A shield starting steel box for a tunnel with a small curvature radius and a construction method thereof

Abstract

The present invention discloses a small curvature radius tunnel shield starting steel box, including a steel box support part and a water stop part arranged on the steel box support part; the steel box support part includes a steel box base and a pre-buried steel ring arranged on the upper end of the steel box base; the water stop part includes a water stop steel ring fixedly connected to the pre-buried steel ring, a first curtain rubber plate is fixedly connected to the inner side of the pre-buried steel ring, a second curtain rubber plate is fixedly connected to the inner side of the water stop steel ring, the first curtain rubber plate and the second curtain rubber plate are respectively located on both sides of the water stop steel ring, the present application has good water stop effect, and the leakage water is controllable, and can be applied to shield construction with complex geological structure and surrounding construction environment and rich groundwater strata. Because its wedge-shaped structure is controllable, it can be applied to shield construction under different curvature radii and linear shield construction by changing the geometric size of the wedge-shaped body.

Description

Technical Field

[0001] The invention relates to a tunnel shield starting device, in particular to a tunnel shield starting steel box with a small curvature radius and a construction method. Background Art

[0002] With the rapid development of my country's economy and society, the pressure on urban ground traffic is increasing. Urban rail transit represented by subways plays a vital role in alleviating urban traffic pressure. Shield construction is one of the most widely used subway tunnel construction methods. However, shield starting and excavation construction in water-rich soil layers has always been a common difficulty in shield tunnel construction.

[0003] The more effective water-stopping measures for shield tunneling in water-rich soil layers include: strengthening the starting end well reinforcement, embedding water-stopping devices in the shield tunneling hole, setting double-layer water-stopping steel rings for the shield tunneling hole door, and installing steel plates on the outside of steel boxes. The use of steel plates on the outside of steel boxes can effectively solve the water leakage problem of linear shield tunneling in water-rich soil layers.

[0004] However, in the shield construction with ultra-small radius, especially in the shield construction with complex geological structure and rich groundwater, affected by geological conditions and surrounding construction environment, the end foundation reinforcement, the original tunnel water-stopping measures and the conventional steel plate external steel box cannot meet the water-stopping requirements of shield construction. In order to ensure that the shield machine can start safely under ultra-small radius conditions, it is urgent to invent a shield construction device that can be quickly installed and has reliable performance to meet the starting conditions and reduce the starting risk of the shield. Summary of the invention

[0005] The purpose of the present invention is to provide a shield starting steel box for a tunnel with a small curvature radius and a construction method to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A shield starting steel box for a tunnel with a small curvature radius, characterized in that it comprises a steel box support portion and a water stop portion arranged on the steel box support portion;

[0008] The steel box support part includes a steel box base and an embedded steel ring arranged on the upper end of the steel box base;

[0009] The waterstop part includes a waterstop steel ring fixedly connected to the embedded steel ring, a first cord rubber plate is fixedly connected to the inner side of the embedded steel ring, a second cord rubber plate is fixedly connected to the inner side of the waterstop steel ring, the first cord rubber plate and the second cord rubber plate are respectively located on both sides of the waterstop steel ring, the first cord rubber plate and the second cord rubber plate are arranged in parallel, a first blocking rod is provided on the side of the first cord rubber plate away from the embedded steel ring, the first blocking rod is fixedly connected to the embedded steel ring, a second blocking rod is provided on the end of the second cord rubber plate away from the waterstop steel ring, and the second blocking rod is fixedly connected to the waterstop steel ring.

[0010] As a further solution of the present invention: a structural bottom plate is provided at the lower end of the steel box base, the steel box base is a concrete structure, and reinforcing steel bars are provided inside the steel box base.

[0011] As a further solution of the present invention: a reinforcing steel plate is fixedly connected to a side of the embedded steel ring away from the water-stop steel ring, and a plurality of the reinforcing steel plates are provided and arranged circumferentially.

[0012] As a further solution of the present invention: an injection valve is fixedly connected to the water-stop steel ring.

[0013] As a further solution of the present invention: one end of the water-stop steel ring close to the embedded steel ring is fixedly connected to the embedded steel ring, and a reinforcing rib is provided on the inner side of the water-stop steel ring, and the reinforcing rib is a triangular structure.

[0014] As a further solution of the present invention: the outer end surface of the embedded steel ring is fixedly connected to the first annular pressure plate by a first fastening bolt, and the first cord rubber sheet is fixedly connected between the first annular pressure plate and the embedded steel ring.

[0015] As a further solution of the present invention: a first folding plate is fixedly provided on a side of the first annular pressure plate away from the first cord rubber plate, and the first blocking rod is located on a side of the first folding plate away from the first cord rubber plate.

[0016] As a further solution of the present invention: the outer end surface of the water-stop steel ring is fixedly connected to the second annular pressure plate by a second fastening bolt, and the second cord rubber sheet is fixedly connected between the second annular pressure plate and the water-stop steel ring.

[0017] As a further solution of the present invention: a second folding plate is fixedly provided on a side of the second annular pressure plate away from the second cord rubber plate, and the second blocking rod is located on a side of the second folding plate away from the second cord rubber plate.

[0018] A construction method for a shield starting steel box for a tunnel with a small curvature radius, characterized in that it comprises the following steps:

[0019] Step 1: Set the starting steel box base, set the structural bottom plate, implant the reinforcing steel bars in the structural bottom plate, spot weld the embedded steel ring on the structural bottom plate, install the embedded grouting pipe on the embedded steel ring, and then cast to form the steel box base;

[0020] Step 2: Install the water stop part, fix the water stop steel ring to the embedded steel ring, and install the first curtain rubber sheet:

[0021] The first rubber sheet of the fabric is annular and provided with bolt holes. The first rubber sheet of the fabric is installed closely to the outer surface of the embedded steel ring, and then the first annular pressure plate and the first folding plate are installed and fixed in sequence. The three are fixed to the side plate by the first fastening bolts. The second rubber sheet of the fabric is installed in the same way.

[0022] Step 3: Install the reinforcement steel plate and the blocking rod, weld the reinforcement steel plate to the embedded steel ring, and install the first blocking rod and the second blocking rod on the outside of the first folding plate and the second folding plate respectively;

[0023] Step 4: Check the size of the starting steel box. Before the shield starts, fill part of the circular cavity of the small steel box water-stop structure with inert water-stopping materials. Place a quilt flat on the inner arc surface of the steel box to prevent the outflow of mud and sand. After the construction starts, continue to inject inert water-stopping materials into the cavity.

[0024] Compared with the prior art, the beneficial effects of the present invention are: a wedge-shaped small steel box structure that can effectively solve the problem of the angle between the axis of the starting tunnel of the ultra-small radius shield and the normal direction of the structural side wall. The present invention has good water-stopping effect and controllable water leakage, and can be applied to shield construction in geological structures, surrounding construction environments with complex and rich groundwater strata. Because its wedge-shaped structure is controllable, it can be applied to shield construction under different curvature radii and linear shield construction by changing the geometric dimensions of the wedge-shaped body. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view of the horizontal centerline of the steel box of this embodiment;

[0026] Figure 2 for Figure 1 Middle Ⅰ-Ⅰ cross section;

[0027] Figure 3 for Figure 1 Middle II-II cross section;

[0028] Figure 4 This is a cross-sectional view above the horizontal center line of the steel ring of this embodiment;

[0029] Figure 5 It is a cross-sectional view below the horizontal center line of the steel ring of this embodiment.

[0030] In the figure: 1-injection valve, 2-steel ring, 3-waterstop steel ring, 4-reinforcement rib, 5-first cord rubber plate, 6-second cord rubber plate, 7-first annular pressure plate, 8-second annular pressure plate, 9-first folding plate, 10-second folding plate, 11-first fastening bolt, 12-second fastening bolt, 13-first blocking rod, 14-second blocking rod, 15-embedded grouting pipe, 16-steel box base, 17-reinforcement steel bars, 18-reinforcement steel plate, 19-structural bottom plate. DETAILED DESCRIPTION

[0031] 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 of the present invention. 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 creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-5 In an embodiment of the present invention, a starting steel box for a tunnel shield with a small curvature radius includes a steel box support portion and a water stop portion arranged on the steel box support portion.

[0033] The steel box support part includes a steel box base 16 and a pre-buried steel ring 2 arranged at the upper end of the steel box base 16. Figure 1 As shown, the horizontal centerline section of the steel box base 16 is a wedge-shaped structure, a structural bottom plate 19 is provided at the lower end of the steel box base 16, the steel box base 16 is a concrete structure, reinforcing steel bars 17 are provided inside the steel box base 16, and a reinforcing steel plate 18 is fixedly connected to the side of the embedded steel ring 2 away from the water-stop steel ring 3. There are multiple reinforcing steel plates 18 and they are arranged around. At the same time, a pre-embedded grouting pipe 15 is also provided on the embedded steel ring 2, which is used for grouting when pouring the steel box base 16.

[0034] The water-stopping part comprises a water-stopping steel ring 3 fixedly connected to the embedded steel ring 2, an injection valve 1 is fixedly connected to the water-stopping steel ring 3, one end of the water-stopping steel ring 3 close to the embedded steel ring 2 is fixedly connected to the embedded steel ring 2, a reinforcing rib 4 is arranged on the inner side of the water-stopping steel ring 3, and the reinforcing rib 4 is a triangular structure, a first cord rubber plate 5 is fixedly connected to the inner side of the embedded steel ring 2, a second cord rubber plate 5 is fixedly connected to the inner side of the water-stopping steel ring 3, the first cord rubber plate 5 and the second cord rubber plate 6 are respectively located on both sides of the water-stopping steel ring 3, the first cord rubber plate 5 and the second cord rubber plate 6 are arranged in parallel, a first blocking rod 13 is arranged on the side of the first cord rubber plate 5 away from the embedded steel ring 2, the first blocking rod 13 is fixedly connected to the embedded steel ring 2, and the first A second blocking rod 14 is provided at one end of the second fabric rubber sheet 6 away from the waterstop steel ring 3, and the second blocking rod 14 is fixedly connected to the waterstop steel ring 3. A first folding plate 9 is fixedly provided on the side of the first annular pressure plate 7 away from the first fabric rubber sheet 5, and the first blocking rod 13 is located on the side of the first folding plate 9 away from the first fabric rubber sheet 5. The outer end surface of the waterstop steel ring 3 is fixedly connected to the second annular pressure plate 8 by a second fastening bolt 12. The second fabric rubber sheet 6 is fixedly connected between the second annular pressure plate 8 and the waterstop steel ring 3. A second folding plate 10 is fixedly provided on the side of the second annular pressure plate 8 away from the second fabric rubber sheet 6, and the second blocking rod 14 is located on the side of the second folding plate 10 away from the second fabric rubber sheet 6.

[0035] When the present invention is used, the specific implementation method is:

[0036] 1. Before construction, the staff conducted a detailed study of the geological and hydrological data at the starting point of the shield to determine the groundwater level.

[0037] 2. The best starting frame and reaction frame placement positions should be calculated based on the center line of the tunnel line, the starting posture of the shield machine should be determined, and the overall size of the small steel box should be determined based on the size of the tunnel portal.

[0038] 3. For the rebar embedding area of ​​the positioning mechanism base plate 19 and the installation positions of the various components of the small steel box, drill holes and embed rebars according to the design requirements of the drawings. First, embed rebars on the structure base plate 19, and then embed rebars on the structure end. The embedding length shall be checked according to the design requirements, and the embedding hole position deviation shall be ±50mm.

[0039] 4. Divide the embedded steel ring 2 evenly into 4 parts, and then spot weld the embedded steel ring 2 on the structural base plate 19 in the order of first bottom and then top. After the installation is completed, check the size (R±20mm).

[0040] 5. Divide the middle water-stop steel ring 3 evenly into 4 parts, and then weld the middle water-stop steel ring 3 to the embedded steel ring 2 in the order of first bottom and then top. After the installation is completed, the size is checked (R±20mm). The middle water-stop steel ring 3 is reinforced with triangular reinforcing ribs 4.

[0041] 6. The pre-buried grouting pipe 15 is installed on the steel box base 16 , and the pre-buried grouting pipe 15 passes through the pre-buried steel ring 2 and penetrates into the structural bottom plate 19 .

[0042] 7. Set up formwork and cast the steel box base according to the drawing dimensions to reinforce the cast-in-place steel box base 16. The formwork dimensions and concrete grade must be verified according to the drawing requirements.

[0043] 8. Install the first rubber sheet 5: The first rubber sheet 5 is annular and provided with bolt holes. The first rubber sheet 5 is installed tightly against the outer surface of the embedded steel ring 2. Then, the first annular pressure plate 7 and the first folding plate 9 are installed and fixed in sequence. The three are fixed to the side plate with the first fastening bolts 11.

[0044] 9. Install the second rubber sheet 6: Install the second rubber sheet 6, fix the second annular pressure plate 8 and the second folding plate 10 on the water-stop steel ring 3 in sequence through the second fastening bolts 12. Ensure that the embedded steel ring 2, the water-stop steel ring 3, the first rubber sheet 5 and the second rubber sheet 6 are matched without gaps to ensure a good sealing effect.

[0045] 10. Weld the reinforcing steel plate 18 to the upper half of the embedded steel ring 2, and install the upper injection valve 1 at the same time. The injection valve 1 is welded to the water stop steel ring 3 and the embedded steel ring 2.

[0046] 11. A first blocking rod 13 and a second blocking rod 14 are welded on the first folding plate 5 and the second folding plate 6 to prevent the first folding plate 5 and the second folding plate 6 from turning outward.

[0047] 12. Before using the steel box, check its quality. For deformed or partially damaged steel boxes, they can only be used after being repaired and qualified.

[0048] 13. After the installation of the small steel box with an ultra-small radius for the shield tunneling portal is completed, the circular cavity of the small steel box water-stopping structure is partially filled with inert water-stopping materials before the shield tunneling starts. A quilt is placed flat on the inner arc surface of the steel box to prevent the outflow of mud and sand. After the construction starts, the inert water-stopping materials are continuously injected into the cavity. After the shield tunneling construction starts, the anti-leakage effect should be checked. When the shield cutterheads are all sealed in the tunnel portal and the mud and water pressure is established, once leakage occurs between the first curtain rubber sheet 5, the second curtain rubber sheet 6 and the shield shell, timely measures should be taken to stop the leakage before normal excavation can be carried out.

[0049] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0050] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A shield starting steel box for a tunnel with a small curvature radius, characterized in that: It comprises a steel box support part and a water stop part arranged on the steel box support part; The steel box support portion comprises a steel box base (16) and a pre-buried steel ring (2) arranged at the upper end of the steel box base (16); the water stop portion comprises a water stop steel ring (3) fixedly connected to the pre-buried steel ring (2); The horizontal centerline section of the steel box base (16) is a wedge-shaped structure, and a reinforcing steel plate (18) is fixedly connected to the side of the embedded steel ring (2) away from the water-stop steel ring (3), and the reinforcing steel plates (18) are provided in plurality and arranged circumferentially; A first rubber sheet (5) is fixedly connected to the inner side of the embedded steel ring (2), and a second rubber sheet (6) is fixedly connected to the inner side of the water-stop steel ring (3). The first rubber sheet (5) and the second rubber sheet (6) are respectively located on both sides of the water-stop steel ring (3). The first rubber sheet (5) and the second rubber sheet (6) are arranged in parallel. A first blocking rod (13) is provided on the side of the first rubber sheet (5) away from the embedded steel ring (2), and the first blocking rod (13) is fixedly connected to the embedded steel ring (2). A second blocking rod (14) is provided on the end of the second rubber sheet (6) away from the water-stop steel ring (3), and the second blocking rod (14) is fixedly connected to the water-stop steel ring (3).

2. The shield starting steel box for a tunnel with a small curvature radius according to claim 1, characterized in that: A structural bottom plate (19) is provided at the lower end of the steel box base (16); the steel box base (16) is a concrete structure; and reinforcing steel bars (17) are provided inside the steel box base (16).

3. The shield starting steel box for a tunnel with a small curvature radius according to claim 1, characterized in that: The water-stop steel ring (3) is fixedly connected with an injection valve (1).

4. The shield starting steel box for a tunnel with a small curvature radius according to claim 1, characterized in that: One end of the water-stop steel ring (3) close to the embedded steel ring (2) is fixedly connected to the embedded steel ring (2), and a reinforcing rib (4) is provided on the inner side of the water-stop steel ring (3), and the reinforcing rib (4) is a triangular structure.

5. The shield starting steel box for a tunnel with a small curvature radius according to claim 1, characterized in that: The outer end surface of the embedded steel ring (2) is fixedly connected to a first annular pressure plate (7) via a first fastening bolt (11), and the first cord rubber sheet (5) is fixedly connected between the first annular pressure plate (7) and the embedded steel ring (2).

6. The shield starting steel box for a tunnel with a small curvature radius according to claim 5, characterized in that: A first folding plate (9) is fixedly provided on a side of the first annular pressure plate (7) away from the first cord rubber plate (5), and the first blocking rod (13) is located on a side of the first folding plate (9) away from the first cord rubber plate (5).

7. The shield starting steel box for a tunnel with a small curvature radius according to claim 1, characterized in that: The outer end surface of the water-stop steel ring (3) is fixedly connected to a second annular pressure plate (8) via a second fastening bolt (12), and the second cord rubber plate (6) is fixedly connected between the second annular pressure plate (8) and the water-stop steel ring (3).

8. The shield starting steel box for a tunnel with a small curvature radius according to claim 7, characterized in that: A second folding plate (10) is fixedly provided on a side of the second annular pressure plate (8) away from the second rubber cord sheet (6), and the second blocking rod (14) is located on a side of the second folding plate (10) away from the second rubber cord sheet (6).

9. A construction method for a shield starting steel box for a small curvature radius tunnel according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1, setting the starting steel box base, setting the structural bottom plate (19), implanting the reinforcing steel bar (17) in the structural bottom plate (19), spot welding the embedded steel ring (2) on the structural bottom plate (19), and installing the embedded grouting pipe (15) on the embedded steel ring (2), and then casting to form the steel box base (16); Step 2, install the water stop part, fix the water stop steel ring (3) to the embedded steel ring (2), and install the first rubber sheet (5): the first rubber sheet (5) is annular and provided with bolt holes, the first rubber sheet (5) is installed tightly against the outer surface of the embedded steel ring (2), and then the first annular pressure plate (7) and the first folding plate (9) are installed and fixed in sequence, and the three are fixed to the side plate by the first fastening bolt (11), and the second rubber sheet (6) is installed in the same way; Step 3: Install the reinforcement steel plate (18) and the blocking rod, weld the reinforcement steel plate (18) to the embedded steel ring (2), and install the first blocking rod (13) and the second blocking rod (14) on the outside of the first folding plate (9) and the second folding plate (10) respectively; Step 4: Check the size of the starting steel box. Before the shield starts, fill part of the circular cavity of the small steel box water-stop structure with inert water-stopping materials. Place a quilt flat on the inner arc surface of the steel box to prevent the outflow of mud and sand. After the construction starts, continue to inject inert water-stopping materials into the cavity.

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