Construction method for extending emergency channel of existing underground tunnel and emergency channel

Abstract

The invention relates to the technical field of tunnel construction, in particular to a construction method of an existing underground tunnel extension emergency channel and the emergency channel, and the construction method comprises the following steps: determining the point positions of anchor rods and joint bars and drilling, installing the anchor rods and the joint bars at the drilling positions, erecting a scaffold, installing a concrete pouring template and skeleton steel bars on the scaffold, and installing a concrete pouring template and skeleton steel bars on the scaffold. The upper end of the concrete pouring formwork is connected with the scaffold, the lower end of the concrete pouring formwork makes contact with the inner wall of the underground tunnel and is higher than the average water level of the underground tunnel for many years, concrete is poured on the inner side of the concrete pouring formwork, the formwork and the scaffold are dismantled after solidification, the emergency channel with the corbel-shaped cross section is obtained, maintenance of the emergency channel is conducted, and the steps are repeated. And the whole line construction of the underground tunnel emergency channel is completed. Compared with a traditional emergency channel and a construction method, the construction method has the advantages that the project amount and the total investment can be greatly reduced, forced shutdown caused by rising of the water level in the flood season can be avoided, and the construction method is short in construction period, high in operability and good in economical efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and in particular to a construction method for expanding an emergency passage in an existing underground tunnel and the emergency passage. Background Art

[0002] Building a deep underground laboratory and forming a low cosmic ray flux and low radiation background environment is a prerequisite for conducting detection of rare physical events such as dark matter and neutrinos. At present, deep underground laboratories in the world are generally divided into two types: tunnel type and mine type. Tunnel type deep underground laboratories are generally formed by expanding to one side in the middle of a mountain tunnel, and most cosmic rays are shielded by the thick mountain cover layer above the laboratory. Compared with mine type deep underground laboratories, tunnel type deep underground laboratories have the advantages of convenient transportation and easier to control environmental conditions.

[0003] The entire underground space of the extremely deep underground ultra-low radiation background frontier physics experimental facility is huge, usually composed of multiple test halls, traffic tunnels and auxiliary tunnels. The traffic inside the facility is relatively complicated. In addition, it is located thousands of meters underground, which leads to huge challenges for the emergency evacuation design of personnel. Considering the construction limitations brought about by the facility being located inside the mountain, one of the preferred options for emergency evacuation design is to effectively build emergency evacuation passages based on auxiliary tunnels.

[0004] The traditional emergency evacuation passage is a right angle, see Figure 1 and Figure 2 As shown, underground tunnels have a certain water level all year round. Construction in water-filled tunnels requires the construction of temporary anti-seepage cofferdams along the entire line to create dry land construction conditions. For tunnels several kilometers long, the temporary anti-seepage cofferdam project is large in scale and has poor economic efficiency. In addition, construction conditions during flood and dry seasons must be considered. Construction needs to be stopped during the flood season, and the construction period is correspondingly extended, making the actual operability low.

[0005] In view of the above-mentioned practical problems and limitations of the prior art, the present invention provides a construction method for expanding an emergency passage in an existing underground tunnel, aiming to solve the problem of emergency evacuation of deep underground buildings such as deep underground laboratories. Summary of the invention

[0006] The purpose of the present invention is to provide a construction method for expanding an emergency passage in an existing underground tunnel, so as to solve the problem of emergency evacuation of deep underground buildings such as deep underground laboratories.

[0007] The embodiment of the present invention is implemented by the following technical solution: A construction method for expanding an emergency passage in an existing underground tunnel comprises the following steps:

[0008] Step 1: Determine the locations of anchor rods and reinforcing bars;

[0009] Step 2: Drill holes at the determined points;

[0010] Step 3: Install anchor rods and reinforcing bars at the corresponding drilling positions;

[0011] Step 4: Set up the first scaffolding on one side of the underground tunnel;

[0012] Step 5: Install a concrete casting template and skeleton steel bars on the first scaffolding, wherein the concrete casting template is tilted, its upper end is connected to the first scaffolding, and its lower end is in contact with the inner wall of the underground tunnel and is higher than the multi-year average water level of the underground tunnel, the anchor rods and dowel bars are located on the inner side of the concrete casting template, and the skeleton steel bars are laid on the inner side of the concrete casting template;

[0013] Step 6: pouring concrete inside the concrete pouring template;

[0014] Step 7: After the poured concrete solidifies, the formwork and the first scaffold are removed to obtain an emergency passage that is formed in construction and has a "bull leg"-shaped cross section, and the emergency passage is maintained;

[0015] Step 8. Repeat steps 1 to 7 until the construction of the underground tunnel emergency passage is completed.

[0016] According to a preferred embodiment, before step one, the method further includes lifting the construction platform in the underground tunnel by hoisting equipment, and determining the positions of anchor rods and inserted bars by line-laying measurement.

[0017] According to a preferred embodiment, the number of the construction platforms is two, and the two construction platforms are respectively located at the front side and the rear side of the lifting equipment.

[0018] According to a preferred embodiment, the construction platform includes a base and a guardrail, the base is composed of a second scaffolding erected above the water level and a steel mesh laid on the top of the second scaffolding, and the guardrail is arranged on the side of the top of the base.

[0019] According to a preferred embodiment, after step eight, step nine is further included, in which a loading spraying machine is used to perform concrete spraying construction on the upper surface of the emergency passage and the corresponding inner wall of the underground tunnel.

[0020] According to a preferred embodiment, after step nine, the method further includes step ten of installing a fence on a side of the emergency passage away from the inner wall of the underground tunnel.

[0021] According to a preferred embodiment, a plurality of dowel bars are installed at the same point, the first ends of the plurality of dowel bars are connected, and the second ends are embedded in the underground tunnel.

[0022] According to a preferred embodiment, the embedded length of the second ends of the plurality of dowels is greater than or equal to 2 meters.

[0023] According to a preferred embodiment, before step 2, it also includes anchor spraying reinforcement of the inserted reinforcement points.

[0024] The present invention also provides an emergency passage expanded in an existing underground tunnel, which is obtained by adopting the construction method as described above.

[0025] The construction method for expanding an emergency passage in an existing underground tunnel and the technical solution for the emergency passage provided by the present invention have at least the following advantages and beneficial effects: (1) The present invention can adapt to local conditions, make maximum use of the existing underground tunnel, innovate the cross-sectional structure of the emergency passage and the supporting highly operable construction method, and achieve the engineering goal of building a long-distance emergency passage in deep ground; (2) The present invention optimizes the right-angled cross-section of the traditional emergency evacuation passage into a "corrugated" shape according to the actual situation of the underground water-containing tunnel. On the one hand, the concrete required for the "corrugated" emergency passage is The volume of concrete is smaller, which can reduce the volume of concrete to a certain extent. On the other hand, the lower edge of the "ox leg" section is designed to be above the groundwater level. Compared with the traditional construction method of building temporary anti-seepage cofferdams along the entire line to achieve dry land construction, it saves the construction work of temporary anti-seepage cofferdams and the process of dismantling temporary anti-seepage cofferdams in the later stage, greatly reducing the construction work and total investment. (3) This construction method can realize high-efficiency assembly line construction of the entire underground water-containing tunnel, and can avoid being forced to stop work due to rising water levels during the flood season. It has the advantages of short construction period, high operability and good economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a cross section of an underground perennial water-bearing tunnel in the background technology;

[0027] Figure 2 It is a schematic diagram of the construction of a traditional emergency evacuation passage in the background technology;

[0028] Figure 3 A schematic diagram of a process for constructing an emergency passage in an existing underground tunnel provided in Example 1 of the present invention;

[0029] Figure 4 A schematic cross-sectional view and a top view of a construction platform provided in Example 1 of the present invention;

[0030] Figure 5 This is a rendering of the effect after steps 4 to 6 provided in Example 1 of the present invention are completed;

[0031] Figure 6 This is a final cross-sectional rendering of the emergency passage provided in Example 1 of the present invention;

[0032] Figure 7 A diagram showing the position relationship between the excavator and the construction platform in step 1 and step 3 provided in Example 1 of the present invention;

[0033] Icons: 1-underground tunnel, 2-groundwater, 3-excavator, 4-construction platform, 401-second scaffolding, 402-guardrail, 403-I-beam, 404-steel mesh, 5-emergency passage, 6-inserted rebar, 7-anchor rod, 8-fence, 9-concrete pouring formwork, 10-first scaffolding, 11-anti-seepage cofferdam. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0035] Example 1

[0036] Figure 3 A schematic diagram of a construction method for expanding an emergency passage in an existing underground tunnel provided by an embodiment of the present invention. Figure 3 As shown, the construction method for expanding the emergency passage of the existing underground tunnel includes the following steps:

[0037] Step 1: Use lifting equipment to lift the construction platform 4 in the underground tunnel 1, and determine the positions of the anchor rods 7 and the inserted bars 6 by means of line-laying and measurement. In this embodiment, the existing underground tunnel referred to is an underground auxiliary construction tunnel or a drainage tunnel that has been excavated and has a circular cross-sectional shape, and there is often water flowing in the tunnel. By making maximum use of the existing underground tunnels, this embodiment can be adapted to local conditions and can achieve the engineering goal of building a long-distance emergency passage 5 in deep ground.

[0038] The hoisting equipment is an excavator 3. In addition, a crane hoisting method on the inner wall of the underground tunnel 1 can also be adopted, which will not be described in detail here.

[0039] In a preferred implementation of this embodiment, the number of the construction platforms 4 is two, and the number of the construction platforms 4 is selected according to the actual construction capacity, and no specific limitation is made here; in this embodiment, see Figure 7 As shown, the two construction platforms 4 are respectively located at the front and rear sides of the lifting equipment; the construction method provided in this embodiment adopts a push-type working mode. First, the excavator 3 carries the two construction platforms 4 first, and performs line laying and measurement during the movement. After arriving at the construction site, the construction platform 4 is installed. By carrying out construction on the two construction platforms 4, the purpose of expanding the length of the working surface is achieved and the construction efficiency is improved.

[0040] Further, see Figure 4As shown, the construction platform 4 includes a base and a guardrail 402. The base is composed of a second scaffolding 401 erected above the water level and an I-beam 403 and a steel mesh 404 laid on the top of the second scaffolding 401. The guardrail 402 is arranged on the side of the top of the base.

[0041] Step 2: Drill holes at the determined points using a drilling rig, such as a crawler excavator-type drilling rig.

[0042] In a preferred implementation manner of the present embodiment, in order to avoid the poor surrounding rock conditions of the underground tunnel 1, which may lead to the loose installation of the inserted reinforcement 6, the present embodiment targets the tunnel sections with poor surrounding rock conditions, especially the points of the inserted reinforcement 6, and performs anchor spraying reinforcement before drilling to ensure the installation stability of the inserted reinforcement 6.

[0043] In a preferred implementation manner of this embodiment, the working surface distance between step one and step two is at least 50 meters to ensure high construction efficiency.

[0044] Step 3: Install anchor rods 7 and dowel bars 6 on the construction platform 4 at the corresponding drilling positions in step 2.

[0045] In a preferred implementation of this embodiment, multiple dowels 6 are installed at the same point, the diameter of the dowels 6 is not less than 28 mm, the first ends of the multiple dowels 6 are connected together to bear the force as a whole, and the second ends are embedded in the underground tunnel 1, and the embedded length is greater than or equal to 2 meters.

[0046] In a preferred implementation manner of this embodiment, the working surface distance between step 2 and step 3 is at least 50 meters to ensure high construction efficiency.

[0047] Step 4: Set up a first scaffold 10 on one side of the underground tunnel 1. The first scaffold 10 is installed vertically to support the construction channel and the concrete pouring formwork 9.

[0048] Step 5, install the concrete casting template 9 and the skeleton steel bars on the first scaffolding 10; wherein the concrete casting template 9 is inclined, its upper end is connected to the first scaffolding 10, and its lower end is in contact with the inner wall of the underground tunnel 1 and is higher than the multi-year average water level of the underground tunnel 1, the anchor rod 7 and the dowel bar 6 are located on the inner side of the concrete casting template 9, and the skeleton steel bars are laid on the inner side of the concrete casting template 9.

[0049] Step 6: Pour concrete inside the concrete pouring template 9. Figure 5 shown.

[0050] Step 7: After the poured concrete solidifies, the formwork and the first scaffold 10 are removed to obtain an emergency passage 5 that is constructed and has a cross-section that is designed to resist overturning and is in the shape of a "column leg". Figure 6 As shown; the width of the upper end surface of the "bull leg" shaped emergency passage 5 should be no less than 1.3 meters to meet the traffic needs.

[0051] It should be noted that, according to the actual situation of the underground water-containing tunnel, this embodiment optimizes the right-angled section of the traditional emergency evacuation passage into a "bull leg" shape. On the one hand, the "bull leg"-shaped emergency passage 5 requires less concrete volume, which can reduce the concrete volume to a certain extent; on the other hand, the lower edge of the "bull leg"-shaped section is designed to be above the groundwater level 2. Compared with the traditional construction method of building a temporary anti-seepage cofferdam 11 along the entire line to achieve dry land construction, it saves the amount of work in building the temporary anti-seepage cofferdam 11, and also eliminates the process of dismantling the temporary anti-seepage cofferdam 11 in the later stage, thereby greatly reducing the amount of work and total investment.

[0052] Furthermore, the emergency passage 5 of the concrete structure is cured with water.

[0053] Step 8: Repeat steps 1 to 7 until the construction of the emergency passage 5 of the underground tunnel 1 is completed.

[0054] Step nine: Use a loading spraying machine to perform concrete spraying construction on the upper surface of the emergency passage 5 and the corresponding inner wall of the underground tunnel 1.

[0055] Step 10: Install a fence 8 on the side of the emergency passage 5 away from the inner wall of the underground tunnel 1 .

[0056] In summary, this construction method can realize high-efficiency assembly line construction of the entire underground water-containing tunnel, and can avoid being forced to stop work due to rising water levels during the flood season. It has the advantages of short construction period, high operability and good economy.

[0057] Example 2

[0058] This embodiment is based on the technical solution provided in Example 1 and provides an emergency passage expanded in an existing underground tunnel. The emergency passage 5 is obtained by the construction method described in Example 1.

[0059] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A construction method for expanding an emergency passage in an existing underground tunnel, characterized in that: The following steps are involved: Step 1: determine the positions of the anchor rod (7) and the inserted reinforcement (6); Step 2: Drill holes at the determined points; Step 3: Install anchor rods (7) and dowel bars (6) at the corresponding drilling positions; Step 4: erecting a first scaffold (10) on one side of the underground tunnel (1); Step 5: Install a concrete casting template (9) and skeleton steel bars on the first scaffold (10), wherein the concrete casting template (9) is tilted, its upper end is connected to the first scaffold (10), and its lower end is in contact with the inner wall of the underground tunnel (1) and is higher than the multi-year average water level of the underground tunnel (1), the anchor rod (7) and the dowel bar (6) are located on the inner side of the concrete casting template (9), and the skeleton steel bars are laid on the inner side of the concrete casting template (9); Step 6: pouring concrete inside the concrete pouring template (9); Step 7: After the poured concrete solidifies, the formwork and the first scaffold (10) are removed to obtain an emergency passage (5) that is constructed and has a "column-shaped" cross section, and the emergency passage (5) is maintained; Step 8: Repeat steps 1 to 7 until the construction of the emergency passage (5) of the underground tunnel (1) is completed.

2. The construction method for expanding an emergency passage in an existing underground tunnel as claimed in claim 1, characterized in that: Prior to step 1, the method further includes hoisting the construction platform (4) in the underground tunnel (1) by means of hoisting equipment, and determining the positions of the anchor rods (7) and the inserted bars (6) by means of line laying and measurement.

3. The construction method for expanding an emergency passage in an existing underground tunnel as claimed in claim 2, characterized in that: The number of the construction platforms (4) is two, and the two construction platforms (4) are respectively located at the front side and the rear side of the lifting equipment.

4. The construction method for expanding an emergency passage in an existing underground tunnel as claimed in claim 2, characterized in that: The construction platform (4) comprises a base and a guardrail (402), wherein the base is composed of a second scaffold (401) erected above the water level and a steel mesh (404) laid on the top of the second scaffold (401), and the guardrail (402) is arranged on the side of the top of the base.

5. The construction method for expanding an emergency passage in an existing underground tunnel according to any one of claims 1 to 4, characterized in that: After step eight, the method further includes step nine, in which a material spraying machine is used to spray concrete on the upper surface of the emergency passage (5) and the corresponding inner wall of the underground tunnel (1).

6. The construction method for expanding an emergency passage in an existing underground tunnel as claimed in claim 5, characterized in that: After step nine, the method further includes step ten of installing a fence (8) on a side of the emergency passage (5) away from the inner wall of the underground tunnel (1).

7. The construction method for expanding an emergency passage in an existing underground tunnel as claimed in claim 1, characterized in that: A plurality of dowel bars (6) are installed at the same point, the first ends of the plurality of dowel bars (6) are connected, and the second ends are embedded in the underground tunnel (1).

8. The construction method for expanding an emergency passage in an existing underground tunnel as claimed in claim 7, characterized in that: The embedding length of the second ends of the plurality of inserted bars (6) is greater than or equal to 2 meters.

9. The construction method for expanding an emergency passage in an existing underground tunnel as claimed in claim 7, characterized in that: Before step 2, the method also includes anchor spraying reinforcement of the points of the inserted reinforcement (6).

10. An emergency passage expanded in an existing underground tunnel, characterized in that: The method is obtained by using the construction method according to any one of claims 1 to 9.

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