Underwater overhead installation construction method for water taking head

Abstract

The invention discloses an underwater overhead installation construction method for a water taking head, the water taking head comprises a horizontally arranged water inlet pipe, a water inlet connected with the water inlet pipe is arranged above the water inlet pipe, the water inlet is connected with the water inlet pipe through a vertical interface, the seaside end of the water inlet pipe is provided with a blocking blind plate, and the other end of the water inlet pipe is provided with a reducer pipe joint; the installation construction method of the water taking head comprises the steps that a plurality of cross beams are adopted for supporting a water inlet pipe, each cross beam is supported by two foundation piles, each cross beam is provided with two parts of structures, one part is a prefabricated empty box, the other part is a cast-in-place underwater concrete structure poured in the prefabricated empty box, and during installation, the water inlet pipe is erected on the prefabricated empty box; the foundation pile extends into the prefabricated empty box, and the foundation pile and the prefabricated empty box are combined into a whole through the cast-in-place underwater concrete structure. The water taking device is convenient to construct, prefabricated on land, spliced and fixed underwater, the water taking head is placed underwater in an overhead mode, and the water taking device is suitable for a water area with the deep water depth.

Description

Technical Field

[0001] The invention belongs to the technical field of water intake engineering, and particularly relates to an underwater overhead installation construction method for a water intake head. Background Art

[0002] As a kind of clean energy, the market demand for LNG is increasing worldwide. LNG receiving stations are generally located at the seaside, which mainly use the seawater temperature to heat and gasify LNG, improve gasification efficiency and reduce energy consumption. Seawater intake adopts gravity water intake, which is placed underwater and transports seawater to the receiving station through pipelines.

[0003] The water intake head usually adopts a box-type water intake head structure. During construction, the reinforced concrete box is first prefabricated in the prefabrication yard, then floated to the water intake head position for precise sinking, and finally connected to the already laid water intake main to form a water intake system. This water intake head is suitable for waters with good foundation conditions. If the geological conditions of the water intake head are complex, a cofferdam needs to be set up for construction, which requires a large amount of work, a long construction period, and certain safety risks.

[0004] Take the water intake head of a certain LNG plant as an example. The geological conditions of the sea area are complex. The surface layer is silty soft soil, the lower layer is steep rock layer, and the water depth at the water intake head exceeds 10m. The construction is affected by the seawater environment, and the factors that need to be considered are very complex. Therefore, determining the appropriate water intake head structure and its construction method is crucial to ensure that the project meets the predetermined water intake standards, the durability and safety of the structure. In addition, it is also directly related to the feasibility of the construction process, the guarantee of construction quality and progress. Summary of the invention

[0005] In order to solve the technical problems existing in the known technology, the present invention provides an underwater overhead installation construction method for a water intake head which can be applied to deep-water water intake projects, can be applied to complex geological conditions and is easy to construct.

[0006] The technical solution adopted by the present invention to solve the technical problems existing in the known technology is as follows: An underwater overhead installation construction method for a water intake head. The water intake head includes a horizontally arranged water inlet pipe. An inlet is provided above the water inlet pipe and is connected to the water inlet pipe. The inlet is connected to the water inlet pipe through a vertical interface. A sealing blind plate is provided at the sea side end of the water inlet pipe, and a reducing pipe joint is provided at the other end. The installation construction method of the water intake head is as follows: Support the water inlet pipe with multiple cross beams, and each cross beam is supported by two foundation piles. The cross beam has two structural parts, one part is a precast empty box, and the other part is a cast-in-place underwater concrete structure poured in the precast empty box. The bottom of the precast empty box is provided with pile insertion holes, and an annular rubber water stop is embedded in the pile insertion holes. Support grooves matching the water inlet pipe are provided on the front and rear side walls of the precast empty box, and embedded bolts are provided on both sides of the support grooves. The construction steps are as follows: 1) Manufacture the water intake head components in a land-based factory; 2) Manufacture the precast empty box in a land-based factory; 3) Carry out foundation pile construction on site, and the pile top elevation is the cross beam design bottom elevation + the set height extending into the precast empty box. A support structure is set at the cross beam design bottom elevation outside the pile top; 4) Transport the components in step 1) and the precast empty box in step 2) to the sinking area; 5) Use a crane ship to hoist the precast empty box. Each precast empty box is supported by two foundation piles. Lower the precast empty box onto the support structure and fix it. The pile top of the foundation pile passes through the pile insertion hole and enters the interior of the precast empty box, and the annular rubber water stop surrounds the outside of the pile top of the foundation pile; 6) Use a crane ship to hoist the water inlet pipe, place the water inlet pipe on the support groove of the precast empty box, and connect the water inlet pipe to the front and rear side walls of the precast empty box with an anchor ring. Both sides of the anchor ring are fixed with two of the embedded bolts respectively; 7) Pour underwater concrete in the precast empty box to form an integral body of the foundation pile and the cross beam, and bury the lower part of the water inlet pipe in the cast-in-place underwater concrete structure; 8) Connect the inlet to the water inlet pipe and connect the water intake head to the water intake pipeline.

[0007] In step 1), weld the sealing blind plate and the reducing pipe joint to the precast water inlet pipe in a land-based factory.

[0008] In step 2), the precast empty box adopts a rectangular empty box structure.

[0009] In step 2), the precast empty box adopts a steel-concrete structure.

[0010] In step 3), the foundation pile adopts a cast-in-place concrete pile.

[0011] The inlet is connected to the water inlet pipe through a vertical interface. The vertical interface is arranged on the water inlet pipe and is connected to the inlet by a flange.

[0012] The advantages and positive effects of the present invention are as follows: By adopting a cast-in-place pile foundation, it is not restricted by the changes in the strata, can penetrate through various soil layers with complex soil conditions or large differences in hardness and softness, adapt to various geological conditions, has stable stress, and can be applied to water intake projects in deep water environments. The water intake structure and its supporting crossbeam structure are simple. The crossbeam adopts a two-part structure of prefabrication and in-situ casting. The prefabricated empty box is prefabricated in a land-based factory, and the quality is easy to guarantee; the single weight of the prefabricated component is light, which is convenient for hoisting and transportation, and does not require large hoisting and installation equipment; the on-site installation and construction are simple, the construction machinery and personnel input are less, the construction period is short, the efficiency is high, and the project cost can be reduced. During the operation period, according to the water supply needs, the water inlet can be disassembled, the maintenance is convenient and efficient, and the impact on the normal water supply is small.

[0013] In summary, the construction of the present invention is convenient. It is prefabricated on land, spliced and fixed underwater, and the water intake head is placed overhead underwater, which is applicable to waters with relatively deep water depths. Brief Description of the Drawings

[0014] Figure 1 is a schematic diagram of the application of the present invention;

[0015] Figure 2 is Figure 1 the side sectional schematic diagram of

[0016] Figure 3 is the cross-sectional schematic diagram of the prefabricated empty box in the present invention.

[0017] In the figure: 1, foundation pile; 2, crossbeam; 3, water inlet pipe; 4, vertical joint; 5, water inlet; 6, reduced-diameter pipe joint; 7, plugging blind plate; 8, anchor ring; 9, embedded bolt; 10, prefabricated empty box; 11, in-situ underwater concrete structure; 12, annular rubber waterstop; 13, support groove; 14, pile insertion hole. Detailed Embodiment

[0018] In order to further understand the invention content, characteristics and effects of the present invention, the following embodiments are cited and described in detail in conjunction with the drawings as follows:

[0019] Please refer to Figures 1 to 3, a method for underwater overhead installation construction of a water intake head. The water intake head includes a horizontally arranged water inlet pipe 3, and an intake port 5 connected thereto is provided above the water inlet pipe 3. The intake port 5 is connected to the water inlet pipe 3 through a vertical interface. A blocking blind plate 7 is provided at the sea side end of the water inlet pipe 3, and a reducer joint 6 is provided at the other end. The installation construction method of the water intake head is as follows: Support the water inlet pipe 3 with multiple cross beams 2, and each cross beam 2 is supported by two foundation piles 1. The cross beam 2 has two parts of structures, one part is a precast empty box 10, and the other part is a cast-in-place underwater concrete structure 11 poured into the precast empty box 10. The bottom of the precast empty box 10 is provided with a pile insertion hole 14, and an annular rubber water stop 12 is embedded in the pile insertion hole 14. Support grooves 13 matching the water inlet pipe 3 are provided on the front and rear side walls of the precast empty box 10, and embedded bolts 9 are provided on both sides of the support grooves 13. The installation construction steps of the water intake head are as follows:

[0020] 1) Fabricate the water intake head components in a land-based factory;

[0021] 2) Fabricate the precast empty box 10 in a land-based factory;

[0022] 3) Conduct the construction of the foundation piles 1 on-site. The pile top elevation is the cross beam design bottom elevation + the set height extending into the precast empty box, and a support structure is set at the cross beam design bottom elevation on the outer side of the pile top;

[0023] 4) Transport the components in step 1) and the precast empty box 10 in step 2) to the sinking area;

[0024] 5) Use a crane ship to hoist the precast empty box 10. Each precast empty box 10 is supported by two foundation piles 1. Lower the precast empty box 10 onto the support structure and fix it. The pile top of the foundation pile 1 passes through the pile insertion hole 14 and enters the interior of the precast empty box 10. The annular rubber water stop 12 surrounds the outer side of the pile top of the foundation pile 1 to prevent leakage of underwater concrete during pouring.

[0025] 6) Use a crane ship to hoist the water inlet pipe 3, place the water inlet pipe 3 on the support groove 13 of the precast empty box 10, and fix the water inlet pipe 3 on the front and rear side walls of the precast empty box 10 with an anchor ring 8. The two sides of the anchor ring 8 are fixed with two of the embedded bolts 10 respectively;

[0026] 7) Pour underwater concrete in the precast empty box 10 to integrate the foundation pile 1 and the cross beam 2 and bury the lower part of the water inlet pipe into the cast-in-place underwater concrete structure 11;

[0027] 8) Connect the intake port 5 to the water inlet pipe 3 and connect the water intake head to the water intake pipeline. The installation height of the intake port should ensure normal water intake under the condition of the design lowest water level working condition.

[0028] A more preferred solution of this embodiment is as follows:

[0029] To reduce underwater operations, in step 1), when prefabricating in the factory, the blind plug 7 and the reducer joint 6 can be welded to the prefabricated intake pipe.

[0030] To simplify fabrication and facilitate installation and construction, in step 2), the prefabricated empty box 10 adopts a rectangular empty box structure. At the same time, the prefabricated empty box 10 adopts a steel-concrete structure, which has high strength, good durability and good economy.

[0031] In step 3), the foundation pile 1 adopts a cast-in-place concrete pile. Cast-in-place concrete piles can be applied to various geological conditions, are not restricted by stratum changes, can penetrate various hard interlayers, embed in rocks and enter various hard bearing strata; the construction quality is easy to control. In this embodiment, according to the actual layout of the pile positions designed for the water intake head, the cast-in-place pile construction is carried out, and the pile top elevation is such that it extends into the prefabricated empty box by a certain length.

[0032] To facilitate installation, disassembly and maintenance, the water inlet 5 is connected to the intake pipe 3 through the vertical interface 4. The vertical interface 4 is arranged on the intake pipe 3, and the vertical interface 4 and the water inlet 5 are connected by flanges.

[0033] A more detailed description is as follows:

[0034] The above cross beam 2 adopts a two-part structure. One part is a prefabricated empty box, which adopts a reinforced concrete structure, and the other part is a cast-in-place underwater concrete structure. To reduce the lifting weight on the water surface, the prefabricated empty box 10 is fabricated on land. A semi-circular support groove 13 is arranged on the empty box to facilitate the placement of the intake pipe 3. A pile insertion hole 14 is arranged at the bottom of the empty box to facilitate the connection with the foundation pile 1. Embedded bolts 9 are arranged inside the front and rear side walls of the empty box for fixing the anchor ring 8. After the prefabricated empty box is fixed on the foundation pile 1, underwater concrete is cast in it for the second time.

[0035] For the above water intake structure, the lower part is a horizontally arranged intake pipe 3, and multiple water inlets 5 are arranged in the upper part. Two are shown in the figure. The water inlets are connected to the lower intake pipe 3 through the vertical joints 4. The sea side end of the intake pipe 3 is blocked by a blind plug 7, and the other end is connected to the water intake pipe through a reducer joint 6.

[0036] The above water inlet 5 is a cylindrical steel structure, and the quantity, diameter and height can be determined according to the water intake. The water inlet 5 and the vertical joint 4 are connected by flanges, which is convenient for disassembling during the operation period to repair the water intake. A trash rack is arranged at the water inlet to intercept floating objects in the water.

[0037] The main body of the above-mentioned vertical joint 4 is made of steel pipe, which is perpendicularly welded to the water inlet pipe 3. The diameter of the vertical joint 4 is the same as that of the water inlet 5, and the height is determined according to the water level to ensure that the water inlet 5 can normally draw water under the condition of the lowest designed water level.

[0038] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit of the present invention and the scope protected by the claims. All of these are within the protection scope of the present invention.

Claims

1. A method for underwater overhead installation of a water intake head, wherein the water intake head comprises a horizontally arranged water inlet pipe, a water inlet connected to the water inlet pipe is arranged above the water inlet pipe, the water inlet is connected to the water inlet pipe through a vertical interface, a blind plate is arranged at the sea side end of the water inlet pipe, and a reducer is arranged at the other end, characterized in that: The installation and construction method of the water intake head is as follows: multiple crossbeams are used to support the water inlet pipe, each crossbeam is supported by two foundation piles, and the crossbeam has two parts, one of which is a prefabricated empty box, and the other is a cast-in-place underwater concrete structure cast in the prefabricated empty box. The bottom of the prefabricated empty box is provided with a pile hole, and an annular rubber water stop is embedded in the pile hole. Support grooves that match the water inlet pipe are provided on the front and rear side walls of the prefabricated empty box, and embedded bolts are provided on both sides of the support groove. The construction steps are as follows: 1) Make the water intake head assembly in the land factory; 2) Make prefabricated empty containers in land-based factories; 3) Carry out foundation pile construction on site. The pile top elevation is the designed bottom elevation of the beam + the height set to extend into the prefabricated empty box. A supporting structure is set at the designed bottom elevation of the beam outside the pile top. 4) transporting the components in step 1) and the prefabricated empty boxes in step 2) to the sinking area; 5) Using a crane ship to hoist the prefabricated empty box, each of the prefabricated empty boxes is supported by two of the foundation piles, the prefabricated empty box is lowered onto the supporting structure and fixed, the top of the foundation pile passes through the pile insertion hole into the interior of the prefabricated empty box, and the annular rubber water stop surrounds the outside of the top of the foundation pile; 6) The water inlet pipe is hoisted by a crane ship, and the water inlet pipe is erected on the support groove of the prefabricated empty box, and the water inlet pipe is connected to the front and rear side walls of the prefabricated empty box by an anchor ring, and the two sides of the anchor ring are respectively fixed by two of the embedded bolts; 7) Pour underwater concrete in the prefabricated empty box so that the foundation piles and the crossbeams form a whole and the lower part of the water inlet pipe is buried in the cast-in-place underwater concrete structure; 8) Connect the water inlet to the water inlet pipe, and connect the water intake head to the water intake pipeline.

2. The underwater overhead installation construction method of the water intake head according to claim 1 is characterized in that: In the step 1), the blind plugging plate and the reducer are welded to the prefabricated water inlet pipe in a land factory.

3. The underwater overhead installation construction method of the water intake head according to claim 1 is characterized in that: In the step 2), the prefabricated empty box adopts a rectangular empty box structure.

4. The underwater overhead installation construction method of the water intake head according to claim 1 is characterized in that: In the step 2), the prefabricated empty box adopts a steel-concrete structure.

5. The underwater overhead installation construction method of the water intake head according to claim 1 is characterized in that: In the step 3), the foundation piles are cast-in-place concrete piles.

6. The underwater overhead installation construction method of the water intake head according to claim 1 is characterized in that: The water inlet is connected to the water inlet pipe via a vertical interface. The vertical interface is arranged on the water inlet pipe and is connected to the water inlet via a flange.

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