Construction technology of radial tension water-stopping seal in shield tunnel

Abstract

The present invention discloses a shield tunnel radial tensioning method water-stopping and sealing construction process, which includes the following steps: S1, pulling the steel strands so that the winding part relatively shrinks along the radial direction of the annular steel plate, and the winding part slides relative to the elastic end of the annular steel plate, and the closing at this time gradually becomes smaller until the closed curtain rubber plate matches and fits on the shield machine shell to form a water-stopping seal; S2, loosening the steel strands, the closing is restored to become larger, the winding part slides relative to the fixed end of the annular steel plate and releases, and the curtain rubber plate is separated from the shield machine shell. The present invention not only improves the sealing between the shield machine shell and the hole, and prevents muddy water and groundwater from pouring into the shield well; and the water-retaining force formed is in the radial direction, and the probability of the shield being flushed open by groundwater during excavation is low. In addition, the space of the shield starting and receiving wells can be appropriately reduced during design, saving land and industrial material consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of shield tunnel construction, and in particular relates to a radial tensioning water-stopping and sealing construction process for a shield tunnel. Background Art

[0002] In recent years, with the rapid development of urban rail transit and large underwater tunnels, the shield method has become the preferred method for urban mainstream tunnel construction due to its advantages of fast construction, no impact on ground traffic, and better control of ground subsidence. During the shield's starting and receiving process, there is an annular gap between the tunnel door ring and the shield shell. When the shield enters and exits the tunnel, the shield tunnel needs to be equipped with a tunnel door sealing and water-stopping device to prevent mud and water from entering the well through the annular gap.

[0003] At present, the commonly used tunnel portal water-stopping device for shield tunnels is generally composed of an annular curtain rubber plate, an annular pressure plate and a folding plate. After the water-stopping device is installed, the circular plate forces the curtain rubber plate to be close to the tunnel opening through the connecting bolts. During the pushing process of the shield, the curtain rubber plate wraps the outer wall of the shield to form a sealed water-stopping. At this time, the fan-shaped flap will hold up the curtain rubber plate after flipping, avoiding the situation where the curtain rubber plate flips back due to excessive water and soil pressure in front; the rubber plate will also be close to the fan-shaped flap under the effect of water and soil pressure in front, and this sealing condition is relatively reliable. In theory, the greater the elongation rate of the inner edge of the curtain rubber plate, the closer the rubber plate and the shield machine are, and the better the sealing and water-stopping effect.

[0004] However, the actual situation is not completely like this. The above-mentioned water-stopping device has the following disadvantages:

[0005] 1. Previous construction experience shows that when the shield is launched and received in high water pressure and water-rich sand and gravel formations, the conventional tunnel portal water-stopping device has a relatively poor water-stopping effect; the outer surface of the shield body of the shield machine is uneven, and the rubber sheet in the water-stopping device does not have the performance of self-tensioning. In addition, the conventional tunnel portal water-stopping device of the large-diameter shield often has a large deadweight, which is easy to deform during the hoisting process, and the true roundness of the device after installation cannot be guaranteed, thus affecting the water-stopping effect. As a result, it cannot be completely close to the shield body, so that an effective closed environment cannot be formed for mud and water storage. At the same time, it is very easy to leak grout during grouting, resulting in economic losses;

[0006] 2. The gap between the shield tunnel and the steel ring is uneven all around, and the water-stopping effect is poor. In particular, the flaps, curtain rubber plates and other water-blocking devices in the conventional sealing water-stopping devices are easily washed away by groundwater because they are consistent with the shield excavation direction;

[0007] 3. The well space is increased and the cost of outsourcing well joints is high.

[0008] In addition, as shield tunnels become deeper and deeper, shield tunnels in high water pressure and water-rich strata are becoming more and more common. It will become very important to deal with the sealing and water-stopping problems of the tunnel portals during the shield tunneling start-up and receiving stages. Summary of the invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an improved radial tensioning waterproof sealing construction process for a shield tunnel.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0011] A shield tunnel radial tensioning water-stopping and sealing construction process, the water-stopping device used in the water-stopping device includes a tunnel portal steel ring, an annular steel plate, a curtain rubber plate, steel strands, and a pre-buried pipeline. The annular steel plate is fixed to the tunnel portal steel ring from one end and elastically connected to the tunnel portal steel ring from the other end, wherein the annular steel plate also has an arc-shaped portion recessed into the tunnel portal steel ring, the curtain rubber plate is similar to the annular steel plate, and is fixed to the end face of the annular steel plate away from the tunnel portal steel ring, the end of the curtain rubber plate away from the annular steel plate forms a closing, the steel strands are wound around the arc-shaped portion corresponding to the closing, and The embedded pipes are passed through the two ends, and the process includes the following steps: S1, pulling the steel strand so that the winding part shrinks relatively in the radial direction along the arc portion of the annular steel plate, and the winding part of the steel strand slides relatively to the elastic end of the annular steel plate, and the closing gradually becomes smaller until the closed curtain rubber plate matches and fits on the shield machine shell to form a water-stop seal; S2, loosening the steel strand, the closing is restored to become larger, the winding part of the steel strand slides relatively to the fixed end of the annular steel plate and is released, and the curtain rubber plate is separated from the shield machine shell.

[0012] Preferably, the steel strand includes a winding portion and a pulling portion which are effectively attached to and wound around the outer circumference of the annular steel plate, wherein the pulling portion has a first pulling end and a second pulling end, and the first pulling end and the second pulling end extend out of the ground surface from the embedded pipe respectively.

[0013] Further, one of the first pulling end and the second pulling end is a fixed end, and the other is a tensioning end, wherein when the tensioning end is pulled or released, the winding portion is tightened or opened synchronously.

[0014] According to a specific implementation and preferred aspect of the present invention, the winding portion has at least 1.5 turns and is wound on the arc portion. When the first pulling end and the second pulling end relatively tighten the winding portion, the winding portion tightens the arc portion inwardly, the arc portion deforms and shrinks the closing, and matches and fits on the shield machine shell from the inner wall of the closing; when the first pulling end and the second pulling end relatively loosen the winding portion, the arc portion opens outwardly, and the cord rubber sheet is separated from the shield machine shell. In this way, the tightening or loosening operation is convenient.

[0015] According to another specific implementation and preferred aspect of the present invention, the steel strand includes a wire body, a plurality of steel beads fixed on the wire body and spaced apart, wherein the winding portion contacts the wall surface of the arc portion from the bead surface of the steel beads. In this way, under the contact of the steel balls, the contact with the annular steel plate is reduced, the wear of the steel strand is reduced, and during the tightening process, the steel strand can move along with the deformation of the annular inner concave portion, facilitating the contraction and opening operation of the closing.

[0016] According to another specific implementation and preferred aspect of the present invention, in S1, when the closing portion is attached to the shield machine housing, the steel balls of the attached portion formed on the arc portion are relatively staggered. In this way, the loosening or displacement of the wrapped portion can be effectively prevented during the water-stopping process, thereby ensuring the best water-stopping effect.

[0017] Preferably, the annular steel plate includes an annular connecting portion and an annular inner concave portion, wherein the annular connecting portion is fitted and fixed to the inner wall of the tunnel portal steel ring; the annular inner concave portion is recessed inward from the annular circumference, and is fixedly connected to the end of the annular connecting portion from one end, and the other end is elastically connected to the inner wall of the tunnel portal steel ring through an elastic member; the curtain rubber sheet is similar in shape to the annular steel plate, and is fixed on the wall surface of the annular connecting portion and the annular inner concave portion facing the shield machine housing, wherein the end of the curtain rubber sheet away from the tunnel portal steel ring forms a closure. This design facilitates the movement of the annular steel plate to implement the tightening or loosening of the closure.

[0018] Furthermore, the annular steel plate is an elastic steel plate, and can move around the connection with the annular connecting portion to shrink the closing end, wherein when the winding portion is loosened, the elastic steel plate and the elastic member are reset together.

[0019] Preferably, the tunnel gate steel ring extends along the shield direction, the shield advances forward, the annular connecting portion is connected to the rear end of the tunnel gate steel ring, and the elastic member connects the front end of the annular inner concave portion with the front end of the tunnel gate steel ring, which is very convenient for the contraction or opening of the tightening portion.

[0020] In addition, there are multiple elastic members, which are spaced around the circumference of the annular steel plate, and each of the elastic members extends along the radial direction of the tunnel door steel ring. In this way, it is ensured that the end of the annular inner concave portion moves synchronously with respect to the tunnel door steel ring.

[0021] Preferably, the tunnel door steel ring is as wide as the inner lining wall, so that an effective installation space can be formed.

[0022] Preferably, the embedded pipe is located at the upper part of the lining wall and passes through the annular steel plate from the ground, and the first pulling end and the second pulling end respectively pass through the ground from the embedded pipe, so as to facilitate the first pulling end and the second pulling end to tighten or release the winding part.

[0023] Due to the implementation of the above technical solution, the present invention has the following advantages compared with the prior art:

[0024] 1. The rubber sheet forms a sealing structure with simple installation and operation, low price and high construction efficiency. When the shield machine passes through, the rubber sheet can be tightened by the steel strands led to the ground, so that it can be elastically deformed and interference fit with the shield machine shell, so that when the shield machine enters and exits the hole, the rubber sheet can be kept in close contact with the shield machine shell, improving the sealing of the gap between the shield machine shell and the hole, and preventing muddy water and groundwater from pouring into the shield shaft;

[0025] 2. When receiving the shield, the steel strands led to the ground can be used to tighten the rubber sheet to make it fit tightly with the shield casing, which can effectively solve the problem that the flaps, rubber sheets and other water-retaining devices in conventional sealing water-stopping devices are easily washed away by groundwater because they are consistent with the shield excavation direction (radial stress is applied);

[0026] 3. This device is installed on the pre-buried steel ring of the tunnel portal. Therefore, the space of the shield starting and receiving wells can be appropriately reduced during the design. At the same time, it saves the space of the starting and receiving wells, the cost of short sleeves and filling materials, and the cost of well joints, and reduces the difficulty of well joint construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a cross-sectional schematic diagram of the tunnel portal water-stopping device in the shield starting or receiving stage of this embodiment (without water-stopping)

[0028] Figure 2 for Figure 1 A schematic diagram of the structure enlargement in the middle;

[0029] Figure 3 for Figure 1 Schematic diagram of the inner concave part of the ring around which the middle steel strand is wound (without water stopping);

[0030] Figure 4 This is a cross-sectional schematic diagram of the tunnel gate water-stopping device in the shield starting or receiving stage of this embodiment (when water-stopping)

[0031] Figure 5 for Figure 4 A magnified schematic diagram of the structure at B in the middle;

[0032] Figure 6 for Figure 4 Schematic diagram of the middle steel strand wrapped around the annular inner concave part (when water is stopped);

[0033] Among them: 1. portal steel ring; 2. annular steel plate; 20. annular connecting part; 21. annular inner recess; 3. cord rubber plate; 4. steel strand; 4a. wire body; 4b. steel ball; 40. winding part; 41. pulling part; 411. first pulling end; 412. second pulling end; 5. embedded pipe; 6. elastic part; Q. lining wall; w. shield machine casing. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0035] like Figure 1 As shown, the shield tunnel radial tensioning water-stopping and sealing construction process of this embodiment adopts a portal water-stopping device including a portal steel ring 1, an annular steel plate 2, a curtain rubber plate 3, a steel strand 4, and a pre-buried pipe 5 (conventionally made of PVC). The portal water-stopping device is particularly suitable for implementing a water-stopping seal between the shield machine and the portal steel ring during the shield starting or receiving stage.

[0036] Specifically, a portal steel ring 1 is pre-buried on the inner lining wall Q of the portal, wherein the interior of the portal steel ring 1 is an annular cavity for the shield machine to pass through, and the portal steel ring 1 is as wide as the inner lining wall Q. In this way, an effective installation space can be formed.

[0037] The annular steel plate 2 is located in the annular cavity and is installed on the tunnel portal steel ring 1 along the forward excavation direction of the shield machine.

[0038] Combination Figure 2 As shown, the annular steel plate 2 includes an annular connecting portion 20 and an annular inner recess 21 (the arc-shaped portion mentioned above), wherein the annular connecting portion 20 is fixedly connected to the rear end of the tunnel gate steel ring, the annular inner recess 21 is recessed inward from the annular circumference, and the rear end is fixedly connected to the front end of the annular connecting portion 20, and the front end of the annular inner recess 21 is elastically connected to the front end of the tunnel gate steel ring 1 through an elastic member 6.

[0039] The elastic member 6 is a tension spring, and there are multiple of them, wherein the multiple tension springs are evenly spaced around the circumference of the tunnel gate steel ring 1, and each tension spring extends along the radial direction of the tunnel gate steel ring 1. In this way, it is ensured that the end of the annular inner recess 21 moves synchronously relative to the tunnel gate steel ring 1.

[0040] The rubber sheet 3 is similar in shape to the annular steel plate 2 and is fixed on the wall of the annular connecting portion 20 and the annular inner recess 21 facing the shield machine casing, wherein the end of the rubber sheet 3 away from the portal steel ring 1 forms a closed end.

[0041] Combination Figure 3 As shown, the steel strand 4 includes a winding portion 40 and a pulling portion 41 which are effectively attached to and wound around the outer circumference of the annular steel plate 2 , wherein the pulling portion 41 has a first pulling end 411 and a second pulling end 412 .

[0042] The fitting portion formed by the winding portion 40 on the annular steel plate 2 has 1.8 turns and is wound on the annular inner recess 21. When the first pulling end 411 and the second pulling end 412 relatively tighten the winding portion 40, the winding portion 40 tightens the annular inner recess 21 inward, and the annular inner recess 21 is deformed and shrinks, and the inner wall of the self-closed opening matches and fits (interference fit) on the shield machine casing w, and the elastic member 6 is in deformation; when the first pulling end 411 and the second pulling end 412 relatively loosen the winding portion 40, the elastic member 6 is reset, the annular inner recess 21 opens outward, and the cord rubber plate 3 is separated from the shield machine casing w.

[0043] The annular steel plate 2 is an elastic steel plate, and can be moved around the connection with the annular connecting portion 20 to shrink and close the opening, wherein when the winding portion 40 is loosened, the elastic steel plate and the elastic member 6 are reset together. In this way, it is convenient to implement the contraction or reset and opening of the closing.

[0044] In this example, the steel strand 4 includes a wire body 4a, and a plurality of steel beads 4b fixed on the wire body 4a and distributed at intervals, wherein the winding portion 40 contacts the wall surface of the annular inner concave portion 21 from the bead surface of the steel beads 4b. In this way, under the contact of the steel beads, the contact with the annular steel plate is reduced, the wear of the steel strand is reduced, and during the tightening process, the steel strand can move with the deformation of the annular inner concave portion, which is more conducive to the deformation of the annular inner concave portion when shrinking or releasing the closing.

[0045] When the winding portion 40 formed on the annular inner concave portion 21 is closed and fitted on the shield machine shell w, the steel balls 4b of the fitting portion are relatively staggered. In this way, the winding portion can be effectively prevented from loosening or shifting during the water stopping process, thereby ensuring the best water stopping effect.

[0046] The pre-buried pipe 5 is pre-buried in the lining wall Q and communicated with the ground surface. The first pulling end 411 and the second pulling end 412 are respectively inserted from the pre-buried pipe 5 .

[0047] The first pulling end 411 is a fixed end, and the second pulling end 412 is a tensioning end, wherein when the tensioning end is pulled or released, the winding portion 40 is tightened or opened synchronously, which is very convenient for the contraction or opening of the tightening portion.

[0048] Combination Figures 4 to 6 As shown, the implementation process of this embodiment is as follows:

[0049] When in the water-stopping state, it is necessary to pull the second pulling end 412, and at this time, the winding part 40 of the steel strand 4 is closer to the annular inner recess 21, so that the annular inner recess 21 moves relative to the annular connecting part 20, and at the same time, the closing of the curtain rubber sheet 3 is tightened while the steel ball 4b slides relative to the annular inner recess 21, so that the closing wall surface is tightly fitted on the shield machine shell w with interference fit, and the tension spring is in a stretched state at this time. Therefore, the curtain rubber sheet, steel strand, and annular steel plate together form a closed annular cylindrical body. When the shield machine passes through, the steel strand can be tensioned from the ground, so that the curtain rubber sheet is closely attached to the shield body of the shield machine, and together with the lining wall Q, it forms a good water-stop box body, which meets the initial pressure building conditions of the shield machine.

[0050] When the second pulling end 412 is released, the winding portion 40 loses its restriction and becomes relatively loose, and gradually releases the closing while the elastic annular steel plate and the tension spring are reset, so that the cord rubber sheet 3 is separated from the shield machine casing w.

[0051] Therefore, the above process comprises the following steps:

[0052] S1. Pull the steel strand so that the winding part relatively contracts along the radial direction of the annular steel plate (the annular inner concave portion 21 moves relative to the annular connecting portion 20), and the winding part slides relative to the elastic end of the annular steel plate, and the closing gradually becomes smaller until the closed curtain rubber plate matches and fits on the shield machine shell to form a water-stop seal, and the elastic member 6 is stretched along the radial direction, and at the same time, the steel balls 4b of the fitting parts of the corresponding annular inner concave portion 21 wound at the closing are relatively staggered;

[0053] S2, loosen the steel strand, the elastic annular steel plate 2 and the tension spring are reset, the winding part slides relative to the fixed end of the annular steel plate and is released, and at the same time the cord rubber sheet is separated from the shield machine casing.

[0054] In summary, this embodiment has the following advantages:

[0055] 1. The rubber sheet forms a sealing structure with simple installation and operation, low price and high construction efficiency. When the shield machine passes through, the rubber sheet can be tightened by the steel strands led to the ground, so that it can be elastically deformed and interference fit with the shield machine shell, so that when the shield machine enters and exits the hole, the rubber sheet can be kept in close contact with the shield machine shell, improving the sealing of the gap between the shield machine shell and the hole, and preventing muddy water and groundwater from pouring into the shield shaft;

[0056] 2. When receiving the shield, the steel strands led to the ground can be used to tighten the rubber sheet to make it fit tightly with the shield casing, which can effectively solve the problem that the flaps, rubber sheets and other water-retaining devices in conventional sealing and water-stopping devices are easily washed away by groundwater because they are consistent with the excavation direction of the shield;

[0057] 3. This device is installed on the pre-buried steel ring of the tunnel portal. Therefore, the space of the shield starting and receiving wells can be appropriately reduced during the design. At the same time, it saves the space of the starting and receiving wells, the cost of short sleeves and filling materials, and the cost of well joints, and reduces the difficulty of well joint construction.

[0058] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A shield tunnel radial tensioning water-stopping and sealing construction process, wherein the water-stopping device used comprises a tunnel portal steel ring, an annular steel plate, a curtain rubber plate, a steel strand, and a pre-buried pipeline, and is characterized in that: The annular steel plate is fixed on the portal steel ring from one end and elastically connected to the portal steel ring at the other end, wherein the annular steel plate also has an arc-shaped portion recessed into the portal steel ring, the curtain rubber plate is similar to the annular steel plate and is fixed on the end face of the annular steel plate away from the portal steel ring, the end of the curtain rubber plate away from the annular steel plate forms a closing, the steel strand is wound on the arc-shaped portion corresponding to the closing, and passes through the embedded pipe from both ends, the process comprises the following steps: S1, pulling the steel strand so that the winding part relatively shrinks along the arc-shaped portion of the annular steel plate in the radial direction, and the winding part of the steel strand slides relatively toward the elastic end of the annular steel plate, at which time the closing gradually becomes smaller until the closed curtain rubber plate matches and fits on the shield machine casing to form a water-stop seal; S2, releasing the steel strand, the closing is restored to become larger, the winding part of the steel strand slides relatively toward the fixed end of the annular steel plate and is released, the curtain rubber plate is connected to the shield machine The outer shell is separated; the steel strand includes a winding portion and a pulling portion which are effectively attached to and wound around the outer periphery of the annular steel plate, wherein the pulling portion has a first pulling end and a second pulling end, the first pulling end and the second pulling end respectively extend from the pre-buried pipe to the ground surface, and in step S1, the first pulling end and the second pulling end are pulled to radially tighten the winding portion; in step S2, the first pulling end and the second pulling end are loosened to radially loosen the winding portion; the annular steel plate includes an annular connecting portion and an annular inner recess, wherein the annular connecting portion is attached and fixed to the inner wall of the tunnel portal steel ring; the annular inner recess is recessed inwardly from the annular circumference, and is fixedly connected to the end of the annular connecting portion from one end, and the other end is elastically connected to the inner wall of the tunnel portal steel ring through an elastic member; the cord rubber sheet is similar in shape to the annular steel plate, and is fixed on the wall surface of the annular connecting portion and the annular inner recess facing the outer shell of the shield machine, wherein the cord rubber sheet forms a closing end away from the end of the tunnel portal steel ring.

2. The shield tunnel radial tensioning water-stopping and sealing construction process according to claim 1 is characterized by: One of the first pulling end and the second pulling end is a fixed end, and the other is a tensioning end, wherein when the tensioning end is pulled or released, the winding portion is tightened or opened synchronously, and the tensioning end in S1 causes the arc portion to swing inward relative to the fixed end of the annular steel plate when the winding portion is tightened, and moves toward the elastic end of the annular steel plate while the winding portion is relatively tightened.

3. The shield tunnel radial tensioning water-stopping and sealing construction process according to claim 1 is characterized by: The winding portion has at least 1.5 turns and is wound around the arc portion.

4. The radial tensioning waterproof sealing construction process for a shield tunnel according to claim 3 is characterized by: When the first pulling end and the second pulling end relatively tighten the winding portion, the winding portion tightens the arc portion inwardly, the arc portion gathers inwardly around the fixed end of the annular steel plate, and the cord rubber sheet shrinks the closing simultaneously, and fits on the shield machine casing from the inner wall of the closing.

5. The radial tensioning waterproof sealing construction process for a shield tunnel according to claim 4 is characterized in that: When the first pulling end and the second pulling end relatively loosen the winding portion, the arc-shaped portion opens outward, and the cord rubber sheet is separated from the shield machine casing.

6. The shield tunnel radial tensioning waterproof sealing construction process according to claim 1, 2, 3, 4 or 5, characterized in that: The steel strand comprises a wire body, and a plurality of steel balls fixed on the wire body and distributed at intervals, wherein the winding portion contacts the wall surface of the arc portion from the bead surface of the steel ball.

7. The shield tunnel radial tensioning water-stopping and sealing construction process according to claim 6 is characterized by: In step S1, when the closing edge of the arc-shaped portion is in contact with the casing of the shield machine, the steel balls of the contacted portion are relatively staggered.

8. The radial tensioning waterproof sealing construction process for a shield tunnel according to claim 1 is characterized by: The annular steel plate is an elastic steel plate and can move around the connection with the annular connecting portion to shrink the closing portion, wherein when the winding portion is loosened, the elastic steel plate and the elastic member are reset together.

9. The shield tunnel radial tensioning water-stopping and sealing construction process according to claim 1 is characterized by: The portal steel ring extends along the direction of the shield, and the shield advances forward. The annular connecting portion is connected to the rear end of the portal steel ring, and the elastic member connects the front end of the annular inner recess with the front end of the portal steel ring.

10. The shield tunnel radial tensioning water-stopping and sealing construction process according to claim 9 is characterized in that: There are a plurality of elastic members, which are distributed at intervals around the circumference of the annular steel plate, and each of the elastic members extends along the radial direction of the tunnel gate steel ring.

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