Construction method for small-radius curve shield tunnel in narrow and small space

Abstract

The invention relates to the technical field of shield tunneling methods, in particular to a narrow-space small-radius curve shield tunnel construction method which comprises the following steps that a hinged type shield tunneling machine with an overbreak cutter is adopted, the overbreak cutter is installed on a cutter head of the hinged type shield tunneling machine, and the diameter of the overbreak cutter is 6-6.5 m. The method has the advantages that the construction precision is improved, and the lateral supporting force is enhanced, the hinged type shield tunneling machine with the overbreak cutter is adopted in the actual using process, the stability of shield tunneling is guaranteed by accurately controlling the overbreak range and the advancing speed, the risks of stratum settlement and excessive overbreak are reduced, and the construction efficiency is improved by installing and adjusting the duct pieces. The linear and stability of a tunnel are ensured, the construction precision is improved, through cooperation of the driving mechanism and the connecting structure, the top plate can move along with tunneling of the shield tunneling machine, lateral supporting force is provided, lateral force generated by curve tunneling of the shield tunneling machine is effectively resisted, and the shield tunneling machine is prevented from deviating.

Description

Technical Field

[0001] The invention relates to the technical field of shield methods, in particular to a construction method for a small-radius curved shield tunnel in a narrow space. Background Art

[0002] The shield method is a method of using a shield machine for tunnel excavation and lining construction. The shield machine is a special machine that integrates the functions of excavation, retaining, excavation, transportation, and lining installation. It has strong support capabilities and is suitable for tunnel projects with complex geological conditions, busy ground traffic, and high requirements for surface settlement control.

[0003] In the construction of narrow space and small radius curved tunnels, the problems of great construction difficulty and high technical requirements are often faced. Traditional construction methods may not be able to ensure the stability and construction accuracy of the tunnel. Due to improper construction control or complex formation conditions, it is often easy to cause formation settlement and deformation, posing a safety hazard to surrounding buildings and underground pipelines. At the same time, during the curve excavation process, the shield machine is prone to displacement due to lateral force, affecting the linearity and stability of the tunnel, increasing the difficulty and risk of construction. Grouting reinforcement measures may have problems such as uneven grouting and limited reinforcement effect, making it difficult to fully meet the requirements of tunnel stability and bearing capacity. Summary of the invention

[0004] The purpose of the present invention is to provide a method for constructing a small-radius curved shield tunnel in a narrow space, which has the advantages of improving construction accuracy and enhancing lateral supporting force, and solves the problems raised by the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for constructing a small radius curved shield tunnel in a narrow space, the method comprising the following steps:

[0006] S1: An articulated shield machine with an over-excavation cutter is used. The over-excavation cutter is installed on the cutterhead with a diameter of 6-6.5 meters. The over-excavation range can be set within the range of 0-359 degrees of the cutting cutterhead rotation angle. During the excavation process, the over-excavation amount is controlled within the range of 20-50mm, and the advancement speed is controlled at 1-2cm / min to ensure the stability of the shield excavation. The incision balance soil pressure is controlled to make the stratum at the shield incision have a slight uplift with an uplift of 0.5-1mm to balance the stratum settlement when the shield is backing the soil. The difference of the actual soil pressure fluctuation around the set soil pressure is controlled within ±20kPa to prevent excessive over-excavation and under-excavation, reduce the balance pressure fluctuation, and control the excavation amount deviation within ±5%. The thrust is generally between 8000-12000kN.

[0007] S2: Install the segments, choose to install the first segment from the bottom, accurately lift the segment to the installation position through the assembly machine, operate the assembly machine to slowly move the segment close to the installed segment or shield tail, adjust the posture of the segment to align it accurately with the installation position, and temporarily fix the first segment with bolts. The tightening torque of the bolts is controlled between 300-500Nm. During the installation process, sealing rubber strips are installed between the segments. The compression rate of the sealing rubber strips is generally controlled at 25%-35% to ensure a good sealing effect.

[0008] S3: After two tunnelling rings are completed, the soil is reinforced by grouting through the pre-buried grouting holes in the tunnel in time. The reinforcement range starts from the outer wall surface of the segment and extends 2m toward the surrounding soil. The grouting pressure is controlled at 0.3-0.5MPa. The grouting rate is 1.6-1.8 in loose and highly permeable strata, and 1.3-1.5 in strata with weak permeability such as clay.

[0009] A method for constructing a small-radius curved shield tunnel in a narrow space includes an anti-deviation structure for a shield machine, the anti-deviation structure includes a placement plate, the placement plate is installed on both sides of the shield machine, a top plate is arranged on the top of the placement plate, a rotating wheel is arranged on the top of the top plate, both sides of the top of the placement plate are fixedly connected with fixed blocks, and a driving mechanism and a connecting structure are arranged on the top of the placement plate.

[0010] Furthermore, as a preferred embodiment of the present invention, the driving mechanism includes a dual-axis motor arranged on the top of the placement plate, the two output shafts of the dual-axis motor are fixedly connected to a threaded rod, one end of the threaded rod is rotatably connected to a fixed block, and the surface of the threaded rod is threadedly connected to a threaded block.

[0011] Furthermore, as a preferred embodiment of the present invention, the connection structure includes a first connecting member fixedly connected to the surface of the threaded block, the inner cavity of the first connecting member is rotatably connected to the adjusting block, one end of the adjusting block is rotatably connected to the second connecting member, and the top of the second connecting member is fixedly connected to the top plate.

[0012] Furthermore, as a preferred embodiment of the present invention, both sides of the bottom of the placement plate are provided with sliding grooves, the inner cavity of the sliding groove is slidably connected with a slider, and the top of the slider is fixedly connected to the threaded block.

[0013] Furthermore, as a preferred embodiment of the present invention, telescopic rods are fixedly connected to both sides of the top of the placement plate, the output end of the telescopic rods is fixedly connected to the top plate, and a spring is sleeved on the surface of the telescopic rods, and the two ends of the spring are respectively fixedly connected to the placement plate and the top plate.

[0014] Furthermore, as a preferred embodiment of the present invention, square blocks are fixedly connected to both sides of the placement plate, and bolts are threadedly connected to the tops of the square blocks.

[0015] Furthermore, as a preferred embodiment of the present invention, a mounting seat is provided on the surface of the dual-axis motor, and the bottom of the mounting seat is fixedly connected to the placement plate.

[0016] In the present invention, the construction method of a small-radius curved shield tunnel in a narrow space, the steps of using the anti-deviation structure are as follows:

[0017] Step 1: By tightening the bolts, the placement plates are installed on both sides of the shield machine, and then the dual-axis motor is started, and the output shaft of the dual-axis motor drives the threaded rod to rotate, and the threaded rod drives the threaded block to move when rotating, and the threaded block drives the first connecting member to move when moving;

[0018] Step 2: The first connecting piece drives one end of the adjusting block to move, and the adjusting block will move the other end outward when it moves. The adjusting block drives the second connecting piece to move, and the second connecting piece drives the top plate to move. When the top plate moves, it will drive the telescopic rod and the spring to stretch. At the same time, when the top plate moves, one side of the wheel will contact the inner wall of the tunnel, thereby providing lateral support force to prevent the shield machine from shifting. It can effectively resist the lateral force generated by the shield machine due to curved excavation, and ensure the linearity and stability of the shield machine.

[0019] Beneficial effects. The technical solution of the present application has the following technical effects: the present invention has the advantages of improving construction accuracy and enhancing lateral supporting force. In actual use, an articulated shield machine with an over-excavation cutter is used. By accurately controlling the over-excavation range and the advancement speed, the stability of the shield excavation is ensured, and the risks of ground settlement and excessive over-excavation are reduced. By installing and adjusting the pipe segments, the linearity and stability of the tunnel are ensured, and the construction accuracy is improved. Through the cooperation of the driving mechanism and the connecting structure, the top plate can move with the excavation of the shield machine and provide lateral supporting force, effectively resisting the lateral force generated by the shield machine due to curved excavation, and preventing the shield machine from shifting. Grouting is performed on the soil through pre-buried grouting holes to enhance the overall stability and bearing capacity of the tunnel, and reduce the risk of ground deformation and settlement.

[0020] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered to be part of the inventive subject matter of the present disclosure, provided such concepts are not mutually inconsistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0023] Figure 2 It is a cross-sectional view of the three-dimensional structure of the present invention.

[0024] In the figure, the meaning of each figure mark is as follows: 1. placement plate; 2. top plate; 3. rotating wheel; 4. fixing block; 5. driving mechanism; 51. dual-axis motor; 52. threaded rod; 53. threaded block; 6. connecting structure; 61. first connecting member; 62. adjusting block; 63. second connecting member; 7. slide groove; 8. slider; 9. telescopic rod; 10. spring; 11. square block; 12. bolt; 13. mounting seat. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. In order to better understand the technical content of the present invention, specific embodiments are cited and described in conjunction with the drawings as follows. Various aspects of the present invention are described in this disclosure with reference to the drawings, in which many illustrative embodiments are shown. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] As attached Figure 1 To Attachment Figure 2 As shown: This embodiment provides a method for constructing a small radius curved shield tunnel in a narrow space, and the method comprises the following steps:

[0027] S1: An articulated shield machine with an over-excavation cutter is used. The over-excavation cutter is installed on the cutterhead with a diameter of 6-6.5 meters. The over-excavation range can be set within the range of 0-359 degrees of the cutting cutterhead rotation angle. During the excavation process, the over-excavation amount is controlled within the range of 20-50mm, and the advancement speed is controlled at 1-2cm / min to ensure the stability of the shield excavation. The incision balance soil pressure is controlled to make the stratum at the shield incision have a slight uplift with an uplift of 0.5-1mm to balance the stratum settlement when the shield is backing the soil. The difference of the actual soil pressure fluctuation around the set soil pressure is controlled within ±20kPa to prevent excessive over-excavation and under-excavation, reduce the balance pressure fluctuation, and control the excavation amount deviation within ±5%. The thrust is generally between 8000-12000kN.

[0028] S2: Install the segments, choose to install the first segment from the bottom, accurately lift the segment to the installation position through the assembly machine, operate the assembly machine to slowly move the segment close to the installed segment or shield tail, adjust the posture of the segment to align it accurately with the installation position, and temporarily fix the first segment with bolts. The tightening torque of the bolts is controlled between 300-500Nm. During the installation process, sealing rubber strips are installed between the segments. The compression rate of the sealing rubber strips is generally controlled at 25%-35% to ensure a good sealing effect.

[0029] S3: After two tunnelling rings are completed, the soil is reinforced by grouting through the pre-buried grouting holes in the tunnel in time. The reinforcement range starts from the outer wall surface of the segment and extends 2m toward the surrounding soil. The grouting pressure is controlled at 0.3-0.5MPa. The grouting rate is 1.6-1.8 in loose and highly permeable strata, and 1.3-1.5 in strata with weak permeability such as clay.

[0030] A method for constructing a small-radius curved shield tunnel in a narrow space includes an anti-deviation structure for a shield machine, wherein the anti-deviation structure includes a placement plate 1, the placement plate 1 is installed on both sides of the shield machine, a top plate 2 is arranged on the top of the placement plate 1, a rotating wheel 3 is arranged on the top of the top plate 2, both sides of the top of the placement plate 1 are fixedly connected with fixed blocks 4, and a driving mechanism 5 and a connecting structure 6 are arranged on the top of the placement plate 1.

[0031] Specifically, the driving mechanism 5 includes a dual-axis motor 51 arranged on the top of the placement plate 1, and the two output shafts of the dual-axis motor 51 are fixedly connected to a threaded rod 52, one end of the threaded rod 52 is rotatably connected to the fixed block 4, and the surface of the threaded rod 52 is threadedly connected to a threaded block 53.

[0032] Specifically, the connecting structure 6 includes a first connecting member 61 fixedly connected to the surface of the threaded block 53, the inner cavity of the first connecting member 61 is rotatably connected to the adjusting block 62, one end of the adjusting block 62 is rotatably connected to the second connecting member 63, and the top of the second connecting member 63 is fixedly connected to the top plate 2.

[0033] Specifically, both sides of the bottom of the placement plate 1 are provided with a slide groove 7 , the inner cavity of the slide groove 7 is slidably connected with a slider 8 , and the top of the slider 8 is fixedly connected to the threaded block 53 .

[0034] In this embodiment, the slide groove 7 and the slider 8 are used in combination to limit the threaded block 53 , thereby improving the stability of the threaded block 53 when moving.

[0035] Specifically, telescopic rods 9 are fixedly connected to both sides of the top of the placement plate 1, the output end of the telescopic rod 9 is fixedly connected to the top plate 2, and a spring 10 is sleeved on the surface of the telescopic rod 9, and the two ends of the spring 10 are fixedly connected to the placement plate 1 and the top plate 2 respectively.

[0036] In this embodiment, the telescopic rod 9 and the spring 10 are used in combination to guide the top plate 2, so that the top plate 2 is not prone to shaking when moving.

[0037] Specifically, square blocks 11 are fixedly connected to both sides of the placement plate 1 , and bolts 12 are threadedly connected to the tops of the square blocks 11 .

[0038] In this embodiment, the square block 11 and the bolt 12 are used in combination to install the placement plate 1, and at the same time, it is convenient for the user to disassemble and store it.

[0039] Specifically, a mounting seat 13 is sleeved on the surface of the dual-axis motor 51 , and the bottom of the mounting seat 13 is fixedly connected to the placement plate 1 .

[0040] In this embodiment, the installation seat 13 is provided to fix the dual-axis motor 51, so that the dual-axis motor 51 is not prone to self-rotation during operation.

[0041] In the present invention, the construction method of a small-radius curved shield tunnel in a narrow space, the steps of using the anti-deviation structure are as follows:

[0042] Step 1: Install the placement plate 1 on both sides of the shield machine by tightening the bolts 12, and then start the dual-axis motor 51. The output shaft of the dual-axis motor 51 drives the threaded rod 52 to rotate. The threaded rod 52 drives the threaded block 53 to move when rotating, and the threaded block 53 drives the first connecting member 61 to move when moving.

[0043] Step 2: The first connecting member 61 drives one end of the adjusting block 62 to move, and the adjusting block 62 will move the other end outward when moving. The adjusting block 62 drives the second connecting member 63 to move, and the second connecting member 63 drives the top plate 2 to move. When the top plate 2 moves, it will drive the telescopic rod 9 and the spring 10 to stretch. At the same time, when the top plate 2 moves, one side of the wheel 3 will contact the inner wall of the tunnel, thereby providing lateral support force to prevent the shield machine from deviating, and can effectively resist the lateral force generated by the shield machine due to curved excavation, thereby ensuring the linearity and stability of the shield machine.

[0044] It should be noted that, in this document, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0045] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A method for constructing a small radius curved shield tunnel in a narrow space, characterized by: The method comprises the following steps: S1: An articulated shield machine with an over-excavation cutter is used. The over-excavation cutter is installed on the cutter head with a diameter of 6-6.5 meters. The over-excavation range can be set within the range of 0-359 degrees of the cutting cutter head rotation angle. The over-excavation amount is controlled within the range of 20-50mm during the excavation process, and the advancement speed is controlled at 1-2cm / min to ensure the stability of the shield excavation. The incision balance soil pressure is controlled to make the stratum at the shield incision have a slight uplift of 0.5-1mm to balance the stratum settlement when the shield is backing the soil. The difference of the actual soil pressure around the set soil pressure fluctuation is controlled within ±20kPa to prevent excessive over-excavation and under-excavation, reduce the fluctuation of the balance pressure, and control the deviation of the excavation amount within ±5%. The thrust is generally between 8000-12000kN; S2: Install the segments, choose to install the first segment from the bottom, accurately lift the segment to the installation position through the assembly machine, operate the assembly machine to slowly move the segment close to the installed segment or shield tail, adjust the segment's posture to align it accurately with the installation position, temporarily fix the first segment with bolts, and control the tightening torque of the bolts between 300-500Nm. During the installation process, install sealing rubber strips between the segments, and the compression rate of the sealing rubber strips is generally controlled at 25%-35% to ensure a good sealing effect; S3: After two tunnelling rings are completed, the soil is reinforced by grouting through the pre-buried grouting holes in the tunnel in time. The reinforcement range starts from the outer wall surface of the segment and extends 2m toward the surrounding soil. The grouting pressure is controlled at 0.3-0.5MPa. The grouting rate is 1.6-1.8 in loose and highly permeable strata, and 1.3-1.5 in strata with weak permeability such as clay.

2. The method for constructing a small radius curved shield tunnel in a narrow space according to claim 1, characterized in that: The invention comprises a shield machine anti-deviation structure, wherein the anti-deviation structure comprises a placement plate (1), wherein the placement plate (1) is installed on both sides of the shield machine, a top plate (2) is arranged on the top of the placement plate (1), a rotating wheel (3) is arranged on the top of the top plate (2), both sides of the top of the placement plate (1) are fixedly connected with fixed blocks (4), and a driving mechanism (5) and a connecting structure (6) are arranged on the top of the placement plate (1).

3. The method for constructing a small radius curved shield tunnel in a narrow space according to claim 2, characterized in that: The driving mechanism (5) comprises a double-axis motor (51) arranged on the top of the placement plate (1), the two output shafts of the double-axis motor (51) are fixedly connected to a threaded rod (52), one end of the threaded rod (52) is rotatably connected to a fixed block (4), and the surface of the threaded rod (52) is threadedly connected to a threaded block (53).

4. The method for constructing a small radius curved shield tunnel in a narrow space according to claim 3, characterized in that: The connection structure (6) comprises a first connection member (61) fixedly connected to the surface of the threaded block (53); the inner cavity of the first connection member (61) is rotatably connected to an adjustment block (62); one end of the adjustment block (62) is rotatably connected to a second connection member (63); and the top of the second connection member (63) is fixedly connected to the top plate (2).

5. The method for constructing a small radius curved shield tunnel in a narrow space according to claim 2, characterized in that: Both sides of the bottom of the placement plate (1) are provided with sliding grooves (7), the inner cavity of the sliding groove (7) is slidably connected with a sliding block (8), and the top of the sliding block (8) is fixedly connected to the threaded block (53).

6. The method for constructing a small radius curved shield tunnel in a narrow space according to claim 2, characterized in that: Both sides of the top of the placement plate (1) are fixedly connected with telescopic rods (9), the output end of the telescopic rod (9) is fixedly connected to the top plate (2), the surface of the telescopic rod (9) is sleeved with a spring (10), and the two ends of the spring (10) are respectively fixedly connected to the placement plate (1) and the top plate (2).

7. The method for constructing a small radius curved shield tunnel in a narrow space according to claim 2, characterized in that: Square blocks (11) are fixedly connected to both sides of the placement plate (1), and bolts (12) are threadedly connected to the top of the square blocks (11).

8. The method for constructing a small-radius curved shield tunnel in a narrow space according to claim 2, characterized in that: A mounting seat (13) is sleeved on the surface of the dual-axis motor (51), and the bottom of the mounting seat (13) is fixedly connected to the placement plate (1).

9. A method for constructing a small radius curved shield tunnel in a narrow space, characterized by: The steps for using the anti-drift structure are as follows: Step 1: By tightening the bolts (12), the placement plate (1) is installed on both sides of the shield machine, and then the double-axis motor (51) is started, and the output shaft of the double-axis motor (51) drives the threaded rod (52) to rotate, and the threaded rod (52) drives the threaded block (53) to move when rotating, and the threaded block (53) drives the first connecting member (61) to move when moving; Step 2: The first connecting member (61) drives one end of the adjusting block (62) to move, and the adjusting block (62) causes the other end of the adjusting block (62) to move outward when moving. The adjusting block (62) drives the second connecting member (63) to move, and the second connecting member (63) drives the top plate (2) to move. When the top plate (2) moves, it drives the telescopic rod (9) and the spring (10) to stretch. At the same time, when the top plate (2) moves, one side of the rotating wheel (3) contacts the inner wall of the tunnel, thereby providing lateral support force to prevent the shield machine from deflecting, and can effectively resist the lateral force generated by the shield machine due to curved excavation, thereby ensuring the linearity and stability of the shield machine.

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