Seabed hard rock shield tunnel nuclear power cold source drainage head construction method

Abstract

The invention belongs to the technical field of vertical jacking of underwater shield tunnels, and particularly relates to a submarine hard rock shield tunnel nuclear power cold source drainage head construction method which comprises the following steps: reinforcing a sludge layer between seawater and a rock stratum; a pile casing is installed in the reinforcement treatment area of the sludge layer; bed rock in the pile casing is removed; the pile casing is backfilled with a sealing material; performing protection treatment on the outer side area of the pile casing; and shield tunneling construction is conducted in the rock stratum, a tunnel is formed, and vertical jacking construction is conducted on the sealing material in the pile casing through the tunnel to form a drainage head. According to the method, the key technology related to subsea tunnel shield internal drainage head construction under the hard rock condition can be achieved; the problems of hard rock treatment and backfilling compaction at the vertical jacking part are solved, the treatment area is reduced to the maximum extent, the cost is saved, the construction progress is accelerated, the construction safety is guaranteed, normal tunneling of slurry balance shield tunneling is guaranteed, and meanwhile the requirement of vertical jacking for the stratum is met.

Description

Technical Field

[0001] This invention belongs to the field of underwater shield tunnel vertical jacking technology, and particularly relates to a construction method for the drainage head of a nuclear power cold source in a submarine hard rock shield tunnel. Background Technology

[0002] With the rapid development of the nuclear power industry, the requirements for nuclear power plant water intake and drainage are becoming increasingly stringent. The use of tunnels combined with vertical jacking for water intake and drainage is becoming more widespread. Previously, the drainage head strata in water intake and drainage tunnels were mostly soft strata, with some areas containing bedrock protrusions or isolated boulders. However, with changes in the construction environment, many areas cannot meet the requirements for vertical jacking construction in soft soil, forcing the selection of drainage heads in hard rock strata. Hard rock strata have a significant impact on the tunneling of the tunnel boring machine, severely affecting the construction progress.

[0003] Therefore, it is necessary to design a construction method for the drainage head of the nuclear power plant cold source in a submarine hard rock shield tunnel to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel. This method solves the problems of hard rock treatment, pressure maintenance during shield tunneling, and the need for soft media during vertical jacking. It ensures both normal shield machine excavation and the smooth implementation of subsequent treatment and jacking operations.

[0005] To achieve the above objectives, the present invention provides the following solution: a construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel, comprising the following steps: reinforcing the silt layer between the seawater and the rock strata; installing a casing within the reinforced area of ​​the silt layer; removing the bedrock inside the casing so that the casing penetrates the top and bottom of the silt layer; backfilling the casing with sealing material to seal the internal space of the casing; protecting the outer area of ​​the casing; conducting shield tunneling within the rock strata to form a tunnel; and vertically jacking the sealing material inside the casing through the tunnel to force the sealing material out of the casing, thus forming the drainage head.

[0006] According to the present invention, a construction method for the drainage head of a nuclear power cold source in a submarine hard rock shield tunnel includes reinforcing the silt layer between the seawater and the rock strata by means of: reinforcing the silt layer with a number of sand piles, the length of the sand piles being 5m-6m and the diameter being 0.5m, the sand piles being arranged in an array, the spacing between adjacent sand piles being 1m, and the row spacing between two adjacent rows of sand piles being 0.7m.

[0007] The present invention relates to a construction method for the drainage head of a nuclear power cold source in a submarine hard rock shield tunnel, wherein the bottom end of the sand pile is located within the rock strata.

[0008] According to the present invention, a construction method for the drainage head of a nuclear power cold source in a submarine hard rock shield tunnel is provided, wherein the bottom end of the casing is inserted into the rock layer to a depth of 0.6m, and the top end of the casing is 0.6m above the seabed surface.

[0009] According to the present invention, a construction method for the drainage head of a nuclear power cold source in a submarine hard rock shield tunnel is provided, wherein the casing is made of steel, the diameter of the casing is 5m, and the wall thickness of the casing is 0.04m.

[0010] According to the present invention, a construction method for the drainage head of a nuclear power cold source tunnel in a submarine hard rock shield tunnel includes removing the bedrock inside the casing so that the casing can penetrate the top and bottom of the silt layer. This method includes removing the bedrock inside the casing by one or more of the following methods: rotary drilling, impact hammer, and blasting.

[0011] According to the present invention, a construction method for the drainage head of a nuclear power cold source in a submarine hard rock shield tunnel is provided, wherein the sealing material inside the casing is one or more of calcium-based clay and sand.

[0012] The present invention provides a construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel, wherein the casing is installed by means of a ship and / or a temporary platform.

[0013] The present invention provides a construction method for the drainage head of a nuclear power cold source in a submarine hard rock shield tunnel, which involves protecting the outer area of ​​the casing by throwing rocks.

[0014] The present invention provides a method for constructing a drainage head for a nuclear power plant cold source in a submarine hard rock shield tunnel. The method involves shield tunneling within the rock strata to form a tunnel, and vertically lifting the sealing material inside the casing through the tunnel to force the sealing material out of the casing and form a drainage head. The method also includes reinforcing the periphery of the drainage head, and after the tunnel is filled with water, removing the top cover of the drainage head and installing a water outlet grid.

[0015] Compared with existing technologies, this invention has the following advantages and technical effects: It effectively solves key technical issues related to the construction of the internal drainage head of a submarine tunnel shield under hard rock conditions; it solves the problem of hard rock treatment at the vertical jacking section, minimizing the treatment area, saving costs, accelerating construction progress, and ensuring construction safety; it solves the problem of backfill compaction at the treatment area, ensuring normal tunneling of the slurry balance shield while meeting the geological requirements for vertical jacking; and it fills the gap in vertical jacking construction under hard rock conditions, providing a reference for similar projects. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the silt layer reinforcement treatment of the present invention.

[0018] Figure 2 This is a schematic diagram of the installation of the protective sleeve for the present invention.

[0019] Figure 3 This is a schematic diagram illustrating the removal of bedrock inside the casing according to the present invention.

[0020] Figure 4 This is a schematic diagram of the sealing material backfilled inside the casing of the present invention.

[0021] Figure 5 This is a schematic diagram illustrating how the outer area of ​​the casing is protected according to the present invention.

[0022] Figure 6 This is a schematic diagram of the completed tunnel of the present invention.

[0023] Figure 7 This is a schematic diagram of the vertical lifting mechanism of the present invention.

[0024] Figure 8 This is a schematic diagram of grouting inside the casing of the present invention.

[0025] Figure 9 This is a schematic diagram of the completed invention.

[0026] Among them, 1. Seawater; 2. Silt layer; 3. Seabed surface; 4. Rock layer; 5. Tunnel; 6. Sand pile; 7. Casing; 8. Sealing material; 9. Rockfill; 10. Segment; 11. Mud; 12. Water outlet grid. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Reference Figures 1 to 9As shown, the present invention provides a construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel, comprising the following steps: reinforcing the silt layer 2 between seawater 1 and rock strata 4; installing a casing 7 within the reinforced area of ​​the silt layer 2; removing the bedrock inside the casing 7 so that the casing 7 penetrates the top and bottom of the silt layer 2; backfilling the casing 7 with sealing material 8 to seal the internal space of the casing 7; protecting the outer area of ​​the casing 7; conducting shield tunneling construction within the rock strata 4 to form a tunnel 5; and vertically jacking the sealing material 8 inside the casing 7 through the tunnel 5 to force the sealing material 8 out of the casing 7, thus forming the drainage head.

[0030] The drainage head may include a casing 7, a riprap 9, a pipe segment 10, a slurry 11, a water outlet grid 12, and a top cover.

[0031] Furthermore, the silt layer 2 between the seawater 1 and the rock layer 4 is reinforced by means of: reinforcing the silt layer 2 with a number of sand piles 6, the length of the sand piles 6 being 5m-6m and the diameter being 0.5m, the sand piles 6 being arranged in an array, the spacing between adjacent sand piles 6 being 1m, and the row spacing between two adjacent rows of sand piles 6 being 0.7m.

[0032] Furthermore, the bottom of the sand pile 6 is located within the rock stratum 4.

[0033] Furthermore, the bottom of the casing 7 is inserted into the rock layer 4 to a depth of 0.6m, and the top of the casing 7 is 0.6m above the seabed surface 3.

[0034] Furthermore, the casing 7 is made of steel, has a diameter of 5m, and a wall thickness of 0.04m.

[0035] Furthermore, the silt, clay, siltstone, and sand piles inside the casing 7 are removed so that the casing 7 penetrates the top and bottom of the silt layer 2, including removing the bedrock inside the casing 7 by one or more of the following methods: rotary drilling, impact hammer, and blasting.

[0036] Furthermore, the sealing material 8 inside the casing 7 is one or more of calcium-based clay and sand.

[0037] Furthermore, the casing 7 is installed on ships and / or temporary platforms. The casing modules are connected by welding, and special parts are connected by flanges and high-strength bolts, and are equipped with sealing strips to ensure a tight fit between the modules and prevent seawater from seeping in.

[0038] Furthermore, the casing is stabilized by reinforcing the outer area of ​​the casing 7 with riprap 9. Stones with sufficient strength and durability are selected, and mechanical equipment is used to uniformly riprap the outer side of the casing.

[0039] Furthermore, shield tunneling is carried out within the rock stratum 4 to form tunnel 5. Through tunnel 5, the sealing material 8 inside the casing 7 is vertically lifted to drive the sealing material 8 out of the casing 7 to form a drainage head. This also includes: reinforcing the periphery of the drainage head. After the tunnel 5 is filled with water, the top cover of the drainage head is removed and a water outlet grid 12 is installed.

[0040] Example: Shield tunnel 5 has an inner diameter of 7m. Tunnel 5 is entirely composed of hard rock. The top of segment 10 has a moderately weathered to slightly weathered rock layer of approximately 2.5-3m. Above rock layer 4 is a silt layer of approximately 6m. Seawater 1 has a depth of approximately 9m. The drainage head has a 100m flat slope. Each drainage tunnel 5 has 8 drainage heads spaced 12m apart. The drainage risers are rectangular risers with an inner cross-section of 1.8m x 1.8m and a wall thickness of 0.3m. The drainage heads use 4m diameter steel grating.

[0041] Sand piles 6 were used to reinforce the silt layer 2. The sand piles 6 had a diameter of 500mm, a spacing of 1000mm, a row spacing of 700mm, and were arranged in a staggered pattern. The vertical construction depth reached the top of the rock layer 4, and the length of the sand piles 6 was approximately 5m-6m. Casing 7 was fabricated using 5m diameter steel casings with a steel plate thickness of 4cm. The casing 7 was approximately 60cm above the seabed surface 3. It was prefabricated in a factory, and the casings 7 were connected by flanges, with rubber sealing rings used to seal the flanges. The center position of the drainage riser was marked out. Casing 7 was installed using a vessel or temporary platform. Based on the actual project conditions, a comprehensive evaluation was conducted to select a large vessel or temporary work platform to meet the installation requirements of casing 7. Based on the actual situation of the project team, rotary drilling, impact drilling, or underwater blasting can be used to treat the bedrock inside the casing 7 that affects vertical jacking; long-arm excavators or telescopic wall excavators can be used to remove large pieces of residual bedrock inside the casing 7; calcium-based clay, sand, and other sealing materials 8 are backfilled inside the casing 7 to ensure the sealing effect of the shield tunneling slurry chamber; riprap 9 is used to reinforce the perimeter of the casing 7 to ensure its stability; the shield tunneling passes through the drainage head treatment section one by one to the end of the tunnel; vertical jacking is carried out one by one inside the tunnel 5; the height of the top of the tunnel 5 is 0.8m higher than the bottom of the drainage head; mud 11 is used to reinforce the drainage head; water is introduced into the tunnel 5, the top cover of the drainage head is removed, and a water outlet grid 12 is installed.

[0042] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0043] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel, characterized in that, Includes the following steps: The silt layer (2) between the seawater (1) and the rock layer (4) is reinforced; Install a protective casing (7) in the reinforced area of ​​the silt layer (2); Remove the bedrock inside the casing (7) so that the casing (7) penetrates the top and bottom of the silt layer (2); Backfill the casing (7) with sealing material (8) to seal the internal space of the casing (7); Protect the outer area of ​​the casing (7); Shield tunneling is carried out in the rock stratum (4) to form a tunnel (5). The sealing material (8) inside the casing (7) is vertically lifted through the tunnel (5) to drive the sealing material (8) out of the casing (7) and form a drainage head.

2. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 1, characterized in that, The reinforcement treatment of the silt layer (2) between the seawater (1) and the rock layer (4) includes: The silt layer (2) is reinforced by a number of sand piles (6). The length of the sand piles (6) is 5m-6m and the diameter is 0.5m. The sand piles (6) are arranged in an array, the spacing between adjacent sand piles (6) is 1m, and the row spacing between two adjacent rows of sand piles (6) is 0.7m.

3. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 2, characterized in that, The bottom of the sand pile (6) is located within the rock stratum (4).

4. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 1, characterized in that, The bottom of the casing (7) is inserted into the rock layer (4) to a depth of 0.6m, and the top of the casing (7) is 0.6m above the seabed surface (3).

5. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 4, characterized in that, The casing (7) is made of steel, the diameter of the casing (7) is 5m, and the wall thickness of the casing (7) is 0.04m.

6. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 1, characterized in that, The removal of the bedrock inside the casing (7) to allow the casing (7) to penetrate the top and bottom of the silt layer (2) includes: One or more of the following methods are used to remove the bedrock inside the casing (7): rotary drilling, impact hammer, and blasting.

7. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 1, characterized in that, The sealing material (8) inside the casing (7) is one or more of calcium-based clay and sand.

8. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 1, characterized in that, The casing (7) is installed by means of a ship and / or a temporary platform.

9. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 1, characterized in that, The outer area of ​​the casing (7) is protected by throwing stones (9).

10. The construction method for the drainage head of a nuclear power plant cold source in a submarine hard rock shield tunnel according to claim 1, characterized in that, The process of tunneling through a shield tunnel within the rock stratum (4) to form a tunnel (5), and then vertically lifting the sealing material (8) inside the casing (7) through the tunnel (5) to force the sealing material (8) out of the casing (7) and form a drainage head, also includes: The outer perimeter of the drainage head is reinforced. After the tunnel (5) is filled with water, the top cover of the drainage head is removed and the water outlet grille (12) is installed.

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