Underwater large hollow prefabricated part mounting method

Abstract

The invention relates to the field of hydraulic engineering construction, in particular to an underwater large hollow prefabricated part mounting method. Comprising the steps of S1, preparation before installation; s2, determining the depth of the diving pit, and dragging the semi-submersible barge into the diving pit; s3, component hoisting; s4, component installation; s5, treatment work after implantation; the large hollow prefabricated part is shipped through a semi-submersible barge and installed through floating assistance of a crane ship, the problems that the blocking requirement of the large hollow prefabricated part is high, and the installation posture control difficulty is large are solved, the investment of large ship machine equipment is effectively reduced, the construction cost is reduced, and the construction time is guaranteed; and by arranging the emergency drainage well, water can be pumped out in time when the component leaks water, and the safety of the floating transportation and installation process of the component is improved.

Description

Technical Field

[0001] The invention relates to the field of water conservancy project construction, and in particular to a method for installing a large underwater hollow prefabricated component. Background Art

[0002] In modern marine engineering and water conservancy engineering construction, large underwater hollow prefabricated components are widely used in the construction of various underwater structures, such as bridge foundations, port docks and supporting structures of offshore platforms. Hollow prefabricated components have become a commonly used structural material in engineering due to their relatively light weight, internal space that can be used to reduce buoyancy and facilitate subsequent filling.

[0003] The installation of existing underwater hollow prefabricated components usually relies on large-scale ship machinery and equipment. The operating stability and hoisting accuracy of ship machinery and equipment are greatly affected by environmental factors such as water flow, wind and waves, which increases the difficulty of construction and equipment loss. At the same time, due to the large size of hollow prefabricated components, the entire construction process is time-consuming and complex, and the construction cost is correspondingly high. Summary of the invention

[0004] In view of the deficiencies existing in the above-mentioned prior art, the present invention provides a method for installing large hollow prefabricated components which has low construction cost and can ensure safe and stable transportation.

[0005] The present invention provides a method for installing a large hollow prefabricated component, which is applicable to a large hollow prefabricated component that is blocked at the top and bottom, and comprises the following steps:

[0006] S1. Preparation before installation:

[0007] A hanging point is set on the large hollow prefabricated component, all water inlet grilles of the component are blocked, and an emergency drainage well is installed at the top manhole of the component. Under high water level conditions of high tide, the wellhead of the emergency drainage well is above the water level. When the component leaks, a water pump is used to drain the water in the component from the manhole through the emergency drainage well;

[0008] A one-way water inlet valve is arranged outside one of the blocked water inlet grilles. When the component needs to be filled with water, the one-way water inlet valve is opened to fill water. When the water filling stops, the one-way water inlet valve is closed.

[0009] S2. Determine the depth of the submersible pit and tow the semi-submersible barge into the submersible pit:

[0010] Calculate the diving depth H of the semi-submersible barge;

[0011] At 0 tide, measure the elevation of the shallowest part of the diving pit and calculate the average bottom elevation of the diving pit; compare the elevation of the shallowest part with the calculated diving depth H, that is, the depth of the diving pit is greater than the larger value of the two;

[0012] Excavating a submersible pit and towing the semi-submersible barge into the submersible pit;

[0013] S3. Component hoisting:

[0014] The crane ship hooks the lifting point of the component, the semi-submersible barge sinks, and the crane provides auxiliary lifting force to eliminate the eccentricity of the component during lifting, so that the component can float stably;

[0015] The component is positioned using a GPS measuring device during the hoisting process, and the crane vessel receives a signal from the GPS measuring device to adjust the ship's position, so that the center of the component is adjusted to coincide with the set installation center position;

[0016] S4. Component installation:

[0017] When the center of the component is adjusted to coincide with the set installation center position, the crane vessel starts to unload the force, opens the one-way water inlet valve to add water to the component to the designed water level, eliminates the freeboard, and continues to add water to the component. At this time, the crane vessel slowly unloads the force, and the component begins to be lowered. The lowering speed of the component is controlled. During the lowering process, the axis position of the component coincides with the designed axis, and the center position coincides with the set installation center position, until the component is stably landed;

[0018] S5. Post-implantation treatment

[0019] After the component is implanted, the crane vessel releases the hook and continues to fill the component with water until it is full, and removes the blockage of the water inlet grille, the one-way water inlet valve, and the emergency drainage well in step S1.

[0020] In this technical solution, large hollow prefabricated components are transported by semi-submersible barges and installed with the assistance of floating cranes, which solves the problems of high sealing requirements and difficult installation posture control of large hollow prefabricated components, effectively reduces the investment in large ship machinery and equipment, reduces construction costs, and ensures construction time.

[0021] In some embodiments of the present application, in step S1, the component is suspended by four points, the suspension points are evenly distributed on the top surface of the component, and each suspension point is at the same distance from the center of the top surface of the component to ensure that the component can be lifted stably.

[0022] In some embodiments of the present application, in step S1, the step of blocking the water inlet grille is:

[0023] When the component is prefabricated, truncated cone nuts are embedded in the concrete around the water inlet grille and around the butt joint of the culvert. After the component is prefabricated, the water inlet grille is sealed with a sealing steel plate.

[0024] In some embodiments of the present application, in order to prevent water leakage from the water inlet grille, the contact surface between the sealing steel plate and the concrete of the component is sealed with a water-stop rubber strip.

[0025] In some embodiments of the present application, in order to facilitate personnel operation, in step S1, an operating platform is also installed on the top of the component, and the height of the installation platform enables it to be 0.5-1.0m above the water surface under high water level conditions. The GPS measuring device is installed on the operating platform, and the GPS measuring device is used for positioning the components in steps S3 and S4.

[0026] In some embodiments of the present application, in step S1, the height of the emergency drainage well is the same as the height of the operating platform, so that the emergency drainage well can be 0.5-1.0m above the water surface under high water level conditions, which is convenient for drainage when the component leaks.

[0027] In some embodiments of the present application, in order to facilitate the operation of the one-way water inlet valve, the valve stem of the one-way water inlet valve is extended to the position of the operating platform. When water injection is required, the one-way water injection valve can be opened by rotating the valve stem on the operating platform for water injection; when water injection is stopped, the one-way water injection valve can be closed by rotating the valve stem on the operating platform.

[0028] In some embodiments of the present application, in step S2, the diving depth H of the semi-submersible barge is:

[0029] H=H 构件 +H 型深 +H 台车 +H 底

[0030] Among them, H 构件 is the critical buoyancy draft of the component;

[0031] H 型深 The moulded depth of the semi-submersible barge;

[0032] H 台车 The height of the semi-submersible barge trolley;

[0033] H 富裕 It is the height from the bottom of the semi-submersible barge to the bottom of the submersible pit.

[0034] In some embodiments of the present application, in step S4, the lowering speed of the component is controlled to be 10 cm / min to ensure smooth lowering of the component.

[0035] Based on the above technical solution, large hollow prefabricated components are transported by semi-submersible barges and installed with the help of crane ships, which solves the problems of high sealing requirements and difficult installation posture control of large hollow prefabricated components, effectively reduces the investment in large ship machinery and equipment, reduces construction costs, and ensures construction time;

[0036] The setting of emergency drainage wells can promptly pump out water when water leakage occurs in components, thereby improving the safety of component floating and installation processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0038] Figure 1 It is a schematic diagram of the top view of the water intake caisson according to an embodiment of the present invention;

[0039] Figure 2 It is a schematic structural diagram of a floating water intake caisson of a crane vessel according to an embodiment of the present invention.

[0040] In the figure:

[0041] 10. Water intake caisson; 11. Lifting point; 20. Crane vessel. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] The terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Thus, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The large hollow prefabricated component installation method provided in this embodiment is suitable for large hollow eccentric prefabricated components that are blocked at both the top and the bottom. The large hollow eccentric prefabricated component in this embodiment is a water intake caisson in a water intake and drainage project, such as Figure 1 As shown, the water intake caisson 10 is a cylindrical structure with a wall diameter of 21m, a toe diameter of 22.6m, and a total height of 10.58m. The caisson is capped from top to bottom, with a manhole of 1m in diameter on the top. There are 5 annular water intake grilles with a height of 1.7m at 3.08m below the top plate, and a water intake culvert interface at 1.2m above the bottom plate, with a specification of 7.5m×4.2m. The caisson has a toe thickness of 1m, a wall thickness of 0.8m, and a top plate thickness of 1m. The caisson is provided with a beam and a center column frame. The total concrete volume of a single water intake caisson is about 1210m 3 , weight about 3000t;

[0047] After the water intake caisson of this embodiment is prefabricated, it is transported to a semi-submersible barge by a capsule trolley in the prefabrication yard, and the semi-submersible barge is transported and submerged to a designated installation location, and installed by a large crane ship; specifically, the following steps are included:

[0048] S1. Preparation before installation:

[0049] A suspension point 11 is provided on the water intake caisson 10, such as Figure 1 As shown, four-point suspension is adopted, the diameter of the suspension point is 80mm, and the material is Q390 steel. Two of the suspension points are installed on both sides of the water intake at the top of the caisson, and the other two suspension points are symmetrically installed at the column position between the water intake windows. The distance between each suspension point and the center of the water intake caisson is 10.1m;

[0050] When the water intake caisson 10 is prefabricated, truncated nuts are embedded in the concrete around the water intake grille and the docking interface of the water intake culvert. After prefabrication, it is sealed with a 6mm thick shaped sealing steel plate; all the contact surfaces between the sealing steel plate and the concrete are sealed with a 1cm thick water-stop rubber strip to prevent water leakage;

[0051] After the water intake caisson 10 is prefabricated, an operating platform is installed on the top plate of the caisson to facilitate personnel operation. Protective railings are set around the operating platform. The operating platform is 1.5m long, 1.5m wide, and 4.0m high. The top of the platform can be 0.5m above the water surface at high tide. Two GPS measuring devices are installed above the platform to meet the installation and positioning requirements of the water intake caisson. When welding the operating platform, its stability must be ensured to prevent the GPS measuring equipment from shaking and causing large positioning errors.

[0052] In order to prevent water leakage in the water intake caisson 10 during floating and installation, an emergency drainage well with a height of 4.0m and a diameter of 1m, which is the same as the operating platform, is installed at the manhole position on the top of the water intake caisson. The well mouth is located above the water level at high tide. If water leakage occurs, a water pump is used to discharge the water in the water intake caisson through the manhole. The water pump uses ship power.

[0053] A one-way water inlet valve with a diameter of 25 cm is arranged on the temporary blocking steel plate of the water inlet grille on one side of the water intake caisson 10. The one-way water inlet valve is connected to the blocking steel plate through a flange, and the height of the valve stem is extended to the position of the operating platform. In this embodiment, the length of the extended stem is about 10m, and the valve stem is fixed to the operating platform. When water injection is required, water can be injected by rotating and opening the one-way water injection valve above the operating platform at the top of the water intake caisson 10. When stopping water injection, the operator can rotate and close the valve.

[0054] S2. Determine the depth of the submersible pit and tow the semi-submersible barge into the submersible pit:

[0055] Calculate the diving depth H of the semi-submersible barge; H = H 构件 +H 型深 +H 台车 +H 富裕

[0056] Among them, H 构件 is the critical draft depth of the water intake caisson 10. In this embodiment, the water intake caisson needs a crane ship to provide auxiliary lifting force to ensure the stable floating of the water intake caisson. The crane provides an auxiliary lifting force of 200t. At this time, H 构件 7.36m, H 型深 The model depth of the semi-submersible barge is 5.5m; 台车 H is the height of the semi-submersible barge trolley, which is 1.65m in this embodiment; 富裕 is the height from the bottom of the semi-submersible barge to the bottom of the diving pit and the height of the sleepers, which is 1.2m in this embodiment; therefore, in this embodiment, the diving depth H of the semi-submersible barge is 7.36+5.5+1.65+1.2=15.71m; the semi-submersible barge has an empty draft of 2.6m, and a draft of 3.46m after the water intake caisson is on board (3000t / 82.6m / 42m+2.6m=3.46m).

[0057] At 0 tide, the elevation of the shallowest part of the submersible pit is measured to be -16.1m, and the average bottom elevation of the submersible pit is calculated to be -16.8m; the submersible depth H of the semi-submersible barge is less than the elevation of the shallowest part, therefore, in this embodiment, the depth of the submersible pit is greater than 16.1m;

[0058] Excavate the submersible pit and tow the semi-submersible barge into the submersible pit;

[0059] S3. Component hoisting:

[0060] First, the crane vessel hooks the water intake caisson. After the four lifting points are hooked, the semi-submersible barge continues to sink. Since the water intake caisson in this embodiment is an eccentric structure, in order to ensure that the water intake caisson is stable after floating, the crane vessel provides auxiliary lifting force to eliminate the eccentricity of the water intake caisson during lifting, so that the water intake caisson floats stably;

[0061] During the hoisting process, the water intake caisson 10 is measured and positioned using a GPS measuring device. The crane ship receives the signal from the GPS measuring device to adjust the ship's position, and slowly adjusts the center control point of the water intake caisson to coincide with the center position of the installation circle.

[0062] S4. Component installation:

[0063] When the center control point of the water intake caisson coincides with the set installation center position, the crane vessel starts to unload the force, and the operator opens the valve stem of the one-way water inlet valve on the operating platform to add water to the inside of the water intake caisson to the designed water level to eliminate the freeboard. In order to ensure the construction safety and allow the operator to intuitively observe the water level height in the water intake caisson, a liquid level monitor needs to be installed in advance inside the water intake caisson. In this embodiment, during the process of eliminating the freeboard, the lifting force is controlled not to exceed the maximum lifting tonnage of the crane vessel minus 90t;

[0064] Continue to add water to the water intake caisson 10 until 90t. At this time, the crane ship slowly unloads the force, and the water intake caisson begins to be lowered. The lowering speed of the water intake caisson is controlled to be 10cm / min. During the lowering process, the axis position of the water intake caisson should coincide with the design axis, and ensure that the center position coincides with the set installation center position until the water intake caisson is stably landed;

[0065] S5. Post-implantation treatment

[0066] After the water intake caisson is planted, the crane ship releases the hook and continues to fill the water intake caisson 10 with water until it is full. The diver removes the hook shackle underwater. After the water intake caisson is installed, the diver removes the sealing steel plate that seals the water inlet grille in step S1, the sealing steel plate of the culvert interface, and the one-way water injection valve, operating platform, emergency drainage well and other facilities underwater.

[0067] The water intake caisson of this embodiment is transported by semi-submersible barge and installed with the help of floating crane. Without using large lifting equipment, it meets the requirements of caisson installation and construction, solves the problems of high sealing requirements and difficult installation posture control of water intake caisson, reduces construction risks, reduces the investment in large ship machinery and equipment, reduces construction costs, and ensures construction time. Similar large hollow prefabricated components can be installed using the installation process of this embodiment;

[0068] The setting of emergency drainage wells can promptly pump out water when water leakage occurs in components, thereby improving the safety of component floating and installation processes.

[0069] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0070] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A method for installing a large hollow prefabricated component, which is suitable for large hollow prefabricated components that are blocked at the top and bottom, and is characterized by: The steps include: S1. Preparation before installation: A hanging point is set on the large hollow prefabricated component, all water inlet grilles of the component are blocked, and an emergency drainage well is installed at the top manhole of the component. Under high water level conditions of high tide, the wellhead of the emergency drainage well is above the water level. When the component leaks, a water pump is used to drain the water in the component from the manhole through the emergency drainage well; A one-way water inlet valve is arranged outside one of the blocked water inlet grilles. When the component needs to be filled with water, the one-way water inlet valve is opened to fill water. When the water filling stops, the one-way water inlet valve is closed. S2. Determine the depth of the submersible pit and tow the semi-submersible barge into the submersible pit: Calculate the diving depth H of the semi-submersible barge; At 0 tide, measure the elevation of the shallowest part of the diving pit and calculate the average bottom elevation of the diving pit; compare the elevation of the shallowest part with the calculated diving depth H, that is, the depth of the diving pit is greater than the larger value of the two; Excavating a submersible pit and towing the semi-submersible barge into the submersible pit; S3. Component hoisting: The crane ship hooks the lifting point of the component, the semi-submersible barge sinks, and the crane provides auxiliary lifting force to eliminate the eccentricity of the component during lifting, so that the component can float stably; The component is positioned using a GPS measuring device during the hoisting process, and the crane vessel receives a signal from the GPS measuring device to adjust the ship's position, so that the center of the component is adjusted to coincide with the set installation center position; S4. Component installation: When the center of the component is adjusted to coincide with the set installation center position, the crane vessel starts to unload the force, opens the one-way water inlet valve to add water to the component to the designed water level, eliminates the freeboard, and continues to add water to the component. At this time, the crane vessel slowly unloads the force, and the component begins to be lowered. The lowering speed of the component is controlled. During the lowering process, the axis position of the component coincides with the designed axis, and the center position coincides with the set installation center position, until the component is stably landed; S5. Post-implantation treatment After the component is implanted, the crane vessel releases the hook and continues to fill the component with water until it is full, and removes the blockage of the water inlet grille, the one-way water inlet valve, and the emergency drainage well in step S1.

2. The method for installing a large hollow prefabricated component according to claim 1, characterized in that: In step S1, the component is suspended by four points, the suspension points are evenly distributed on the top surface of the component, and the distance between each suspension point and the center of the top surface of the component is the same, so as to ensure that the component can be lifted stably.

3. The method for installing a large hollow prefabricated component according to claim 2, characterized in that: When the component is prefabricated, truncated cone nuts are embedded in the concrete around the water inlet grille and around the butt joint of the culvert. After the component is prefabricated, the water inlet grille is sealed with a sealing steel plate.

4. The method for installing a large hollow prefabricated component according to claim 3, characterized in that: The contact surfaces between the sealing steel plate and the concrete of the component are sealed with water-stop rubber strips.

5. The method for installing a large hollow prefabricated component according to claim 1, characterized in that: In step S1, an operating platform is also installed on the top of the component. The height of the installation platform can make it 0.5-1.0m above the water surface under high water level conditions. The GPS measuring device is installed on the operating platform. The GPS measuring device is used to locate the components in steps S3 and S4.

6. The method for installing a large hollow prefabricated component according to claim 5, characterized in that: In step S1, the height of the emergency drainage well is the same as that of the operating platform, so that the emergency drainage well can be 0.5-1.0m above the water surface under high water level conditions, which is convenient for drainage when components leak.

7. The method for installing a large hollow prefabricated component according to claim 5, characterized in that: The valve stem of the one-way water inlet valve is extended to the position of the operating platform. When water injection is needed, the one-way water injection valve can be opened by rotating the valve stem on the operating platform for water injection; when water injection is stopped, the one-way water injection valve can be closed by rotating the valve stem on the operating platform.

8. The method for installing a large hollow prefabricated component according to claim 1, characterized in that: In step S2, the diving depth H of the semi-submersible barge is: H=H 构件 +H 型深 +H 台车 +H 底 Among them, H 构件 is the critical buoyancy draft of the component; H 型深 The moulded depth of the semi-submersible barge; H 台车 The height of the semi-submersible barge trolley; H 富裕 It is the height from the bottom of the semi-submersible barge to the bottom of the submersible pit.

9. The method for installing a large hollow prefabricated component according to claim 1, characterized in that: In step S4, the lowering speed of the component is controlled to be 10 cm / min.

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