Reinforcing structure for penetration of tunnel collapse section

Abstract

The utility model discloses a reinforcing structure for penetration of a tunnel collapse section. The reinforcing structure comprises an inlet end reinforcing structure and an outlet end reinforcing structure which are located on the two sides of the tunnel collapse penetration section respectively. The inlet end reinforcing structure comprises inlet end back pressure earth and stone backfilling the rear side of the inlet end supporting face and the space on the lower side of the inlet end vault collapse body, the end, away from the inlet end tunnel face, of the inlet end back pressure earth and stone protrudes out of the inlet end vault collapse body, a working platform is arranged above the protruding part, and an inlet end temporary cover arch is arranged on the working platform. The inlet end reinforcing structure further comprises an inlet end pipe shed supporting structure which penetrates through the tunnel contour line, one end of the inlet end pipe shed supporting structure is supported by the inlet end temporary cover arch, the middle of the inlet end pipe shed supporting structure supports an inlet end vault collapse body, and the other end of the inlet end pipe shed supporting structure extends into a stable rock stratum. The outlet end reinforcing structure is consistent with the inlet end reinforcing structure; the steel pipes of the inlet end pipe shed supporting structure and the steel pipes of the outlet end pipe shed supporting structure are staggered in the annular direction of the tunnel.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel construction, and particularly relates to a reinforcement structure for tunnel collapse section penetration. Background Technique

[0002] Tunnel collapse is a serious safety accident during tunnel construction, and its causes are often complex and diverse. The main causes of collapse can be summarized into several aspects such as geological factors, construction factors, management factors, and unforeseeable factors. Geological factors are one of the most critical and difficult-to-control factors in tunnel collapse incidents. First of all, the geological bodies passed through by the tunnel are complex and changeable, and there may be unknown weak interlayers, fault fracture zones, or karsts and other adverse geological bodies. These adverse geological bodies are easily disturbed during tunnel excavation, resulting in local or overall instability, thus triggering collapse. Secondly, the influence of groundwater cannot be ignored. Groundwater may not only soften the surrounding rock, reduce its strength, but also form a confined aquifer, exerting huge pressure on the tunnel structure and inducing collapse. Construction factors are one of the important reasons for tunnel collapse. Blasting operations during construction may cause excessive disturbance and damage to the surrounding rock, reducing its stability. At the same time, if the support measures are not timely or in place, it may also lead to the instability of the surrounding rock, thus triggering collapse. During tunnel construction, the penetration position is usually selected in a location with good surrounding rock conditions to reduce the occurrence of collapse and roof fall accidents. However, due to reasons such as construction period and construction procedures, the penetration section of some tunnels is located in a section with poor geological conditions, or even in a collapsed section. The situation applicable to the present invention is that during the construction of the tunnel entrance section, a collapse occurs at the crown. In order to save the construction period, the exit end is used for entering the tunnel for construction. When the construction reaches near the collapsed section at the entrance, a collapse occurs at the crown, making the penetration position located in the collapsed section. To solve the problems of structural stability and safety of the tunnel during penetration in the collapsed section, it is of great significance to design a reinforcement structure for tunnel collapse section penetration. Content of the Utility Model

[0003] In view of this, the purpose of the present utility model is to provide a reinforcement structure for tunnel collapse section penetration to solve the problems of structural stability and safety of the tunnel during penetration in the collapsed section.

[0004] The purpose of the present utility model is achieved through the following technical solutions:

[0005] A reinforcement structure for tunnel collapse section penetration,

[0006] which includes an entrance end reinforcement structure and an exit end reinforcement structure respectively located on both sides of the tunnel collapse penetration section;

[0007] The entrance end reinforcement structure includes the entrance end counter-pressure earth and rock that backfills the space between the rear side of the entrance end support surface and the lower side of the entrance end arch collapse body, the end of the entrance end counter-pressure earth and rock that is away from the entrance end face protrudes from the entrance end arch collapse body, and a working platform is provided above the protruding part, and a temporary entrance end sleeve arch is provided on the working platform. The entrance end reinforcement structure also includes the entrance end pipe shed support structure, which passes through the tunnel contour line and is supported by the temporary entrance end sleeve arch at one end, supports the entrance end arch collapse body in the middle, and extends into the stable rock formation at the other end;

[0008] The exit end reinforcement structure includes an exit end counter-pressure earth and rock that backfills the space between the rear side of the exit end support surface and the lower side of the exit end arch collapse body, the end of the exit end counter-pressure earth and rock that is away from the exit end face protrudes from the exit end arch collapse body, and a working platform is provided above the protruding part, and a temporary exit end sleeve arch is provided on the working platform. The exit end reinforcement structure also includes an exit end pipe shed support structure, which passes through the tunnel contour line and is supported by the temporary exit sleeve arch at one end and supports the exit end arch collapse body in the middle, and the other end extends into the stable rock formation;

[0009] The steel pipes of the pipe shed support structure at the inlet end and the steel pipes of the pipe shed support structure at the outlet end are staggered in the tunnel ring direction.

[0010] Furthermore, the working platform height is 2 meters.

[0011] Furthermore, the temporary arch at the inlet end and the temporary arch at the outlet end are both formed by two I-beams connected in parallel.

[0012] The beneficial effects of the utility model are:

[0013] The utility model provides a reinforcement structure for tunnel collapse section penetration, which has the following beneficial effects:

[0014] (1) When landslides occur at both the entrance and exit of the tunnel, the use of a bidirectional pipe-roof support structure can improve construction safety.

[0015] (2) The bidirectional pipe-roof support structure scheme is used to carry out excavation under the condition of fully reinforcing the front face and the front surrounding rock. This saves costs and construction time while ensuring safety, and has great economic value.

[0016] (3) Pipe shed support structures are set up on both sides of the penetration position. The pipe shed support structures on both sides form a scaffolding effect, ensuring the safety of construction.

[0017] Other advantages, objectives and features of the present utility model will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present utility model. The objectives and other advantages of the present utility model can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below in conjunction with the drawings, where:

[0019] Figure 1 is a cross-sectional view of the present utility model in the longitudinal direction of the tunnel.

[0020] Figure 2 is an end view of the tunnel constructed using the present utility model.

[0021] In the figure: backfill soil and rock at the inlet end 1, temporary arch support at the inlet end 2, pipe shed support structure at the inlet end 3, initial support at the inlet end 4, roof collapse body at the inlet end 5, backfill soil and rock at the outlet end 6, temporary arch at the outlet end 7, pipe shed support structure at the outlet end 8, roof collapse body at the outlet end 10, heading face at the inlet end 11, heading face at the outlet end 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The following will refer to the drawings to describe in detail the preferred embodiments of the present utility model. It should be understood that the preferred embodiments are only for explaining the present utility model and not for limiting the protection scope of the present utility model.

[0023] As Figure 1-2 shown, a reinforcement structure for tunnel collapse section breakthrough includes an inlet end reinforcement structure and an outlet end reinforcement structure. The inlet end reinforcement structure is constructed when a roof collapse is encountered during the excavation of the tunnel inlet end, and the outlet end reinforcement structure is constructed when a roof collapse is encountered near the inlet end roof collapse during the excavation of the tunnel outlet end.

[0024] The inlet end reinforcement structure includes backfill soil and rock at the inlet end 1, in the excavation direction of the tunnel inlet end ( Figure 1In the direction of the arrow), the backfill soil and stone 1 at the inlet end backfills the space below the back side of the inlet end support surface 11 and the lower side of the inlet end crown collapse body 5 (if there is already some crown collapse soil and stone in this space, there is no need to clean it up. Just use the backfill soil and stone 1 at the inlet end to backfill until this space is filled up). The rear end of the backfill soil and stone 1 at the inlet end protrudes from the inlet end crown collapse body to form a protruding part. A working platform is provided between the protruding part and the initial support 4 at the inlet end. An inlet end temporary casing arch 2 is provided on the working platform. The inlet end reinforcement structure further includes an inlet end pipe shed support structure 3. The rear end of the inlet end pipe shed support structure 3 is supported by the inlet end temporary casing arch 2, the middle part supports the inlet end crown collapse body 5, and the front end extends into the stable rock formation.

[0025] The outlet end reinforcement structure includes the backfill soil and stone 6 at the outlet end. In the tunnel outlet end excavation direction ( Figure 1 In the direction of the arrow), the backfill soil and stone 6 at the outlet end backfills the space below the back side of the outlet end support surface 12 and the lower side of the outlet end crown collapse body 10 (if there is already some crown collapse soil and stone in this space, there is no need to clean it up. Just use the backfill soil and stone 1 at the outlet end to backfill until this space is filled up). The rear end of the backfill soil and stone 6 at the outlet end protrudes from the outlet end crown collapse body to form a protruding part. A working platform is provided between the protruding part and the initial support 9 at the outlet end. An outlet end temporary casing arch 7 is provided on the working platform. The outlet end reinforcement structure further includes an outlet end pipe shed support structure 8. The rear end of the outlet end pipe shed support structure 8 is supported by the outlet end temporary casing arch 7, the middle part supports the outlet end crown collapse body 10, and the front end extends into the stable rock formation.

[0026] The steel pipes of the inlet end pipe shed support structure 3 and the steel pipes of the outlet end pipe shed support structure 8 are staggered one by one in the tunnel circumferential direction.

[0027] After the reinforcement structure backfills and counter-presses the collapse bodies at the tunnel inlet and outlet to form a platform, pipe shed support structures are driven at both the tunnel inlet and outlet to achieve the stability of the tunnel through structure and construction safety in the collapse section.

[0028] A construction method for a reinforcement structure for tunnel penetration in a collapse section includes the following steps:

[0029] The following description of front and back is relative to the tunnel excavation direction (the tunnel excavation direction is Figure 1 In the direction of the arrow);

[0030] 1) During the excavation of the inlet end of a large-section tunnel, due to poor surrounding rock conditions, a collapse occurred. To quickly stabilize the face 11 at the inlet end, backfill the inlet end counterweight soil and rock 1 under the collapse body at the inlet end arch crown to prevent the continued expansion of the collapse body 5 at the inlet end arch crown. During backfilling, to ensure safety, use an excavator to deliver soil and rock to the collapse location, ensuring that there are no voids in front of the collapse body 5 at the inlet end arch crown to stably support the face at the inlet end. After the inlet end counterweight soil and rock 1 stabilizes the face 11 at the inlet end, after the initial support 4 at the inlet end is stable through monitoring and measurement, start clearing a working platform on the upper rear of the inlet end counterweight soil and rock 1. The height of the working platform should meet the space requirements for pipe shed construction, generally controlled at 2 meters. Then construct the inlet end temporary casing arch 2 on the working platform. The inlet end temporary casing arch 2 is made of two sets of I-beams to serve as the end support points for the pipe shed support structure 3 at the inlet end. Then drive the inlet end pipe shed support structure 3 to pass through the tunnel contour line and extend into the stable rock formation. The steel pipes of the inlet end pipe shed support structure 3 are ∅108×6mm steel pipes with a length of 18 meters, and the circumferential spacing is 40 cm. The number of steel pipe joints in the same cross-section of the tunnel does not exceed 50%, and the joints of adjacent steel pipes must be staggered by at least 1 m.

[0031] 2) After the construction of the inlet end pipe shed support structure 3, due to reasons such as the construction period, start the excavation from the outlet end of the tunnel. At the end of the inlet end pipe shed support structure 3, due to its limited bearing capacity, a collapse also occurred at the outlet end of the tunnel, and at the same time, the end of the inlet end pipe shed support structure 3 was damaged. Therefore, use the same method at the outlet end. First, backfill the outlet end counterweight soil and rock 6 under the collapse body at the outlet end arch crown to control the displacement of the collapse body 10 at the outlet end arch crown. After the outlet end counterweight soil and rock 6 stabilizes the face 10 at the outlet end, after the initial support 9 at the outlet end is stable through monitoring and measurement, start clearing a working platform on the upper rear of the outlet end counterweight soil and rock 6. Then construct the outlet end temporary casing arch 7 on the working platform. Then drive the outlet end pipe shed support structure 8 to pass through the tunnel contour line and extend into the stable rock formation. The steel pipes of the outlet end pipe shed support structure 8 are ∅108×6mm steel pipes with a length of 18 meters, and the circumferential spacing is 40 cm.

[0032] The steel pipes of the inlet end pipe shed support structure 3 and the steel pipes of the outlet end pipe shed support structure 8 are staggered one by one in the tunnel circumferential direction.

[0033] 3) After the construction of the pipe shed support structures at the inlet and outlet ends is completed, carry out grouting reinforcement. The grouting uses cement slurry, and add 5% water glass by volume of the cement slurry in the collapse body with large water volume. After the grouting is completed, according to the monitoring and measurement data of the initial support in this section, when the data of crown settlement and peripheral convergence are stable, and on the premise of ensuring safety, carry out the excavation of the main tunnel. The main tunnel excavation method can be carried out by the bench method or the CD method according to the on-site surrounding rock conditions and the tunnel contour dimensions (remove the rear end of the pipe shed support structure during excavation).

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A reinforcement structure for tunnel collapse section penetration, characterized in that: It includes an inlet end reinforcement structure and an outlet end reinforcement structure respectively located on both sides of the collapsed through section of the tunnel; The entrance end reinforcement structure includes an entrance end counter-pressure soil and rock (1) which backfills the space between the rear side of the entrance end support surface (11) and the lower side of the entrance end arch collapse body (5); one end of the entrance end counter-pressure soil and rock (1) which is away from the entrance end face (11) protrudes from the entrance end arch collapse body (5) to form a protruding portion, and a working platform is provided above the protruding portion, and an entrance end temporary sleeve arch (2) is provided on the working platform; the entrance end reinforcement structure also includes an entrance end pipe shed support structure (3), the entrance end pipe shed support structure (3) passes through the tunnel contour line, one end of which is supported by the entrance end temporary sleeve arch (2), the middle part of which supports the entrance end arch collapse body (5), and the other end of which protrudes into the stable rock layer; The exit end reinforcement structure includes an exit end counter-pressure soil and rock (6) backfilling the space between the rear side of the exit end support surface (12) and the lower side of the exit end arch collapse body (10), one end of the exit end counter-pressure soil and rock (1) away from the exit end face (12) protrudes from the exit end arch collapse body (10) to form a protruding portion, and a working platform is provided above the protruding portion, and an exit end temporary sleeve arch (7) is provided on the working platform. The exit end reinforcement structure also includes an exit end pipe shed support structure (8), the exit end pipe shed support structure (8) passes through the tunnel contour line, one end of which is supported by the exit end temporary sleeve arch (7), the middle part of which supports the exit end arch collapse body (10), and the other end of which protrudes into the stable rock formation; The steel pipes of the pipe shed support structure at the inlet end and the steel pipes of the pipe shed support structure at the outlet end are staggered in the tunnel ring direction.

2. The reinforcement structure for tunnel collapse section penetration according to claim 1, characterized in that: The working platform is 2 meters high.

3. The reinforcement structure for tunnel collapse section breakthrough according to claim 1 or 2, characterized in that: The temporary sleeve arch (2) at the inlet end and the temporary sleeve arch (7) at the outlet end are both formed by two I-beams connected in parallel.

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