Shield tunnel safely crossing building isolation reinforcing structure and construction method

Abstract

The present application relates to a shield tunnel safety crossing building isolation reinforcing structure and a construction method, comprising a shield machine cutterhead, a shield shell, a shield advanced horizontal grouting isolation reinforcing area and a shield radial grouting permanent reinforcing area, characterized in that the shield machine cutterhead is arranged at one end of the shield shell for tunneling and excavation, the outer surface of the shield shell is provided with advanced horizontal grouting holes, and the advanced horizontal grouting holes are communicated with the inside of the shield shell through advanced horizontal grouting pipes. The present application is suitable for deep-buried or underwater shield tunnel crossing buildings under complex conditions, and when the surface reinforcing process is difficult to implement and cannot ensure the effect, the shield advanced horizontal grouting isolation reinforcing and the shield radial grouting permanent reinforcing are adopted, so that the integrity of the reinforcing operation can be ensured, the in-hole grouting detection is assisted, and the effect of the grouting reinforcing is ensured. The present application has the advantages of simple structure, simple process operation, strong implementability, good reinforcing quality, effect detection in the shield hole, etc.

Description

Technical Field

[0001] This invention relates to the field of shield tunnel construction, specifically to a shield tunnel isolation and reinforcement structure and construction method that is simple in structure, easy to operate, highly feasible, provides good reinforcement quality, and enables detection inside the shield tunnel. Background Technology

[0002] For deep underwater shield tunnels crossing rivers and seas, conventional grouting techniques such as sleeve valve grouting are not feasible due to the thick overlying strata or the presence of underwater operations. High-pressure jet grouting and MJS (Mechanical Junction Jet Grouting) techniques are not only expensive in terms of equipment and difficult to drill, but also lack the ability to monitor effectiveness later, making it difficult to guarantee the actual grouting results. Therefore, during actual shield tunneling, the smooth progress of the project is mainly ensured through mechanical means such as shield machine attitude control and relying on shield tunneling experience. Thus, how to implement effective ground reinforcement measures to ensure the safe passage of deep underwater shield tunnels through buildings and structures has become an urgent problem to be solved. Summary of the Invention

[0003] To address the aforementioned defects and shortcomings of existing surface grouting reinforcement methods for deep-buried underwater shield tunnels, this invention proposes a combined isolation reinforcement structure and construction method for shield tunnels that is simple in structure, easy to operate, highly feasible, provides good reinforcement quality, and enables in-tunnel inspection.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a shield tunnel safety crossing structure isolation and reinforcement structure, including shield machine cutterhead, shield shell, shield advanced horizontal grouting isolation and reinforcement zone and shield radial grouting permanent reinforcement zone, characterized in that the shield machine cutterhead is set at one end of the shield shell for tunneling and excavation, the outer surface of the shield shell is provided with advanced horizontal grouting holes, and the advanced horizontal grouting holes are connected to the inside of the shield shell through advanced horizontal grouting pipes;

[0005] The shield tunnel's advanced horizontal grouting isolation and reinforcement zone includes the outermost advanced horizontal grouting zone and the inner advanced horizontal grouting zone.

[0006] The outer surface of the shield shell forms an outermost horizontal grouting zone and an inner horizontal grouting zone between it and the soil layer. The inner wall of the shield shell is provided with shield tunnel segments for laying the tunnel. Several pre-reserved radial grouting holes and several pre-reserved core sampling holes are opened on the shield segments. The outer surface of the shield shell is also provided with shield radial grouting pipes. A shield radial grouting permanent reinforcement zone is also provided between the shield shell and the soil layer. Several grout outlet holes are opened on the shield radial grouting pipes. A self-propelled drill bit is provided at one end of the shield radial grouting pipes.

[0007] Furthermore, the grouting reinforcement range should extend at least 5.0m beyond both sides of the building along the tunneling route, after the shield tunneling grouting is completed.

[0008] Furthermore, core sampling is performed through the central inspection hole to ensure that the reinforcement meets the requirements.

[0009] The specific construction method includes the following steps:

[0010] S1. The tunnel boring machine is equipped with several advanced horizontal grouting holes on the shield shell. The grouting holes are about 5.0m away from the cutterhead, the diameter of the grouting holes is 100mm, and the outward angle θ is 10°~15°.

[0011] S2. Set up and fix grouting drilling equipment at the advanced horizontal grouting hole where grouting is required. The diameter of the drill rod and drill bit of the drilling rig is 42mm. When performing advanced grouting, open the gate valve at the reserved hole position and drill through the advanced horizontal grouting hole equipped by the shield machine. The drilling depth is (H-0.5-R1) / tanθ, where H is the distance between the building and the tunnel structure, and R1 is the outermost diffusion radius of the grout. When the building is far from the tunnel structure, the drilling depth can be taken in the area 4 to 7m in front of the cutterhead.

[0012] S3. After drilling is completed, replace the grouting equipment in a timely manner. The grout should be a fast-setting special grout, such as cement + water glass. The cement should be ultrafine silicate cement. The water-cement ratio of the cement grout should be 0.8:1 to 1:1. The volume ratio of cement grout to water glass should be 1:1. The concentration of water glass should be 40be (1:1 dilution). The pressure during the grouting process should be 0.2 to 0.5 MPa higher than the soil and water pressure, and controlled at 1.0 to 1.5 MPa. The final pressure should not exceed 2.0 MPa.

[0013] S4. Adopt a backward grouting process, grouting the sides while raising the drill rod. The lifting range should be 0.3-0.4m. Pull back at a uniform speed. The outermost grouting radius R1 should be controlled at 1.5m or 2.0m, and the remaining inner grouting radius R2 should be controlled at 1.0m to prevent excessive grout from entering the shield cutterhead.

[0014] S5. After the first grouting cycle is completed, cyclic grouting operations shall be carried out according to the grouting reinforcement area, and the grouting cycle overlap length shall not be less than 2.0m;

[0015] S6. After the tunnel boring machine has safely passed through, the segment ring is assembled. Two radial grouting holes and one central inspection hole are reserved on the tunnel segment. The diameter of the radial grouting hole and the central inspection hole is 100mm.

[0016] S7. After the shield tunneling advance horizontal grouting isolation reinforcement zone is completed, for triangular areas that cannot be reinforced and for situations where the quick-setting special grout is prone to failure in the later stage, shield tunneling radial grouting is adopted for permanent reinforcement. During shield tunneling radial grouting construction, the radial grouting holes of the segments are broken first, and the drilling and grouting integrated equipment is erected and fixed. The diameter of the drill rod and drill bit of the drilling rig is 42mm, and the drilling depth is H-0.5m. Or, when the building is far away from the tunnel structure, the drilling depth can be (9~12)tanθm.

[0017] S8. The grout should be made of ultrafine silicate cement, and the water-cement ratio of the cement grout should be 0.8:1 to 1:1. The grouting pressure should be 0.2 to 0.5 MPa higher than the soil and water pressure, and controlled at 1.0 to 1.5 MPa. The final pressure should not exceed 1.5 MPa.

[0018] S9. Grouting pipe sidewalls are provided with grout outlet holes of different shapes and sizes, such as round or long strip, with radii controlled between 1.0 and 1.5 m. After grouting is completed, the grout outlet holes are sealed.

[0019] Compared with existing technologies, the beneficial effects of this invention are: This invention is applicable to complex conditions such as deep-buried or underwater shield tunnels passing through buildings, where surface reinforcement processes are difficult to implement and their effectiveness cannot be guaranteed. By employing shield tunneling pre-horizontal grouting isolation reinforcement and shield tunneling radial grouting permanent reinforcement, the integrity of the reinforcement operation can be ensured, and in-tunnel grouting detection can be assisted to ensure the effectiveness of the grouting reinforcement. It has advantages such as simple structure, convenient operation, strong feasibility, good reinforcement quality, and the ability to detect the effect inside the shield tunnel. Attached Figure Description

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

[0021] Figure 1 This is a schematic plan view of a shield tunneling pre-horizontal grouting isolation and reinforcement method according to an embodiment of the present invention;

[0022] Figure 2 This is a cross-sectional schematic diagram of a shield tunneling advanced horizontal grouting isolation and reinforcement method according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic plan view of a combined isolation and reinforcement method for safe passage of shield tunnels through buildings and structures, as described in an embodiment of the present invention.

[0024] Figure 4 This is a cross-sectional view of a shield tunnel radial grouting permanent reinforcement method according to an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of reserved holes for tunnel segments;

[0026] Figure 6 This is a detailed drawing of the radial grouting pipe for a tunnel boring machine.

[0027] Labeling Explanation: 1. Tunnel Boring Machine (TBM) Cutterhead; 2. Shield Shell; 3. Advanced Horizontal Grouting Hole; 4. Advanced Horizontal Grouting Pipe; 5. Outermost Advanced Horizontal Grouting Zone; 6. Inner Advanced Horizontal Grouting Zone; 7. TBM Segment; 8. Reserved Radial Grouting Hole for Segment; 9. Reserved Core Sampling Inspection Hole for Segment; 10. Radial Grouting Pipe for TBM; 11. Radial Grouting Permanent Reinforcement Zone for TBM; 12. Grout Outlet Hole; 13. Self-Drilling Bit. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The following embodiments are explanations of the present invention and are not limited to the following embodiments.

[0029] Please see Figure 1-6 The present invention provides a technical solution: including a shield machine cutterhead 1, a shield shell 2, a shield advanced horizontal grouting isolation reinforcement zone and a shield radial grouting permanent reinforcement zone 11, characterized in that the shield machine cutterhead 1 is set at one end of the shield shell 2 for tunneling and excavation, and the outer surface of the shield shell 2 is provided with advanced horizontal grouting holes 3, and the advanced horizontal grouting holes 3 are connected to the interior of the shield shell 2 through advanced horizontal grouting pipes 4;

[0030] The shield tunnel's advanced horizontal grouting isolation and reinforcement zone includes the outermost advanced horizontal grouting zone 5 and the inner advanced horizontal grouting zone 6.

[0031] The outer surface of the shield shell 2 forms an advanced horizontal outermost grouting zone 5 and an advanced horizontal inner grouting zone 6 between the outer surface of the shield shell 2 and the soil layer. The inner wall of the shield shell 2 is provided with shield tunnel segments 7 for laying the tunnel. Several pre-reserved radial grouting holes 8 and several pre-reserved core sampling holes 9 are opened on the shield tunnel segments 7. The outer surface of the shield shell 2 is also provided with a shield radial grouting pipe 10. A shield radial grouting permanent reinforcement zone 11 is also provided between the shield shell 2 and the soil layer. Several grout outlet holes 12 are opened on the shield radial grouting pipe 10. A self-propelled drill bit 13 is provided at one end of the shield radial grouting pipe 10.

[0032] like Figures 1 to 6As shown, in a railway tunnel project spanning a river and sea, the shield tunneling method was used for construction. The tunnel has an outer diameter of 12.8m, an inner diameter of 11.7m, a segment thickness of 550mm, a ring width of 2.0m, and a maximum water depth of 80m. The shield tunnel needs to pass through the bridge piles of a certain bridge, with the closest distance being approximately 3.5m.

[0033] To ensure the safe and smooth excavation of the project, a shield tunnel was used to safely pass through buildings and structures, employing isolation and reinforcement structures and construction methods. These included shield tunneling advance horizontal grouting isolation and reinforcement zones 5 and 6, and shield tunneling radial grouting permanent reinforcement zone 11. The grouting reinforcement range should extend at least 5.0m beyond both sides of the buildings and structures along the excavation route. The steps included were:

[0034] The tunnel boring machine is equipped with several advanced horizontal grouting holes 3 on the shield shell. The distance between the grouting holes and the tunnel boring machine 1 is 5.0m. The diameter of the grouting hole 3 is 100mm and the outward angle θ is 11°.

[0035] Before the tunnel boring machine (TBM) begins tunneling, the advanced horizontal grouting isolation and reinforcement zones 5 and 6 are reinforced. Grouting drilling equipment is erected and fixed at the advanced horizontal grouting hole 3 where grouting is required. The drill rod and drill bit 4 of the drilling rig have a diameter of 42mm. During the advanced grouting operation, the gate valve at the reserved hole position is opened, and drilling is carried out through the advanced horizontal grouting hole 3 equipped with the TBM. The drilling depth is 5m, and the diffusion radius of the outermost grouting zone 5 is 2.0m.

[0036] After drilling is completed, the grouting equipment should be replaced in time. The grout is a fast-setting special grout (cement + water glass). The cement is ultrafine silicate cement, the water-cement ratio of the cement grout is 0.8:1, the volume ratio of cement grout to water glass is 1:1, the water glass concentration is 40be (1:1 dilution), the pressure during the grouting process is controlled at 1.0~1.5MPa, and the final pressure is 2.0MPa.

[0037] A backward grouting process is adopted, with grouting performed while simultaneously lifting the drill rod. The lifting range should be 0.3–0.4 m, and the grouting should be pulled back at a uniform speed. The diffusion radius of the outermost grouting zone 5 is 2.0 m, and the radius of the remaining inner grouting zones 6 is 1.0 m to prevent grout from entering the shield cutterhead and causing accidents such as cutter blockage. After the first grouting cycle is completed, the overlap length of the grouting cycle is 2.0 m.

[0038] After the tunnel boring machine safely passes through, the assembly of the 7th ring of tunnel segment is completed. Two radial grouting holes 8 and one central inspection hole 9 are reserved on the tunnel segment 7. The diameter of the radial grouting hole 8 and the central core sampling inspection hole 9 is 100mm.

[0039] During the radial grouting construction of the shield tunnel, the radial grouting holes 8 of the segment 7 are first broken, and the drilling and grouting integrated equipment is erected and fixed. The diameter of the drill rod 10 and drill bit 13 of the drilling rig is 42mm, and the drilling depth is 3.0m.

[0040] The grout uses ultrafine silicate cement, and the water-cement ratio of the cement grout should be 1:1. The grouting pressure is 1.0 to 1.5 MPa, and the final pressure is 1.5 MPa.

[0041] A circular grout outlet hole 12 is provided on the side wall of the grouting pipe, with a grouting radius of 1.5m. After grouting is completed, the grouting hole 8 is sealed.

[0042] The shield tunnel segments are equipped with a central inspection hole 9. After the radial grouting permanent reinforcement zone 11 of the shield is completed, core sampling is carried out through the central inspection hole 9 to ensure that the reinforcement meets the requirements.

[0043] Furthermore, it should be noted that the shapes and names of the parts and components described in the specific embodiments described in this specification may differ. All equivalent or simple variations made to the construction, features, and principles described in this patent concept are included within the scope of protection of this patent. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the structure of this invention or exceed the scope defined by the claims, and all such modifications and additions shall fall within the scope of protection of this invention.

Claims

1. A construction method for a shield tunnel safely crossing a building structure with isolation and reinforcement, wherein the shield tunnel safely crossing a building structure with isolation and reinforcement includes a shield machine cutterhead (1), a shield shell (2), a shield machine advanced horizontal grouting isolation and reinforcement zone, and a shield machine radial grouting permanent reinforcement zone (11), characterized in that, The cutterhead (1) of the tunnel boring machine is set at one end of the shield shell (2) for tunneling and excavation. The outer surface of the shield shell (2) is provided with advanced horizontal grouting holes (3), and the advanced horizontal grouting holes (3) are connected to the inside of the shield shell (2) through advanced horizontal grouting pipes (4). The shield tunnel's advanced horizontal grouting isolation and reinforcement zone includes the outermost advanced horizontal grouting zone (5) and the inner advanced horizontal grouting zone (6). The outer surface of the shield shell (2) forms an advanced horizontal outermost grouting zone (5) and an advanced horizontal inner grouting zone (6) between the outer surface of the shield shell (2) and the soil layer. The inner wall of the shield shell (2) is provided with shield tunnel segments (7) for laying tunnels. Several pre-reserved radial grouting holes (8) and several pre-reserved core sampling holes (9) are opened on the shield tunnel segments (7). The outer surface of the shield shell (2) is also provided with a shield radial grouting pipe (10). A shield radial grouting permanent reinforcement zone (11) is also provided between the shield shell (2) and the soil layer. Several grout outlet holes (12) are opened on the shield radial grouting pipe (10). A self-propelled drill bit (13) is provided at one end of the shield radial grouting pipe (10). The construction method includes the following steps: S1. The tunnel boring machine is equipped with several advanced horizontal grouting holes on the shield shell. The grouting holes are about 5.0m away from the cutterhead, the diameter of the grouting holes is 100mm, and the outward angle θ is 10°~15°. S2. Set up and fix grouting drilling equipment at the advanced horizontal grouting hole where grouting is required. The diameter of the drill rod and drill bit of the drilling rig is 42mm. When performing advanced grouting, open the gate valve at the reserved hole position and drill through the advanced horizontal grouting hole equipped by the shield machine. The drilling depth is (H-0.5-R1) / tanθ, where H is the distance between the building and the tunnel structure, and R1 is the outermost diffusion radius of the grout. When the building is far from the tunnel structure, the drilling depth is in the area 4 to 7m in front of the cutterhead. S3. After drilling is completed, replace the grouting equipment in a timely manner. The grout is cement + water glass. The cement is ultrafine silicate cement. The water-cement ratio of the cement grout is 0.8:1 to 1:

1. The volume ratio of cement grout to water glass is 1:

1. The concentration of water glass is 40°Bé. The pressure during the grouting process is 0.2 to 0.5 MPa higher than the soil and water pressure and controlled at 1.0 to 1.5 MPa. The final pressure does not exceed 2.0 MPa. S4. The retreating grouting process is adopted, and the drill rod is lifted while grouting. The lifting range is 0.3-0.4m, and the drill rod is pulled back at a uniform speed. The outermost grouting radius R1 is controlled at 1.5m or 2.0m, and the inner grouting radius R2 is controlled at 1.0m to prevent excessive grout from entering the shield cutterhead. S5. After the first grouting cycle is completed, cyclic grouting operations shall be carried out according to the grouting reinforcement area, and the grouting cycle overlap length shall not be less than 2.0m; S6. After the tunnel boring machine has safely passed through, the segment ring is assembled. Two radial grouting holes and one core sampling inspection hole are reserved on the tunnel segment. The diameter of the radial grouting hole and the core sampling inspection hole is 100mm. S7. After the shield tunneling advance horizontal grouting isolation reinforcement zone is completed, for triangular areas that cannot be reinforced and for cases where the quick-setting special grout is prone to failure in the later stage, the shield tunneling radial grouting is adopted for permanent reinforcement. During the shield tunneling radial grouting construction, the radial grouting holes of the segments are broken first, and the grouting drilling equipment is set up and fixed. The diameter of the drill rod and drill bit of the drilling rig is 42mm, and the drilling depth is H-0.5m. Or when the building structure is far away from the tunnel structure, the drilling depth is (9~12)tanθ,m. S8. The grout uses ultrafine silicate cement, the water-cement ratio of the cement grout is 0.8:1 to 1:1, the pressure during the grouting process is 0.2 to 0.5 MPa higher than the soil and water pressure, and is controlled at 1.0 to 1.5 MPa, with the final pressure not exceeding 1.5 MPa; S9. The radial grouting pipe of the shield is equipped with grout outlet holes of different sizes, such as circular and elongated shapes. The grouting radius is controlled between 1.0 and 1.5 m. After grouting is completed, the grouting holes are sealed.

2. The construction method for the isolation and reinforcement structure of a shield tunnel safely passing through a building or structure according to claim 1, characterized in that, The grouting reinforcement range extends no less than 5.0m beyond both sides of the building along the tunneling route.

3. The construction method for the isolation and reinforcement structure of a shield tunnel safely crossing a building or structure according to claim 1, characterized in that, The tunnel segments are equipped with core sampling inspection holes. After the tunnel grouting is completed, core samples are taken through these holes to ensure that the reinforcement meets the requirements.

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