Variable-diameter tunneling machine and in-hole variable-diameter tunneling method

Abstract

The application provides a variable-diameter shield tunneling machine, which comprises a shield body, a main drive, a variable-diameter cutter head, a propulsion device, a segment assembling system and a mechanical excavation device; the shield body comprises a variable-diameter front shield, a shield body shell and a tail shield; the mechanical excavation device comprises an extension mechanism and an expansion mechanism; the extension mechanism is arranged on the segment assembling system and can translate and rotate with the segment assembling system; the expansion mechanism is arranged on the extension mechanism and can extend and retract along the radial direction under the driving of the extension mechanism to excavate the soil layer between the tail shield and the variable-diameter front shield and form an expansion space after the tail shield and the variable-diameter front shield are disconnected. Meanwhile, the application also provides a hole-in variable-diameter construction method of the variable-diameter shield tunneling machine. Compared with the prior art, the variable-diameter shield tunneling machine and the hole-in variable-diameter construction method thereof can realize variable diameter in a hole, can shorten a construction period, and make the variable-diameter operation process simple and convenient; the method is not only suitable for variable diameter of a shield tunneling machine, but also can adapt to variable diameter of a TBM.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction equipment, in particular to a variable-diameter shield tunneling machine and a tunnel-in variable-diameter construction method thereof. BACKGROUND

[0002] In the construction of a metro interval tunnel and a station structure, the interval tunnel is often constructed by a shield method, and the metro station is often constructed by an open excavation method. The open excavation construction of the station structure has a greater impact on the surrounding environment, and some areas are subject to existing ground structures or buildings and do not have open excavation conditions. The platform tunnel and the main line tunnel have different sizes, the main line tunnel is constructed by a small-diameter construction, and the station platform position is constructed by a large-diameter construction. In recent years, the platform tunnel has been expanded by a freezing method / consolidation method and other mining methods, but the mining method has a long construction period, low safety, and high cost.

[0003] The shield tunneling machine is a mechanical construction equipment commonly used in tunnel construction. In order to cooperate with the construction of different tunnels, the shield tunneling machine often needs to be changed in diameter. However, the existing technology is still limited to expanding the diameter of the shell outside the tunnel and shrinking the diameter of the shell inside the tunnel. This method can only change the diameter of the shield tunneling machine from large to small in the tunnel construction process, and it is still necessary to change the diameter outside the tunnel if the diameter of the shield tunneling machine is to be changed from small to large. This method has the problems of a long construction period and a complicated diameter changing operation process. Or a working well needs to be set at the diameter changing position, and then another specification of shield tunneling machine is used to re-excavate. However, this method still has the problems of a long construction period and a complicated diameter changing operation process. Moreover, some occasions do not have the condition to set a working well, and the diameter cannot be changed in the tunnel, which causes great inconvenience to the construction. SUMMARY

[0004] In order to cooperate with the construction of different tunnels, the shield tunneling machine needs to be changed in diameter according to the existing technology. However, the construction period of the diameter changing is long, and the diameter changing operation process is complicated. The present application provides a variable-diameter shield tunneling machine and a tunnel-in variable-diameter construction method thereof. The mechanical excavation device is provided, and the mechanical excavation device can excavate the space required for diameter changing in the tunnel. Therefore, the shield tunneling machine can change in diameter in the tunnel, that is, the diameter of the shield tunneling machine can be changed from large to small in the tunnel, and the diameter of the shield tunneling machine can also be changed from small to large in the tunnel. The construction period can be shortened. The diameter changing operation process is realized in the tunnel, the shield tunneling machine does not need to be pulled out of the tunnel, and a working well does not need to be additionally set. The diameter changing operation process is simple and convenient.

[0005] A variable-diameter shield tunneling machine includes a shield body, a main drive, a variable-diameter cutterhead, a propulsion device, a segment assembly system, and a mechanical excavation device.

[0006] The shield body includes a variable-diameter front shield and a tail shield, and the tail shield is connected to the tail end of the variable-diameter front shield.

[0007] The main drive is arranged inside the variable-diameter front shield;

[0008] The variable-diameter cutterhead is arranged on the main drive and located at the front end of the variable-diameter front shield;

[0009] The propulsion device is arranged inside the variable-diameter front shield to push the variable-diameter front shield to move;

[0010] The segment assembling system is arranged inside the variable-diameter front shield to assemble segments;

[0011] The mechanical excavation device comprises a telescopic mechanism and an expansion mechanism;

[0012] The telescopic mechanism is arranged on the segment assembling system and can translate and rotate with the segment assembling system;

[0013] The expansion mechanism is arranged on the telescopic mechanism and can expand and contract in the radial direction under the driving of the telescopic mechanism to excavate the soil layer between the tail shield and the variable-diameter front shield to form an expansion space after the tail shield and the variable-diameter front shield are disconnected;

[0014] The shield body further comprises a shield body shell, which is arranged on the outer periphery of the variable-diameter front shield to expand the diameter of the shield body when the variable-diameter shield machine expands.

[0015] Preferably, the mechanical excavation device further comprises a protection mechanism arranged on the telescopic mechanism and corresponding to the expansion mechanism to receive the soil cut off by the expansion mechanism.

[0016] Preferably, the anchor rod supporting device and the reinforcing device are further included.

[0017] The anchor rod supporting device is arranged on the segment assembling system and can translate and rotate with the segment assembling system to support the soil layer.

[0018] The reinforcing device is arranged on the segment assembling system and can translate and rotate with the segment assembling system to freeze or grout the soil layer.

[0019] Preferably, the temporary support assembling device is further included.

[0020] The temporary support assembling device is arranged on the segment assembling system and can translate and rotate with the segment assembling system to install a temporary support at the expansion space formed by the expansion mechanism.

[0021] Preferably, the shield body shell assembling device is further included.

[0022] The shield shell assembling device is arranged on the segment assembling system and can translate and rotate with the segment assembling system to install the shield shell on the temporary support.

[0023] A tunnel diameter-variable construction method of a variable-diameter shield machine, which can be applied to a construction method of a shield method or a TBM method, comprises the following steps:

[0024] S1, tunneling by using the variable-diameter shield machine according to any one of the above;

[0025] S2, diameter expansion preparation: disconnecting the tail shield from the variable-diameter front shield;

[0026] S3, continuing tunneling: continuing to advance the variable-diameter front shield forward by the advancing device to expose the peripheral soil layer in the region between the variable-diameter front shield and the tail shield;

[0027] S5, radial excavation: extending the excavation mechanism to excavate the peripheral soil layer in the region between the variable-diameter front shield and the tail shield to form an excavation space;

[0028] S8, excavation cycle: repeating steps S3 and S5 to extend the excavation space to a required length;

[0029] S10, assembling shield shell: pre-assembling a shield shell in the excavation space;

[0030] S11, shield machine retreat: retreating the variable-diameter front shield backward as a whole to the excavation space and connecting the variable-diameter front shield with the shield shell;

[0031] S12, cutterhead diameter expansion and force transmission ring installation: expanding the diameter of the variable-diameter cutterhead at the excavation space, installing a force transmission ring at the advancing device, and continuing tunneling.

[0032] Preferably, between the step S3 and the step S5, the method further comprises:

[0033] S4, anchoring soil: anchoring the peripheral soil layer between the variable-diameter front shield and the tail shield by anchor rods and reinforcing the peripheral soil layer by freezing or grouting.

[0034] Preferably, between the step S5 and the step S8, the method further comprises:

[0035] S6, soil layer reinforcement support: installing a temporary support on the soil layer wall in the excavation space;

[0036] S7, segment installation: installing a segment at the excavation space and connecting the segment with the temporary support;

[0037] The step S8, the extension cycle through the cycle S3 to S7, in order to extend the excavation space to the required length;

[0038] The step S10 also includes before:

[0039] S9, the pipe piece removal: all installed pipe pieces at the excavation space are removed.

[0040] Preferably, the step S12 also includes after:

[0041] S13, the cutter head, the shield body shrinkage: the cutter head unit installed outside the variable diameter cutter head is removed, and the variable diameter front shield is separated from the shield body cover, and the force transmission ring is removed from the propulsion device;

[0042] S14, the installation of the tail shield: the tail shield is installed at the tail end of the variable diameter front shield.

[0043] Preferably, the step S14 also includes after:

[0044] S15, the pipe piece connection: the small diameter pipe piece is connected with the large diameter pipe piece through the conversion rib.

[0045] Compared with existing technologies, the variable-diameter tunnel boring machine provided by this invention includes a shield body, a main drive, a variable-diameter cutterhead, a propulsion device, a segment assembly system, and a mechanical excavation device. The shield body includes a variable-diameter front shield and a tail shield, with the tail shield connected to the tail end of the variable-diameter front shield. The main drive is located inside the variable-diameter front shield. The variable-diameter cutterhead is mounted on the main drive and located at the front end of the variable-diameter front shield. The propulsion device is located inside the variable-diameter front shield to move it. The segment assembly system is located inside the variable-diameter front shield to assemble tunnel segments. The mechanical excavation device includes a telescopic mechanism and a widening mechanism. The telescopic mechanism is mounted on the segment assembly system and can move and rotate with the segment assembly system. The widening mechanism is mounted on the telescopic mechanism and can extend and retract radially under the drive of the telescopic mechanism. After the tail shield is disconnected from the variable diameter front shield, it excavates the soil layer between the tail shield and the variable diameter front shield to form a widening space. The shield body also includes a shield body shell, which is installed on the outer periphery of the variable diameter front shield when the variable diameter shield machine expands its diameter to increase the diameter of the shield body. The variable diameter shield machine is equipped with the mechanical excavation device, which can move and rotate with the segment assembly system. Therefore, when the variable diameter shield machine needs to change its diameter, the mechanical excavation device can radially excavate the soil layer in the tunnel to form the widening space, thereby allowing the diameter of the variable diameter shield machine to be increased from small to large within the widening space. The diameter of the variable-diameter tunnel boring machine can be changed inside the tunnel without having to drag it out of the tunnel or set up an additional working shaft. This can shorten the construction cycle and make the diameter-changing operation simpler and more convenient. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 A structural schematic diagram of a variable-diameter tunnel boring machine in one state, as provided in one embodiment;

[0048] Figure 2 for Figure 1 The diagram shows a structural schematic of a variable-diameter tunnel boring machine in another state.

[0049] Figure 3 for Figure 1 A schematic diagram of the shield body in the variable diameter tunnel boring machine;

[0050] Figure 4 Figure 9 is a structural schematic diagram of a variable-diameter cutterhead in a variable-diameter tunneling machine according to an embodiment of the present application; Figure 1 Figure 10 is a structural schematic diagram of a variable-diameter cutterhead variable-diameter process in the variable-diameter tunneling machine shown in Figure 9;

[0051] Figure 5 Figure 11 is a partial structural schematic diagram of a mechanical excavation device in the variable-diameter tunneling machine shown in Figure 9; Figure 1 Figure 12 is a partial structural schematic diagram of a mechanical excavation device in the variable-diameter tunneling machine shown in Figure 9;

[0052] Figure 6 Figure 13 is a structural schematic diagram of a protection mechanism in the variable-diameter tunneling machine shown in Figure 9; Figure 5 Figure 14 is a structural schematic diagram of a protection mechanism in the variable-diameter tunneling machine shown in Figure 9;

[0053] Figure 7 Figure 15 is a structural schematic diagram of a segment assembly system and an anchor rod support device in the variable-diameter tunneling machine shown in Figure 9; Figure 1 Figure 16 is a structural schematic diagram of a segment assembly system and an anchor rod support device in the variable-diameter tunneling machine shown in Figure 9;

[0054] Figure 8 Figure 17 is a structural schematic diagram when preparing for expansion;

[0055] Figure 9 Figure 18 is a structural schematic diagram of a tail shield provided by an embodiment;

[0056] Figure 10 Figure 19 is a structural schematic diagram when anchoring soil;

[0057] Figure 11 Figure 20 is a structural schematic diagram when expanding radially;

[0058] Figure 12 Figure 21 is a structural schematic diagram when reinforcing soil;

[0059] Figure 13 Figure 22 is a structural schematic diagram when expanding in a cycle;

[0060] Figure 14 Figure 23 is a structural schematic diagram when assembling a shield shell;

[0061] Figure 15 Figure 24 is a structural schematic diagram when the tunneling machine is retracting;

[0062] Figure 16 Figure 25 is a structural schematic diagram when the cutterhead is expanding;

[0063] Figure 17 Figure 26 is a structural schematic diagram when the force transmission ring is installed;

[0064] Figure 18 Figure 27 is a structural schematic diagram when the cutterhead and the shield are contracting;

[0065] Figure 19 Figure 28 is a structural schematic diagram when the segments are connected;

[0066] Figure 20 Figure 29 is a structural schematic diagram after the contraction modification. DETAILED DESCRIPTION

[0067] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0068] It should be noted that when a component is referred to as being "fixed", "attached" or "disposed" on another component, it can be directly on the other component or indirectly on the other component; when a component is "connected" with another component, or a component is referred to as being "connected" to another component, it can be directly connected to the other component or indirectly connected to the other component.

[0069] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0070] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of", "several" is two or more, unless otherwise explicitly specified.

[0071] It should be understood that the structures, proportions, sizes and the like shown in the drawings of the present application are only used to cooperate with the content disclosed in the specification, to enable those skilled in the art to understand and read, and do not have technical substantive significance, and any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effect and purpose that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application.

[0072] The application provides a variable-diameter shield tunneling machine, which comprises a shield body, a main drive, a variable-diameter cutter head, a propelling device, a segment assembling system and a mechanical excavation device. The shield body comprises a variable-diameter front shield and a tail shield, the tail shield is connected to the tail end of the variable-diameter front shield, the main drive is arranged inside the front shield, the variable-diameter cutter head is arranged on the main drive and located at the front end of the variable-diameter front shield, the propelling device is arranged inside the variable-diameter front shield to push the variable-diameter front shield to move, the segment assembling system is arranged inside the variable-diameter front shield to assemble segments, the mechanical excavation device comprises a telescopic mechanism and an expansion mechanism, the telescopic mechanism is arranged on the segment assembling system and can translate and rotate with the segment assembling system, the expansion mechanism is arranged on the telescopic mechanism and can expand and contract in the radial direction under the drive of the telescopic mechanism to excavate soil layers between the tail shield and the variable-diameter front shield and form an expansion space after the tail shield is disconnected from the variable-diameter front shield, and the shield body further comprises a shield body shell, which is arranged on the outer periphery of the variable-diameter front shield to expand the diameter of the shield body when the variable-diameter shield tunneling machine is expanded. The mechanical excavation device is arranged in the variable-diameter shield tunneling machine and can translate and rotate with the segment assembling system, so that the mechanical excavation device can excavate soil layers in the hole in the radial direction to form the expansion space when the variable-diameter shield tunneling machine needs to be expanded, and the diameter of the variable-diameter shield tunneling machine can be expanded in the expansion space. The diameter of the variable-diameter shield tunneling machine can be expanded in the hole, the variable-diameter shield tunneling machine does not need to be pulled out of the hole, and no additional working well is needed, so that the construction period can be shortened and the expansion operation process can be simple and convenient.

[0073] Please refer to Figures 1 to 7 The embodiment provides a variable-diameter shield tunneling machine 100, which can freely convert the diameter of a tunnel formed in a tunnel construction process in situ in the hole, the conversion process is reversible and can be performed multiple times, one machine can be used for multiple purposes, the time consumed in the conversion process outside the hole is reduced, unnecessary construction wells are reduced, and the value of the equipment is maximized.

[0074] The variable-diameter shield tunneling machine 100 comprises a shield body 10, a main drive 20, a variable-diameter cutter head 30, a propelling device 40, a segment assembling system 50 and a mechanical excavation device 60. The shield body 10 comprises a variable-diameter front shield 11 and a tail shield 12, and the tail shield 12 is connected to the tail end of the variable-diameter front shield 11. The shield body 10 is mainly used to support the stability of the surrounding stratum and provide mounting interfaces for various internal devices such as the main drive, hydraulic devices and electrical components.

[0075] It should be noted that the shield body 10 can be composed of "front shield + middle shield + tail shield", or can be composed of "front shield + tail shield". Since the conversion process of the front shield and the middle shield is similar, the variable-diameter front shield 11 is used instead in this embodiment.

[0076] The variable-diameter front shield 11 in this embodiment refers to that corresponding shield body components can be installed on the outer periphery of the variable-diameter front shield 11, so as to change the overall diameter of the front shield.

[0077] The shield body 10 further comprises a shield shell 13, which is used to be installed on the outer periphery of the variable-diameter front shield 11 when the variable-diameter shield tunneling machine 100 is expanded in diameter, so as to expand the diameter of the shield body 10.

[0078] Specifically, in this embodiment, when the variable-diameter shield tunneling machine 100 is excavated in the small-diameter mode, the front shield can only be provided with the variable-diameter front shield 11. When the variable-diameter shield tunneling machine 100 is excavated in the large-diameter mode, the front shield can be composed of the variable-diameter front shield 11 and the shield shell 13, and the shield shell 13 is correspondingly fixed on the outer periphery of the variable-diameter front shield 11, so as to cooperate with the large-diameter mode of the variable-diameter shield tunneling machine 100.

[0079] Correspondingly, in order to cooperate with the two different diameters of the front shield, the tail shield can also have two different sizes. Specifically, in this embodiment, for the convenience of description, the small-diameter tail shield is the tail shield 12, and the large-diameter tail shield is the large shield tail shield 14. That is to say, the shield body of the variable-diameter shield tunneling machine 100 is a double-layer structure, so as to adapt to different excavation diameters. Preferably, in order to prevent external mud, slurry, water and the like from entering the inside of the shield tunneling machine, the tail end of the tail shield 12 and the large shield tail shield 14 can be provided with a shield tail brush 15, so as to form a seal with the segment. Of course, in other embodiments, the shield tail brush 15 can also be replaced by a steel plate bundle, so as to form a seal with the segment.

[0080] The main drive 20 is arranged inside the variable-diameter front shield 11, and the variable-diameter cutterhead 30 is arranged on the main drive 20 and located at the front end of the variable-diameter front shield 11. The main drive 20 is a power source for driving the variable-diameter cutterhead 30 to rotate, and can adopt different driving forms such as electric drive and hydraulic drive. The variable-diameter cutterhead 30 plays a role of rotating and excavating the working face of rock and soil.

[0081] It should be noted that, in this embodiment, the variable diameter cutterhead 30 refers to the additional cutterhead units that can be spliced ​​onto the outer periphery of the variable diameter cutterhead 30, thereby changing the overall diameter of the cutterhead. Specifically, in this embodiment, when the variable diameter tunnel boring machine 100 is tunneling in small-diameter mode, the cutterhead may only consist of the variable diameter cutterhead 30. However, when the variable diameter tunnel boring machine 100 is tunneling in large-diameter mode, the cutterhead may be composed of the variable diameter cutterhead 30 and cutterhead units 31 spliced ​​onto the outer periphery of the variable diameter cutterhead 30, thus accommodating the large-diameter mode of the variable diameter tunnel boring machine 100.

[0082] Of course, in other embodiments, the different diameters of the cutterhead can also be achieved by replacing the outermost cutterhead units of the variable diameter tunnel boring machine 100 with different lengths, thereby changing the cutterhead diameter. In this embodiment, the cutterhead units are directly spliced ​​onto the outer periphery of the variable diameter cutterhead 30, further reducing the difficulty of installation and disassembly.

[0083] The propulsion device 40 is disposed inside the variable-diameter front shield 11 to move the variable-diameter front shield 11. The segment assembly system 50 is disposed inside the variable-diameter front shield to assemble the segment 200. The propulsion device 40 consists of several hydraulic cylinders, which provide forward propulsion to the main machine by pressing against the segment. The segment assembly system 50 is the same as a conventional shield tunnel segment assembly machine, used for assembling the segment 200, and has the translation and rotation functions of a conventional shield tunnel segment assembly machine.

[0084] The mechanical excavation device 60 includes a telescopic mechanism 61 and a widening mechanism 62. The telescopic mechanism 61 is mounted on the segment assembly system 50 and can move and rotate with the segment assembly system 50. The widening mechanism 62 is mounted on the telescopic mechanism 61 and can extend and retract radially under the drive of the telescopic mechanism 61, so as to excavate the soil layer between the tail shield 12 and the variable diameter front shield 11 to form a widening excavation space after the tail shield 12 is disconnected from the variable diameter front shield 11.

[0085] When the variable-diameter tunnel boring machine 100 needs to expand its diameter, the tail shield 12 can be disconnected from the variable-diameter front shield 11. As the variable-diameter front shield 11 continues to advance, the soil layer between the tail end 12 and the variable-diameter front shield 11 is exposed. This allows the expansion mechanism 61 to move the digging mechanism 62, bringing it into contact with the exposed soil layer. The digging mechanism 62 then expands the soil layer radially. Simultaneously, since the telescopic mechanism 61 is mounted on the segment assembly system 50, the digging mechanism 62 can simultaneously rotate and translate, ultimately creating a ring-shaped expansion space.

[0086] In other words, the mechanical excavation device 60 is used to excavate the soil layer radially to create an enlarged excavation space. This enlarged excavation space provides corresponding installation space for the variable diameter cutterhead 30 and the variable diameter front shield 11, allowing the variable diameter tunnel boring machine 100 to change its diameter inside the tunnel.

[0087] The specific structure of the excavation mechanism 62 for excavating the soil layer can be a roller cone drill, a cutting head, a bucket, or other mechanisms, which can be selected according to the actual soil layer conditions.

[0088] Understandably, current tunnel boring machines (TBMs) can only reduce their diameter during tunnel construction. Increasing the diameter requires operating outside the tunnel, resulting in long construction periods and cumbersome diameter-changing procedures. Alternatively, a working shaft can be installed at the diameter-changing point, followed by a different TBM of a different size. However, this method also suffers from long construction periods and cumbersome procedures. Furthermore, some situations lack the conditions for setting up a working shaft, making diameter-changing within the tunnel impossible and causing significant inconvenience. Therefore, a new method for diameter-changing in tunnels using tunnel boring machines is needed, enabling the simultaneous construction of mainline tunnels and station tunnels. This method requires the ability to perform large-scale diameter changes on-site, both increasing and decreasing in size. This remains a problem that urgently needs to be solved by those skilled in the art.

[0089] The variable diameter tunnel boring machine 100 provided in this embodiment is equipped with a mechanical excavation device 60, which is installed in the segment assembly system 50. Driven by the translation and rotation of the segment assembly system 50, the mechanical excavation device 60 can radially expand the excavation space inside the tunnel, thereby enabling the variable diameter tunnel boring machine 100 to change its diameter from small to large inside the tunnel without having to drag the variable diameter tunnel boring machine 100 out of the tunnel or set up an additional working shaft. This shortens the construction cycle and makes the diameter-changing operation simpler and more convenient.

[0090] The telescopic mechanism 61 can be driven by different methods, such as electric drive or hydraulic drive, like electric cylinders or hydraulic cylinders.

[0091] Preferably, the mechanical excavation device 60 further includes a protective mechanism 63, which is mounted on the telescopic mechanism 61 and corresponds to the widening excavation mechanism 62 to receive the soil excavated by the widening excavation mechanism 62. Thus, the protective mechanism 63 prevents the excavated soil from falling and damaging the machine and protects the safety of construction personnel. Specifically, the protective mechanism 63 has a guide groove on the side near the widening excavation mechanism 62, which better receives and guides the soil excavated by the widening excavation mechanism 62. Of course, in other embodiments, the shape and structure of the protective mechanism 63 can also adopt any other shape and structure, as long as it can correspondingly receive the soil excavated by the cutting structure 62. The soil excavated by the widening excavation mechanism 62 can be transported to the outside of the tunnel by manual cleaning or other arbitrary methods.

[0092] Preferably, the variable-diameter tunnel boring machine 100 further includes an anchor bolt support device 70, which is mounted on the segment assembly system 50 and can move and rotate with the segment assembly system 50 to support the soil layer. Thus, before the mechanical excavation device 60 excavates, the anchor bolt support device 70 can perform a series of functions such as pre-anchoring the soil layer to support and reinforce the surrounding exposed soil layer. Specifically, the anchor bolt support device 70 is used to perform functions such as driving anchor bolts and drilling in radial and oblique directions. Both the mechanical excavation device 60 and the anchor bolt support device 70 can adopt a modular design for easy assembly and disassembly of components. Furthermore, the mechanical excavation device 60, the anchor bolt support device 70, and the segment assembly system 50 can all be detachably connected to facilitate the assembly and disassembly of the mechanical excavation device 60 and the anchor bolt support device 70.

[0093] Preferably, the variable-diameter tunnel boring machine 100 further includes a reinforcement device, which is mounted on the segment assembly system 50 and can move and rotate with the segment assembly system 50 to reinforce the soil layer through freezing or grouting. It is understood that when the soil condition is poor, the reinforcement device can reinforce the soil layer through freezing or grouting, thus better ensuring the stability of the soil layer. In one embodiment, the reinforcement device can also be integrated into the anchor bolt support device 70.

[0094] Preferably, the variable-diameter shield machine 100 further includes a temporary support assembly device. This device is mounted on the segment assembly system 50 and can move and rotate with the segment assembly system 50 to install temporary support 300 at the location where the excavation space is formed by the widening mechanism 62. This allows the temporary support 300 to be installed at the widened space, further enhancing soil stability and preventing risks such as collapse in subsequent processes. Furthermore, installing the temporary support 300 using the temporary support assembly device also improves installation efficiency. In this embodiment, the temporary support 300 is specifically a steel arch support. Of course, in other embodiments, anchor mesh, shotcrete, or other forms of support can also be used. Different reinforcement supports can be selected based on the degree of soil stability. In some embodiments, the temporary support 300 can even be installed by the segment assembly system 50.

[0095] Preferably, the variable-diameter tunnel boring machine 100 further includes a shield shell assembly device. This device is mounted on the segment assembly system 50 and can translate and rotate with the segment assembly system 50 to install the shield shell 13 on the temporary support 300. This installation of the shield shell 13 via the shield shell assembly device further improves installation efficiency and saves construction time.

[0096] Preferably, the variable diameter tunnel boring machine 100 further includes a force transmission ring 91, which is installed at the tail end of the variable diameter front shield 11. The main function of the force transmission ring 91 is to solve the problem of misalignment between the propulsion device 40 and the large shield segment when the variable diameter tunnel boring machine 100 changes from a small diameter to a large diameter, thus preventing the transmission of thrust. The force transmission ring 91 is assembled from segments, specifically consisting of steel structural components, wedge-shaped segment assembly cylinders, and buffer pads. The wedge-shaped segment assembly cylinders are concealed inside the force transmission ring and can extend to assist in the installation of the wedge-shaped segments. The buffer pads are installed at the tail end of the force transmission ring to buffer the stress of the segments, and can be made of nylon / polyurethane / rubber.

[0097] Meanwhile, this embodiment also provides a method for in-tunnel diameter change construction of a variable-diameter shield machine, which is applicable to shield tunneling or TBM construction methods. The construction method includes the following steps:

[0098] S1. The variable diameter tunnel boring machine 100 is used for tunneling.

[0099] In normal construction mode, the variable diameter tunnel boring machine 100 excavates the soil through the variable diameter cutterhead 30, the shield body 10 supports the surrounding soil, the segment assembly system 50 assembles the segments 200, and the propulsion device 40 pushes against the segments 200 to generate forward power for the entire equipment.

[0100] Please refer to the following: Figure 8 S2. Diameter expansion preparation: Disconnect the tail shield 12 from the variable diameter front shield 11.

[0101] During the tunnel expansion and conversion preparation stage, the last ring of the tunnel segment 200 is first assembled by the segment assembly system 50. After the assembly is completed, the tail shield 12 is disconnected from the variable diameter front shield 11, and the disconnection position is such that the mechanical excavation device 60 can drill and expand the tunnel.

[0102] Please refer to the following: Figure 9 The connection structure between the tail shield 12 and the variable-diameter front shield 11 can take various forms. It can be a mechanical bolted connection, requiring only the removal of the connecting bolts for disassembly; it can also be a welded integral connection, requiring cutting during disassembly; or other common mechanical connection methods can be used. For ease of disassembly, in this embodiment, the tail shield 12 is in a modular form, which facilitates assembly and transportation.

[0103] It is understood that the last segment 200 can be made of conventional reinforced concrete, steel, or other materials. In this embodiment, preferably, the last segment 200 is a steel segment, which facilitates its connection with the remaining structures.

[0104] S3. Continue tunneling: The variable diameter front shield 11 is continued to be tunneled forward by the propulsion device 40 so that the outer soil layer in the area between the variable diameter front shield 11 and the tail shield 12 is exposed.

[0105] That is, the variable diameter shield machine 100 continues to excavate forward, the propulsion device 40 pushes against the tunnel segment 200 to advance the variable diameter shield machine 100 forward by one stroke, while the tail shield 12 remains in place. After one stroke of excavation, the outer soil layer in the area between the variable diameter front shield 11 and the tail shield 12 is exposed, ensuring the implementation of subsequent steps.

[0106] Preferably, after step S3, the method further includes:

[0107] Please refer to the following: Figure 10 S4. Anchoring the soil: Anchor bolts are used to support the outer soil layer in the area between the variable diameter front shield 11 and the tail shield 12, and the outer soil layer is reinforced by freezing or grouting.

[0108] Specifically, in this embodiment, the surrounding soil is supported and reinforced by radial and oblique anchor bolts 500 driven by the anchor bolt support device 70 and the reinforcement device, and by grouting.

[0109] It should be noted that during the installation of the anchor bolts 500, the anchor bolts 500 are drilled into the deep soil layer, while they are not present in the shallow soil layer; otherwise, it would affect the subsequent radial excavation. This step ensures better support for the subsequent radial excavation and better prevents soil collapse.

[0110] It is understandable that anchoring and freezing or grouting reinforcement of the soil layer are only necessary when the soil condition is poor. When the soil condition is stable, freezing or grouting reinforcement can be omitted, or the anchoring step can be skipped entirely.

[0111] Please refer to the following: Figure 11 S5. Radial Excavation: The excavation mechanism 62 extends to excavate the outer soil layer of the area between the variable diameter front shield 11 and the tail shield 12 to form an excavation space 400.

[0112] Specifically, the excavation expansion mechanism 62 extends radially under the drive of the telescopic mechanism 61, thereby expanding the outer soil layer in the area between the variable diameter front shield 11 and the tail shield 12. At the same time, the mechanical excavation device 60 rotates circumferentially with the segment assembly system 50, excavating the shallow soil layer by layer, and finally forming the expanded excavation space 400.

[0113] Preferably, after step S5, the method further includes:

[0114] Please refer to the following: Figure 12 and Figure 13 S6. Soil reinforcement support: Install the temporary support 300 on the soil wall in the excavated space 400.

[0115] Specifically, the temporary support 300 is installed using the temporary support assembly device or the segment assembly system 50, thereby preventing risks such as collapse in subsequent processes. Specifically, in this embodiment, the temporary support 300 is a steel arch support.

[0116] Preferably, after step S6, the method further includes:

[0117] S7. Segment installation: Install segment 200 at the excavated space 400 and connect segment 200 to the temporary support 300.

[0118] Specifically, a new ring of the tunnel segment 200 is installed, and a reinforcing rib 600 is used to fix the temporary support 300 and the tunnel segment 200 to improve the overall structural strength and rigidity and prevent the tunnel segment 200 from failing to provide sufficient propulsion reaction force during the tunneling process.

[0119] S8. Expanding the excavation cycle: Repeat steps S3 and S5 to extend the expanded excavation space 400 to the required length.

[0120] After the excavation expansion mechanism 62 excavates to form an expanded excavation space 400 of a certain length, the variable-diameter shield machine 100 continues to excavate forward, increasing the distance between the variable-diameter front shield 11 and the tail shield 12, exposing more of the surrounding soil layers. At the same time, the excavation expansion mechanism 62 continues to excavate more of the surrounding soil layers to extend the length of the expanded excavation space 400.

[0121] Preferably, in step S8, the excavation cycle involves repeating steps S3 to S7 to extend the excavated space 400 to the required length. That is, in this embodiment, the process involves a progressive cycle of forward advancement—soil anchoring—radial excavation—soil reinforcement support—segment installation—forward advancement until the length of the excavated space 400 is sufficient for subsequent work. This method better prevents collapse during the extension of the excavated space 400.

[0122] It should be noted that the axial length of the enlarged excavation space 400 should be greater than the total length of the 13 + the tail shield 14 + the variable diameter cutterhead 30, so as to provide operating space for the subsequent enlargement of the variable diameter cutterhead 30.

[0123] Preferably, after step S8, the method further includes:

[0124] S9. Segment Removal: Remove all installed segments 200 at the excavated space 400.

[0125] Specifically, the variable diameter tunnel boring machine 100 is stopped from tunneling, and all the tunnel segments 200 and reinforcing ribs 600 in the expanded excavation space 200 are removed.

[0126] Please refer to the following: Figure 14 S10. Assemble the shield casing: Pre-install the shield casing 13 within the enlarged excavation space 400.

[0127] Preferably, when the shield shell 13 is installed in step S10, the large shield tail shield 14 with the tail brush 15 is installed simultaneously after the shield shell 13.

[0128] Specifically, in step S10, pre-installing the shield housing 13 within the excavated space 400 means temporarily fixing the shield housing 13 to the temporary support 300 to prevent the shield housing 13 from shifting in subsequent steps. The method of temporary fixing is not limited; for example, a detachable pin may be used.

[0129] It is understood that the pre-installed shield housing 13 should have a certain gap with the left end of the enlarged excavation space 400 so that it can be used to enlarge the diameter of the variable diameter cutterhead 30.

[0130] Please refer to the following: Figure 15 S11. Tunnel Boring Machine Retraction: The variable diameter front shield 11 is moved backward to the enlarged excavation space 400, and the variable diameter front shield 11 is connected to the shield shell 13.

[0131] The variable-diameter front shield 11 and other components retract as a whole, which can be achieved using any method such as a winch or a tunnel crawler. Once the variable-diameter front shield 11 and the shield shell 13 are aligned, they are connected. The connection can be achieved using any method such as a pin, partial welding, or a transition bolt ring. At this point, the shield body 10 has completed its diameter expansion, and the temporary fixing between the shield shell 13 and the temporary support 300 is removed.

[0132] Please refer to the following: Figure 16 and Figure 17 S12. Cutterhead diameter expansion and force transmission ring installation: The variable diameter cutterhead 30 is expanded at the expanded excavation space 400, and a force transmission ring 91 is installed at the propulsion device 40 to continue tunneling.

[0133] Specifically, by adding an outer ring cutter head unit 31 to the variable diameter cutter head 30, the diameter of the variable diameter cutter head 30 can be expanded. Simultaneously, the propulsion device 40 is connected to the force transmission ring 91.

[0134] It should be noted that cutterhead diameter expansion can be achieved in various ways, such as: expanding the diameter by extending the over-digging cutter outward; using a segmented cutterhead structure; or other arbitrary cutterhead diameter expansion structures.

[0135] The force transmission ring 91 can adopt two structural forms: one is a block design, with guide grooves between the blocks, each block can move independently with the propulsion device, and the force of the propulsion device 40 is applied to the large-diameter tube segment 200; the other is an integral structure, in which the propulsion device 40 will no longer actively generate action, but will provide thrust through the relay cylinder 900.

[0136] Preferably, the force transmission ring 91 is installed in sections, which facilitates transportation and assembly.

[0137] Understandably, after the variable-diameter tunnel boring machine 100 is enlarged, it needs to use tunnel segments 200 with a larger diameter for installation. Preferably, transition ribs 700 can be used to transition and reinforce the large / small diameter tunnel segments 200, while grouting is injected on the outer side of the last few rings of small-diameter tunnel segments 200 to form a reinforced zone 800, providing a good load-bearing foundation for the large-diameter tunnel segments 200. At this time, a seal is formed between the tail shield brush 14 and the large-diameter tunnel segments 200, preventing surrounding mud, water, and sand from entering the equipment. Thus, the variable-diameter tunnel boring machine 100 completes the conversion process of the cutterhead, shield body, and tunnel segments, and the entire diameter expansion conversion is completed. After the diameter is expanded, the variable diameter tunnel boring machine 100 can select two propulsion modes: the first mode is that the hydraulic cylinder of the propulsion device 40 extends and abuts against the force transmission ring 91, the force transmission ring 91 moves synchronously with it and transmits the thrust to the tunnel segment 200, thereby propelling the equipment forward; the second mode is that the propulsion device 40 and the force transmission ring 91 are both stationary relative to the shield body 10, and the relay hydraulic cylinder 900 directly abuts against the tunnel segment 200 to propel the equipment forward.

[0138] Understandably, in strata with poor stability, freezing reinforcement or pre-grouting reinforcement can be used to improve strata stability and ensure personnel safety during open-diameter construction.

[0139] To enable the variable-diameter tunnel boring machine 100 to reduce its diameter inside the tunnel, preferably, step S12 may be followed by the following:

[0140] Please refer to the following: Figure 18 S13. Cutterhead and shield body diameter reduction: Remove the cutterhead unit installed on the outer ring of the variable diameter cutterhead, separate the variable diameter front shield 11 from the shield body shell 13, and remove the force transmission ring 91 from the propulsion device 40.

[0141] Specifically, by adopting a direct in-situ separation method for the outer ring of the cutter head without replacing the cutter head unit structure, the variable diameter cutter head 30 can directly reduce its diameter at the current position, and the variable diameter cutter head 30 can directly detach from the middle of the outer ring of the large cutter head.

[0142] The direct in-situ removal of the shield shell 13 and the variable diameter front shield 11 is the reverse process of connecting the variable diameter front shield 11 to the shield shell 13 in step S11. The tail shield 14 of the large shield tunnel is directly disconnected, using the same removal method as in step S2, such as cutting or dismantling.

[0143] After all the components have been removed, the force transmission ring 91 and other structures are completely disassembled and transported away.

[0144] Preferably, before step S13, the last few rings of the assembled tube segments 200 should be made of steel tube segments to facilitate connection with subsequent devices.

[0145] Please refer to the following: Figure 19 and Figure 20 S14. Install the tail shield: Install the tail shield 12 onto the tail end of the variable diameter front shield 11.

[0146] Preferably, after step S14, the method further includes:

[0147] S15. Segment connection: Connect small-diameter segments to large-diameter segments using transition ribs.

[0148] After the tail shield 12 is installed, the segment assembly system 50 continues to assemble several rings of small-diameter segments 200. The large and small diameter segments 200 are connected to each other using transition ribs 700, improving the structural stability of the newly installed segments 200 and providing stable support reaction force for the variable-diameter tunnel boring machine 100 to continue tunneling. At this point, the in-situ diameter reduction modification of the variable-diameter tunnel boring machine 100 within the tunnel is completed.

[0149] After the diameter reduction modification, the variable diameter shield machine 100 continues to excavate forward, excavating the soil through the variable diameter cutterhead 30, the shield body 10 supports the surrounding soil, the segment assembly system 50 assembles the segment 200, and the propulsion device 40 pushes against the segment 200 to generate forward power for the entire equipment.

[0150] In this process, immediately after the diameter reduction is completed, grouting is used to fill the gap between the large shield tail shield 14 and the small-diameter segment 200 during tunneling, forming a reinforced zone, thereby improving the stability of the newly installed segment 200 and ensuring normal tunneling.

[0151] It should be noted that the variable diameter tunnel boring machine 100 is not limited to changing from small to large and then from large to small; it can also change from large to small and then from small to large, both of which are possible.

[0152] The variable-diameter tunnel boring machine 100 and its in-tunnel diameter-changing construction method provided in this embodiment enable in-situ free conversion of the tunnel diameter during tunnel construction. This conversion process is reversible and can be performed multiple times, achieving multi-purpose functionality, reducing the time spent on external conversion, minimizing unnecessary tunnel boring machine shaft construction, and maximizing equipment value. It achieves in-situ diameter expansion and contraction within the tunnel, with the expansion range freely adjustable according to the cutterhead and shield casing, providing a wide adaptability range and allowing for continuous multiple diameter-changing operations. Furthermore, the conversion can be completed without the need for a working shaft, saving costs.

[0153] It should be noted that the in-tunnel diameter change method for the variable-diameter shield tunneling machine is applicable not only to shield tunneling machines but also to TBMs. In other words, the diameter change method of the variable-diameter shield tunneling machine 100 is applicable not only to shield tunneling machine diameter changes but also to TBM diameter changes. Any technical solution employing the same or similar concept as this invention to achieve in-tunnel diameter change is within the protection scope of this invention.

[0154] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A variable-diameter tunnel boring machine, characterized in that, Includes shield body, main drive, variable diameter cutterhead, propulsion device, segment assembly system, and mechanical excavation device; The shield body includes a variable-diameter front shield and a tail shield, with the tail shield connected to the tail end of the variable-diameter front shield; The main drive is located inside the variable-diameter front shield; The variable diameter cutter head is mounted on the main drive and located at the front end of the variable diameter front shield; The propulsion device is disposed inside the variable diameter front shield to drive the variable diameter front shield to move; The segment assembly system is located inside the variable diameter front shield to assemble the segments; The mechanical excavation device includes a telescopic mechanism and a widening mechanism; The telescopic mechanism is mounted on the segment assembly system and can move and rotate with the segment assembly system. The excavation expansion mechanism is mounted on the telescopic mechanism and can extend and retract radially under the drive of the telescopic mechanism, so as to excavate the soil layer between the tail shield and the variable diameter front shield to form an excavation space after the tail shield is disconnected from the variable diameter front shield. The shield body also includes a shield body shell, which is used to be installed on the outer periphery of the variable diameter front shield when the variable diameter shield machine expands its diameter, so as to expand the diameter of the shield body.

2. The variable diameter tunnel boring machine according to claim 1, characterized in that, The mechanical excavation device also includes a protective mechanism, which is mounted on the telescopic mechanism and corresponding to the widening excavation mechanism, to receive the soil cut off by the widening excavation mechanism.

3. The variable diameter tunnel boring machine according to claim 1, characterized in that, It also includes anchor bolt support devices and reinforcement devices; The anchor bolt support device is installed on the segment assembly system and can move and rotate with the segment assembly system to support the soil layer; The reinforcement device is installed on the segment assembly system and can move and rotate with the segment assembly system to reinforce the soil layer by freezing or grouting.

4. The variable diameter tunnel boring machine according to claim 1, characterized in that, It also includes temporary support assembly devices; The temporary support assembly device is installed on the segment assembly system and can move and rotate with the segment assembly system to install temporary support in the excavated space formed by the excavation mechanism.

5. The variable diameter tunnel boring machine according to claim 4, characterized in that, It also includes a shield body casing assembly device; The shield shell assembly device is installed on the segment assembly system and can move and rotate with the segment assembly system to install the shield shell on the temporary support.

6. A method for in-tunnel diameter reduction construction using a variable-diameter shield machine, characterized in that, A construction method applicable to shield tunneling or TBM methods, the construction method comprising the following steps: S1. Tunneling is carried out using a variable diameter tunnel boring machine as described in any one of claims 1 to 5; S2. Diameter expansion preparation: Disconnect the tail shield from the variable diameter front shield; S3. Continue tunneling: The variable diameter front shield is continued to be tunneled forward by the propulsion device so that the outer soil layer in the area between the variable diameter front shield and the tail shield is exposed. S5. Radial Excavation: The excavation mechanism extends to excavate the outer soil layer of the area between the variable diameter front shield and the tail shield to form an excavation space; S8. Expanding the excavation cycle: Repeat steps S3 and S5 to extend the expanded excavation space to the required length; S10. Assemble the shield casing: Pre-install the shield casing in the enlarged excavation space; S11. Tunnel Boring Machine Retraction: The variable diameter front shield is moved backward to the enlarged excavation space, and the variable diameter front shield is connected to the shield body shell. S12. Cutterhead diameter expansion and force transmission ring installation: The variable diameter cutterhead is expanded at the expanded excavation space, and a force transmission ring is installed at the propulsion device to continue tunneling.

7. The method for in-tunnel diameter changing construction of a variable-diameter shield machine according to claim 6, characterized in that, Between step S3 and step S5, the following is also included: S4. Anchoring the soil: Anchor bolts are used to support the outer soil layer in the area between the variable diameter front shield and the tail shield, and the outer soil layer is reinforced by freezing or grouting.

8. The method for in-tunnel diameter changing construction of a variable-diameter shield machine according to claim 7, characterized in that, Between step S5 and step S8, the following is also included: S6. Soil layer reinforcement support: Temporary support is installed on the soil layer wall in the excavated space; S7. Segment installation: Install segments in the excavated space and connect the segments to the temporary support; In step S8, the excavation cycle is repeated from S3 to S7 to extend the excavation space to the required length. The procedure preceding step S10 also includes: S9. Segment Removal: Remove all installed segments in the excavated space.

9. The method for in-tunnel diameter changing construction of a variable-diameter shield machine according to any one of claims 6 to 8, characterized in that, The process following step S12 also includes: S13. Cutterhead and shield body diameter reduction: Remove the cutterhead unit installed on the outer ring of the variable diameter cutterhead, separate the variable diameter front shield from the shield body shell, and remove the force transmission ring from the propulsion device. S14. Install the tail shield: Install the tail shield at the tail end of the variable diameter front shield.

10. The method for in-tunnel diameter changing construction of a variable-diameter shield machine according to claim 9, characterized in that, Following step S14, the following is also included: S15. Segment connection: Connect small-diameter segments to large-diameter segments using transition ribs.

Images