High-pressure-bearing shield tail brush

Abstract

A high-pressure-bearing shield tail brush comprises a plurality of base steel plate layers installed on a shield tail, a sealing structure layer capable of abutting against the end face of a segment is fixed to each base steel plate layer, an annular grease cavity is formed between every two adjacent sealing structure layers in the annular direction, and a reinforced pressure maintaining layer capable of abutting against the end face of the segment is further fixed to each base steel plate layer. And the enhanced pressure maintaining layer and the sealing structure layer on the same base steel plate layer are arranged at an interval, so that the annular grease cavity between the adjacent sealing structure layers is divided into a first grease cavity and an enhanced grease cavity by the enhanced pressure maintaining layer. According to the shield tail brush, the independent reinforced grease cavities can be formed between the adjacent shield tail brushes, the number of original shield tail sealing cavities is doubled, the shield tail sealing performance is effectively improved, no extra space is occupied after improvement, and the installation and replacement cost is low.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine technology, specifically to a high-pressure-bearing tail brush. Background Technology

[0002] In shield tunneling, the tail brush is installed in the annular gap between the shield shell and the outer arc surface of the tunnel segment at the tail of the shield machine. It is the last line of defense to prevent groundwater, synchronous grouting fluid and soil and sand from flowing into the tunnel. The reliability of its sealing performance directly determines the construction safety.

[0003] Currently, tunnel boring machine (TBM) construction is developing in depth towards "four supers" – super large diameter, super long distance, super deep burial, and super high water pressure. This places unprecedentedly stringent requirements on the sealing performance of the tail shield. In particular, under super high water pressure conditions, the seepage pressure in cross-river and cross-sea tunnels can reach over 0.9 MPa. Once the tail shield fails to seal due to wear, fatigue, or partial detachment, high-speed and high-pressure water will rush in instantly, which can easily induce catastrophic water and sand inrush. At best, it can lead to machine shutdown and maintenance; at worst, it can cause surface subsidence, damage to buildings and structures, or even the collapse of the entire tunnel.

[0004] like Figure 1 and Figure 2 As shown, a conventional shield tail brush mainly consists of a base steel plate layer 3, a protective plate 4, a wire bundle 7, and a clamping plate 5. The protective plate is tightly fitted to the tunnel segment 2 and, together with the wire bundle and shield tail grease, provides a sealing function. The shield tail brushes are radially spliced ​​and welded into rings along the shield tail 1. Shield tail grease is injected between two rings to form a sealed cavity, thus sealing the shield tail and preventing groundwater, synchronous grouting fluid, and soil / sand from entering the tunnel. The sealing capacity of the shield tail is related to the number of shield tail brush layers; increasing the number of layers improves the sealing capacity, but excessively many layers of shield tail brushes occupy more space and increase replacement costs later.

[0005] Faced with the challenges of the superposition of four extreme composite working conditions, the existing shield tail brush design can hardly meet the safety redundancy requirements of "high pressure resistance". There is an urgent need to develop a new type of shield tail brush with high sealing performance that can adapt to and resist ultra-high pressure, so as to provide reliable protection for tunnel construction safety in extreme environments. Summary of the Invention

[0006] The purpose of this invention is to propose a high-pressure shield tail brush that can form independent reinforced grease cavities between adjacent shield tail brushes, thereby doubling the number of original shield tail sealing cavities, effectively improving shield tail sealing performance, and without occupying additional space, and with low installation and replacement costs.

[0007] The technical solution adopted in this invention is: a high-pressure shield tail brush, comprising multiple base steel plate layers installed at the shield tail, each base steel plate layer having a sealing structure layer fixed thereon that can abut against the end face of the tunnel segment, adjacent sealing structure layers forming annular grease cavities in the circumferential direction, each base steel plate layer also having a reinforcing pressure-retaining layer fixed thereon that can abut against the end face of the tunnel segment, the reinforcing pressure-retaining layer and the sealing structure layer on the same base steel plate layer being spaced apart, such that the reinforcing pressure-retaining layer divides the annular grease cavity between adjacent sealing structure layers into a first grease cavity and a reinforcing grease cavity.

[0008] As a preferred embodiment, each sealing structure layer is composed of no less than two sealing structures arranged in a ring. One end of the sealing structure is fixedly connected to the base steel plate layer, and the other end is raised and can abut against the end face of the tube segment. Each sealing structure includes a protective plate, a clamping plate, and a wire bundle assembly located between the protective plate and the clamping plate, wherein the protective plate is located on the side facing the segment.

[0009] As a preferred embodiment, the reinforcing pressure-holding layer is formed by a ring of pressure-holding plates, one end of which is fixed to the base steel plate layer, and the other end is raised and can abut against the end face of the tube segment; the first grease chamber is located between the pressure-holding plate and the adjacent sealing structure layer, and the reinforcing grease chamber is located between the protective plate and the pressure-holding plate.

[0010] As a preferred option, adjacent pressure-holding plates of the same reinforced pressure-holding layer are staggered.

[0011] As a preferred option, the pressure plate and the protective plate are tilted in the same direction.

[0012] As a preferred embodiment, a fixing mounting part is provided on the base steel plate layer, and one end of each sealing structure is fixed in the fixing mounting part.

[0013] As a preferred embodiment, the length of the wire-wrapped assembly is greater than the length of the protective plate.

[0014] As a preferred embodiment, the wire bundle assembly includes at least two layers of wire bundles, with a screen placed between adjacent wire bundles.

[0015] As a preferred embodiment, the end of the wire-wrapped assembly away from the base steel plate layer is stepped.

[0016] As a preferred embodiment, one end of the pressure holding plate is fixedly connected to the base steel plate layer via a connector; Each connector includes a locating pin and a pressure plate with a pin hole. The locating pin is fixed to the base steel plate layer, and the end of the locating pin passes through the pin hole and is welded to the pressure plate, thereby pressing the end of the pressure plate between the pressure plate and the base steel plate layer.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. The shield tail brush of the present invention adds an enhanced pressure-retaining layer on the basis of the conventional shield tail brush. Under the condition that the shield tail installation size remains unchanged, an additional grease chamber can be added on the basis of the original grease chamber, which effectively enhances the sealing performance of the shield tail brush, prevents the risk of sealing failure, and can completely block the leakage channel of the shield tail, so as to achieve construction safety under high water pressure and long-distance tunneling conditions.

[0018] 2. The reinforced pressure-holding layer is made by adding a pressure-holding plate to the conventional shield tail brush structure, and the processing cost and subsequent replacement cost are not high.

[0019] 3. The staggered multi-layer "pressure-holding plates" can form a seal on their own. When the shield tail brush of other sealing cavities is damaged, they can play a sealing role and prevent groundwater, synchronous grouting fluid and soil and sand from flowing into the tunnel. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the structure of a single conventional shield tail brush; Figure 2 This is a schematic diagram illustrating the working principle of a conventional shield tail brush seal. Figure 3 This is a schematic diagram of a single shield tail brush in this invention; Figure 4 This is a schematic diagram illustrating the working principle of the shield tail brush sealing mechanism of the present invention; Figure 5 for Figure 4 A partial schematic diagram.

[0022] Reference numerals: 1. Shield tail, 2. Segment, 3. Base steel plate layer, 301. Fixed installation part, 4. Protective plate, 5. Pressing plate, 6. Pressure holding plate, 7. Wire bundle, 8. Screen, 9. Positioning pin, 10. Pressure plate, 11. Annular grease chamber, 12. First grease chamber, 13. Reinforcing grease chamber. Detailed Implementation

[0023] The present invention will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0024] It should be noted that, unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "a," "an," or "the," etc., used in the specification and claims of this patent application do not express a limitation on quantity, but rather indicate the presence of at least one; the terms "first," "second," and "third," as used herein, should not be considered as a limitation on the order of components, but are merely for distinguishing different components; the terms "comprising," "including," etc., indicate that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects having the same function.

[0025] To more clearly describe this high-pressure shield tail brush, combined with the attached... Figure 3-5 This embodiment is described as follows: like Figure 3-5 As shown, a high-pressure shield tail brush includes multiple base steel plate layers 3 installed on the shield tail 1. Each base steel plate layer 3 is fixed with a sealing structure layer that can abut against the end face of the segment 2. An annular grease cavity 11 is formed circumferentially between adjacent sealing structure layers (similar to a conventional shield tail brush, see reference). Figure 2 Each base steel plate layer 3 is also fixed with a reinforcing pressure-retaining layer that can abut against the end face of the tube segment 2. The reinforcing pressure-retaining layer and the sealing structure layer on the same base steel plate layer 3 are spaced apart so that the reinforcing pressure-retaining layer divides the annular grease cavity 11 between adjacent sealing structure layers into a first grease cavity 12 and a reinforcing grease cavity 13.

[0026] Each sealing structure layer consists of at least two sealing structures arranged in a ring. The base steel plate layer 3 is provided with a fixed mounting part 301. One end of each sealing structure is fixed in the fixed mounting part 301 and is connected and fixed by plugging, clamping or other common mechanical connection methods. The other end of the sealing structure is raised and can abut against the end face of the tube segment 2. Each sealing structure includes a protective plate 4, a pressing plate 5 and a wire bundle assembly between the protective plate 4 and the pressing plate 5, wherein the protective plate 4 is located on the side facing the tube segment 2.

[0027] The wire mesh assembly includes at least two layers of wire mesh 7. One end of all the wire mesh 7 is fixed by a clamping plate and inserted into the fixing mounting part 301 for clamping. The wire mesh 7 is in direct contact with the shield tail grease. A screen 8 is set between adjacent wire mesh 7. The screen 8 has fine holes, which can prevent the shield tail grease from leaking from the gaps in the wire mesh, thereby improving the sealing performance.

[0028] The length of the wire bundle assembly is greater than the length of the protective plate 4 to ensure stable contact between the wire bundle 7 and the shield tail grease on the end face of the segment 2; the end of the wire bundle assembly away from the base steel plate layer 3 is stepped, which can increase the contact area with the shield tail grease and improve the sealing ability.

[0029] The reinforced pressure-retaining layer is formed by pressure-retaining plates 6 arranged in a ring. One end of the pressure-retaining plate 6 is fixed to the base steel plate layer 3, and the other end is raised and can abut against the end face of the segment 2. The raised direction of the pressure-retaining plate 6 and the protective plate 4 is the same, without occupying additional space. Both the protective plate 4 and the pressure-retaining plate 6 have a certain degree of toughness. After they are in close contact with the end face of the segment 2, a first grease cavity 12 is formed between the pressure-retaining plate 6 and the adjacent sealing structure layer, and a reinforced grease cavity 13 is formed between the protective plate 4 and the pressure-retaining plate 6. The first grease cavity 12 and the reinforced grease cavity 13 are distributed in pairs along the radial direction of the shield tail 1. This can add a grease cavity on the basis of the original grease cavity, effectively enhance the sealing performance of the shield tail brush, prevent the risk of sealing failure, and completely block the leakage channel of the shield tail, so as to achieve construction safety under high water pressure and long-distance tunneling conditions.

[0030] To improve the sealing capability of the reinforced pressure-retaining layer, adjacent pressure-retaining plates 6 of the same reinforced pressure-retaining layer are staggered. That is, each reinforced pressure-retaining layer actually consists of two layers of pressure-retaining plates 6. First, multiple pressure-retaining plates 6 are installed circumferentially along the tail of the shield to form a ring, which is the first layer. Then, a second layer of pressure-retaining plates 6 is installed outside the first layer of pressure-retaining plates 6. In the second layer, the middle position of each pressure-retaining plate 6 is aligned with the joint position of the first layer of pressure-retaining plates 6. This staggered design not only improves the sealing capability of each reinforced pressure-retaining layer, but also maintains its sealing performance when other sealing cavities or the tail of the shield are damaged, preventing groundwater, synchronous grouting fluid, and soil and sand from flowing into the tunnel.

[0031] One end of the pressure-holding plate 6 is fixedly connected to the base steel plate layer 3 via a connector. Each connector includes a positioning pin 9 and a pressure plate 10 with a pin hole. The positioning pin 9 is fixed to the base steel plate layer 3, and the end of the positioning pin 9 passes through the pin hole and is welded to the pressure plate 10, thus pressing the end of the pressure-holding plate 6 between the pressure plate 10 and the base steel plate layer 3. Depending on installation requirements, the positioning pin 9 is designed to be slightly longer. After the pressure-holding plate 6 is installed in place, it is welded to the positioning pin 9. The excess portion of the positioning pin 9 is cut off. The reinforced pressure-holding layer is formed by adding the pressure-holding plate to a conventional shield tail brush structure, resulting in low processing and replacement costs.

[0032] The parts not described in detail in the above embodiments are existing technologies.

[0033] It should be noted that although the present invention has been described through the above embodiments, the present invention may have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and modifications to the present invention, but all such changes and modifications should fall within the scope of protection of the appended claims and their equivalents.

Claims

1. A high-pressure-bearing shield tail brush, comprising multiple base steel plate layers (3) installed on the shield tail (1), each base steel plate layer (3) having a sealing structure layer fixed thereon that can abut against the end face of the tube segment (2), and adjacent sealing structure layers forming an annular grease cavity in the circumferential direction, characterized in that: Each base steel plate layer (3) is also fixed with a reinforcing pressure-retaining layer that can abut against the end face of the tube segment (2). The reinforcing pressure-retaining layer and the sealing structure layer on the same base steel plate layer (3) are spaced apart so that the reinforcing pressure-retaining layer divides the annular grease cavity between adjacent sealing structure layers into a first grease cavity and a reinforcing grease cavity.

2. The high-pressure-bearing tail brush according to claim 1, characterized in that: Each sealing structure layer consists of no less than two sealing structures arranged in a ring. One end of the sealing structure is fixedly connected to the base steel plate layer (3), and the other end is raised and can abut against the end face of the tube segment (2). Each sealing structure includes a protective plate (4), a clamping plate (5), and a wire bundle assembly located between the protective plate (4) and the clamping plate (5), wherein the protective plate (4) is located on the side facing the segment (2).

3. A high-pressure-bearing tail brush according to claim 2, characterized in that: The reinforcing pressure layer is formed by the pressure plate (6) arranged in a ring. One end of the pressure plate (6) is fixed to the base steel plate layer (3), and the other end is raised and can abut against the end face of the tube segment (2). The first grease chamber is located between the pressure plate (6) and the adjacent sealing structure layer, and the reinforcing grease chamber is located between the protective plate (4) and the pressure plate (6).

4. A high-pressure-bearing shield tail brush according to claim 3, characterized in that: Adjacent pressure plates (6) of the same reinforced pressure layer are staggered.

5. A high-pressure-bearing shield tail brush according to claim 2, characterized in that: The pressure plate (6) and the protective plate (4) are tilted in the same direction.

6. A high-pressure-bearing tail brush according to claim 1, characterized in that: A fixed mounting part (301) is provided on the base steel plate layer (3), and one end of each sealing structure is fixed in the fixed mounting part (301).

7. A high-pressure-bearing tail brush according to claim 2, characterized in that: The length of the wire wrapping assembly is greater than the length of the protective plate (4).

8. A high-pressure-bearing tail brush according to claim 2, characterized in that: The wire bundle assembly includes at least two layers of wire bundles (7), with a screen (8) placed between adjacent wire bundles (7).

9. A high-pressure-bearing shield tail brush according to claim 2, characterized in that: The end of the wire-wrapped assembly away from the base steel plate layer (3) is stepped.

10. A high-pressure-bearing tail brush according to claim 1, characterized in that: One end of the pressure plate (6) is fixedly connected to the base steel plate layer (3) through a connector; Each connector includes a positioning pin (9) and a pressure plate (10) with a pin hole. The positioning pin (9) is fixed on the base steel plate layer (3). The end of the positioning pin (9) passes through the pin hole and is welded to the pressure plate (10) to press the end of the pressure plate (6) between the pressure plate (10) and the base steel plate layer (3).

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