CN116084976A

CN116084976A - Variable-diameter tunnel construction method, system and shield equipment

Info

Publication number: CN116084976A
Application number: CN202310081213.0A
Authority: CN
Inventors: 贾连辉; 袁文征; 蒲晓波; 闫阳; 董亚岭; 阴书玉; 周罘鑫; 王昆
Original assignee: China Railway Engineering Equipment Group Co Ltd CREG
Current assignee: China Railway Engineering Equipment Group Co Ltd CREG
Priority date: 2022-09-09
Filing date: 2023-02-08
Publication date: 2023-05-09

Abstract

The disclosure relates to a construction method, a system and shield equipment for a variable-diameter tunnel, wherein the construction method comprises the following steps: setting a hidden excavation cavity on a preset tunneling path of shield equipment, setting a reducing operation space outside the preset tunneling path of the shield equipment, and setting a pilot tunnel between the reducing operation space and the hidden excavation cavity; tunneling and supporting a first-diameter tunnel along the preset tunneling path by the shield equipment through a first cutter head and a first shield body; after the shield equipment is tunneled into the underground excavation cavity, the shield equipment is moved from the underground excavation cavity to the reducing operation space through the pilot tunnel; respectively assembling and adjusting a first cutterhead and a first shield body of the shield equipment in the reducing operation space to form a second cutterhead and a second shield body; moving the shield equipment from the reducing operation space back to the underground excavation chamber through the pilot tunnel; and tunneling and supporting the tunnel with the second diameter along the preset tunneling path by the shield equipment through the second cutterhead and the second shield body.

Description

Variable-diameter tunnel construction method, system and shield equipment

Technical Field

The disclosure relates to the field of tunnel construction, in particular to a reducing tunnel construction method, a reducing tunnel construction system and shield equipment.

Background

At present, manual or mechanical excavation construction including an open excavation method and a hidden excavation method is generally carried out by adopting a mining method, and some related technologies propose the idea of carrying out station construction through a reducing tunnel boring machine and continuously carry out excavation of a front tunnel and a station hall.

Disclosure of Invention

The inventor finds that the mining method manual/mechanical excavation (open excavation/underground excavation) in the related technology can occupy larger ground roads and facility resources, and influence normal urban traffic. Meanwhile, station excavation and normal tunnel excavation which is constructed by a shield method cannot be continuously carried out, project construction progress is restricted to a certain extent, and construction efficiency is affected.

While other related technologies adopt a variable-diameter tunnel boring machine, the lack of the technology mature variable-diameter tunnel boring machine often has the defects of complex structure and narrow application range.

In view of the above, embodiments of the present disclosure provide a reducing tunnel construction method, a reducing tunnel construction system, and a shield apparatus, which are conducive to improving tunnel construction efficiency.

In one aspect of the present disclosure, there is provided a variable diameter tunnel construction method including:

setting a hidden excavation cavity on a preset tunneling path of shield equipment, setting a reducing operation space outside the preset tunneling path, and setting a pilot tunnel between the reducing operation space and the hidden excavation cavity;

tunneling and supporting a first-diameter tunnel by the shield equipment along a preset tunneling path through a first cutter head and a first shield body;

after the shield equipment is tunneled into the underground excavation chamber, the shield equipment is moved from the underground excavation chamber to a reducing operation space through the pilot tunnel;

in the reducing operation space, respectively assembling and adjusting a first cutterhead and a first shield body of shield equipment to form a second cutterhead and a second shield body;

moving the shield equipment from the reducing operation space back to the underground excavation chamber through the pilot tunnel;

tunneling and supporting a tunnel with a second diameter along a preset tunneling path by the shield equipment through a second cutter head and a second shield body;

wherein the diameter of the first diameter tunnel is smaller than the diameter of the second diameter tunnel.

In some embodiments, the volume of the variable diameter operating space is greater than the volume of the undercut cavity.

In some embodiments, further comprising:

the method comprises the steps that a first moving device is arranged in a underground excavation chamber, and after shield equipment is tunneled into the underground excavation chamber, the shield equipment is moved onto the first moving device, so that the shield equipment can be moved into a reducing operation space through a pilot tunnel by the first moving device.

In some embodiments, the operation of transferring the shield apparatus from the pilot tunnel to the reducing operation space specifically includes:

and placing a second shield block of the second shield body on the first moving device so that the first shield body moves onto the second shield block and is assembled with the second shield block when the shield equipment moves onto the first moving device.

In some embodiments, further comprising:

and a transition block is placed on the first mobile device and is arranged between the second shield body block and the entrance of the underground excavation chamber.

In some embodiments, the reducing operation space comprises a silo.

In some embodiments, the assembly adjustment of the first cutterhead and the first shield body of the shield apparatus to form the second cutterhead and the second shield body respectively specifically includes:

the second shield body is arranged on the outer side of the first shield body along the circumferential direction of the first shield body.

In some embodiments, further comprising:

before the shield equipment is moved to the reducing operation space, the first tail shield and the rear matching mechanism which are connected with the first shield body are removed.

In some embodiments, further comprising:

connecting a second front shield and a second middle shield of the second shield body with the first shield body in the reducing operation space;

and after the shield equipment moves back to the underground excavation chamber, connecting a second tail shield of the second shield body with a rear matching mechanism and a second middle shield.

In some embodiments, the shield apparatus is moved from the entrance to the underground excavation chamber by cylinder pushing or chain block.

In another aspect of the present disclosure, there is provided a shield apparatus, comprising: a variable diameter shield assembly; the variable diameter shield body assembly has:

the first shield body is configured to support the first diameter tunnel;

a second shield body mounted on an outer periphery of the first shield body and configured to support a second diameter tunnel;

In some embodiments, the second shield body comprises a plurality of second shield body blocks for circumferential stitching into an annular shield body.

In some embodiments, further comprising:

the variable-diameter cutter head assembly is rotatably arranged on the front side of the variable-diameter shield body assembly;

the variable diameter cutterhead assembly has:

a first cutterhead configured to tunnel a first diameter tunnel; and

and the cutter head block is used for being arranged on the periphery of the first cutter head to form a second cutter head together with the first cutter head, and the first cutter head is configured to tunnel a second-diameter tunnel.

In yet another aspect of the present disclosure, there is provided a variable diameter tunnel construction system including:

a shield apparatus as in any one of the above;

the underground excavation chamber is arranged on a preset tunneling path of the shield equipment;

the variable-diameter operation space is arranged outside a preset tunneling path of the shield equipment; and

the pilot tunnel is arranged between the reducing operation space and the undercut cavity.

In some embodiments, further comprising:

the first moving device is configured to bear the shield equipment and drive the shield equipment to move in the underground excavation cavity, the reducing operation space and the pilot tunnel.

Therefore, according to the embodiment of the disclosure, the underground excavation chamber is arranged on the preset tunneling path of the shield equipment, and the underground excavation chamber is communicated with the reducing operation space communicated with the ground through the guide hole, so that the first shield body can be moved to a region with enough space according to actual topography requirements to assemble large-diameter components, uncertain factors brought by municipal approval when a large number of demolitions are required around a forward tunnel are avoided, the ground is not required to be transported out after the tunneling of the first shield body is completed, the matched space for the tunneling of the second shield body is not required to be re-excavated, the construction efficiency can be effectively improved, the construction cost and public resources are saved, and the damage to the surrounding environment of the tunnel is reduced as much as possible.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The disclosure may be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic illustration of a shield apparatus, about to complete a first diameter tunnel excavation, according to some embodiments of a variable diameter tunnel construction method of the present disclosure;

FIG. 2 is a schematic view of section A-A of FIG. 1;

FIG. 3 is a schematic illustration of a shield apparatus positioned in a sub-excavation chamber according to some embodiments of the variable diameter tunnel construction method of the present disclosure;

FIG. 4 is a schematic illustration of a first shield body with a tail shield disassembled from a rear mating mechanism in accordance with some embodiments of the reducing tunnel construction method of the present disclosure;

FIG. 5 is a schematic view of section B-B of FIG. 4;

FIG. 6 is a schematic diagram of an assembled second shield body according to some embodiments of the reducing tunnel construction method of the present disclosure;

FIG. 7 is a schematic view of a second shield body of a shield apparatus traversing a pilot tunnel according to some embodiments of the variable diameter tunnel construction method of the present disclosure;

FIG. 8 is a schematic view of a second shield body of a shield apparatus positioned in a undermined cavity according to some embodiments of the variable diameter tunnel construction method of the present disclosure;

FIG. 9 is a schematic diagram of an assembled tail shield and slag conveying device of a second shield body according to some embodiments of the variable diameter tunnel construction method of the present disclosure;

fig. 10 is a schematic structural view of some embodiments of shield apparatus according to the present disclosure.

In the figure: 1. a first diameter tunnel; 2. the first shield body; 3. digging a cavity in a hidden way; 4. a second shield block; 5. a second diameter tunnel; 6. a first mobile device; 7. a pilot tunnel; 8. reducing the operation space; 9. a second mobile device; 10. a transition block; 11. an out-hole overhead hoist; 12. the second shield body; 13. the second tail shield; 21. a variable diameter cutterhead assembly; 22. a propulsion mechanism; 24. a thrust cylinder; 25. a first tail shield; 26. a duct piece assembling mechanism; 27. and a slag conveying device.

It should be understood that the dimensions of the various elements shown in the figures are not drawn to actual scale. Further, the same or similar reference numerals denote the same or similar members.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative, and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments should be construed as exemplary only and not limiting unless otherwise specifically stated.

The terms "first," "second," and the like, as used in this disclosure, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises" and the like means that elements preceding the word encompass the elements recited after the word, and not exclude the possibility of also encompassing other elements. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

In this disclosure, when a particular device is described as being located between a first device and a second device, there may or may not be an intervening device between the particular device and either the first device or the second device. When it is described that a particular device is connected to other devices, the particular device may be directly connected to the other devices without intervening devices, or may be directly connected to the other devices without intervening devices.

All terms (including technical or scientific terms) used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs, unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

In the related art, station excavation and normal tunnel excavation (shield method construction) cannot be continuously performed, and normal construction of projects is restricted to a certain extent.

Fig. 1 is a schematic view of a first shield body to be tunneled according to some embodiments of the variable diameter tunnel construction method of the present disclosure, and fig. 2 is a schematic structural view of a section A-A of fig. 1, and referring to fig. 1 and 2, the variable diameter tunnel construction method includes: the method comprises the steps of arranging a hidden excavation chamber 3 on a preset tunneling path of shield equipment, arranging a reducing operation space 8 outside the preset tunneling path of the shield equipment, and arranging a pilot tunnel 7 between the reducing operation space 8 and the hidden excavation chamber 3. The reducing operation space 8 communicates with the ground to convey the assembly of the second shield body 12 from the ground to the underground space, and the undercut cavity 3 and the pilot tunnel 7 do not communicate with the ground. The length of the pilot tunnel 7 can be adjusted according to factors such as actual geological conditions, so that the first shield body 2 can be guided to an area which does not influence the traffic environment and is not influenced by geological factors for reducing operation. The horizontal projection of the reducing operation space 8 is not overlapped with the entrance of the undercut cavity 3, but is positioned at the side of the undercut cavity 3.

After the shield equipment is tunneled into the underground excavation chamber 3, the shield equipment is moved from the underground excavation chamber 3 to a reducing operation space 8 through a pilot tunnel 7, a component of a second shield body 12 hoisted in from the ground is assembled with the first shield body 2 in the reducing operation space 8 to form a second cutterhead and a second shield body 12, and the assembled shield equipment is moved back into the underground excavation chamber 3 through the pilot tunnel 7 to tunnele and support the second diameter tunnel 5 along the preset tunneling path. The diameter of the first diameter tunnel 1 is smaller than that of the second diameter tunnel 5, the diameter of the first cutter head is smaller than that of the second cutter head, and the diameter of the first shield body 2 is smaller than that of the second shield body 12.

In this embodiment, through setting up the undermining hole room 3 on shield equipment's the advance tunneling route to through setting up pilot tunnel 7 with undermining hole room 3 and with ground intercommunication's reducing operation space 8 intercommunication, can remove the first shield body 2 to the region that the space is enough according to actual topography needs and carry out the assembly of major diameter subassembly, in order to avoid removing the uncertain factor that needs municipal approval to bring and the condition that the ground position that major diameter tunnel corresponds around the positive line tunnel in a large number does not allow the excavation, need not to transport out ground after first shield body 2 and first blade disc tunnelling are accomplished, also need not to excavate the supporting space that supplies the tunnelling of second shield body 12 again, no influence personnel, vehicles etc. traffic, thereby can effectively improve the efficiency of construction, practice thrift construction cost and public resources.

The embodiment allows the underground excavation chamber 3 to be small in size, avoids collapse risk and saves construction cost, and the upper parts of the underground excavation chamber 3 and the pilot tunnel 7 do not affect the passing of personnel and vehicles, so that the influence and damage to the surrounding environment and traffic of the tunnel are reduced as much as possible, and a design thought is provided for the large-small tunnel butt joint problem which is difficult to solve in urban traffic construction.

Referring to fig. 2, in some embodiments, the variable diameter operation space 8 has a volume larger than the undercut cavity 3. In this embodiment, the reducing operation space 8 can be adjusted according to actual needs, so as to facilitate assembly of the second shield body 12.

Referring to fig. 1 and 3, in some embodiments, the reducing tunnel construction method further includes: the first moving device 6 is arranged in the underground excavation chamber 3, the shield equipment is moved onto the first moving device 6 after tunneling into the underground excavation chamber 3, and the shield equipment path guide hole 7 is transferred into the reducing operation space 8 by the first moving device 6. In this embodiment, the first moving device 6 is provided, so that the shield apparatus can be moved in the underground space conveniently. The first moving device 6 includes, but is not limited to, a sliding frame, and can move in a form of pushing by an oil cylinder or pulling by a hoist, so as to drag the shield equipment to slide transversely, receive the shield equipment to exit the tunnel, and move the shield equipment to an initial position.

Referring to fig. 1 and 3, in some embodiments, the operation of transferring the shield apparatus from the pilot tunnel 7 to the reducing operation space 8 specifically includes: the second shield block 4 of the second shield body 12 is placed on the first moving device 6 so that the first shield body is moved onto the second shield block 4 to be assembled with the second shield block 4 after the shield equipment is tunneled into the undercut cavity 3. In this embodiment, the second shield block 4 may be placed on the first moving device 6 before the shield apparatus exits the tunnel, so that the shield apparatus can complete the assembly of the first shield block 2 and the second shield block 4 when moving onto the first moving device 6.

Referring to fig. 1 and 3, in some embodiments, the reducing tunnel construction method further includes: a transition block 10 is placed on the first moving device 6, and the transition block 10 is arranged between the second shield body block 4 and the entrance of the undercut cavity 3. Wherein, the entrance to the cavity of the cavity 3 sets up between the end of first diameter tunnel 1 and cavity 3, and the exit of cavity 3 sets up between the entry of second diameter tunnel 5 and cavity 3. In this embodiment, by providing the transition block 10, sufficient space is provided at the trailing end of the first shield body 2 for removal of the first trailing shield 25 and support is provided at the bottom of the first shield body 2 during removal.

Referring to fig. 2, 5-7, in some embodiments, pilot hole 7 includes, but is not limited to, a pilot hole that is parallel to or at an angle to the horizontal, and pilot hole 7 includes, but is not limited to, a pilot hole that is formed along a straight line, a curve, or a combination of straight and curved lines.

Referring to fig. 5-7, in some embodiments, pilot tunnel 7, reducing operation space 8, and the floor of undercut cavity 3 are flush. In this embodiment, the pilot tunnel 7, the reducing operation space 8 and the bottom surface of the undercut cavity 3 are disposed on the same horizontal plane, so that the movement and transportation of each component can be facilitated.

In some embodiments, the reducing operation space 8 comprises a shaft. In this embodiment, the reducing operation space 8 includes, but is not limited to, a shaft form.

Referring to fig. 5 to 7, in some embodiments, the operations of assembling and adjusting the first cutterhead and the first shield body 2 of the shield apparatus to form the second cutterhead and the second shield body 12 respectively specifically include: the second shield body 12 is installed outside the first shield body 2 in the circumferential direction of the first shield body 2.

Referring to fig. 5, in some embodiments, the reducing tunnel construction method further includes: before moving the shield equipment to the reducing operation space 8, removing a first tail shield 25 and a rear supporting mechanism connected with the first shield body 2, wherein the first tail shield 25 is used for stabilizing an excavated tunnel and wrapping a duct piece. In this embodiment, the first tail shield 25 and the rear mating mechanism are removed before moving the shield apparatus to the reducing operation space 8 for transportation and movement of the shield apparatus in the underground space.

Referring to fig. 7 to 8, in some embodiments, the variable diameter tunnel construction method further includes: in the reducing operation space 8, a second front shield and a second middle shield of the second shield body 12 are connected with the first shield body 2; after the shield equipment returns to the underground excavation chamber 3, the second tail shield 13 and the rear supporting mechanism of the second shield body 12 are connected with the second middle shield, and the second tail shield 13 is used for stabilizing an excavated tunnel and wrapping the duct piece.

In some embodiments, the shield apparatus is moved from the entrance of the undercut cavity 3 to the undercut cavity 3 by cylinder pushing or chain block.

Referring to fig. 1 to 9, a description will be given below of a reducing tunnel construction method by taking a reducing process of the first shield body 2 as an example:

the method comprises the steps of arranging a hidden hole chamber 3 on a preset tunneling path of shield equipment, arranging a reducing operation space 8 on the side of the hidden hole chamber 3, and arranging a pilot tunnel 7 between the reducing operation space 8 and the hidden hole chamber 3. A first moving device 6 is arranged in the undercut cavity 3, and a second shield block 4 and a transition block 10 are arranged on the first moving device 6.

The shield equipment is driven and supported along a preset driving path through a first cutter head and a first shield body 2, after the driving and supporting of the first diameter tunnel 1 are completed, the shield equipment is driven by an oil cylinder or a chain block to move to a first moving device 6 of the underground excavation chamber 3, and the shield equipment is assembled with a second shield body block 4 placed on the first moving device 6. And then the first tail shield 25 and the rear supporting mechanism connected with the first shield body 2 are removed, and the second moving device 9 conveys the first tail shield 25 and the rear supporting mechanism into the first tunnel 1 for temporary storage. The second movement means 9 include, but are not limited to, an in-tunnel trolley.

The shield equipment path pilot tunnel 7 assembled with the second shield body block 4 is transferred into the reducing operation space 8 through the first moving device 6, the outside-tunnel lifting device 11 lifts the components of the second shield body 12 downwards from the ground of the reducing operation space 8, and a second front shield, a second middle shield and the like of the second shield body 12 are sequentially connected with the periphery of the first shield body 2 along the circumferential direction, so that the first cutterhead and the first shield body 2 of the shield equipment are respectively assembled and adjusted to form a second cutterhead and the second shield body 12.

After the second shield body 12 and the second cutter head are assembled, the shield body equipment is conveyed back to the underground excavation chamber 3 through the first moving device 6, the second tail shield 13 and the rear supporting mechanism are connected with the second middle shield, so that the diameter of the tunneling machine is changed, and tunneling and supporting of a second-diameter tunnel can be performed by the shield equipment through the second cutter head and the second shield body 12.

In another aspect of the disclosed embodiments, a shield apparatus is provided. Fig. 10 is a schematic structural view of some embodiments of shield apparatus according to the present disclosure, referring to fig. 10, the shield apparatus includes: a variable diameter shield assembly; the variable diameter shield body assembly has: a first shield body 2 and a second shield body 12, the first shield body 2 being configured to support the first diameter tunnel 1 and to carry the internal structural components of the heading machine. The second shield body 12 is configured to be mounted on the outer periphery of the first shield body 2 or separated from the first shield body 2, configured to support the second diameter tunnel 5, and to carry the internal structural members of the heading machine. Wherein the first diameter is smaller than the second diameter.

Referring to fig. 10, in some embodiments, the second shield body 12 includes a plurality of second shield body blocks 4 for circumferentially wrapping the first shield body 2 and then splicing into an annular shield body of the second shield body 12. In this embodiment, the second shield body 12 includes, but is not limited to, a plurality of second shield body pieces 4 in a form that facilitates transportation and assembly.

Referring to fig. 10, in some embodiments, the second shield body 12 is securely and sealingly connected to the outer periphery of the first shield body 2 by a circumferential fastener and a circumferential seal. In this embodiment, the connection between the second shield body 12 and the first shield body 2 can be more stable and reliable by the circumferential fastener and the circumferential sealing member, so as to improve the construction safety.

In some embodiments, the shield apparatus further comprises: the variable diameter cutterhead assembly 21 for excavating a tunnel section, the variable diameter cutterhead assembly 21 is rotatably arranged at the front side of the variable diameter shield body assembly, and the variable diameter cutterhead assembly 21 has: the cutter comprises a first cutter head and a cutter head outer ring. The first cutterhead is configured to tunnel into a first diameter tunnel 1, and the cutterhead outer ring is used for being installed on the periphery of the first cutterhead to form a second cutterhead together with the first cutterhead or separate from the first cutterhead, and the first cutterhead is configured to tunnel into a second diameter tunnel 5.

In some embodiments, the shield apparatus further comprises: the cutter driving mechanism is arranged in the variable-diameter shield assembly, is in driving connection with the first cutter and is configured to drive the first cutter to rotate. In this embodiment, the first cutterhead mechanism may be disposed in the variable diameter shield assembly, so as to facilitate the diameter variation of the shield apparatus.

In some embodiments, the shield apparatus further comprises: and the main beam is arranged in the first shield body 2 and is connected with the first shield body 2.

In some embodiments, the shield apparatus further includes a propulsion mechanism 22 and a segment assembly mechanism 26, the propulsion mechanism 22 being selectively disposed on the first shield body 2 or the second shield body 12 and configured to power the apparatus to propel the first shield body 2 or the second shield body 12 for tunneling. The segment splicing mechanism 26 is disposed on the main beam and configured to splice segments within the first diameter tunnel 1 or the second diameter tunnel 5.

In some embodiments, the propulsion mechanism 22 includes a plurality of propulsion cylinders 24 spaced circumferentially along the first shield body 2 to propel the roadheader forward.

In some embodiments, the system further comprises a muck delivery device 27, the muck delivery device 27 being configured to remove muck generated during the tunneling process, and a mud water circulation system configured to replenish the slurry during the tunneling process.

In still another aspect of the embodiments of the present disclosure, a reducing tunnel construction system is provided, including a shield apparatus as any one of the above, a pilot tunnel 3, a pilot tunnel 7, and a reducing operation space 8, wherein the reducing operation space 8 is disposed outside a preset tunneling path of the shield apparatus, the pilot tunnel 3 is disposed on the preset tunneling path of the shield apparatus, and the pilot tunnel 7 is disposed between the reducing operation space 8 and the pilot tunnel 3.

In some embodiments, the reducing tunnel construction system further comprises a first moving device 6, and the first moving device 6 carries the shield equipment and drives the shield equipment to move in the undercut cavity 3, the pilot tunnel 7 and the reducing operation space 8 so as to enable the shield equipment to perform reducing operation.

Thus, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concepts of the present disclosure, some details known in the art are not described. How to implement the solutions disclosed herein will be fully apparent to those skilled in the art from the above description.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that the foregoing embodiments may be modified and equivalents substituted for elements thereof without departing from the scope and spirit of the disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. The construction method of the variable-diameter tunnel is characterized by comprising the following steps of:

a hidden excavation cavity (3) is arranged on a preset tunneling path of shield equipment, a reducing operation space (8) is arranged outside the preset tunneling path, and a pilot tunnel (7) is arranged between the reducing operation space (8) and the hidden excavation cavity (3);

tunneling and supporting a first diameter tunnel (1) along the preset tunneling path by the shield equipment through a first cutter head and a first shield body (2);

after the shield equipment is tunneled into the underground excavation chamber (3), the shield equipment is moved from the underground excavation chamber (3) to the reducing operation space (8) through the pilot tunnel (7);

in the reducing operation space (8), respectively assembling and adjusting a first cutterhead and a first shield body (2) of the shield equipment to form a second cutterhead and a second shield body (12);

moving the shield equipment back to the underground excavation chamber (3) from the reducing operation space (8) through the pilot tunnel (7);

tunneling and supporting a second diameter tunnel (5) along the preset tunneling path by the shield equipment through the second cutterhead and the second shield body (12);

wherein the diameter of the first diameter tunnel (1) is smaller than the diameter (5) of the second diameter tunnel.

2. The reducing tunnel construction method according to claim 1, characterized in that the volume of the reducing operation space (8) is larger than the volume of the undercut cavity (3).

3. The reducing tunnel construction method according to claim 1, further comprising:

a first moving device (6) is arranged in the underground excavation chamber (3), and after the shield equipment is tunneled into the underground excavation chamber (3), the shield equipment is moved onto the first moving device (6) so as to be moved into the variable-diameter operation space (8) through the guide hole (7) by the first moving device (6).

4. A variable diameter tunnel construction method according to claim 3, wherein the operation of transferring the shield apparatus from the pilot tunnel (7) to the variable diameter operation space (8) specifically comprises:

and placing a second shield block (4) of the second shield body (12) on the first moving device (6) so as to enable the first shield body (2) to move onto the second shield block (4) and be assembled with the second shield block (4) when the shield equipment moves onto the first moving device (6).

5. The reducing tunnel construction method according to claim 4, further comprising:

and a transition block (10) is placed on the first moving device (6), and the transition block (10) is arranged between the second shield body block (4) and the entrance of the undercut cavity (3).

6. A reducing tunnel construction method according to claim 1, characterized in that the reducing operation space (8) comprises a shaft.

7. The method for constructing the variable-diameter tunnel according to claim 1, wherein the operations of assembling and adjusting the first cutterhead and the first shield body (2) of the shield apparatus to form the second cutterhead and the second shield body (12) respectively specifically comprise:

and the second shield body (12) is arranged on the outer side of the first shield body (2) along the circumferential direction of the first shield body (2).

8. The reducing tunnel construction method according to claim 1, further comprising:

before the shield equipment is moved to the reducing operation space (8), a first tail shield (25) and a rear matching mechanism which are connected with the first shield body (2) are removed.

9. The reducing tunnel construction method according to claim 8, further comprising:

connecting a second front shield and a second middle shield of the second shield body (12) with the first shield body (2) in the reducing operation space (8);

and after the shield equipment moves back to the underground excavation chamber (3), connecting a second tail shield (13) of the second shield body (12) with the rear matching mechanism and the second middle shield.

10. The variable-diameter tunnel construction method according to claim 1, wherein the shield equipment is moved from the entrance of the underground excavation chamber (3) to the underground excavation chamber (3) by pushing with an oil cylinder or by a chain block.

11. A shield apparatus, comprising: a variable diameter shield assembly; the variable diameter shield body assembly has:

a first shield body (2) configured to support a first diameter tunnel (1);

a second shield body (12) for being mounted on the outer periphery of the first shield body (2) and configured to support a second diameter tunnel (5);

wherein the diameter of the first diameter tunnel (1) is smaller than the diameter of the second diameter tunnel (5).

12. Shield apparatus according to claim 11, wherein the second shield body (12) comprises a plurality of second shield body blocks (4) for circumferential concatenation into an annular shield body.

13. The shield apparatus of claim 11, further comprising:

the variable-diameter cutter head assembly (21) is rotatably arranged on the front side of the variable-diameter shield body assembly;

the variable diameter cutterhead assembly (21) comprises:

a first cutterhead configured to tunnel the first diameter tunnel (1); and

and the cutter head block is used for being arranged on the periphery of the first cutter head to form a second cutter head together with the first cutter head, and the first cutter head is configured to tunnel the second diameter tunnel (5).

14. A variable diameter tunnel construction system, comprising:

shield apparatus according to any one of claims 11 to 13;

the underground excavation chamber (3) is arranged on a preset tunneling path of the shield equipment;

the reducing operation space (8) is arranged outside a preset tunneling path of the shield equipment; and

the pilot tunnel (7) is arranged between the reducing operation space (8) and the undercut cavity (3).

15. The variable diameter tunnel construction system according to claim 14, further comprising:

the first moving device (6) is configured to bear the shield equipment and drive the shield equipment to move in the underground excavation cavity (3), the reducing operation space (8) and the pilot tunnel (7).