A temporary water stop method for the interface between the mechanical connection channel and the main tunnel

Abstract

The present invention provides a temporary water-stop method for the interface between a mechanically constructed connecting passage and the main tunnel. A connecting passage steel segment is provided at the interface between the connecting passage and the main tunnel. A circumferential grouting body for the connecting passage and a circumferential grouting body for the main tunnel are constructed in the gap between the outer skin of the connecting passage steel segment and the opening in the segment of the main tunnel to form a grouting accumulation body. The micro-freezing technology is used to freeze the grouting accumulation body and the soil body at the interface between the connecting passage and the main tunnel to form a frozen body, so as to meet the requirements for temporary water-stop at the interface. After meeting the requirements for temporary water-stop, a permanent water-stop steel plate is welded at the interface between the connecting passage and the main tunnel, and a portal ring beam is constructed. After the construction of the permanent water-stop steel plate and the portal ring beam is completed, the micro-freezing is stopped to complete the transition from temporary water-stop to permanent water-stop. The present invention meets the temporary water-stop requirements at the interface between the connecting passage and the main tunnel, and the temporary water-stop method can be applied to the temporary water-stop requirements in various complex water-rich strata.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel engineering, and particularly relates to a temporary water stop method for the interface between a mechanically constructed connecting passage and a main tunnel. Background Art

[0002] The mechanically constructed connecting passage is still a new technology for the construction of connecting passages in China. To meet the requirements for the construction of connecting passages by mechanical methods such as shield tunneling or pipe jacking in the main tunnel, the opening size of the main tunnel is relatively large compared to the outer skin size of the connecting passage tunnel. Therefore, there is a large gap at the interface between the connecting passage and the main tunnel. The temporary water stop method for this gap has become the key to the success or failure of this construction method, and the temporary water stop measure should ensure a safe and reliable transition from temporary water stop to permanent water stop at the interface between the connecting passage and the main tunnel.

[0003] Currently, in some areas, the mechanically constructed connecting passage has been constructed. The temporary water stop method at the interface between the connecting passage and the main tunnel mostly adopts a simple grouting process. Most of the implementation areas are in non-water-rich strata, and the tunnel burial depth is relatively shallow, which can basically meet the temporary water stop requirements. However, for water-rich strata, especially strata rich in confined water, it is difficult to achieve the temporary water stop effect by using a simple grouting process, and the construction risk is relatively high. Therefore, it is necessary to develop a temporary water stop method for the interface between the connecting passage and the main tunnel in water-rich strata to ensure the temporary water stop effect. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a temporary water stop method for the interface between a mechanically constructed connecting passage and a main tunnel, which realizes temporary water stop by combining grouting and micro-freezing technology at the interface between the connecting passage and the main tunnel, and meets the requirements for temporary water stop at the interface between the connecting passage and the main tunnel under the high water pressure state in water-rich strata.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides a temporary water stop method for the interface between a mechanically constructed connecting passage and a main tunnel, and the method comprises the following steps:

[0007] Step S1, a connecting passage steel segment is arranged at the interface between the connecting passage and the main tunnel. A connecting passage circumferential grouting body and a main tunnel circumferential grouting body are constructed in the gap between the outer skin of the connecting passage steel segment and the opening of the main tunnel segment to form a grouting accumulation body;

[0008] Step S2, the micro-freezing technology is used to freeze the grouting accumulation body and the soil body at the interface between the connecting passage and the main tunnel to form a frozen body to meet the requirements for temporary water stop at the interface;

[0009] Step S3: After meeting the requirements of temporary water stop, weld the permanent water stop steel plate at the interface between the connecting passage and the main tunnel and construct the portal ring beam. After the construction of the permanent water stop steel plate and the portal ring beam is completed, stop the micro-freezing to complete the transition from temporary water stop to permanent water stop.

[0010] Preferably, the circumferential grouting body of the connecting passage is realized by pre-grouting inside the segment of the connecting passage through a plurality of circumferential grouting holes arranged on the segment of the connecting passage.

[0011] Preferably, the circumferential grouting body of the main tunnel is realized by pre-grouting inside the main tunnel through the reserved grouting holes on the segment of the main tunnel, and the reserved grouting holes are arranged circumferentially around the portal of the main tunnel.

[0012] Preferably, in step S2, the micro-freezing technology is to form a frozen body by embedding freezing pipes in the segment of the connecting passage to freeze the grouting accumulation body and the soil at the interface between the connecting passage and the main tunnel.

[0013] Preferably, the freezing pipes are fixed in the partition cavity of the segment of the connecting passage. One end of the freezing pipe is the brine inlet and the other end is the brine outlet; two-way freezing pipes are arranged on each segment of the connecting passage, and the freezing pipes are arranged closely against the back plate of the segment of the connecting passage. Flexible hoses are used to connect the freezing pipes between the segments of the connecting passage.

[0014] Preferably, pressure tests are carried out before and after the laying of the freezing pipes to ensure the tightness of the pipeline.

[0015] Preferably, ball valves are installed at the positions of the brine inlet and outlet of the freezing pipes.

[0016] The present invention has the following beneficial effects:

[0017] The present invention combines the spatial structure form at the interface between the connecting passage and the main tunnel, and proposes a temporary water stop method for the interface between the mechanical connecting passage and the main tunnel. The method uses grouting combined with micro-freezing technology to form a frozen body to meet the temporary water stop requirements at the interface between the connecting passage and the main tunnel. The present invention is applicable to the temporary water stop at the interface between the mechanical connecting passage and the main tunnel, and can also be applicable to other similar underground tunnel projects. The temporary water stop method can be applicable to the temporary water stop requirements in various complex water-rich strata, especially has a good implementation effect for high water pressure strata such as those rich in confined water, and improves the safety and reliability of temporary water stop. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the embodiments of the present invention.

[0019] Figure 1Schematic plan view of the water stop measure at the interface between the connecting passage and the main tunnel in the embodiment of the present invention;

[0020] Figure 2 Schematic sectional view of the water stop measure at the interface between the connecting passage and the main tunnel in the embodiment of the present invention;

[0021] Figure 3 Schematic view of the grouting holes around the portal of the main tunnel in the embodiment of the present invention;

[0022] Figure 4 Schematic elevation view of the pre-buried freezing pipes for the segmental freezing of the connecting passage steel segment in the embodiment of the present invention;

[0023] Figure 5 Schematic sectional view of the pre-buried freezing pipes for the segmental freezing of the connecting passage steel segment in the embodiment of the present invention;

[0024] Explanation of reference numerals:

[0025] 1. Circumferential grouting body of the connecting passage; 2. Frozen body; 3. Circumferential grouting body of the main tunnel; 4. Connecting passage steel segment; 5. Freezing pipe; 6. Portal ring beam; 7. Permanent water stop steel plate; 8. Main tunnel segment; 9. Circumferential grouting hole; 10. Reserved grouting hole. Detailed implementation manners

[0026] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] When constructing the connecting passage by the mechanical method, the method of plugging the portal at the interface between the connecting passage and the main tunnel is the key to the success or failure of the project. Since there is a large gap between the outer wall of the connecting passage tunnel and the opening of the main tunnel, it is necessary to consider the plugging and water stop measures for this gap. The plugging of the portal needs to solve the transition from temporary water stop to permanent water stop, and this process has a relatively high risk, which determines whether the project can be successfully and safely completed.

[0028] In this embodiment, in combination with the spatial structure form at the interface between the connecting passage and the main tunnel, a temporary water stop method for the interface between the mechanical connecting passage and the main tunnel is provided. The method includes the following steps:

[0029] Step S1, a connecting passage steel segment 4 is provided at the interface between the connecting passage and the main tunnel. A connecting passage circumferential grouting body 1 and a main tunnel circumferential grouting body 3 are constructed in the gap between the outer skin of the connecting passage steel segment 4 and the opening of the main tunnel segment 8 to form a grouting accumulation body;

[0030] Step S2, the micro-freezing technology is used to freeze the grouting accumulation body and the soil at the interface between the connecting passage and the main tunnel to form a frozen body 2 to meet the requirements of temporary water stop at the interface;

[0031] Step S3: After meeting the requirements of temporary water stop, weld the permanent water stop steel plate 7 at the interface between the connecting passage and the main tunnel and construct the portal ring beam 6. After the construction of the permanent water stop steel plate 7 and the portal ring beam 6 is completed, stop the micro-freezing to complete the transition from temporary water stop to permanent water stop.

[0032] Furthermore, the circumferential grouting body 1 of the connecting passage is realized by pre-grouting inside the segment of the connecting passage steel pipe 4 through a plurality of circumferential grouting holes 9 provided on the segment of the connecting passage steel pipe 4 to meet the requirements of grouting and water stop at the interface between the connecting passage and the main tunnel.

[0033] Furthermore, the circumferential grouting body 3 of the main tunnel is realized by pre-grouting inside the main tunnel through the reserved grouting holes 10 on the segment of the main tunnel lining 8. The reserved grouting holes 10 are arranged circumferentially around the portal of the main tunnel, and other necessary grouting holes are arranged circumferentially along the main tunnel to meet the requirements of grouting and water stop at the interface between the main tunnel and the connecting passage.

[0034] Furthermore, in the micro-freezing technology in step S2, freezing pipes 5 are embedded in the segment of the connecting passage steel pipe 4 to freeze the grouting accumulation body and soil at the interface between the connecting passage and the main tunnel to form a frozen body 2. The micro-freezing technology is realized by controlling the necessary thickness and freezing temperature of the frozen body 2 in combination with the water stop requirements.

[0035] Furthermore, the freezing pipes 5 are fixed in the partition cavity of the segment of the connecting passage steel pipe 4. One end of the freezing pipe 5 is the brine inlet, and the other end is the brine outlet. Two paths of freezing pipes 5 are arranged on each segment of the connecting passage steel pipe 4. The freezing pipes 5 are arranged closely against the back plate of the segment of the connecting passage steel pipe 4. The freezing pipes 5 between the divided blocks of the segment of the connecting passage steel pipe 4 are connected by hoses. Through the freezing pipes closely against the back plate of the segment of the connecting passage steel pipe 4, a frozen body at the interface is formed in combination with the micro-freezing technology to meet the requirements of temporary water stop.

[0036] Furthermore, pressure tests are carried out before and after the laying of the freezing pipes 5 to ensure the tightness of the pipeline.

[0037] Furthermore, ball valves are installed at the positions of the brine inlet and outlet of the freezing pipes 5.

[0038] It can be seen from the above technical solutions that the temporary water stop method for the interface between the mechanical connecting passage and the main tunnel provided in this embodiment uses grouting combined with micro-freezing technology to form a frozen body to meet the temporary water stop requirements at the interface between the connecting passage and the main tunnel. The present invention is applicable to the temporary water stop at the interface between the mechanical connecting passage and the main tunnel, and can also be applicable to other similar underground tunnel projects. The temporary water stop method can be applicable to the temporary water stop requirements in various complex water-rich strata, especially has good implementation effects for high water pressure strata such as those rich in confined water, and improves the safety and reliability of temporary water stop.

[0039] The embodiments of the present invention have been described in detail through the examples above. However, the above content is only an exemplary embodiment of the embodiments of the present invention and cannot be considered as defining the scope of implementation of the embodiments of the present invention. The protection scope of the embodiments of the present invention is defined by the claims. All those who use the technical solutions described in the embodiments of the present invention, or those skilled in the art, inspired by the technical solutions in the embodiments of the present invention, within the essence and protection scope of the embodiments of the present invention, design similar technical solutions to achieve the above technical effects, or make equivalent changes and improvements to the scope of the application, etc., should still fall within the scope of patent protection covered by the embodiments of the present invention.

Claims

1. A temporary water stop method for the interface between a mechanically constructed connecting passage and a main tunnel, characterized in that, The method comprises the following steps: Step S1, a communication channel steel pipe segment (4) is arranged at the interface between the communication channel and the main tunnel, and a communication channel annular grouting body (1) and a main tunnel annular grouting body (3) are constructed in the gap between the outer skin of the communication channel steel pipe segment (4) and the opening of the main tunnel segment (8) to form a grouting accumulation body; Step S2, using micro-freezing technology to freeze the grouting accumulation body and soil at the interface between the communication channel and the main tunnel to form a frozen body (2) to meet the temporary water stopping requirements at the interface; Step S3, after the temporary water-stopping requirements are met, a permanent water-stopping steel plate (7) is welded at the interface between the communication channel and the main tunnel and a tunnel gate ring beam (6) is constructed. After the permanent water-stopping steel plate (7) and the tunnel gate ring beam (6) are constructed, micro-freezing is stopped to complete the transition from temporary water-stopping to permanent water-stopping; In step S2, the micro-freezing technology is to pre-embed a freezing lead pipe (5) in the steel pipe segment (4) of the connecting channel, so that the grouting accumulation body and the soil body at the interface between the connecting channel and the main tunnel are frozen to form a frozen body (2); The freezing lead pipe (5) is fixed in the compartment of the connecting channel steel pipe segment (4), one end of the freezing lead pipe (5) is a salt water inlet, and the other end is a salt water outlet; each connecting channel steel pipe segment (4) is provided with two freezing lead pipes (5), the freezing lead pipes (5) are arranged close to the back plate of the connecting channel steel pipe segment (4), and the freezing lead pipes (5) are connected between the blocks of the connecting channel steel pipe segment (4) by a hose.

2. The temporary water stop method for the interface between the mechanical connection channel and the main tunnel according to claim 1, characterized in that The communication channel annular grouting body (1) is realized by pre-grouting in the communication channel steel pipe segment 4 through a plurality of annular grouting holes (9) arranged on the communication channel steel pipe segment (4).

3. The temporary water stop method for the interface between the mechanical connection passage and the main tunnel according to claim 1, characterized in that, The main tunnel annular grouting body (3) is pre-grouted inside the main tunnel through the reserved grouting holes (10) on the main tunnel segments (8), and the reserved grouting holes (10) are arranged annularly around the main tunnel portal.

4. The temporary water stop method for the interface between the mechanical connection passage and the main tunnel according to claim 1, wherein A pressure test is performed on the freezing lead pipe (5) before and after it is laid to ensure the tightness of the pipeline.

5. The temporary water stop method for the interface between the mechanical connection channel and the main tunnel according to claim 1, characterized in that, Ball valves are installed at the brine water inlet and outlet of the freezing lead pipe (5).

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