A method for excavating a variable-section cavern and a variable-section cavern structure

Abstract

The present invention belongs to the field of building construction technology and discloses a variable-section cavern excavation method and a variable-section cavern structure. The variable-section cavern excavation method includes the following steps: excavating a first cavern along the designed outline of the first cavern and setting a first support structure and a first inverted arch structure; excavating an inclined guide tunnel at a preset angle, the inclined guide tunnel having the same cross-sectional area as the first cavern; excavating a first cavern body in a horizontal direction and setting a second support structure; excavating a first cavern section along the designed outline of the first cavern section and setting a third support structure; excavating a second cavern body along the designed outline of the second cavern body and setting a fourth support structure; setting a second inverted arch structure at the bottom of the first cavern and the bottom of the second cavern; and setting a secondary lining structure inside the first cavern and the second cavern. The excavation method is simple in construction, can shorten the construction period, and improve work efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular to an excavation method for a variable-section cavern and a variable-section cavern structure. Background Art

[0002] As urban populations continue to grow, transportation demands are surging, rendering surface transportation systems unable to meet these demands. To alleviate this pressure, underground transportation facilities (such as subways and underground passages) have emerged. The construction of these facilities often requires the construction of underground tunnels, and some complex projects often involve sudden changes in tunnel cross-section.

[0003] The existing construction method for sudden-section tunnels involves first excavating a small tunnel until it reaches the junction of the small and large tunnels, i.e., the location of the variable cross-section. An inclined pilot tunnel is then excavated until it reaches the designed outline of the large tunnel. A step method is then used to reversely excavate the areas above and below the inclined pilot tunnel. Using this construction method for variable-section tunnel excavation is not only cumbersome and slow in progress, but also requires manual labor due to the small cross-section of the excavated inclined pilot tunnel and limited space. This results in low overall project efficiency, a long construction period, and increased labor intensity. Summary of the Invention

[0004] The purpose of the present invention is to provide a variable-section cave excavation method and a variable-section cave structure, which has a simple construction method, can shorten the construction period, improve work efficiency, and reduce the labor intensity of staff.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, a variable-section cavern excavation method is provided, which is used to excavate a variable-section cavern structure, wherein the cavern structure includes a first cavern and a second cavern, wherein the cross-sectional area of ​​the first cavern is smaller than the cross-sectional area of ​​the second cavern, and the second cavern includes a first tunnel section and a second tunnel section, and the first cavern is connected to the second tunnel section through the first tunnel section. The variable-section cavern excavation method includes the following steps:

[0007] S1. Excavating the first cavern along the designed outline of the first cavern and setting a first supporting structure along the inner wall of the first cavern until the excavation reaches the junction of the first cavern and the first tunnel section;

[0008] S2. Installing a first inverted arch structure at the bottom of the first cavern, wherein the first inverted arch structure is connected to the first supporting structure;

[0009] S3. Excavating an inclined pilot tunnel at a preset angle along the extension direction of the first tunnel section until it reaches the junction of the first tunnel section and the second tunnel section, and the top contour line of the inclined pilot tunnel coincides with the top contour line of the first tunnel section, and the cross-sectional area of ​​the inclined pilot tunnel is the same as the cross-sectional area of ​​the first tunnel;

[0010] S4. The second tunnel section includes a first tunnel body and a second tunnel body distributed vertically. The first tunnel body is excavated horizontally to form a temporary operating platform until the excavation reaches the designed outline of the first tunnel body, and a second support structure is set along the outline of the first tunnel body.

[0011] S5. Excavating the first tunnel section along the designed contour line of the first tunnel section, and setting up a third support structure along the contour line of the first tunnel section until the excavation reaches the junction of the first tunnel section and the second tunnel section, wherein the third support structure is connected to the second support structure;

[0012] S6. Excavating the second cavern along the designed outline of the second cavern, and setting up a fourth supporting structure along the outline of the second cavern, wherein the fourth supporting structure is integrally connected with the second supporting structure and the third supporting structure;

[0013] S7. Disposing a second inverted arch structure at the bottom of the first cavern and the bottom of the second cavern, wherein the second inverted arch structure is integrally connected to the first inverted arch structure and is connected to the first supporting structure, the third supporting structure, and the fourth supporting structure;

[0014] S8. A secondary lining structure is set inside the first cavern and the second cavern, and the secondary lining structure is connected to the first supporting structure, the second supporting structure, the third supporting structure and the fourth supporting structure as a whole.

[0015] Optionally, step S1 specifically includes the following steps:

[0016] S11, setting up an operating frame at the location to be constructed, placing explosives at preset positions along the designed outline of the first cavern using the operating frame, and excavating the first cavern;

[0017] S12, installing the first supporting structure along the inner wall of the first tunnel, and moving the operating frame along the extension direction of the first tunnel;

[0018] S13. Repeat steps S11 and S12 until excavation reaches the junction of the first tunnel and the first tunnel section.

[0019] Optionally, the operating frame includes a frame body and a plurality of running wheels, and the plurality of running wheels are arranged on opposite sides of the frame body.

[0020] Optionally, taking the preset explosion range of the explosives as the excavation period, step S3 specifically includes the following steps:

[0021] S31, excavating the inclined guide tunnel at the preset angle along the extending direction of the first tunnel section, and excavating for at least one excavation cycle;

[0022] S32, providing a first operating platform on a side of the operating frame facing the first hole section, wherein the inclination angle of the upper surface of the first operating platform is the same as the preset angle;

[0023] S33. Move the operating frame along the inclined guide tunnel, and use the first operating platform to cyclically excavate the inclined guide tunnel at the preset angle along the extension direction of the first tunnel section until it is excavated to the junction of the first tunnel section and the second tunnel section, and the top contour line of the inclined guide tunnel coincides with the top contour line of the first tunnel section, and the cross-sectional area of ​​the inclined guide tunnel is the same as the cross-sectional area of ​​the first tunnel.

[0024] Optionally, step S4 specifically includes the following steps:

[0025] S41, excavating the first cave in a horizontal direction to form a temporary operating platform;

[0026] S42, dismantling the first operating platform and installing a second operating platform on the upper end of the operating frame;

[0027] S43, moving the operating frame along the temporary operating platform, and using the second operating platform to continue excavating the first cave in a horizontal direction to extend the temporary operating platform;

[0028] S44, setting up the second supporting structure along the contour line of the excavated first cave body;

[0029] S45. Repeat steps S43 and S44 until the excavation reaches the designed outline of the first cave body.

[0030] Optionally, the inclined guide tunnel divides the first tunnel section into a third tunnel body and a fourth tunnel body, the third support structure includes a first support section and a second support section connected to each other, and step S5 specifically includes the following steps:

[0031] S51, setting up a support platform in the inclined guide tunnel in a direction away from the first tunnel, moving the operating frame onto the support platform, and excavating the third tunnel along the designed outline of the third tunnel;

[0032] S52: setting up the first support section along the contour line of the excavated third tunnel body and the contour line of the inclined pilot tunnel, wherein the first support section is connected to the second support structure;

[0033] S53, repeating steps S51 and S52 until excavation reaches the junction of the first tunnel section and the first tunnel;

[0034] S54, dismantling the support platform and excavating the fourth cave body in a horizontal direction along the designed outline of the fourth cave body;

[0035] S55, setting the second supporting section along the contour line of the excavated fourth cavern;

[0036] S56. Repeat steps S54 and S55 until the excavation reaches the junction of the first tunnel section and the second tunnel section.

[0037] Optionally, the support platform includes multiple connected support sections, and multiple step structures are set at the bottom of the inclined guide tunnel. The heights of the multiple step structures gradually decrease along the direction from the first tunnel body to the first tunnel library. Each step structure is provided with a support section, and the multiple step structures correspond one-to-one to the multiple support sections.

[0038] Optionally, a temporary support structure is provided in the inclined guide tunnel, and the temporary support structure is used to maintain the stability of the inclined guide tunnel.

[0039] Optionally, water stops are provided at the junction of the first inverted arch structure and the first supporting structure, the junction of the second inverted arch structure and the first supporting structure, the junction of the second inverted arch structure and the third supporting structure, and the junction of the second inverted arch structure and the fourth supporting structure.

[0040] In a second aspect, a variable-section cavern structure is provided, which is excavated using the variable-section cavern excavation method as described above. The variable-section cavern structure is characterized in that the variable-section cavern structure includes a first cavern and a second cavern that are interconnected, and the cross-sectional area of ​​the first cavern is smaller than the cross-sectional area of ​​the second cavern.

[0041] Beneficial effects of the present invention:

[0042] The present invention provides a variable-section cavern excavation method and a variable-section cavern structure. The variable-section cavern excavation method is used to excavate the variable-section cavern structure. The variable-section cavern structure includes a first cavern and a second cavern.

[0043] In this variable-section tunnel excavation method, cyclic blasting excavation is adopted. When excavating a variable-section tunnel structure, the first tunnel is first excavated along the design contour line of the first tunnel, and the first supporting structure is set along the inner wall of the first tunnel until the excavation reaches the junction of the first tunnel and the first tunnel section. Then, a first inverted arch structure is set at the bottom of the first tunnel to protect the structural stability of the first tunnel. An inclined guide tunnel is excavated at a preset angle in the first tunnel section. The cross-sectional area of ​​the inclined guide tunnel is the same as that of the first tunnel. Then, the first tunnel body at the upper part of the second tunnel section is excavated horizontally to form a temporary operating platform until the excavation reaches the design wheel of the first tunnel body. The first tunnel section is excavated along the designed outline of the first tunnel section, and a third support structure connected to the second support structure is set up to complete the excavation of the first tunnel section. The second tunnel section is then excavated along the designed outline of the second tunnel section, and a fourth support structure is set up along the outline of the second tunnel section. The fourth support structure is connected to the second support structure and the third support structure to complete the initial support work of the tunnel structure. Finally, a secondary lining structure and a second inverted arch structure are set up inside the first tunnel section and the second tunnel section.

[0044] The variable-section tunnel excavation method excavates an inclined guide tunnel with the same cross-sectional area as the first tunnel at the variable section, which can expand the operating space, facilitate the installation of excavation equipment and the construction work of the staff, and also facilitate the transportation of waste residues generated by the excavation, reduce the labor intensity of the staff, improve work efficiency, shorten the construction period, and excavate according to the designed contour line of the tunnel, that is, full-section excavation method. The excavation method is simple and can further speed up the construction speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a first flow chart of a method for excavating a variable-section tunnel provided by an embodiment of the present invention;

[0046] Figure 2 This is a second flow chart of the variable-section tunnel excavation method provided by an embodiment of the present invention;

[0047] Figure 3 This is a side view of the first tunnel excavation completed in the variable-section tunnel excavation method provided by an embodiment of the present invention;

[0048] Figure 4 This is a side view of the excavation method of the variable-section tunnel provided by the embodiment of the present invention after the excavation of the inclined pilot tunnel is completed;

[0049] Figure 5 This is a side view of the first tunnel body of the variable-section tunnel excavation method provided by an embodiment of the present invention after excavation is completed;

[0050] Figure 6This is a first side view of the excavation method of the variable-section tunnel provided by the embodiment of the present invention when the third tunnel body is excavated;

[0051] Figure 7 This is a second side view of the excavation method of the variable-section tunnel provided by the embodiment of the present invention when the third tunnel body is excavated;

[0052] Figure 8 This is a third side view of the variable-section tunnel excavation method provided by an embodiment of the present invention when excavating a third tunnel body;

[0053] Figure 9 This is a side view of the third tunnel body of the variable-section tunnel excavation method provided by an embodiment of the present invention after excavation is completed;

[0054] Figure 10 This is a side view of the fourth tunnel body excavated using the variable-section tunnel excavation method provided by an embodiment of the present invention;

[0055] Figure 11 It is a side view of the variable-section tunnel excavation method provided by an embodiment of the present invention when the tunnel structure excavation is completed.

[0056] In the picture:

[0057] 1. Cavern structure; 11. First cavern; 12. Second cavern; 121. First cavern section; 1211. Third cavern body; 1212. Fourth cavern body; 122. Second cavern section; 1221. First cavern body; 1222. Second cavern body; 123. Temporary operating platform; 13. Inclined guide tunnel; 131. Step structure;

[0058] 2. The first inverted arch structure;

[0059] 3. Second inverted arch structure;

[0060] 4. Operating frame; 41. Frame; 42. Travel wheels;

[0061] 5. The first operating platform;

[0062] 6. Second operating platform;

[0063] 7. Support platform. DETAILED DESCRIPTION

[0064] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0065] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0066] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0067] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0068] Example 1

[0069] This embodiment provides a method for excavating a variable cross-section cavern structure 1, such as Figures 1 to 11 As shown, the excavation method of the variable-section tunnel is simple in construction, can shorten the construction period, improve work efficiency, and reduce the labor intensity of the staff.

[0070] The tunnel structure 1 includes a first tunnel 11 and a second tunnel 12. The cross-sectional area of ​​the first tunnel 11 is smaller than that of the second tunnel 12. The second tunnel 12 includes a first tunnel section 121 and a second tunnel section 122. The first tunnel 11 is connected to the second tunnel section 122 via the first tunnel section 121. The excavation method of the variable cross-section tunnel includes the following steps:

[0071] S1. See Figure 1 and Figure 3As shown, the first cavern 11 is excavated along the design outline of the first cavern 11, and a first supporting structure (not shown in the figure) is set along the inner wall of the first cavern 11 until the excavation reaches the junction of the first cavern 11 and the first tunnel section 121;

[0072] S2. See Figure 1 and Figure 3 As shown, a first inverted arch structure 2 is provided at the bottom of the first cavern 11, and the first inverted arch structure 2 is connected to the first supporting structure;

[0073] S3, see Figure 1 and Figure 4 As shown, an inclined guide tunnel 13 is excavated at a preset angle along the extension direction of the first tunnel section 121 until it reaches the junction of the first tunnel section 121 and the second tunnel section 122, and the top contour line of the inclined guide tunnel 13 coincides with the top contour line of the first tunnel section 121. The cross-sectional area of ​​the inclined guide tunnel 13 is the same as the cross-sectional area of ​​the first tunnel 11.

[0074] S4. See Figure 1 and Figure 5 As shown, the second tunnel section 122 includes a first tunnel body 1221 and a second tunnel body 1222 distributed vertically. The first tunnel body 1221 is excavated horizontally to form a temporary operating platform 123 until the excavation reaches the designed outline of the first tunnel body 1221. A second supporting structure (not shown in the figure) is set along the outline of the first tunnel body 1221.

[0075] S5. See Figure 1 As shown, the first tunnel section 121 is excavated along the designed outline of the first tunnel section 121, and a third support structure (not shown in the figure) is set along the outline of the first tunnel section 121 until the excavation reaches the junction of the first tunnel section 121 and the second tunnel section 122, and the third support structure is connected to the second support structure;

[0076] S6. See Figure 1 and Figure 11 As shown, the second cave body 1222 is excavated along the design outline of the second cave body 1222, and a fourth supporting structure (not shown in the figure) is set along the outline of the second cave body 1222. The fourth supporting structure is connected to the second supporting structure and the third supporting structure into one;

[0077] S7, see Figure 1 and Figure 11 As shown, a second inverted arch structure 3 is provided at the bottom of the first cavern 11 and the bottom of the second cavern 12. The second inverted arch structure 3 is connected to the first inverted arch structure 2 as a whole, and is connected to the first supporting structure, the third supporting structure and the fourth supporting structure.

[0078] S8, see Figure 1 and Figure 11As shown, a secondary lining structure (not shown in the figure) is set inside the first cave 11 and the second cave 12, and the secondary lining structure is connected to the first supporting structure, the second supporting structure, the third supporting structure and the fourth supporting structure into one.

[0079] In the excavation method of the variable-section tunnel, cyclic blasting excavation is adopted. When excavating the variable-section tunnel structure 1, the first tunnel 11 is first excavated along the design outline of the first tunnel 11, and a first supporting structure is set along the inner wall of the first tunnel 11 until the excavation reaches the junction of the first tunnel 11 and the first tunnel section 121. Then, a first inverted arch structure 2 is set at the bottom of the first tunnel 11 to protect the structural stability of the first tunnel 11. An inclined guide tunnel 13 is excavated at a preset angle in the first tunnel section 121. The cross-sectional area of ​​the inclined guide tunnel 13 is the same as that of the first tunnel 11. Then, a first cave body 1221 is excavated horizontally at the upper part of the second tunnel section 122, thereby forming a temporary operating platform 123, until the excavation reaches the first cave body 1221. The first tunnel section 121 is excavated along the design contour line of the first tunnel section 121, and a third support structure connected to the second support structure is set, thereby completing the excavation of the first tunnel section 121. The second tunnel section 1222 is excavated along the design contour line of the second tunnel section 1222, and a fourth support structure is set along the contour line of the second tunnel section 1222. The fourth support structure is connected to the second support structure and the third support structure, thereby completing the initial support work of the cave structure 1. Finally, a secondary lining structure and a second inverted arch structure 3 are set inside the first tunnel section 11 and the second tunnel section 12.

[0080] The variable-section tunnel excavation method excavates an inclined guide tunnel 13 with the same cross-sectional area as the first tunnel 11 at the variable section, which can expand the operating space, facilitate the installation of excavation equipment and the construction work of the staff, and also facilitate the transportation of waste residues generated by the excavation, reduce the labor intensity of the staff, improve work efficiency, shorten the construction period, and excavate according to the designed contour line of the tunnel, that is, full-section excavation method. The excavation method is simple and can further speed up the construction speed.

[0081] It should be noted that when the first cavern 1221 is excavated, the second cavern 1222 is not excavated. Therefore, the area where the second cavern 1222 is intended to be located is still the surrounding rock, thereby forming a temporary operating platform 123. The operating platform is the upper surface of the unexcavated second cavern 1222. After the second cavern 1222 is excavated, the temporary operating platform 123 will disappear.

[0082] Optionally, step S1 specifically includes the following steps:

[0083] S11. See Figure 2 and Figure 3As shown, an operating frame 4 is set at the location to be constructed, and explosives are set at preset positions along the design outline of the first cavern 11 using the operating frame 4 to excavate the first cavern 11;

[0084] S12, see Figure 2 and Figure 3 As shown, a first supporting structure is provided along the inner wall of the first cave 11, and the operating frame 4 is moved along the extension direction of the first cave 11;

[0085] S13, see Figure 2 and Figure 3 As shown, steps S11 and S12 are repeated until the excavation reaches the junction of the first cavern 11 and the first tunnel section 121.

[0086] When excavating the first cavern 11, it is first necessary to set up an operating frame 4, on which workers can stand. The operating frame 4 provides a construction platform for the workers. Then, along the design outline of the first cavern 11, the explosives are set at a preset position using the operating frame 4, the explosives are detonated, and the first cavern 1221 is blasted and excavated. After that, the debris generated by the blasting is cleaned up, and a first support structure is set along the inner wall of the excavated portion of the first cavern 11. The operating frame 4 is moved along the extension direction of the first cavern 11 to the unexcavated section, and the above operation is repeated until the junction of the first cavern 11 and the first tunnel section 121 is excavated, thereby completing the excavation of the first cavern 11. The full-section excavation method is adopted, which is simple in construction and easy to operate. Moreover, each time a section of the first cavern 1221 is excavated, a section of the first support structure can be set up in time, thereby ensuring the stability of the surrounding rock, preventing the collapse of the first cavern 11, and providing a guarantee for construction safety.

[0087] It should be noted that the preset position is determined based on factors such as the geological conditions of the excavation location of the cave structure 1, the design depth of the cave structure 1, and the specific conditions of the construction site.

[0088] Alternatively, as Figure 3 As shown, the operating frame 4 includes a frame body 41 and a plurality of running wheels 42. The running wheels 42 are disposed on opposite sides of the frame body 41. To move the operating frame 4, a worker simply pushes the frame body 41, which drives the running wheels 42 to roll, thereby moving the operating frame 4 to the target location. This simple structure and convenient operation save time and effort, thereby improving work efficiency.

[0089] Exemplarily, there are two, four, or six running wheels 42. In other embodiments, other numbers of running wheels 42 can be provided according to actual needs, which is not limited here.

[0090] In this embodiment, a cyclic excavation method is adopted with the preset explosion range of the explosives as the excavation cycle.

[0091] Optionally, step S3 specifically includes the following steps:

[0092] S31, see Figure 2 and Figure 4 As shown, along the extension direction of the first tunnel section 121, an inclined guide tunnel 13 is excavated at a preset angle and at least one excavation cycle is performed;

[0093] S32, see Figure 2 and Figure 4 As shown, a first operating platform 5 is provided on the side of the operating frame 4 facing the first hole section 121, and the inclination angle of the upper surface of the first operating platform 5 is the same as the preset angle;

[0094] S33, see Figure 2 and Figure 4 As shown, the operating frame 4 is moved along the inclined guide tunnel 13, and the first operating platform 5 is used to cyclically excavate the inclined guide tunnel 13 at a preset angle along the extension direction of the first tunnel section 121 until it is excavated to the junction of the first tunnel section 121 and the second tunnel section 122, and the top contour line of the inclined guide tunnel 13 coincides with the top contour line of the first tunnel section 121, and the cross-sectional area of ​​the inclined guide tunnel 13 is the same as the cross-sectional area of ​​the first tunnel 11.

[0095] When excavating the inclined guide tunnel 13, the inclined guide tunnel 13 is first excavated at a preset angle along the extension direction of the first tunnel section 121, and at least one excavation cycle is excavated. Then, a first operating platform 5 is set on the side of the operating frame 4 facing the first tunnel section 121, and the inclination angle of the upper surface of the first operating platform 5 is the same as the preset angle. Then, the operating frame 4 is moved along the inclined guide tunnel 13, that is, the operating frame 4 is moved into the excavated inclined guide tunnel 13. At this time, the upper surface of the operating frame 4 is inclined at a preset angle, so that the first operating platform 5 is in a horizontal state, which is convenient for the staff to deploy explosives. Then, the staff uses the first operating platform 5 to cyclically excavate the inclined guide tunnel 13 at a preset angle along the extension direction of the first tunnel section 121 until it reaches the junction of the first tunnel section 121 and the second tunnel section 122. At this time, the top contour line of the inclined guide tunnel 13 coincides with the top contour line of the first tunnel section 121, and the cross-sectional area of ​​the inclined guide tunnel 13 is the same as the cross-sectional area of ​​the first cavern 11. By providing the first operating platform 5 , a horizontal operating site can be provided for the workers, facilitating the excavation of the inclined guide tunnel 13 , preventing the workers from falling from the operating frame 4 , and ensuring construction safety.

[0096] It should be noted that the preset angle is determined based on factors such as the geological conditions of the excavation location of the cave structure 1, the design depth of the cave structure 1, and the specific conditions of the construction site.

[0097] Optionally, step S4 specifically includes the following steps:

[0098] S41, see Figure 2As shown, a first hole 1221 is excavated in the horizontal direction to form a temporary operating platform 123;

[0099] S42, see Figure 2 As shown, the first operating platform 5 is disassembled, and a second operating platform 6 is provided on the upper end of the operating frame 4;

[0100] S43, see Figure 2 and Figure 5 As shown, the operating frame 4 is moved along the temporary operating platform 123, and the second operating platform 6 is used to continue excavating the first cave 1221 in the horizontal direction to extend the temporary operating platform 123;

[0101] S44, see Figure 2 As shown, the second supporting structure is set along the outline of the excavated first cave body 1221;

[0102] S45, see Figure 2 and Figure 5 As shown, step S43 and step S44 are repeated until the excavation reaches the designed outline of the first hole 1221.

[0103] When excavating the first cave body 1221, the first cave body 1221 is first excavated in the horizontal direction to form a temporary operating platform 123 to facilitate the installation of the operating frame 4. The first operating platform 5 on the operating frame 4 is then removed, and a second operating platform 6 is set at the upper end of the operating frame 4 to increase the height of the operating frame 4 vertically, so that the staff can lay explosives along the designed outline of the first cave body 1221 to facilitate the excavation of the first cave body 1221. The operating frame 4 is then moved along the temporary operating platform 123 to the unexcavated section, and the first cave body 1221 is excavated in the horizontal direction using the second operating platform 6 to extend the temporary operating platform 123, and the second supporting structure is promptly set along the outline of the excavated first cave body 1221 to protect the structural stability of the first cave body 1221. The above operations are repeated until the excavation reaches the designed outline of the first cave body 1221.

[0104] Optionally, the inclined guide tunnel 13 divides the first tunnel section 121 into a third tunnel body 1211 and a fourth tunnel body 1212. The third support structure includes the first support section and the second support section connected. Step S5 specifically includes the following steps:

[0105] S51, see Figure 2 and Figure 7 As shown, a support platform 7 is set up in the inclined guide tunnel 13 in a direction away from the first tunnel 1221 , the operating frame 4 is moved onto the support platform 7 , and the third tunnel 1211 is excavated along the designed outline of the third tunnel 1211 ;

[0106] S52, see Figure 2As shown, a first support section is set along the outline of the excavated third tunnel 1211 and the outline of the inclined guide tunnel 13, and the first support section is connected to the second support structure;

[0107] S53, see Figure 2 、 Figure 8 and Figure 9 As shown, steps S51 and S52 are repeated until the excavation reaches the junction of the first tunnel section 121 and the first tunnel 11;

[0108] S54, see Figure 2 and Figure 10 As shown, the support platform 7 is dismantled, and the fourth cave body 1212 is excavated in the horizontal direction along the design outline of the fourth cave body 1212;

[0109] S55, setting a second support section along the outline of the excavated fourth cave body 1212;

[0110] S56, see Figure 2 As shown, step S54 and step S55 are repeated until the excavation reaches the junction of the first tunnel section 121 and the second tunnel section 122 .

[0111] After the inclined guide tunnel 13 is excavated, the inclined guide tunnel 13 divides the first tunnel section 121 into a third tunnel body 1211 and a fourth tunnel body 1212. At this time, the third tunnel body 1211 and the fourth tunnel body 1212 are not excavated. When excavating the third tunnel body 1211, first, a support platform 7 is set up in the inclined guide tunnel 13 in a direction away from the first tunnel body 1221, and the operating frame 4 is moved to the support platform 7 and located at the unexcavated section. The third tunnel body 1211 is excavated along the designed contour line of the third tunnel body 1211. Then, the first support section is set along the contour line of the excavated third tunnel body 1211 and the contour line of the inclined guide tunnel 13, so as to timely protect the stability of the third tunnel body 1211 and part of the surrounding rock of the inclined guide tunnel 13. The above operation is repeated until the excavation reaches the junction of the first tunnel section 121 and the first cavern 11, thereby completing the excavation of the third tunnel body 1211.

[0112] When excavating the fourth cave body 1212, first dismantle the supporting platform 7, and excavate the fourth cave body 1212 in the horizontal direction along the designed contour line of the fourth cave body 1212. Then, set the second support section along the contour line of the excavated fourth cave body 1212, and repeat the above operation until the excavation reaches the junction of the first cave section 121 and the second cave section 122, thereby completing the excavation of the fourth cave body 1212. At this time, the first support section is connected to the second support section to form a third support structure, and the third support structure is connected to the second support.

[0113] Optionally, the support platform 7 includes a plurality of connected support segments. A plurality of step structures 131 are provided at the bottom of the guide tunnel, and the heights of the plurality of step structures 131 gradually decrease along the direction from the first cave body 1221 to the first cavern 11. A support segment is provided on each step structure 131, and the plurality of step structures 131 correspond one to one to the plurality of support segments. When setting up the support platform 7, first, a plurality of step structures 131 are excavated in sequence along the bottom of the inclined guide tunnel 13. The upper surface of the step structure 131 is a horizontal surface, thereby providing a horizontal installation space for the setting up of the support segment. Then, according to the excavation needs, a plurality of support segments are set up in sequence. The support platform 7 is formed by the support segments, thereby providing support for the operating frame 4, facilitating the excavation construction of the third cave body 1211.

[0114] Optionally, a temporary support structure is installed within the inclined guide tunnel 13 to maintain the stability of the inclined guide tunnel 13. During excavation of the inclined guide tunnel 13, a temporary support structure is promptly installed along the contour of the existing inclined guide tunnel 13 at each end of the excavated inclined guide tunnel 13 until the excavation of the inclined guide tunnel 13 is completed. The temporary support structure supports the inner wall of the inclined guide tunnel 13, thereby maintaining the stability of the inclined guide tunnel 13, preventing rocks from falling and injuring workers, and ensuring construction safety.

[0115] It should be noted that when excavating the third tunnel body 1211, as the third tunnel body 1211 is continuously excavated, the temporary support structure of the inclined guide tunnel 13 will be gradually dismantled to avoid affecting the excavation of the third tunnel body 1211 and the construction of the first support section.

[0116] In this embodiment, waterstops are installed at the junctions of the first inverted arch structure 2 and the first supporting structure, the second inverted arch structure 3 and the first supporting structure, the second inverted arch structure 3 and the third supporting structure, and the second inverted arch structure 3 and the fourth supporting structure. The waterstops prevent groundwater from seeping into the cavern structure 1, preventing groundwater from corroding the cavern structure 1 and thus ensuring the overall stability of the cavern structure 1.

[0117] Exemplarily, the waterstop comprises a rubber waterstop.

[0118] Example 2

[0119] This embodiment provides a variable-section cavern structure, which is excavated using the variable-section cavern excavation method described above. The variable-section cavern structure 1 includes a first cavern 11 and a second cavern 12 that are interconnected, wherein the cross-sectional area of ​​the first cavern 11 is smaller than the cross-sectional area of ​​the second cavern 12.

[0120] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for excavating a variable-section cavern, for excavating a variable-section cavern structure (1), wherein the variable-section cavern structure (1) comprises a first cavern (11) and a second cavern (12), wherein the cross-sectional area of ​​the first cavern (11) is smaller than the cross-sectional area of ​​the second cavern (12), and the second cavern (12) comprises a first cave segment (121) and a second cave segment (122), and wherein the first cavern (11) is connected to the second cave segment (122) via the first cave segment (121), and wherein the method comprises: The excavation method of the variable-section cavern comprises the following steps: S1, excavating the first cavern (11) along the design outline of the first cavern (11), and setting a first supporting structure along the inner wall of the first cavern (11) until the excavation reaches the junction of the first cavern (11) and the first tunnel section (121); S2. Arranging a first inverted arch structure (2) at the bottom of the first cavern (11), wherein the first inverted arch structure (2) is connected to the first supporting structure; S3, excavating an inclined guide tunnel (13) at a preset angle along the extension direction of the first tunnel section (121) until the excavation reaches the junction of the first tunnel section (121) and the second tunnel section (122), and the top contour line of the inclined guide tunnel (13) coincides with the top contour line of the first tunnel section (121), and the cross-sectional area of ​​the inclined guide tunnel (13) is the same as the cross-sectional area of ​​the first tunnel (11); S4, the second tunnel section (122) includes a first tunnel body (1221) and a second tunnel body (1222) distributed vertically, the first tunnel body (1221) is excavated in the horizontal direction to form a temporary operating platform (123), until the excavation reaches the designed outline of the first tunnel body (1221), and a second supporting structure is set along the outline of the first tunnel body (1221); S5, excavating the first tunnel section (121) along the designed outline of the first tunnel section (121), and setting a third supporting structure along the outline of the first tunnel section (121), until the excavation reaches the junction of the first tunnel section (121) and the second tunnel section (122), and the third supporting structure is connected to the second supporting structure; S6. Excavating the second cave body (1222) along the designed outline of the second cave body (1222), and setting a fourth supporting structure along the outline of the second cave body (1222), wherein the fourth supporting structure is connected to the second supporting structure and the third supporting structure to form a whole; S7. A second inverted arch structure (3) is provided at the bottom of the first cavern (11) and the bottom of the second cavern (12), wherein the second inverted arch structure (3) is connected to the first inverted arch structure (2) as a whole and is connected to the first supporting structure, the third supporting structure and the fourth supporting structure; S8. A secondary lining structure is provided inside the first cavern (11) and inside the second cavern (12), and the secondary lining structure is integrally connected with the first supporting structure, the second supporting structure, the third supporting structure and the fourth supporting structure.

2. The excavation method of a variable cross-section tunnel according to claim 1, characterized in that: The step S1 specifically includes the following steps: S11, setting an operating frame (4) at a location to be constructed, setting explosives at preset positions along a design outline of the first cavern (11) using the operating frame (4), and excavating the first cavern (11); S12, arranging the first supporting structure along the inner wall of the first cave (11), and moving the operating frame (4) along the extension direction of the first cave (11); S13, repeating steps S11 and S12 until excavation reaches the junction of the first cavern (11) and the first tunnel section (121).

3. The excavation method of a variable cross-section tunnel according to claim 2, characterized in that: The operating frame (4) comprises a frame body (41) and a plurality of running wheels (42), wherein the plurality of running wheels (42) are arranged on two opposite sides of the frame body (41).

4. The excavation method of a variable cross-section tunnel according to claim 2, characterized in that: Taking the preset explosion range of the explosives as the excavation period, step S3 specifically includes the following steps: S31, excavating the inclined guide tunnel (13) at the preset angle along the extension direction of the first tunnel section (121), and excavating for at least one excavation cycle; S32, arranging a first operating platform (5) on a side of the operating frame (4) facing the first hole section (121), wherein the inclination angle of the upper surface of the first operating platform (5) is the same as the preset angle; S33, moving the operating frame (4) along the inclined guide tunnel (13), using the first operating platform (5), cyclically excavating the inclined guide tunnel (13) at the preset angle along the extension direction of the first tunnel section (121), until the excavation reaches the junction of the first tunnel section (121) and the second tunnel section (122), and the top contour line of the inclined guide tunnel (13) coincides with the top contour line of the first tunnel section (121), and the cross-sectional area of ​​the inclined guide tunnel (13) is the same as the cross-sectional area of ​​the first tunnel (11).

5. The excavation method of a variable cross-section tunnel according to claim 4 is characterized in that: The step S4 specifically includes the following steps: S41, excavating the first hole (1221) in a horizontal direction to form a temporary operating platform (123); S42, disassembling the first operating platform (5), and setting a second operating platform (6) on the upper end of the operating frame (4); S43, moving the operating frame (4) along the temporary operating platform (123), and using the second operating platform (6) to continue excavating the first hole (1221) in the horizontal direction to extend the temporary operating platform (123); S44, setting up the second supporting structure along the outline of the excavated first cave body (1221); S45. Repeat steps S43 and S44 until the excavation reaches the designed outline of the first cave body (1221).

6. The excavation method of a variable cross-section tunnel according to claim 4, characterized in that: The inclined guide tunnel (13) divides the first tunnel section (121) into a third tunnel body (1211) and a fourth tunnel body (1212); the third support structure comprises a first support section and a second support section connected to each other; and step S5 specifically comprises the following steps: S51, setting up a support platform (7) in the inclined guide tunnel (13) in a direction away from the first tunnel (1221), moving the operating frame (4) onto the support platform (7), and excavating the third tunnel (1211) along the designed outline of the third tunnel (1211); S52, setting the first support section along the outline of the excavated third tunnel (1211) and the outline of the inclined guide tunnel (13), wherein the first support section is connected to the second support structure; S53, repeating steps S51 and S52 until excavation reaches the junction of the first tunnel section (121) and the first tunnel (11); S54, dismantling the support platform (7), and excavating the fourth cave body (1212) in a horizontal direction along the designed outline of the fourth cave body (1212); S55, setting the second supporting section along the contour line of the excavated fourth cave body (1212); S56. Repeat steps S54 and S55 until the excavation reaches the junction of the first hole section (121) and the second hole section (122).

7. The variable cross-section tunnel excavation method according to claim 6, characterized in that: The support platform (7) includes a plurality of connected support sections. A plurality of step structures (131) are provided at the bottom of the inclined guide hole (13). The heights of the plurality of step structures (131) gradually decrease along the direction from the first hole body (1221) to the first cavern (11). Each of the step structures (131) is provided with one of the support sections. The plurality of step structures (131) correspond one to one with the plurality of support sections.

8. The excavation method of a variable cross-section tunnel according to any one of claims 1 to 7, characterized in that: A temporary support structure is provided in the inclined guide tunnel (13), and the temporary support structure is used to maintain the stability of the inclined guide tunnel (13).

9. The excavation method of a variable cross-section tunnel according to any one of claims 1 to 7, characterized in that: Waterstops are provided at the junction of the first inverted arch structure (2) and the first supporting structure, at the junction of the second inverted arch structure (3) and the first supporting structure, at the junction of the second inverted arch structure (3) and the third supporting structure, and at the junction of the second inverted arch structure (3) and the fourth supporting structure.

10. A variable cross-section cavern structure, wherein the variable cross-section cavern structure (1) is excavated using the variable cross-section cavern excavation method according to any one of claims 1 to 9, characterized in that: The variable-section cavern structure (1) comprises a first cavern (11) and a second cavern (12) that are interconnected, wherein the cross-sectional area of ​​the first cavern (11) is smaller than the cross-sectional area of ​​the second cavern (12).

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