its stern draft. Once the semi-submersible barge is docked, the transport modular vehicles begin to drive onto it. Ballast is applied to the bow of the semi-submersible barge, and water is discharged from its stern. Based on the anchor block installation location, the anchor blocks are placed on the port side of the semi-submersible barge. One side of the anchor block rests on the existing steel piers of the barrel foundation structure, and the other side rests on concrete piers (prefabricated concrete piers for the anchor blocks). The concrete piers are installed using a forklift, with two concrete piers for each anchor block, for a total of four. The steel piers are 1.3m high, and the concrete piers are 1.2m high. 10cm rubber pads are placed on the concrete piers for leveling. After the anchor blocks are lowered, they are secured with cables from the existing barrel-type foundation structure.

[0035] Step 4: Install the anchor blocks; The anchor block of the present invention is installed by the "Qinhanggong 66" crane vessel, which lifts the anchor block at a 65° angle.

[0036] In a preferred but non-limiting embodiment of the present invention, step 4 specifically includes: Step 4-1: Install the anchor chain; In a preferred but non-limiting embodiment of the present invention, in step 4-1: Currently, the anchor chain is at the steel reinforcement processing plant at the temporary dock, and will be transported from the temporary dock to the semi-submersible barge via a transport barge. Before the anchor block is lowered, the anchor chain is installed using a semi-submersible barge crane in coordination with workers. One end of the anchor chain is attached to the anchor ring, and the other end is connected to one end of a 52mm diameter steel wire rope using a clip. The other end of the 52mm diameter steel wire rope is connected to the anchor float wire rope. The nominal specifications of the anchor chain are d=60mm, AM3 grade, 27.5m long, 52mm diameter, the steel wire rope is 25m long and 30mm diameter, and the anchor float wire rope is 40m long.

[0037] Step 4-2: Semi-submersible barge approach point; In a preferred but non-limiting embodiment of the present invention, in step 4-2: The semi-submersible barge faces east and slowly enters the submersible area as the water rises. The barge's bow faces downstream. After arriving at the site, it is positioned at the submersible location under the guidance of the ship's GPS. First, the anchor boat drops one chain anchor, and then two bow main anchor cables are dropped.

[0038] Step 4-3: Crane vessel enters the designated location; In a preferred but non-limiting embodiment of the present invention, in steps 4-3: After the semi-submersible barge is in place, the crane vessel is then positioned. The crane vessel is arranged perpendicular to the semi-submersible barge on the upstream side. The front and rear side anchors of the crane vessel are both figure-eight anchors, and front and rear core-pulling cables are deployed.

[0039] Step 4-4: Execute the hook; In a preferred but non-limiting embodiment of the present invention, in step 4-4: After the crane vessel is in position, the crane vessel's winch is slowly moved to the semi-submersible barge. The crane vessel adjusts the boom angle and aligns the hook with the anchor block. Workers climb up the top of the anchor block using ladders to first contact the reinforcing cable, and then connect the anchor block's lifting ring to the sling; at the same time, the other end of the anchor chain is connected to the crane vessel's auxiliary hook. The sling is 35m long, the deepest excavation depth is 6m, the mud surface elevation is -18.5m, 6m + 18.5 = 24.5m < 35m, the sling length meets the construction requirements.

[0040] The auxiliary hook of the crane vessel is raised first to raise the anchor chain, and then the lifting force of the main hook is gradually increased to 2× (50~100t).

[0041] Steps 4-5: Measurement and positioning; In a preferred but non-limiting embodiment of the present invention, in steps 4-5: The surveyor, holding a handheld GPS, stood at the bow of the crane ship to indicate the direction for the crane ship to move its anchor. When there were still 50 meters left to the installation position, the transport ship took the surveyor to the anchor block surface for precise positioning.

[0042] Steps 4-6: Perform the installation.

[0043] In a preferred but non-limiting embodiment of the present invention, in steps 4-6: Using a semi-submersible barge as a reference, the direction of the crane vessel is adjusted to control the orientation of the anchor ring, ensuring that the anchor ring is accurately aligned with the axis. Once the anchor block position is set, the crane vessel's two hooks are released simultaneously, and the angle is strictly adjusted according to the 5m interval between laying. When lowering the anchor block, the speed should be controlled, and the anchor winch controls the anchor chain. While releasing the hooks, the anchor chain is lowered, and the anchor chain should be lowered as straight as possible. Before entering the water, check whether the axis of the anchor ring is accurate. Finally, the float was attached, the anchor light was installed, and the markings were made to complete the installation. At low tide, the divers went underwater to untie the mooring line.

[0044] Step 5: Backfill.

[0045] In a preferred but non-limiting embodiment of the present invention, in step 5: The dredger re-enters the anchor block position based on the latitude and longitude of the excavation, and backfills the original mud from both sides of the pit to the elevation.

[0046] In a preferred but non-limiting embodiment of the present invention, the anchor block 1 is a frog-shaped reinforced concrete structure, 6.8m long, 5m wide, 3.6m high, and weighing approximately 173t; one anchor ring 2 and four hooks 3 are pre-embedded inside the anchor block 1, the exposed length of the anchor ring 2 is 0.65m, and the exposed part is coated with epoxy asphalt paint twice, the hooks 3 are pre-embedded 3m into the anchor block, and the exposed length is 0.695m; after the anchor block 1 is installed, it is backfilled with natural soil.

[0047] In a preferred but non-limiting embodiment of the present invention, the anchor block is connected by an anchor chain with a length of 27.5m. One end of the anchor chain is connected to the anchor ring on the anchor block, and the other end of the anchor chain is connected to a steel wire rope with a diameter of 52mm and a length of 25m. A section of steel wire rope with a float attached is attached to the outside of the steel wire rope. The direction of the anchor blocks should coincide with the center line of the anchor chain wire rope of the floating vessel. When the anchor blocks are buried, the direction of the anchor ring should be on the same straight line as the anchor chain.

[0048] Having the anchor ring aligned with the anchor chain has the following advantages: 1. Optimize force transmission efficiency: When the anchor ring and anchor chain are in the same direction, the twisting and lateral stress of the anchor chain under force can be reduced, so that the tension when the anchor grips the bottom can be transmitted to the anchor chain more evenly, reducing the risk of local wear.

[0049] 2. Maintain a horizontal anchor bolt: When the anchor chain is pulled in a straight line, the anchor bolt's elevation angle approaches zero, ensuring that the anchor claws fully grip the bottom and maximizing the anchor's holding power. This state also avoids a decrease in holding power due to an excessive elevation angle (e.g., the holding power may decrease by 50% at an elevation angle of 15°).

[0050] 3. Enhance compatibility with anchor winch sprockets: Anchor chain discs are often designed with alternating horizontal and vertical grooves. When the anchor ring direction is consistent with the anchor chain, special chain links such as Kent shackles can be stably embedded in the horizontal groove, avoiding loosening or jamming due to size mismatch, and improving the smoothness of anchoring and anchoring operations.

[0051] 4. Improve the overall stability of anchor chains: Straight-lined anchor chains lie flat on the seabed, cushioning the impact of external forces (such as wind, waves, and currents) on the ship through their own weight and friction, reducing the risk of dragging anchor.27 At the same time, the consistency of the anchor chain direction helps maintain the tensile strength of the mooring system and reduces the probability of breakage.

[0052] The beneficial effects of the present invention are as follows, compared with the prior art: The surveyor first uses a handheld GPS to perform preliminary positioning at the bow of the crane vessel. Once near the installation area, the onboard surveyor precisely positions the anchor block structure. By dropping anchor, the orientation of the crane vessel's bow is controlled to ensure that the anchor ring's orientation is consistent with the anchor chain's direction.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention without departing from the spirit and scope of the present invention. Any modifications or equivalent substitutions should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for installing anchor blocks under a barrel-type foundation structure, characterized in that, include: Step 1: Prefabricate the anchor blocks; Step 2: Excavate the foundation pit for the anchor blocks; Step 3: Deploy the anchor blocks; Step 4: Install the anchor blocks; Step 4 specifically includes: Step 4-1: Install the anchor chain; Step 4-2: Semi-submersible barge approach point; Step 4-3: Crane vessel enters the designated location; Step 4-4: Execute the hook; Steps 4-5: Measurement and positioning; In steps 4-5: The surveyor stands at the bow of the crane ship with a handheld GPS to indicate the direction for the crane ship to move its anchor. When there are still 50m left to the installation position, the transport ship takes the surveyor to the anchor block surface for precise positioning. Steps 4-6: Perform the installation; In steps 4-6: Using a semi-submersible barge as a reference, the orientation of the anchor ring is controlled by adjusting the direction of the crane vessel; Once the anchor block position is set, the crane vessel simultaneously releases both hooks and strictly adjusts the angle every 5 meters. When lowering the anchor block, the anchor winch controls the anchor chain, releasing the hooks and lowering the anchor chain simultaneously. Before entering the water, check whether the axis of the anchor ring is accurate. Finally, attach the buoy, install the anchor light, and mark the location to complete the installation. Once the tide is low, the divers will dive into the water to untie the cable underwater. Step 5: Backfill.

2. The installation and construction method for the anchor block submerged under the barrel foundation structure according to claim 1, characterized in that, In step 1: The precast anchor blocks are cast in one go; All the reinforcing bars for the hooks of the prefabricated anchor blocks are made of HPB235 steel; The corrosion protection range of the precast anchor block embedded parts is from 100mm into the concrete to all surfaces exposed outside the concrete; the corrosion protection treatment of the embedded parts is: after rust removal, a 40um thick zinc-rich primer is applied, followed by a 280um thick blue polyurethane topcoat, while the pull ring embedded parts are galvanized.

3. The installation and construction method for the anchor block submerged under the barrel foundation structure according to claim 2, characterized in that, In step 2: After the grab vessel enters the construction area, the bow of the grab vessel faces east and the stern faces west. The grab vessel uses anchoring rods to deploy one anchor on the left bow and one on the right bow, which are deployed in a figure-eight pattern to achieve anchoring. After anchoring, the grab vessel is precisely positioned using the GPS system. The grab vessel's own anchor winch is used to raise and lower the cables to adjust the vessel's position, so that the grab vessel is on the excavation centerline and the grab is in the starting position, and then excavation begins. The undisturbed mud excavated during excavation is placed on both sides of the foundation pit for backfilling the foundation pit used for anchor blocks.

4. The installation and construction method for the anchor block submerged under the barrel foundation structure according to claim 3, characterized in that, In step 3: The anchor blocks are transported to the semi-submersible barge using modular vehicles, and then transported to the construction site by the semi-submersible barge. The modular vehicle arrives at the dock before low tide. When the semi-submersible barge docks, the ship's ballast adjustment is completed simultaneously. The stern deck of the semi-submersible barge overlaps with the dock and is 5-10cm higher than the dock surface. The overlap between the stern deck and the dock is covered with a 2.5cm steel plate. The semi-submersible barge tilts its bow. The draft of the bow of the semi-submersible barge is 0.5m-1m greater than the draft of the stern. Once the semi-submersible barge is docked, the transport modular vehicles begin to drive onto it. Ballast is applied to the bow of the semi-submersible barge, and water is discharged from its stern. Based on the installation location of the anchor block, the anchor block is placed on the port side of the semi-submersible barge, that is, one side of the anchor block rests on the steel support pier of the original barrel foundation structure, and the other side of the anchor block rests on the concrete support pier. After the anchor blocks are lowered, they are secured with cables from the existing barrel-type foundation structure.

5. The installation and construction method for the anchor block submerged under the barrel foundation structure according to claim 4, characterized in that, In step 4-1: The anchor chains were transported from the temporary dock to the semi-submersible barge via a transport barge at the steel reinforcement processing plant at the temporary dock. Before the anchor block is lowered, the crane of the semi-submersible barge is used in conjunction with the workers to install the anchor chain. One end of the anchor chain is tied to the anchor ring, and the other end of the anchor chain is connected to one end of a 52mm diameter steel wire rope with a buckle. The other end of the 52mm diameter steel wire rope is connected to the anchor float steel wire rope. In step 4-2: The semi-submersible barge enters the submersion area with its bow facing east and its bow facing downstream. After arriving at the site, it is located at the submersion position under the guidance of the ship's GPS. First, the anchor boat drops one chain anchor, and then two main anchor cables are dropped.

6. The installation and construction method for the anchor block submerged under the barrel foundation structure according to claim 5, characterized in that, In step 4-3: After the semi-submersible barge is in place, the crane vessel is then positioned. The crane vessel is arranged perpendicular to the semi-submersible barge on the upstream side. The front and rear side anchors of the crane vessel are both figure-eight anchors, and front and rear core-pulling cables are deployed. In step 4-4: After the crane vessel is in position, the crane vessel's winch is moved to the semi-submersible barge. The crane vessel adjusts the boom angle and aligns the hook with the anchor block. Workers climb up the top of the anchor block using a ladder to first contact the reinforcing cable, and then connect the anchor block's lifting ring to the sling. At the same time, the other end of the anchor chain is connected to the crane vessel's auxiliary hook. The auxiliary hook of the crane vessel is raised first to raise the anchor chain, and then the lifting force of the main hook is increased to 2× (50~100t).

7. The installation and construction method for the anchor block submerged under the barrel foundation structure according to claim 6, characterized in that, In step 5: The dredger re-enters the anchor block position based on the latitude and longitude of the excavation, and backfills the original mud from both sides of the pit to the elevation.

8. The installation and construction method for the anchor block submerged under the barrel foundation structure according to claim 7, characterized in that, The anchor block is a frog-shaped reinforced concrete structure; one anchor ring and four hooks are pre-embedded in the anchor block, the exposed length of the anchor ring is 0.65m, and the exposed part is coated with two coats of epoxy asphalt paint, the hooks are pre-embedded 3m into the anchor block, and the exposed length is 0.695m; after the anchor block is installed, it is backfilled with natural soil.

9. The installation and construction method for the anchor block submerged under the barrel foundation structure according to claim 8, characterized in that, The anchor blocks are connected by anchor chains. One end of the anchor chain is connected to the anchor ring on the anchor block, and the other end of the anchor chain is connected to the wire rope. A section of wire rope with a float attached is attached to the outside of the wire rope. The anchor blocks are arranged in the same direction as the center line of the anchor chain wire rope of the floating vessel. When the anchor blocks are buried, the direction of the anchor ring is on the same straight line as the anchor chain.

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