Variable-diameter tunnel construction method and system

Abstract

The present disclosure relates to a variable-diameter tunnel construction method and system. The method comprises: causing the tunneling equipment to tunnel a first diameter tunnel to a reloading position through a first cutterhead form variable-diameter cutterhead assembly and a first shield body; causing the variable-diameter cutterhead assembly to be in situ variable-diameter to a second cutterhead form at the reloading position, and to be excavated; causing the tunneling equipment to tunnel a preset length of a second diameter tunnel through the second cutterhead form variable-diameter cutterhead assembly and the first shield body to form a shield body installation space, and to support the first shield body through a support shoe mechanism arranged on the first shield body; in the shield body installation space, installing a second shield body on the outer periphery of the first shield body; causing the tunneling equipment to continue to tunnel the second diameter tunnel through the second cutterhead form variable-diameter cutterhead assembly and the second shield body.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of tunnel construction, and in particular, to a variable-diameter tunnel construction method and system. BACKGROUND

[0002] At present, station excavation generally adopts mine manual / mechanical excavation (open excavation / underground excavation), in which process, a large amount of ground resources (roads / facilities) are occupied, and normal urban traffic is affected. Meanwhile, station excavation generally cannot be continuously performed with shield tunnel excavation of the main line, which to some extent, restricts the project construction process and affects the construction efficiency.

[0003] Some related technologies propose the idea of performing station construction by using a variable-diameter tunnel boring machine. However, there is a lack of a mature variable-diameter tunnel boring machine, and there are defects such as complex structure and narrow application range. SUMMARY

[0004] Therefore, the present disclosure provides a variable-diameter tunnel construction method and system, which can improve the tunnel construction process.

[0005] In one aspect of the present disclosure, a variable-diameter tunnel construction method is provided, comprising:

[0006] causing the tunnel boring equipment to excavate a first diameter tunnel to a reloading position by a first cutterhead form of a variable-diameter cutterhead assembly and a first shield body;

[0007] causing the variable-diameter cutterhead assembly to change diameter to a second cutterhead form in situ at the reloading position and perform overbreak;

[0008] causing the tunnel boring equipment to excavate a second diameter tunnel of a preset length by the second cutterhead form of the variable-diameter cutterhead assembly and the first shield body to form a shield body installation space, and supporting the first shield body by a support shoe mechanism arranged on the first shield body;

[0009] installing a second shield body on an outer periphery of the first shield body in the shield body installation space;

[0010] causing the tunnel boring equipment to continue excavating the second diameter tunnel by the second cutterhead form of the variable-diameter cutterhead assembly and the second shield body.

[0011] In some embodiments, the step of forming the shield body installation space comprises:

[0012] after causing the tunnel boring equipment to excavate a first preset length of the second diameter tunnel by the second cutterhead form of the variable-diameter cutterhead assembly and the first shield body, an auxiliary muck discharge mechanism is arranged between the variable-diameter cutterhead assembly and the first shield body, so as to discharge muck received by the auxiliary muck discharge mechanism outward by a muck conveying mechanism.

[0013] continuing tunneling of the tunneling equipment through the second cutter head form of the variable-diameter cutter head assembly and the first shield body by a portion of the support shoe mechanism disposed at a front position on the first shield body;

[0014] continuing tunneling of the tunneling equipment through the second cutter head form of the variable-diameter cutter head assembly and the first shield body by a portion of the support shoe mechanism disposed at a rear position on the first shield body;

[0015] continuing tunneling of the tunneling equipment through the second cutter head form of the variable-diameter cutter head assembly and the first shield body by a portion of the support shoe mechanism disposed at a rear position on the first shield body;

[0016] In some embodiments, the step of disposing an auxiliary slagging mechanism between the variable-diameter cutter head assembly and the first shield body comprises:

[0017] fixing and connecting a cutter head slagging plate on the telescopic beam of the variable-diameter cutter head assembly;

[0018] fixing and connecting a slagging plate on the bottom of the front end of the first shield body;

[0019] disposing a bottom slagging plate on the lower side of the bottom of the front end of the first shield body.

[0020] In some embodiments, during the process of continuing tunneling of the tunneling equipment through the second cutter head form of the variable-diameter cutter head assembly and the first shield body, a segment erector in the tunneling equipment lays a lower half ring segment of the first diameter tunnel and provides counterforce for tunneling through the lower half ring segment.

[0021] In some embodiments, during the process of laying the lower half ring segment, further comprising disposing at least one support seat on the lower side of the lower half ring segment to support the lower half ring segment.

[0022] In some embodiments, the step of installing the second shield body on the outer periphery of the first shield body in the shield body installation space comprises:

[0023] In the shield body installation space, assembling the plurality of shield body segments by a segment erector in the tunneling equipment to form the second shield body in the form of a ring on the outer periphery of the first shield body.

[0024] In some embodiments, the step of assembling the plurality of shield body segments by the segment erector in the tunneling equipment comprises:

[0025] The tunneling equipment is made to pass through the variable-diameter cutterhead assembly of the second cutterhead mode and the first shield body to retreat by a fifth preset length;

[0026] The multiple front shield sub-blocks are assembled into a front shield whole-ring structure by the segment erector;

[0027] The tunneling equipment is made to pass through the variable-diameter cutterhead assembly of the second cutterhead mode and the first shield body to continue to retreat by a sixth preset length, and a part of the support shoe mechanism at the rear position on the first shield body is retracted during the retreat;

[0028] The multiple middle shield sub-blocks are assembled into a middle shield whole-ring structure by the segment erector;

[0029] The tunneling equipment is made to pass through the variable-diameter cutterhead assembly of the second cutterhead mode and the first shield body to continue to retreat, and a part of the support shoe mechanism at the front position on the first shield body is retracted during the retreat;

[0030] The multiple tail shield sub-blocks are assembled into a tail shield whole-ring structure by the segment erector;

[0031] The front shield whole-ring structure, the middle shield whole-ring structure and the tail shield whole-ring structure are sequentially connected and fixedly connected with the first shield body.

[0032] In some embodiments, the variable-diameter tunnel construction method further comprises:

[0033] After the tunneling equipment is excavated to the replacement position, the rear matching mechanism of the tunneling equipment is disconnected.

[0034] In some embodiments, the variable-diameter tunnel construction method further comprises:

[0035] After the second shield body is installed on the outer periphery of the first shield body, the replacement propulsion oil cylinder is replaced, and the rear matching mechanism is connected.

[0036] In some embodiments, the variable-diameter tunnel construction method further comprises:

[0037] Before the tunneling equipment excavates to the replacement position, the stratum pre-grouting reinforcement of the replacement area is carried out in advance by the horizontal and pre-grouting system of the tunneling equipment.

[0038] In one aspect of the present disclosure, a variable-diameter tunnel construction system is provided, comprising:

[0039] A replacement area;

[0040] A tunneling equipment, which implements the aforementioned variable-diameter tunnel construction method in the replacement area.

[0041] Based on the embodiments of the present disclosure, in the process of tunnel variable-diameter construction, the variable-diameter of the variable-diameter cutter head assembly is used to realize in-situ excavation, and tunneling is carried out based on the larger-diameter cutter head form. In order to stabilize the first shield body of smaller diameter, the support shoe mechanism arranged on the first shield body is used to support the first shield body in the larger-diameter tunnel, so as to effectively control the posture of the tunneling equipment and meet the continuous tunneling construction requirement of the equipment. In this way, after the shield body installation space is formed, the second shield body is installed on the outer periphery of the first shield body, so as to meet the construction requirements of larger-diameter tunneling and supporting. BRIEF DESCRIPTION OF DRAWINGS

[0042] The accompanying drawings, which form a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0043] The present disclosure can be more clearly understood and appreciated from the following detailed description, taken in conjunction with the following drawings, in which:

[0044] Figure 1 is a flowchart of some embodiments of the variable-diameter tunnel construction method according to the present disclosure;

[0045] Figure 2A is a schematic diagram of tunneling equipment grouting reinforcement of the dressing area according to an embodiment of the variable-diameter tunnel construction method of the present disclosure;

[0046] Figure 2B is a schematic diagram of tunneling equipment starting excavation to the dressing position according to an embodiment of the variable-diameter tunnel construction method of the present disclosure;

[0047] Figure 3A is a schematic diagram of cutter head variable-diameter excavation according to an embodiment of the variable-diameter tunnel construction method of the present disclosure;

[0048] Figure 3B is an AA cross-sectional schematic diagram of Figure 3A ;

[0049] Figure 4A is a flowchart of forming a shield body installation space according to an embodiment of the variable-diameter tunnel construction method of the present disclosure;

[0050] Figure 4B is a schematic diagram of tunneling equipment forward excavation and setting auxiliary slag discharge mechanism according to an embodiment of the variable-diameter tunnel construction method of the present disclosure;

[0051] Figure 4C is a BB cross-sectional schematic diagram of Figure 4B ;

[0052] Figure 5A is a schematic diagram of cutter head forward continuous excavation of tunneling equipment and support by front shield support shoe mechanism according to an embodiment of the variable-diameter tunnel construction method of the present disclosure;

[0053] Figure 5B is a CC cross-sectional schematic diagram of Figure 5A ;

[0054] Figure 6A is a schematic diagram of the tunneling equipment according to the variable-diameter tunnel construction method embodiment of the present disclosure continuing to excavate forward and being supported by the front shield support shoe mechanism and the middle shield support shoe mechanism;

[0055] Figure 6B is a DD cross-sectional schematic diagram of Figure 6A ;

[0056] Figure 7A is a schematic diagram of the tunneling equipment according to the variable-diameter tunnel construction method embodiment of the present disclosure providing a counterforce through the semi-ring segment to continue to excavate forward to form a large chamber;

[0057] Figure 7B is an EE cross-sectional schematic diagram of Figure 7A ;

[0058] Figure 8A is a schematic diagram of removing the segment and the support seat in the large chamber according to the variable-diameter tunnel construction method embodiment of the present disclosure;

[0059] Figure 8B is an FF cross-sectional schematic diagram of Figure 8A ;

[0060] Figure 9A is a schematic diagram of the tunneling equipment according to the variable-diameter tunnel construction method embodiment of the present disclosure assembling the second shield body through the segment assembling machine;

[0061] Figure 9B is a schematic diagram of the tunneling equipment according to the variable-diameter tunnel construction method embodiment of the present disclosure retreating and adjusting the cutter head;

[0062] Figure 10A is a schematic diagram of the tunneling equipment according to the variable-diameter tunnel construction method embodiment of the present disclosure assembling the multiple front shields into a front shield whole-ring structure through the segment assembling machine;

[0063] Figure 10B is a GG cross-sectional schematic diagram of Figure 10A ;

[0064] Figure 11A is a schematic diagram of the tunneling equipment according to the variable-diameter tunnel construction method embodiment of the present disclosure assembling the multiple middle shields into a middle shield whole-ring structure through the segment assembling machine;

[0065] Figure 11B is an HH cross-sectional schematic diagram of Figure 11A ;

[0066] Figure 12A This is a schematic diagram of the tunnel boring machine assembling the multiple tail shields into a complete tail shield ring structure using a segment assembly machine, according to an embodiment of the variable diameter tunnel construction method disclosed herein.

[0067] Figure 12B yes Figure 12A Schematic diagram of section II;

[0068] Figure 13 This is a schematic diagram showing how the front shield ring structure, middle shield ring structure and tail shield ring structure of the tunnel boring equipment are sequentially connected and fixedly connected to the first shield body according to the embodiment of the variable diameter tunnel construction method disclosed herein.

[0069] Figure 14 This is a schematic diagram of the tunnel excavation equipment connected to the supporting mechanism and starting excavation in an embodiment of the variable diameter tunnel construction method disclosed herein.

[0070] It should be understood that the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components.

[0071] Explanation of reference numerals in the attached drawings: 1-Variable diameter cutterhead assembly; 10-Cutterhead body; 11-Telescopic beam; 12-Fixed beam; 13-Replaceable tearing blade; 2-First shield body; 21-First front shield; 22-First middle shield; 23-First tail shield; 31-Main drive mechanism; 32-Propulsion cylinder; 33-Segment assembly machine; 34-Screw conveyor; 35-Rear supporting mechanism; 4-Second shield body; 41-Front shield ring structure; 411-Front shield segment; 42-Middle shield ring structure; 421-Middle shield segment; 43-Tail shield ring structure; 431-Tail shield segment; 51-Front shield support shoe mechanism; 52-Middle shield support shoe mechanism; 61-Cutterhead scraper plate; 62-Bottom baffle plate; 63-Slag receiving plate; 71-Spraying reinforcement support operation platform; 72-Spraying anchor anti-torsion block; 81-Support seat; 82-Segment; 83-Second shield launching guide rail. Detailed Implementation

[0072] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0073] The terms "first", "second", and similar terms used in the present disclosure do not denote any order, quantity, or importance, but are used to distinguish different parts. The terms "comprise", "include" or "contain" and similar terms mean that the elements before the term encompass the elements listed after the term, and do not exclude the possibility of also encompassing other elements. "Up", "down", "left", "right", and the like are only used to indicate relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0074] In the present disclosure, when it is described that a specific device is located between a first device and a second device, there can be an intervening device between the specific device and the first device or the second device, or there can be no intervening device. When it is described that a specific device is connected to another device, the specific device can be directly connected to the other device without an intervening device, or can not be directly connected to the other device with an intervening device.

[0075] All terms used in the present disclosure, including technical terms or scientific terms, have the same meanings as understood by a person of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted in a manner consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or extremely formalized sense, unless otherwise specifically defined herein.

[0076] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered part of the specification where appropriate.

[0077] In order to improve the tunnel construction process, with reference to Figures 1 to 14 The embodiment of the present disclosure provides a variable-diameter tunnel construction method, comprising steps S10 to S50.

[0078] In step S10, the tunneling equipment passes through the first cutterhead form variable-diameter cutterhead assembly 1 and first shield body 2 to excavate a first diameter tunnel T1 to a replacement position. The tunneling equipment here can include: a first shield body 2, a variable-diameter cutterhead assembly 1, and a support shoe mechanism.

[0079] The first shield body 2 is used for supporting the first diameter tunnel T1. The variable-diameter cutterhead assembly 1 is rotatably arranged on the front side of the first shield body 2, and can form a first cutterhead form for excavating the first diameter tunnel T1 and a second cutterhead form for excavating a second diameter tunnel T2. The diameter of the first diameter tunnel T1 can be smaller than the diameter of the second diameter tunnel T2. The support shoe mechanism is arranged on the first shield body 2, and is used to support the first shield body 2 when the variable-diameter cutterhead assembly 1 is in the second cutterhead form for tunnel expansion construction.

[0080] In step S20, the variable-diameter cutterhead assembly 1 is changed in diameter to a second cutterhead form in situ at the retooling position, and overbreakage is performed. The retooling position here refers to a specified position at which the variable-diameter cutterhead assembly changes the cutterhead form, and the variable-diameter cutterhead assembly 1 can be changed from the first cutterhead form to the second cutterhead form at this position. The variable-diameter cutterhead assembly 1 in the second cutterhead form can excavate a second-diameter tunnel T2 having a larger diameter, while the variable-diameter cutterhead assembly 1 in the first cutterhead form can excavate a first-diameter tunnel T1 having a smaller diameter.

[0081] In step S30, the tunneling apparatus excavates a second-diameter tunnel T2 of a predetermined length by the variable-diameter cutterhead assembly 1 in the second cutterhead form and the first shield 2 to form a shield installation space, and supports the first shield 2 by a support shoe mechanism provided on the first shield 2. The first shield 2 has a diameter smaller than that of the second-diameter tunnel T2, and thus the height position of the first shield 2 is maintained by the support shoe mechanism during excavation.

[0082] In step S40, a second shield 4 is installed on the outer periphery of the first shield 2 in the shield installation space. After the shield installation space is formed, the second shield 4 can be installed in the space formed between the first shield 2 and the second-diameter tunnel T2.

[0083] In step S50, the tunneling apparatus continues to excavate the second-diameter tunnel T2 by the variable-diameter cutterhead assembly 1 in the second cutterhead form and the second shield 4. After the second shield 4 is installed, the diameter of the second shield 4 matches that of the second-diameter tunnel T2, and thus the second-diameter tunnel T2 can be supported during excavation.

[0084] In the tunnel diameter-changing construction process of the present embodiment, overbreakage is performed in situ by changing the diameter of the variable-diameter cutterhead assembly 1, and excavation is performed based on the larger-diameter cutterhead form. In order to stabilize the smaller-diameter first shield 2, the first shield 2 is supported in the larger-diameter tunnel by the support shoe mechanism provided on the first shield 2, thereby effectively controlling the posture of the tunneling apparatus and satisfying the requirement for continuous excavation construction. Thus, after the shield installation space is formed, the second shield 4 is installed on the outer periphery of the first shield 2, thereby satisfying the requirement for larger-diameter tunnel excavation and support construction.

[0085] Reference Figure 4A In some embodiments, the step of forming the shield installation space in step S30 includes steps S31 to S34.

[0086] Reference Figure 4B and Figure 4CIn step S31, after the tunneling equipment passes through the second cutter head mode variable diameter cutter head assembly 1 and the first shield body 2 to excavate a second diameter tunnel T2 of a first preset length (for example, about 2m), an auxiliary muck removal mechanism is arranged between the variable diameter cutter head assembly 1 and the first shield body 2, so that the muck received by the auxiliary muck removal mechanism is transported outward through a muck conveying mechanism.

[0087] Specifically, the step of arranging the auxiliary muck removal mechanism between the variable diameter cutter head assembly 1 and the first shield body 2 in step S31 can include: fixedly connecting (for example, welding) a cutter head muck scraping plate 61 on the telescopic beam 11 of the variable diameter cutter head assembly 1; fixedly connecting (for example, welding) a muck receiving plate 63 on the bottom of the front end of the first shield body 2; and arranging a bottom muck blocking plate 62 on the lower side of the bottom of the front end of the first shield body 2.

[0088] Referring to Figure 5A and Figure 5B In step S32, the tunneling equipment continues to pass through the second cutter head mode variable diameter cutter head assembly 1 and the first shield body 2 to excavate a second preset length (for example, 1m), and then a part of the support shoe mechanism (for example, the front shield support shoe mechanism 51 arranged on the first front shield 21) arranged at a front position on the first shield body 2 supports the first shield body 2.

[0089] Referring to Figure 6A and Figure 6B In step S33, the tunneling equipment continues to pass through the second cutter head mode variable diameter cutter head assembly 1 and the first shield body 2 to excavate a third preset length (for example, 4.2m), and then a part of the support shoe mechanism (for example, the middle shield support shoe mechanism 52 arranged on the first middle shield 22) arranged at a rear position on the first shield body 2 supports the first shield body 2. At this time, the front shield support shoe mechanism 51 and the middle shield support shoe mechanism 52 both support the first shield body 2.

[0090] Referring to Figure 7A and Figure 7B In step S34, the tunneling equipment continues to pass through the second cutter head mode variable diameter cutter head assembly 1 and the first shield body 2 to excavate a fourth preset length, for example, 22m, to form the shield body installation space. In the previous steps S32, S33 and S34, the support shoe mechanism slides on the surface of the second diameter tunnel T2 as the first shield body 2 moves.

[0091] In Figure 7AIn the process of making the tunneling equipment continue tunneling through the second cutter configuration variable-diameter cutter assembly 1 and the first shield 2, the lower half-ring segment 82 can be laid by the segment erector 33 in the tunneling equipment, and the tunneling is carried out by the reaction force provided by the lower half-ring segment 82. In this way, the tunneling equipment can continue to tunnel forward, so as to form a shield installation space with sufficient length.

[0092] In order to ensure the stability of the lower half-ring segment 82, in some embodiments, at least one support seat 81 can be arranged on the lower side of the lower half-ring segment 82 to support the lower half-ring segment 82 during the laying of the lower half-ring segment 82. Figure 7A And Figure 7B In the process of tunneling, the support seat 81 can be arranged in multiple groups according to the extension length of the lower half-ring segment 82 in the tunneling direction, and each group of support seats 81 can include multiple support seats 81 arranged adjacent in the circumferential direction. The multiple support seats 81 can be symmetrical with respect to the vertical center plane of the second diameter tunnel T2.

[0093] Referring to Figure 8A And Figure 8B After the shield installation space is formed, the lower half-ring segment 82 and the support seat 11 in the space can be removed. And the first tail shield 23 of the first shield 2 can be cut off, and a second shield launching rail 83 can be laid on the lower side surface of the tunnel.

[0094] In some embodiments, the step of installing the second shield 4 around the outer periphery of the first shield 2 in the shield installation space in step S40 includes the step of assembling the multiple shield blocks by the segment erector 33 in the tunneling equipment in the shield installation space to form the annular second shield 4 around the outer periphery of the first shield 2.

[0095] Since the size of the shield installation space obtained by tunneling through the second cutter configuration variable-diameter cutter assembly 1 is relatively limited in the radial direction of the shield, it is difficult to achieve the installation of the second shield 4 on the first shield 2 by setting a crane or other equipment. The present embodiment assembles the shield blocks from the inside by the segment erector 33 in the equipment to form the annular second shield 4, which effectively reduces the construction difficulty.

[0096] Referring to Figure 9A In some embodiments, the step of assembling the multiple shield blocks by the segment erector 33 in the tunneling equipment includes steps S41 to S47. Referring to Figure 9BIn step S41, the tunneling equipment retreats through the variable-diameter cutterhead assembly 1 in the second cutterhead mode and the first shield body 2 by a fifth preset length (for example, 2 m). When the tunneling equipment retreats, the first shield body 2 moves backward under the sliding support of the front shield support shoe mechanism 51 and the middle shield support shoe mechanism 52.

[0097] Referring to Figure 10A and Figure 10B In step S42, the plurality of front shield segments 411 are assembled into the front shield whole-ring structure 41 by the segment erector 33.

[0098] Referring to Figure 11A and Figure 11B In step S43, the tunneling equipment continues to retreat through the variable-diameter cutterhead assembly 1 in the second cutterhead mode and the first shield body 2 by a sixth preset length, for example, 3.2 m, and retracts a part of the support shoe mechanism (for example, the middle shield support shoe mechanism 52 arranged on the first middle shield 22) at the rear position on the first shield body 2 during the retreat. In step S44, the plurality of middle shield segments 421 are assembled into the middle shield whole-ring structure 42 by the segment erector 33.

[0099] Referring to Figure 12A and Figure 12B In step S45, the tunneling equipment continues to retreat through the variable-diameter cutterhead assembly 1 in the second cutterhead mode and the first shield body 2, and retracts a part of the support shoe mechanism (for example, the front shield support shoe mechanism 51 arranged on the first front shield 21) at the front position on the first shield body 2 during the retreat. In step S46, the plurality of rear shield segments 431 are assembled into the rear shield whole-ring structure 43 by the segment erector 33.

[0100] In step S47, the front shield whole-ring structure 41, the middle shield whole-ring structure 42, and the rear shield whole-ring structure 43 are sequentially connected and fixedly connected with the first shield body 2.

[0101] In the specific installation process of the second shield body 4, the front shield, the middle shield, and the rear shield of the second shield body 4 are sequentially assembled by the segment erector 33 in cooperation with the retreat of the tunneling equipment, and after the front shield whole-ring structure 41, the middle shield whole-ring structure 42, and the rear shield whole-ring structure 43 are formed, they are fixedly connected with the first shield body 2, so as to form the second shield body 4 supported and fixed on the inner side by the first shield body 2, thereby realizing the supporting role of the second-diameter tunnel T2.

[0102] In some embodiments, the variable-diameter tunnel construction method further comprises: disconnecting the rear matching mechanism 35 after the tunneling equipment excavates to the changing position. Since the tunneling equipment needs to perform multiple operations such as excavation, retreat and changing during this process, disconnecting the rear matching mechanism 35 first helps to reduce the construction difficulty. Correspondingly, referring to Figure 13 After the second shield body 4 is installed on the outer periphery of the first shield body 2, the changing propulsion oil cylinder 32 is changed and the rear matching mechanism 35 is connected. Here, the propulsion oil cylinder 32 is changed from the first middle shield 22 of the first shield body 2 to the middle shield whole-ring structure of the second shield body 4.

[0103] Referring to Figure 14 , the tunneling equipment can excavate forward through the variable-diameter cutterhead assembly 1 in the second cutterhead mode, and support the second-diameter tunnel T2 through the second shield body 4. Moreover, segment assembly is performed through the segment assembly machine, so as to provide the reaction force of the forward excavation of the tunneling equipment through the segment.

[0104] Referring to Figure 2A In some embodiments, the variable-diameter tunnel construction method further comprises: before the tunneling equipment excavates to the changing position, the stratum pre-grouting reinforcement of the changing area is performed in advance through the horizontal and pre-grouting system of the tunneling equipment.

[0105] Referring to the foregoing various construction method embodiments and Figures 1 to 14 , an example is provided below for illustration. In this example, the construction method comprises:

[0106] Step one: referring to Figure 1 , the stratum pre-grouting reinforcement of the changing area A1 is performed in advance through the horizontal and pre-grouting system of the tunneling equipment, so that additional stratum processing measures can be saved.

[0107] Step two: referring to FIG. 2, the tunneling equipment starts excavation to the changing position by about 4m forward through the variable-diameter cutterhead assembly 1 in the first cutterhead mode and the first shield body 2, and then disconnects the rear matching mechanism 35.

[0108] Step three: referring to Figure 3A and Figure 3B , the variable-diameter cutterhead assembly 1 can adopt a telescopic cutterhead, that is, a telescopic beam 11 capable of telescoping is arranged on the cutterhead body 10, and cutters are arranged on the telescopic beam 11, so that the cutters expand the excavation diameter of the cutterhead along with the extension of the telescopic beam 11. Through the in-situ variable-diameter of the variable-diameter cutterhead assembly 1, the cutterhead can be expanded to the required diameter, realizing the in-situ large-size variable-diameter of the cutterhead;

[0109] Step four: referring to Figure 4B and Figure 4CThe tunneling equipment is excavated and expanded by about 2m through the second cutter head form variable diameter cutter head assembly 1 and the first shield 2. Then, the cut ring of the first shield 2 is removed, and the bottom slag blocking plate 62, the cutter head slag scraping plate 61 and the slag receiving plate 63 are welded to more efficiently discharge the muck of the soil chamber A2 to the outside through the screw conveyor 34 during the expansion, thereby realizing the requirement of efficient and continuous muck discharge. The bottom slag blocking plate 62 can effectively block the muck in the soil chamber A2 from entering the bottom of the first shield 2, and the cutter head slag scraping plate 61 can scrape the muck at the bottom and fall onto the slag receiving plate 63 as the cutter head rotates, and then the muck on the slag receiving plate 63 is conveyed backward by the screw conveyor 34.

[0110] Step five: refer to Figure 5A and Figure 5B , the tunneling equipment is excavated and expanded by 1m through the second cutter head form variable diameter cutter head assembly 1 and the first shield 2, the front shield support shoe mechanism 51 on the left and right sides of the first front shield 21 is extended, abuts against the bottom of the tunnel, and installs a support beam to prevent the posture of the tunneling equipment from being difficult to control. The outer side of the front shield support shoe mechanism 51 can be provided with an anchor injection anti-twist stop block 72 to prevent the tunneling equipment from rolling during excavation.

[0111] In Figure 5A and Figure 6A and Figure 7A , the anchor injection anti-twist stop block 72 can be configured as a strip-shaped structure protruding relative to the lower side surface of the tunnel, having a preset width and extending in the tunneling direction. The anchor injection anti-twist stop block 72 can be provided in two strips, and the front shield support shoe mechanism 51 is located between and abuts against the two strips of the anchor injection anti-twist stop block 72, which is equivalent to that the two strips of the anchor injection anti-twist stop block 72 form a guide rail for the front shield support shoe mechanism 51 to slide, avoiding the rotation of the shield during the rotation of the cutter head.

[0112] In addition, a jet grouting support operation platform 71 can also be installed to synchronize the in-hole jet grouting reinforcement, prevent the excavation outer contour from collapsing and the muck from falling, and ensure the safety of the construction personnel.

[0113] Step six: refer to Figure 6A and Figure 6B , the tunneling equipment continues to excavate and expand by 4.2m through the second cutter head form variable diameter cutter head assembly 1 and the first shield 2, and the middle shield support shoe mechanism 52 is extended on both sides of the first middle shield 22, abuts against the bottom of the tunnel, and installs a support beam to prevent the posture of the tunneling equipment from being difficult to control.

[0114] Step seven: refer to Figure 7A and Figure 7B, the tunneling equipment continues to excavate 22 m through the second cutter head form of the variable diameter cutter head assembly 1 and the first shield 2, and completes the excavation of the shield installation space. During the excavation process, the tunneling equipment adopts semi-ring excavation, that is, the support seats 81 are placed on the left and right sides of the bottom, the semi-ring segments 82 are placed on the support seats 81, and the semi-ring segments 82 are pushed by the push oil cylinder 32 to provide a counterforce to realize semi-ring excavation.

[0115] Step eight: referring to Figure 8A and Figure 8B , the semi-ring segments 82 and the support seats 81 in the shield installation space are removed, and the first tail shield 23 of the first shield 2 is cut off, and the second shield starting guide rail 83 is laid on the lower surface of the tunnel.

[0116] Step nine: the variable diameter cutter head assembly 1 in the second cutter head form can be set to different overall diameters of the cutter head according to the extension length of the telescopic beam 11 relative to the circumferential outer edge of the cutter head body 10. Correspondingly, the variable diameter cutter head assembly 1 with different overall diameters of the cutter head can excavate second diameter tunnels T2 with different diameters.

[0117] In order to meet the space requirement of the tunnel surface injection reinforcement treatment in the shield installation space, when the cutter head is expanded in the previous step, the telescopic beam 11 of the cutter head variable diameter cutter head assembly 1 can be extended to the maximum distance to form a cutter head with a diameter of 12 meters, so as to excavate a shield installation space with a diameter of 12 meters, so as to support and reinforce the upper surface of the tunnel. Subsequently, before excavating the second diameter tunnel T2 of 10 meters, the variable diameter cutter head assembly 1 is adjusted to a cutter head with a diameter of 10 meters.

[0118] Referring to Figure 9B , the tunneling equipment retreats 2 m through the second cutter head form of the variable diameter cutter head assembly 1 and the first shield 2. At this time, the cutter head can be re-diametered and reformed to meet the subsequent excavation needs of the second diameter tunnel T2.

[0119] Step ten: referring to Figure 10A and Figure 10B , a plurality of front shield segments 411 are assembled into a front shield whole ring structure 41 by the segment assembling machine 33, and auxiliary assembling tools can be used for assistance during the process.

[0120] Step eleven: referring to Figure 11A and Figure 11B, the tunneling equipment continues to retreat 3.2 m through the second cutter head form variable diameter cutter head assembly 1 and the first shield 2, and the middle shield support shoe mechanism 52 is retracted during the retreat process to avoid interference with the second shield 4. A plurality of middle shield segments 421 are assembled into a middle shield whole ring structure 42 by the segment erector 33, and auxiliary assembly tooling can be used to assist in this process.

[0121] Step twelve: refer to Figure 12A and Figure 12B , the tunneling equipment continues to retreat through the second cutter head form variable diameter cutter head assembly 1 and the first shield 2, and the front shield support shoe mechanism 51 is retracted during the retreat process to avoid interference with the second shield 4. A plurality of tail shield segments 431 are assembled into a tail shield whole ring structure 43 by the segment erector 33, and auxiliary assembly tooling can be used to assist in this process.

[0122] In the above steps, the plurality of shield segments used to splice to form the second shield 4 can be set in multiple specifications according to the design size of the second shield 4, thereby meeting the support needs of tunnels of different diameters. The tunneling equipment can realize adaptive shield segment assembly function through the segment erector 33. For the second shield 4 with different diameter requirements, the segment erector 33 can complete the assembly process of the second shield 4 by assembling shield segments of corresponding specifications.

[0123] Step thirteen: refer to Figure 13 , the front shield whole ring structure 41, the middle shield whole ring structure 42, and the tail shield whole ring structure 43 are sequentially connected and fixedly connected with the first front shield 21 and the first middle shield 22 of the first shield 2, and the welding flanges, rib plates, seals, and other devices are connected, and the vacuum suction cups are replaced, and the thrust cylinders 32 are replaced.

[0124] Step fourteen: refer to Figure 14 , the matching mechanism 35 is connected, so that the tunneling equipment starts tunneling through the second cutter head form variable diameter cutter head assembly 1 and the second shield 4 mother shield, thereby realizing hole expansion and excavation variable diameter in a small-to-large manner, and being able to meet the needs of station construction mechanized excavation technology and similar complex environment urban underground space various types of underground construction engineering.

[0125] Compared with the station construction method such as open cut / underground excavation in the related art, the embodiment does not need to increase additional hoisting work wells, underground excavation work rooms, and other auxiliary measures required in the variable diameter conversion process, is environmentally friendly, is not affected by sudden factors, at the same time meets the needs of continuous excavation of station and main line tunnels, provides comprehensive construction efficiency, and reduces construction cost. It has great social and economic benefits for current urban underground space development in complex environments, has high popularization value, and provides a new feasible solution for underground space development.

[0126] Based on the foregoing various embodiments of the variable-diameter tunnel construction method, the present disclosure further provides a variable-diameter tunnel construction system, comprising a changeover area A and a tunneling device. The tunneling device is used to implement the variable-diameter tunnel construction method of any one of the foregoing embodiments in the changeover area A1.

[0127] With reference to Figures 1 to 14 , the tunneling device can comprise a first shield body 2, a variable-diameter cutterhead assembly 1, and a support shoe mechanism. The first shield body 2 is used for supporting the first-diameter tunnel T1. The variable-diameter cutterhead assembly 1 is rotatably arranged on the front side of the first shield body 2 and can form a first cutterhead configuration for tunneling the first-diameter tunnel T1 and a second cutterhead configuration for tunneling the second-diameter tunnel T2.

[0128] The diameter of the first-diameter tunnel T1 is smaller than the diameter of the second-diameter tunnel T2. The support shoe mechanism is arranged on the first shield body 2 and is used to support the first shield body 2 when the variable-diameter cutterhead assembly 1 is in the second cutterhead configuration for tunnel expansion construction.

[0129] The first shield body 2 can comprise a first front shield 21, a first middle shield 22, and a first tail shield 23 connected in sequence, and the support shoe mechanism comprises a front shield support shoe mechanism 51 arranged on the first front shield 21 and used to support the first front shield 21 when the variable-diameter cutterhead assembly 1 is in the second cutterhead configuration for tunnel expansion construction.

[0130] The front shield support shoe mechanism 51 can comprise a first fixed seat fixedly connected to the first front shield 21, a first telescopic member slidably connected to the first fixed seat, and a first arc-shaped support shoe hingedly connected to the lower end of the first telescopic member and used to slidably abut against the lower side surface of the second-diameter tunnel T2 when the first telescopic member extends relative to the first fixed seat.

[0131] Alternatively, the front shield support shoe mechanism 51 can comprise two groups of first fixed seats, two groups of first telescopic members, two groups of first arc-shaped support shoes, and a first support crossbeam. The two groups of first fixed seats are respectively located on the left and right sides of the axis of the first front shield 21. The two groups of first telescopic members are respectively slidably connected to the two groups of first fixed seats. The two groups of first arc-shaped support shoes are respectively hingedly connected to the lower ends of the two groups of first telescopic members. The two ends of the first support crossbeam are respectively detachably connected to the two groups of first arc-shaped support shoes.

[0132] Further, the support shoe mechanism can further comprise a middle shield support shoe mechanism 52 arranged on the first middle shield 22 and used to support the first middle shield 22 when the variable-diameter cutterhead assembly 1 is in the second cutterhead configuration for tunnel expansion.

[0133] The middle shield supporting shoe mechanism 52 can include a second fixed seat fixedly connected with the first middle shield 22, a second telescopic member slidably connected with the second fixed seat, and a second arc-shaped supporting shoe hingedly connected with the lower end of the second telescopic member, and used for being slidably abutted against the lower side surface of the second diameter tunnel T2 when the second telescopic member extends relative to the second fixed seat.

[0134] Optionally, the middle shield supporting shoe mechanism 52 can include two groups of the second fixed seat, two groups of the second telescopic member, two groups of the second arc-shaped supporting shoe and a second supporting cross beam. The two groups of the second fixed seat are respectively located on the left and right sides of the axis of the second middle shield. The two groups of the second telescopic member are respectively slidably connected with the two groups of the second fixed seat. The two groups of the second arc-shaped supporting shoe are respectively hingedly connected with the lower ends of the two groups of the second telescopic member. The two ends of the second supporting cross beam are respectively detachably connected with the two groups of the second arc-shaped supporting shoe.

[0135] The tunneling equipment can further include a second shield body 4 for supporting the second diameter tunnel T2, wherein the second shield body 4 can be sleeved on the outer periphery of the first shield body 2 or separated from the first shield body 2. Optionally, the second shield body 4 is formed by splicing a plurality of shield body blocks.

[0136] The tunneling equipment can further include a segment assembling machine 33 arranged inside the first shield body 2, used for assembling segments 82 in the first diameter tunnel T1 or the second diameter tunnel T2, and assembling the plurality of shield body blocks.

[0137] Further, the second shield body 4 can include a front shield whole ring structure 41, a middle shield whole ring structure 42 and a tail shield whole ring structure 43 connected in sequence. The plurality of shield body blocks include a plurality of front shield blocks 411 for splicing the front shield whole ring structure 41, a plurality of middle shield blocks 421 for splicing the middle shield whole ring structure 42, and a plurality of tail shield blocks 431 for splicing the tail shield whole ring structure 43.

[0138] In the above embodiment, the variable diameter cutter head assembly 1 can include a cutter head body 10, a plurality of fixed beams 12 fixedly connected with or integrally formed with the cutter head body 10, a plurality of telescopic beams 11 slidably arranged on the cutter head body 10, a telescopic driving mechanism arranged between the cutter head body 10 and the telescopic beams 11, used for driving the telescopic beams 11 to extend or retract along the radial direction relative to the cutter head body 10, and a cutter installed on the plurality of fixed beams 12 and the plurality of telescopic beams 11.

[0139] The plurality of telescopic beams 11 can be retracted in the cutter disc body 10 when the variable-diameter cutter disc assembly 1 is in the first cutter disc form, and can be extended outward in the circumferential direction of the cutter disc body 10 when the variable-diameter cutter disc assembly 1 is in the second cutter disc form, wherein part of the cutters mounted on the telescopic beams 11 can be extended synchronously with the telescopic beams 11.

[0140] Optionally, the variable-diameter cutter disc assembly 1 can further comprise a cutter disc ring rib fixedly connected with the extended part of the plurality of telescopic beams 11 when the variable-diameter cutter disc assembly 1 is in the second cutter disc form. The variable-diameter cutter disc assembly 1 can further comprise a replaceable tearing cutter 13 arranged at the radially outer end of the plurality of telescopic beams 11.

[0141] Optionally, the variable-diameter cutter disc assembly 1 further comprises a cutter disc slag scraping plate 61 arranged on one side of the telescopic beams 11 adjacent to the first shield body 2 and fixedly connected with the telescopic beams 11, for realizing one-way or two-way rotational slag scraping with the rotation of the cutter disc body 10.

[0142] The tunneling equipment can further comprise a slag receiving plate 63 fixedly connected at the bottom of the front end of the first shield body 2, i.e. the bottom of the first front shield 21, for receiving the slag soil scraped out from the bottom of the muck pile by the cutter disc slag scraping plate 61, and a slag soil conveying mechanism screw conveyor 34 arranged in the first shield body 2, for conveying the slag soil in the slag receiving plate 63 outward. The tunneling equipment can further comprise a bottom slag blocking plate 62 arranged on the lower side of the bottom of the front end of the first shield body 2.

[0143] So far, the embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein according to the above description.

[0144] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration, and are not intended to limit the scope of the present disclosure. Those skilled in the art should understand that the above embodiments can be modified or some technical features can be replaced equivalently without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A method for constructing a variable-diameter tunnel, characterized in that, include: The tunnel boring machine is driven through a variable diameter cutterhead assembly in the shape of a first cutterhead and a first shield body to excavate a tunnel of a first diameter to the replacement position; The variable diameter cutterhead assembly is changed to the second cutterhead shape in place at the replacement position, and then enlarged. The tunnel boring machine is made to excavate a second diameter tunnel of a preset length through the variable diameter cutterhead assembly of the second cutterhead shape and the first shield body to form a shield body installation space, and the first shield body is supported by the support shoe mechanism set on the first shield body; Within the shield installation space, a second shield is installed on the outer periphery of the first shield. The tunnel boring machine continues to excavate a tunnel of a second diameter through the variable diameter cutterhead assembly of the second cutterhead shape and the second shield body; The step of installing a second shield on the outer periphery of the first shield within the shield installation space includes: assembling multiple shield blocks in the tunnel boring machine within the shield installation space so as to install a ring-shaped second shield on the outer periphery of the first shield. The step of assembling the multiple shield blocks using the segment assembly machine in the tunnel boring equipment includes: The tunnel boring machine is moved back a fifth preset length by passing the variable diameter cutterhead assembly of the second cutterhead shape and the first shield body; The segment assembly machine is used to assemble multiple front shields into a complete front shield ring structure. The tunnel boring equipment continues to retreat a sixth preset length through the variable diameter cutterhead assembly in the second cutterhead shape and the first shield body, and during the retreat process, the second part of the support shoe mechanism at the rear position on the first shield body is retracted. The segment assembly machine is used to assemble multiple central shield sections into a complete central shield ring structure. The tunnel boring equipment continues to retreat through the variable diameter cutterhead assembly in the second cutterhead shape and the first shield body, and during the retreat, the first part of the support shoe mechanism at the front position on the first shield body is retracted; The segment assembly machine is used to assemble multiple tail shields into a complete ring structure of tail shields in sections. The front shield ring structure, the middle shield ring structure, and the tail shield ring structure are connected in sequence and fixedly connected to the first shield body.

2. The variable-diameter tunnel construction method according to claim 1, characterized in that, The steps for forming the shield installation space include: After the tunnel boring machine has tunneled a second diameter tunnel of a first preset length through the variable diameter cutterhead assembly of the second cutterhead shape and the first shield body, an auxiliary muck removal mechanism is set between the variable diameter cutterhead assembly and the first shield body so that the muck received by the auxiliary muck removal mechanism can be transported outward by the muck conveying mechanism. The tunnel boring machine continues to excavate a second preset length through the variable diameter cutterhead assembly in the second cutterhead shape and the first shield body, and then the first shield body is slidably supported by the first part of the support shoe mechanism set at the front position on the first shield body. The tunnel boring machine continues to excavate a third preset length through the variable diameter cutterhead assembly in the form of the second cutterhead and the first shield body. Then, the first shield body is slidably supported by the second part of the support shoe mechanism located at the rear position on the first shield body together with the first part of the support shoe mechanism. The tunnel boring machine continues to excavate a fourth preset length through the variable diameter cutterhead assembly in the second cutterhead shape and the first shield body, forming the shield body installation space.

3. The variable-diameter tunnel construction method according to claim 2, characterized in that, The step of setting an auxiliary slag removal mechanism between the variable diameter cutterhead assembly and the first shield body includes: A scraper plate is fixedly connected to the telescopic beam of the variable diameter cutter head assembly; A slag-receiving plate is fixedly connected to the bottom front end of the first shield body; A bottom baffle plate is installed on the lower side of the front bottom of the first shield body.

4. The variable-diameter tunnel construction method according to claim 2, characterized in that, During the process of the tunnel boring machine continuing to excavate through the variable diameter cutterhead assembly of the second cutterhead shape and the first shield, the lower half-ring segments of the first diameter tunnel are laid by the segment assembler in the tunnel boring machine, and the tunnel is excavated by the reaction force provided by the lower half-ring segments.

5. The variable-diameter tunnel construction method according to claim 4, characterized in that, The process of laying the lower half-ring segment also includes setting at least one support seat on the underside of the lower half-ring segment to support it.

6. The variable-diameter tunnel construction method according to claim 5, characterized in that, The step of providing at least one support seat on the lower side of the lower half-ring segment to support the lower half-ring segment includes: Multiple sets of support seats are arranged at intervals according to the extension length of the lower half-ring segment in the tunneling direction, and each set of support seats includes multiple support seats arranged adjacent to each other in the circumferential direction.

7. The method for constructing variable-diameter tunnels according to any one of claims 1 to 6, characterized in that, Also includes: After the tunnel boring machine has advanced to the replacement position, the rear supporting mechanism of the tunnel boring machine is disconnected.

8. The variable-diameter tunnel construction method according to claim 7, characterized in that, Also includes: After installing the second shield on the outer periphery of the first shield, the propulsion cylinder is replaced and connected to the rear supporting mechanism.

9. The method for constructing a variable-diameter tunnel according to any one of claims 1 to 8, characterized in that, Also includes: Before the tunnel boring machine advances to the replacement position, the ground in the replacement area is reinforced by advance grouting through the horizontal and advanced grouting system of the tunnel boring machine.

10. A variable-diameter tunnel construction system, characterized in that, include: Changing area; The tunnel boring machine is used in the transshipment area to implement the variable diameter tunnel construction method according to any one of claims 1 to 9.

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