A back-embedded device and method for supporting a pipe section in a water-rich stratum

Abstract

The application provides a back-embedded device and method for supporting a water-rich stratum segment, relates to the field of tunnel engineering, and aims at the problem of poor adhesion of a support member arranged between a segment and surrounding rock. Under the action of a shear member, the initial strength is improved, under the stable action of a support layer, water seepage into the shell can be evenly diffused by the fiber cotton, the expansive cement is uniformly expanded, small gaps are filled, and thus the adhesion effect of the segment and the surrounding rock is ensured, and the support strength on the segment is improved.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering, specifically to a pre-embedded device and method for supporting tunnel segments in water-rich strata. Background Technology

[0002] During tunnel boring machine (TBM) excavation, the TBM's excavation diameter is slightly larger than the outer diameter of the tunnel segments, leaving a certain gap between the segments and the surrounding rock. When a segment detaches from the TBM's tail section, the segment at the bottom of the ring sinks due to its own weight and intrudes into the gap between the segment and the surrounding rock, causing misalignment and leakage. During long-term tunnel operation, factors such as grouting defects and groundwater seepage may cause the segments to float, resulting in misalignment between segments and affecting the tunnel's safety performance and normal operation.

[0003] Chinese patent (publication number CN210118140U) discloses an invert arch support assembly suitable for precast segment lining structures in tunnel boring machines (TBMs). This assembly features a support structure on the outside of the precast segments, connected via threaded embedded sleeves, serving to support the segments and bridge the gap between them and the surrounding rock. However, the diameter of the surrounding rock fluctuates during TBM excavation, and the gap between the segments and the rock is uncertain. Therefore, the dimensions of the support components cannot be determined in advance, resulting in poor matching between the support components and the gap. Even after the support components are installed, it is still difficult to effectively support the segments, and the fit between the segments and the surrounding rock is insufficient, causing problems such as misalignment, leakage, and segment misalignment. Summary of the Invention

[0004] The purpose of this invention is to address the deficiencies of existing technologies by providing a pre-embedded device and method for supporting tunnel segments in water-rich strata. This method uses fiber cotton to wrap expansive cement to form an expansion layer, which enhances the initial strength under the action of shearing components. With the stabilizing effect of the support layer, seepage water entering the outer shell can be evenly diffused by the fiber cotton, causing the expansive cement to expand uniformly and fill small gaps, thereby ensuring the adhesion between the tunnel segment and the surrounding rock and improving the support strength for the tunnel segment.

[0005] The first objective of this invention is to provide a back-embedded device for supporting segments in water-rich strata, which adopts the following scheme: including:

[0006] An expansion block includes an expansion layer and a support layer that are alternately stacked. An elastic element penetrates the expansion block along the stacking direction. The expansion layer includes expansion cement and fiber cotton covering the expansion cement.

[0007] A scissor-type component is arranged on both sides of the expansion block. The scissor-type component is connected to a spring-loaded component. The spring-loaded component's spring-loaded direction is parallel to the direction of the elastic force applied by the elastic component.

[0008] The outer casing includes a cavity for accommodating the expansion block and the scissor mechanism, and the outer casing is provided with perforations.

[0009] Furthermore, the elastic element is a spring, with one end of the spring fixed to the bottom surface of the expansion block and the other end fixed to the top surface of the expansion block. One end of the connector is fixed to the expansion block, and the other end passes through the outer shell to connect to the embedded part on the tube segment.

[0010] Furthermore, the elastic element penetrates the expansion layer, and the expansion cement encapsulates the elastic element within the expansion layer.

[0011] Furthermore, the scissor-type components on both sides of the expansion block are connected by connecting rods, which are located outside the expansion block and whose axes are arranged along the tunnel extension direction.

[0012] Furthermore, spring-loaded components are provided on both sides of the rotating shaft of the scissor-type component, and the spring-loaded components are arranged at the corner positions of the cavity.

[0013] Furthermore, the outer shell is an elastic shell, and the internal cavity is rectangular in shape.

[0014] Furthermore, the seepage holes are distributed on the outer peripheral surface of the shell, and each seepage hole penetrates the side wall of the shell, connecting the inside and outside of the shell.

[0015] Furthermore, the support layer is an elastic support structure, and the support plate contains rigid dopants.

[0016] A second objective of this invention is to provide a method for operating a pre-embedded device behind a water-rich stratum tunnel segment as described in the first objective, comprising:

[0017] The embedded device is installed on the tunnel segments, and the tunnel segments are assembled into a ring. The embedded device is located at the support position between the tunnel segments and the surrounding rock.

[0018] The outer shell is attached to the outer wall of the segment at one end along the radial direction, and to the surrounding rock at the other end;

[0019] Water seeping from the surrounding rock enters the outer shell through the seepage holes and comes into contact with the expansive cement, causing the expansive cement to increase in volume, press against the surrounding rock, and provide support for the tunnel lining segments.

[0020] Furthermore, when expansive cement comes into contact with water, the elastic element is encased by the expansive cement in the expansive layer. After the expansive cement solidifies, the elastic element acts as the skeleton of the expansive cement, increasing the strength of the expansive block.

[0021] Compared with the prior art, the advantages and positive effects of this invention are:

[0022] (1) To address the problem of poor fit between the supporting components between the pipe segments and the surrounding rock, fiber cotton is used to wrap the expansive cement to form an expansion layer. Under the action of the shear component, the initial strength is improved. Under the stabilizing effect of the supporting layer, the seepage water entering the shell can be evenly diffused by the fiber cotton, so that the expansive cement expands evenly and fills the small gaps, thereby ensuring the fit between the pipe segments and the surrounding rock and improving the support strength of the pipe segments.

[0023] (2) The elastic element is inserted into the expansion block and plays a guiding role when the expansion block expands. At the same time, the elastic element itself is a skeleton structure. The expansion cement in the expansion layer surrounds and wraps the elastic element. As the expansion cement reacts with water, the elastic element, as the skeleton after the expansion cement solidifies, further increases the strength of the entire expansion block and resists the damage caused by external stress.

[0024] (3) An elastic shell is adopted, which can deform with the deformation of the expansion block and the scissor component. The insertion direction of the elastic element is collinear with the direction of its rebound. The elastic shell can be stretched or shortened along the insertion direction of the elastic element to keep the expansion block and the scissor component wrapped.

[0025] (4) In order to meet the installation requirements of different thickness gaps between the surrounding rock and the pipe segments, after the pipe segments are installed, when the pipe segments are formed into a ring, they can squeeze the pre-embedded device together with the surrounding rock, so that the support layer and shear components can deform along the direction of the elastic element, thereby adapting to the gap size between the surrounding rock and the pipe segments, so that it can be stably supported between the pipe segments and the surrounding rock. At the same time, the expansion block can expand when it encounters water, thereby improving its tightness with the surrounding rock and the pipe segments. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 This is a schematic diagram of the pre-embedded device behind the supporting water-rich strata segments in Embodiments 1 and 2 of the present invention.

[0028] Figure 2 This is a schematic diagram of the scissor-type component in Embodiments 1 and 2 of the present invention.

[0029] Figure 3 This is a schematic diagram of the internal structure of the pre-embedded device behind the supporting water-rich strata segments in Embodiments 1 and 2 of the present invention.

[0030] Figure 4 This is a schematic diagram of the rubber layer in Embodiments 1 and 2 of the present invention.

[0031] Figure 5 This is a schematic diagram of the scissor-type component in Embodiments 1 and 2 of the present invention.

[0032] Figure 6 This is a schematic diagram of the internal structure of the pre-embedded device behind the supporting water-rich strata segments in Embodiments 1 and 2 of the present invention.

[0033] Among them, 1. Bolt, 2. Elastic element, 3. Support layer, 4. Expansion layer, 5. Outer shell, 6. Seepage hole, 7. Support rod, 8. Iron wire, 9. Steel shavings, 10. Embedded part, 11. Tube segment, 12. Embedded device, 13. Rebound element, 14. Connecting rod. Detailed Implementation

[0034] Example 1

[0035] In a typical embodiment of the present invention, such as Figures 1-6 As shown, a back-embedded device for supporting segments in water-rich strata is presented.

[0036] The diameter of the surrounding rock fluctuates during the tunnel boring machine's excavation process, and the gap size between the tunnel segment 11 and the surrounding rock is uncertain. Traditional support components have fixed dimensions and poor support strength reliability, which can easily cause problems such as misalignment, water leakage, and misalignment of the tunnel segment 11, making it difficult to meet the construction requirements of the tunnel segment 11 inside the tunnel.

[0037] Based on this, this embodiment provides a pre-embedded device behind the supporting segment of water-rich strata. It adopts a multi-layer superimposed structure formed by expansion layer 4 and support layer 3. The expansion layer 4 is made of fiber cotton wrapped with expansion cement. After the expansion cement reacts with the seepage water, it can increase in thickness, thereby filling the small gaps in the unbonded area, ensuring the bonding effect between the segment 11 and the surrounding rock, and improving the support strength of the segment 11.

[0038] The following section provides a detailed description of the pre-embedded device behind the supporting segments in water-rich strata, with reference to the accompanying drawings.

[0039] See Figure 1 The pre-embedded device behind the supporting water-rich strata segments includes an expansion block, a shearing component, and a shell 5. The shearing component is arranged on both sides of the expansion block and can work together with the expansion block to achieve temporary support. The shell 5 is wrapped around the expansion block and the shearing component. The shell 5 is provided with seepage holes 6. After seepage water enters the interior of the shell 5 through the seepage holes 6, it reacts with the expansion block to achieve expansion, thereby filling the small gaps and improving the bonding effect.

[0040] Specifically, in combination Figure 1 and Figure 3 The expansion block includes alternating layers of expansion 4 and support layers of 3, with a support layer of 3 placed between two layers of expansion 4, forming a structure as shown in the figure. Figure 3 The superimposed structure is shown. The elastic element 2 penetrates the expansion block along its superposition direction, and the direction of the elastic force applied by the elastic element 2 is the same as the superposition direction.

[0041] Meanwhile, the scissor-type component is X-shaped and connected to a spring-loaded component 13. The spring-loaded component 13 can drive the scissor-type component to rotate, changing its support height. The spring-loaded component 13's spring-loaded direction is parallel to the direction of the elastic force applied by the elastic component 2. Figure 3 As shown in the example, after being arranged in the tunnel segment 11, the elastic force of the elastic element 2 is applied in the radial direction of the tunnel along the axial direction of the elastic element 2.

[0042] The expansion layer 4 includes expansive cement and fiber cotton covering the expansive cement. On the one hand, the fiber cotton can cover and constrain the loose expansive cement, keeping it inside the expansion block. On the other hand, the fiber cotton can deform under pressure, reducing the overall thickness of the expansion block, making it easier to pre-press the entire pre-embedded device 12 into the gap between the pipe segment 11 and the surrounding rock. Furthermore, the seepage water entering the outer shell 5 can be evenly diffused by the fiber cotton, causing the expansive cement to expand evenly, filling the small gaps and ensuring the bonding effect between the pipe segment 11 and the surrounding rock.

[0043] It should be noted that the bottom of the expansion block is the expansion layer 4, and the outer shell 5 is an elastic shell. One side of the bottom surface of the expansion block faces the surrounding rock and contacts the surrounding rock through the elastic shell 5. After water seeps into the shell 5, the expansion cement inside the expansion block expands when it comes into contact with water and expands along the stacking direction. During the expansion process, it is also limited by the surrounding rock surface it contacts, so that it can gradually conform to the shape of the surrounding rock surface during the expansion process. Finally, the shape after expansion and deformation matches the surrounding rock surface it is attached to, filling the small gaps in the contact between the planar structure and the surrounding rock, and improving the matching between the pre-embedded device 12 and the gap size.

[0044] like Figure 3 and Figure 5 As shown, the elastic element 2 is a spring, with one end fixed to the bottom surface of the expansion block and the other end fixed to the top surface of the expansion block. One end of the connector is fixed to the expansion block, and the other end passes through the outer casing 5 to connect to the embedded part 10 on the tube segment 11. The connector is coaxially arranged with the spring, as shown... Figure 6 As shown, this fixes the entire pre-embedded device 12 onto the segment 11.

[0045] The axial direction of the elastic element 2 is the same as the superposition direction of the multi-layer structure of the expansion block. Therefore, by using the elastic element 2 to pass through the expansion block, it plays a guiding role when the expansion block expands, so that the expansion of the expansion block has a partial movement along the axial direction of the elastic element 2, which meets the needs of filling small gaps and adapting to gaps of different sizes.

[0046] The elastic element 2 penetrates the expansion layer 4, and the expansion cement wraps the elastic element 2 inside the expansion layer 4. The expansion cement and the local elastic element 2 are in contact. After the expansion cement reacts with water, the expansion cement and the elastic element 2 become one.

[0047] Specifically, the elastic element 2 itself serves as a skeleton structure. The expansive cement located within the expansion layer 4 surrounds and wraps the elastic element 2. As the expansive cement gradually reacts with water, the elastic element 2, as the skeleton after the expansive cement solidifies, further increases the strength of the entire expansion block and resists damage caused by external stress.

[0048] Combination Figure 1 , Figure 2 and Figure 5 The scissor-type components on both sides of the expansion block are connected by a connecting rod 14, which is located outside the expansion block and whose axis is arranged along the tunnel extension direction. Rebound members 13 are provided on both sides of the rotation axis of the scissor-type components, and the rebound members 13 are arranged at the corner positions of the cavity.

[0049] In this embodiment, the rebound member 13 is a high-strength compression spring, the connecting member is a bolt 1, the elastic member 2 is a high-strength spring to meet the support strength requirements, and the fiber cotton is ES fiber hot air cotton.

[0050] The scissor component is an X-shaped structure formed by two support rods 7 connected by a pin. Two spring-loaded parts 13 are connected to the same scissor component. The spring-loaded parts 13 are located on both sides of the pin axis. One end of the spring-loaded part 13 is connected to one end of a support rod 7, and the other end of the spring-loaded part 13 is connected to one end of another support rod 7. The axes of the two spring-loaded parts 13 are arranged in parallel.

[0051] To ensure the initial rigidity of the embedded device 12, support rods 7 are arranged in an "X" shape to form a scissor-like component, connected by pins to prevent them from dispersing and to allow relative rotation. Simultaneously, to increase the elasticity of the scissor-like component, a spring-loaded member 13 is added to connect the upper and lower parts, ensuring both the rigidity of the scissor-like component and, during compression, utilizing the elasticity of the spring-loaded member 13 to guarantee the vertical extensibility of the scissor-like component.

[0052] The support layer 3 and the shear component can also deform along the penetration direction of the elastic element 2. After being installed on the segment 11, when the segment 11 forms a ring, it can squeeze the pre-embedded device 12 together with the surrounding rock, so that the support layer 3 and the shear component can deform along the penetration direction of the elastic element 2, thereby adapting to the gap size between the surrounding rock and the segment 11, so that it can be stably supported between the segment 11 and the surrounding rock, without affecting the subsequent expansion of the expansion block when it encounters water, thus improving the ease of installation.

[0053] like Figure 5 As shown, the outer shell 5 includes a cavity for accommodating the expansion block and the scissor component. The outer shell 5 is an elastic shell, and the inner cavity is rectangular in shape.

[0054] The elastic outer shell 5 can deform with the expansion block and the scissor component. The insertion direction of the elastic element 2 is collinear with its rebound direction. The elastic outer shell 5 can be stretched or shortened along the insertion direction of the elastic element 2 to keep the expansion block and the scissor component wrapped.

[0055] like Figure 4 As shown, the support layer 3 is an elastic support structure, and the support plate contains rigid dopants.

[0056] In this embodiment, the support layer 3 is a rubber sheet. To prevent the component from having too little stiffness before the expansion cement reacts with water, iron wire 8 and steel scrap 10 are added as rigid admixtures when the rubber sheet is made, so as to improve the stiffness of the support layer 3 under initial conditions and prevent it from being damaged by pressure.

[0057] It is understood that in other alternative embodiments, the support layer 3 may be made of modified rubber sheet, which can meet the requirements of elasticity and stiffness; other rigid dopants, such as steel fibers and iron filings, may also be added to the rubber sheet.

[0058] like Figure 5 As shown, seepage holes 6 are distributed on the outer peripheral surface of the outer shell 5, and each seepage hole 6 penetrates the side wall of the outer shell 5, connecting the inside and outside of the outer shell 5. It can be understood that the pore size and distribution position of the seepage holes 6 can be adjusted according to requirements to meet the water absorption needs of the expansion block.

[0059] like Figure 6 As shown, the segment 11 is a prefabricated structure, and the embedded part 10 set on the segment 11 is an embedded sleeve. One end of the connector is connected to the expansion block, and the other end is threaded to the embedded sleeve.

[0060] Example 2

[0061] In another typical embodiment of the present invention, such as Figures 1-6 As shown, a working method for a pre-embedded device behind a segment supporting a water-rich stratum is presented.

[0062] The method of using the pre-embedded device behind the supporting water-rich strata segment as shown in Example 1 includes the following steps:

[0063] The embedded device 12 is installed on the segment 11, and the segment 11 is assembled into a ring. The embedded device 12 is located at the support position between the segment 11 and the surrounding rock.

[0064] The outer shell 5 is attached to the outer wall of the segment 11 at one end along the radial direction of the segment, and to the surrounding rock at the other end;

[0065] Water seeping from the surrounding rock enters the outer shell 5 through the seepage holes 6 and comes into contact with the expansive cement, causing the expansive cement to increase in volume, press against the surrounding rock, and provide support for the tunnel lining segments 11. (Outer shell)

[0066] When the expansive cement comes into contact with water, the expansive cement wrapped by the elastic element 2 in the inner and outer rings of the expansive layer 4 solidifies, serving as the skeleton of the expansive cement to increase the strength of the expansive block.

[0067] When the thickness of the embedded device 12 along the radial direction of the segment 11 is less than the thickness of the gap between the segment 11 and the surrounding rock at the installation location, the embedded device 12 will be squeezed during the ring formation process of the segment 11, causing the expansion block and shear component to be in a compressed state, thereby making the entire embedded device 12 fill the gap between the segment 11 and the surrounding rock. As water seeps into the outer shell 5, the expansion cement expands, filling the small gaps and making the embedded device 12 fit tightly with the surrounding rock and the segment 11.

[0068] When the thickness of the embedded device 12 along the radial direction of the segment 11 is equal to the thickness of the gap between the segment 11 and the surrounding rock at the installation location, during the ring formation process of the segment 11, one end of the embedded device 12 just contacts the surrounding rock, and the entire embedded device 12 fills the gap between the segment 11 and the surrounding rock. As water seeps into the outer shell 5, the expanding cement expands and fills the gaps, filling the small gaps so that the embedded device 12 forms a tight fit with the surrounding rock and the segment 11.

[0069] When the thickness of the pre-embedded device 12 along the radial direction of the segment 11 is greater than the thickness of the gap between the segment 11 and the surrounding rock at the installation location, during the ring formation of the segment 11, a gap is still left between the outer end of the pre-embedded device 12 and the surrounding rock. As water seeps into the outer shell 5, the expanding cement expands and fills the gap, making the pre-embedded device 12 fit tightly with the surrounding rock and the segment 11.

[0070] The expansion layer 4 is formed by wrapping the expansion cement with fiber cotton. Under the action of the shear structure, the initial strength is improved. Under the stabilizing effect of the support layer 3, the seepage water entering the outer shell 5 can be evenly diffused by the fiber cotton, so that the expansion cement expands evenly and fills the small gaps, thereby ensuring the bonding effect between the segment 11 and the surrounding rock and improving the support strength of the segment 11.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pre-embedded device for supporting tunnel lining segments in water-rich strata, characterized in that, include: An expansion block includes an expansion layer and a support layer that are alternately stacked. An elastic element penetrates the expansion block along the stacking direction. The expansion layer includes expansion cement and fiber cotton covering the expansion cement. A scissor-type component is arranged on both sides of the expansion block. The scissor-type component is connected to a spring-loaded component. The spring-loaded component's spring-loaded direction is parallel to the direction of the elastic force applied by the elastic component. The outer casing includes a cavity for accommodating the expansion block and the scissor mechanism, and the outer casing is provided with perforations.

2. The pre-embedded device behind the supporting segments in water-rich strata as described in claim 1, characterized in that, The elastic element is a spring, with one end fixed to the bottom surface of the expansion block and the other end fixed to the top surface of the expansion block. One end of the connector is fixed to the expansion block, and the other end passes through the outer shell to connect to the embedded part on the tube segment.

3. The pre-embedded device behind the supporting segments in water-rich strata as described in claim 2, characterized in that, The elastic element penetrates the expansion layer, and the expansion cement encapsulates the elastic element within the expansion layer.

4. The pre-embedded device behind the supporting segments in water-rich strata as described in claim 1, characterized in that, The scissor-type components on both sides of the expansion block are connected by a connecting rod. The connecting rod is located outside the expansion block, and its axis is arranged along the tunnel extension direction.

5. The pre-embedded device behind the supporting segments in water-rich strata as described in claim 4, characterized in that, The scissor-type component has spring-loaded components on both sides of its rotating shaft, and the spring-loaded components are arranged at the corners of the cavity.

6. The pre-embedded device behind the supporting segments in water-rich strata as described in claim 1, characterized in that, The outer shell is an elastic shell, and the internal cavity is rectangular in shape.

7. The pre-embedded device behind the supporting segments in water-rich strata as described in claim 6, characterized in that, The seepage holes are distributed on the outer peripheral surface of the shell, and each seepage hole penetrates the side wall of the shell, connecting the inside and outside of the shell.

8. The pre-embedded device behind the supporting segments in water-rich strata as described in claim 1, characterized in that, The support layer is an elastic support structure, and the support plate contains rigid dopants.

9. A method for operating the pre-embedded device behind the supporting water-rich strata segment as described in any one of claims 1-8, characterized in that, include: The embedded device is installed on the tunnel segments, and the tunnel segments are assembled into a ring. The embedded device is located at the support position between the tunnel segments and the surrounding rock. The outer shell is attached to the outer wall of the segment at one end along the radial direction, and to the surrounding rock at the other end; Water seeping from the surrounding rock enters the outer shell through the seepage holes and comes into contact with the expansive cement, causing the expansive cement to increase in volume, press against the surrounding rock, and provide support for the tunnel lining segments.

10. The working method of the pre-embedded device behind the supporting water-rich strata segment as described in claim 9, characterized in that, When expansive cement comes into contact with water, the elastic element is encased by the expansive cement layer. After the expansive cement solidifies, the elastic element acts as the skeleton of the expansive cement, increasing the strength of the expansive block.

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