Floating assisting method for long-distance floating transportation of large-scale steel open caisson in sea

Abstract

The invention provides a long-distance floating transportation and floating assisting method for a large steel open caisson in the sea, and belongs to the technical field of bridge construction, the steel open caisson is of a cuboid structure and is divided into field subgrids by partition walls, and in order to increase the buoyancy and reduce the immersion depth, floating assisting plates are adopted to seal the bottoms of the field subgrids. The immersion depth of the steel open caisson is reduced by adopting a floating assisting method, so that the steel open caisson smoothly passes through a dock and a channel shallow point and is remotely transported to a preset water area in a floating manner. The floating-assisting plate device and the bottom of the open caisson wall plate are horizontally arranged, or the floating-assisting plate device is lower than the bottom of the open caisson wall plate, the immersion depth of the steel open caisson is reduced, and the steel open caisson can be transported out of a dock or a channel shallow point in a floating mode under the lower water level condition and smoothly and remotely transported to a preset water area in a floating mode. And an arranged water inlet valve device can carry out automatic water feeding after reaching a designated place, so that the floating-assisting plate device automatically falls off, and the construction is more convenient.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a method for long-distance floating and buoyancy assistance of a large steel caisson in the sea. Background Art

[0002] With the continuous development of bridge foundation construction technology, bridge construction is increasingly developing in the direction of deep water and large span. As a representative of super-large span bridges, the number of suspension bridges built is increasing. Some anchors of offshore suspension bridges and cross-river suspension bridges are located in the water. At present, the more common underwater anchor foundation is the caisson foundation. The underwater caisson involves the floating and positioning of the caisson steel shell. Therefore, the floating and positioning of the caisson steel shell in the construction of such caisson steel shell becomes the focus and difficulty of the construction.

[0003] Since most caisson steel shells are relatively heavy and have a deep draft when self-floating, the requirements for the caisson's launching, docking and waterway are relatively high. Therefore, in most cases, flotation-aiding measures will be taken for the caisson to offset part of the gravity through buoyancy, maintain the caisson steel shell in a stable floating state during floating, and prevent the caisson steel shell from being difficult to float due to its excessive weight.

[0004] At present, the more common caisson flotation-aiding structure is to weld a bottom plate at the bottom or top of the wellbore, use dense welds to achieve water sealing of the wellbore, and generate buoyancy during floating. After the caisson steel shell is floated to the sinking position, the bottom plate welded at the bottom or top of the wellbore is usually removed by underwater cutting and dismantling. The underwater cutting construction of the bottom plate requires special underwater operators, and has high requirements on the water quality and transparency of the construction water area. The process is complicated and difficult, and it is easy to cause damage to the steel caisson structure, and the construction safety risk is high. Therefore, it is necessary to design a long-distance floating and flotation-aiding method for large steel caissons in the sea. Summary of the invention

[0005] The purpose of the present invention is to provide a method for long-distance floating and buoyancy assistance of a large steel caisson in the sea, so as to solve the technical problem that the existing steel caisson structure cannot be transported and cannot pass through a dock or shallow point in a waterway.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea, the method comprising the following steps:

[0008] Step 1: A detachable and sealed floating plate device is arranged at the bottom of the steel caisson, the bottom of which is level with or lower than the bottom of the steel caisson, so that the steel caisson can pass through a lower water level;

[0009] Step 2: Install a positioning device on the floating plate device, and install a water inlet valve device on the steel caisson and the floating plate device;

[0010] Step 3: After the installation of the floating board device is completed, a back pressure test should be carried out, that is, water is injected into the floating board device to check the water tightness of the floating board. After the water tightness is qualified, it is marked as qualified. After the steel caisson is fully assembled, a positive pressure test of the floating board is carried out;

[0011] Step 4: After the steel caisson is completed, water is poured into the dock, and then the steel caisson is towed to the construction waters using a towing device;

[0012] Step 5: Then open the water inlet valve device to allow seawater to enter the wellbore through the water inlet valve device. When the water levels inside and outside are consistent, the floating board device automatically falls off and falls into the sea. The coordinates of the floating board device are recorded, and then the floating board device is salvaged.

[0013] Furthermore, in step 1, the steel caisson is a rectangular structure, and a partition wall is set to divide the interior of the steel caisson into a field grid structure. The flotation plate device is set at the bottom of the field grid structure. The bottom of the flotation plate device is level with or lower than the bottom of the steel caisson, which effectively avoids the lowest end of the steel caisson from getting stuck. As long as it is calculated that the passing water area is deeper than the draft of the steel caisson, it can pass.

[0014] Furthermore, the buoyancy aid device comprises a main keel and a sealing plate, the main keel and the inner part of the caisson wall plate are detachably sealed, and the sealing plate and the bottom of the main keel are sealed.

[0015] Furthermore, the main keel is connected to the corbels arranged inside the caisson wall plate by bolts.

[0016] Furthermore, the main keel is configured as an I-beam, and pressure-bearing rubber and sealing rubber are provided between the top of the I-beam and the corbel, and the pressure-bearing rubber and sealing rubber are provided on the outside of the bolt.

[0017] Furthermore, the sealing rubber is arranged on the outer side of the pressure-bearing rubber, and the height of the pressure-bearing rubber is lower than that of the sealing rubber.

[0018] Furthermore, in step 2, the water inlet valve device connects the inside of the steel caisson with the outside, and the water inlet valve device includes an external water inlet pipe, a water inlet valve and an internal water inlet pipe. The outside of the external water inlet pipe is arranged flush with the outside of the caisson wall panel (1) and the bottom of the buoyancy plate device. The inner end of the external water inlet pipe is connected to the water inlet valve, and the lower end of the internal water inlet pipe is connected to the water inlet valve. The internal water inlet pipe is arranged as a curved structure.

[0019] Furthermore, in step 5, the coordinates of the buoyancy plate are recorded and compared with the positioning information fixed on the buoyancy plate, so as to facilitate the salvage of the buoyancy plate device after the sinking of the steel caisson is completed.

[0020] The present invention has the following beneficial effects due to the adoption of the above technical solution:

[0021] The floating plate device of the present invention is arranged horizontally with the bottom of the caisson wall plate, or the floating plate device is lower than the bottom of the caisson wall plate, so as to reduce the draft of the steel caisson and can be smoothly floated to a predetermined water area over a long distance through a dock or a shallower waterway. The arranged water inlet valve device can automatically fill with water after arriving at the designated location, so that the floating plate device can automatically fall off, and the construction is more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the arrangement structure of the steel caisson well hole of the present invention;

[0023] Figure 2 It is a schematic diagram of the internal structure of the floating plate device of the present invention;

[0024] Figure 3 It is a schematic diagram of the main keel arrangement structure of the present invention.

[0025] In the attached drawings, 1-caisson wall plate, 2-corbel, 3-bolt, 4-main keel, 5-sealing plate, 6-pressure-bearing rubber, 7-sealing rubber. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are only for the purpose of enabling the reader to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be implemented even without these specific details.

[0027] A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea, the method comprising the following steps:

[0028] Step 1: A removable and sealed floating plate device is set at the bottom of the steel caisson. The bottom of the floating plate device is level with or lower than the bottom of the steel caisson, so that the steel caisson can pass through shallower waters. The steel caisson is a rectangular structure, and a partition wall is set to divide the interior of the steel caisson into a field grid structure. The floating plate device is set at the bottom of the field grid structure. The bottom of the floating plate device is level with or lower than the bottom of the steel caisson, which effectively avoids the lowest end of the steel caisson from getting stuck. As long as it is calculated that the water area to be passed is deeper than the draft of the steel caisson, it can pass.

[0029] like Figure 1As shown, the buoyancy plate device includes a main keel 4 and a sealing plate 5. The main keel 4 is detachably sealed with the interior of the caisson wall plate 1, and the sealing plate 5 is sealed with the bottom of the main keel 4. The main keel 4 is connected to the corbel 2 set inside the caisson wall plate 1 by bolts 3. The main keel 4 is set as an I-beam, and a pressure-bearing rubber 6 and a sealing rubber 7 are set between the top of the I-beam and the corbel 2. The pressure-bearing rubber 6 and the sealing rubber 7 are set on the outside of the bolt 3. The sealing rubber 7 is set on the outside of the pressure-bearing rubber 6, and the thickness of the pressure-bearing rubber 6 is thinner than that of the sealing rubber 7.

[0030] The main keel is welded into a lattice frame with I-beams, and its size is 50mm smaller than the bottom plate of the steel caisson partition wall on each side, mainly to ensure that the steel caisson can automatically detach from the steel caisson when it sinks; the sealing plate is an 8mm steel plate, which is fully spread and welded on the main keel steel, and the welding position must ensure water tightness; the corbel is fully welded to the steel caisson partition wall panel to support the auxiliary floating plate, and bolt holes are set on the flange of the main keel and the bottom plate of the corbel; after the auxiliary floating plate is completed, 10mm thick pressure-bearing rubber is pasted on the outermost circle around it, and 50mm sealing rubber is pasted close to the inside of the pressure-bearing rubber. The pressure-bearing rubber has small deformation under pressure and can withstand 20m water pressure. The sealing rubber has good elasticity and can be adjusted as the pressure increases. Gradually compress until the thickness is the same as the pressure-bearing rubber; weld a 6mm stopper on the inside of the sealing rubber to prevent the rubber from being squeezed out under pressure; the water inlet valve is installed on the sealing plate of the floating plate, which can connect the inside and outside of the floating plate. Steel pipes of the same diameter are set on both sides of the water inlet valve, and an elbow is set on the upper side to control the direction of water flow after the valve is opened to prevent excessive water pressure from hurting people; after the rubber is completed, use high-strength bolts to fix the floating plate and the corbel, tighten the bolts to meet the watertight requirements between the floating plate and the bottom plate of the corbel. After the floating plate is subjected to buoyancy, the sealing rubber is further compressed. At this time, the high-strength bolts only play a limiting role; fix the GPS positioning device on the floating plate, and salvage the floating plate according to the GPS positioning signal after the floating plate falls off.

[0031] Step 2: Install the positioning device on the buoyancy board device, and install the water inlet valve device on the steel caisson and the buoyancy board device. The water inlet valve device connects the inside of the steel caisson with the outside, and the water inlet valve device includes an external water inlet pipe, a water inlet valve, and an internal water inlet pipe. The outside of the external water inlet pipe is arranged flush with the outside of the caisson wall plate 1 and the bottom of the buoyancy board device. The inner end of the external water inlet pipe is connected to the water inlet valve, and the lower end of the internal water inlet pipe is connected to the water inlet valve. The internal water inlet pipe is arranged as a curved structure.

[0032] Step 3: After the installation of the floating board device is completed, a reverse pressure test should be carried out, that is, water is poured into the floating board device to check the water tightness of the floating board. After the water tightness is qualified, it is marked as qualified. After the steel caisson is fully assembled, a positive pressure test of the floating board is carried out. That is, when the dock is filled with water to 500mm below the floating water level of the steel caisson (the water level is above the floating board at this time), check the water leakage of the floating board. If there is no leakage, the inspection is qualified.

[0033] Step 4: Fill the dock with water to make the steel caisson float, and then use a towing device to tow the steel caisson to the construction waters.

[0034] Step 5: Then open the water inlet valve device to allow seawater to enter the wellbore through the water inlet valve device. When the water levels inside and outside are consistent, the buoyancy board device automatically falls off and falls into the sea. Record the coordinates of the buoyancy board device and then salvage the buoyancy board device. Record the coordinates of the buoyancy board and compare them with the positioning information fixed on the buoyancy board to facilitate the salvage of the buoyancy board device after the sinking of the steel caisson. After the steel caisson is floated out of the dock and successfully passes the shallow point of the channel, remove the bolts on the buoyancy board (since the bolt holes are inside the steel flange, the bolt holes will not leak water), open the water inlet valve on the buoyancy board, connect the inside and outside of the buoyancy board, and allow seawater to enter the wellbore through the water valve. When the water levels inside and outside are consistent, the buoyancy board automatically falls off and falls into the sea. Record the coordinates of the buoyancy board and compare them with the positioning information fixed on the buoyancy board to facilitate the salvage of the buoyancy board after the sinking of the steel caisson. The float plate device is horizontally arranged with the bottom of the caisson wall plate, or the float plate device is lower than the bottom of the caisson wall plate, so as to reduce the draft of the steel caisson, and can be smoothly floated to the predetermined waters over long distances through a dock or a shallower waterway. The water inlet valve device can automatically fill with water after arriving at the designated location, so that the float plate device can automatically fall off, and the construction is more convenient.

[0035] Matters not covered by the present invention are known technologies.

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea, characterized by: The method comprises the following steps: Step 1: A removable and sealed floating plate device is arranged at the bottom of the steel caisson, and the bottom of the floating plate device is level with or lower than the bottom of the steel caisson, so that the steel caisson can pass through a lower water level; Step 2: Install a positioning device on the floating plate device, and install a water inlet valve device on the steel caisson and the floating plate device; Step 3: After the installation of the floating board device is completed, a back pressure test should be carried out, that is, water is injected into the floating board device to check the water tightness of the floating board. After the water tightness is qualified, it is marked as qualified. After the steel caisson is fully assembled, a positive pressure test of the floating board is carried out; Step 4: After the steel caisson is completed, water is poured into the dock, and then the steel caisson is towed to the construction waters using a towing device; Step 5: Then open the water inlet valve device to allow seawater to enter the wellbore through the water inlet valve device. When the water levels inside and outside are consistent, the floating board device automatically falls off and falls into the sea. The coordinates of the floating board device are recorded, and then the floating board device is salvaged.

2. A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea according to claim 1, characterized in that: In step 1, the steel caisson is a rectangular structure, and a partition wall is set to divide the interior of the steel caisson into a field grid structure. The flotation plate device is set at the bottom of the field grid structure. The bottom of the flotation plate device is level with or lower than the bottom of the steel caisson, which effectively avoids the lowest end of the steel caisson from getting stuck. As long as it is calculated that the shallow point of the waterway is deeper than the draft of the steel caisson, it can pass.

3. A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea according to claim 2, characterized in that: The buoyancy aid device comprises a main keel (4) and a sealing plate (5); the main keel (4) and the inner part of the caisson wall plate (1) are detachably sealed; and the sealing plate (5) and the bottom of the main keel (4) are sealed.

4. A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea according to claim 3, characterized in that: The main keel (4) is connected to the corbel (2) arranged inside the caisson wall plate (1) via bolts (3).

5. A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea according to claim 4, characterized in that: The main keel (4) is configured as an I-beam, and a pressure-bearing rubber (6) and a sealing rubber (7) are provided between the top of the I-beam and the corbel (2), and the pressure-bearing rubber (6) and the sealing rubber (7) are provided on the outside of the bolt (3).

6. A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea according to claim 5, characterized in that: The sealing rubber (7) is arranged on the outside of the pressure-bearing rubber (6), and the thickness of the pressure-bearing rubber (6) is thinner than the thickness of the sealing rubber (7).

7. A method for long-distance floating and buoyancy assistance of a large steel caisson in the sea according to claim 4, characterized in that: In step 2, the water inlet valve device connects the inside of the steel caisson with the outside. The water inlet valve device includes an external water inlet pipe, a water inlet valve and an internal water inlet pipe. The outside of the external water inlet pipe is arranged flush with the outside of the caisson wall plate (1) and the bottom of the buoyancy plate device. The inner end of the external water inlet pipe is connected to the water inlet valve, and the lower end of the internal water inlet pipe is connected to the water inlet valve. The internal water inlet pipe is arranged as a curved structure.

8. The method for long-distance floating and buoyancy assistance of a large steel caisson in the sea according to claim 4 is characterized by: In step 5, the coordinates of the buoyancy board are recorded and compared with the positioning information fixed on the buoyancy board, so as to facilitate the salvage of the buoyancy board device after the sinking of the steel caisson is completed.

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