Shield structure of a shield tunneling machine and method for supporting the same

Abstract

The application provides a shield structure of a shield tunneling machine and a supporting method thereof, and belongs to the technical field of open rock tunnel boring machines; the shield structure comprises a shield supporting structure, a main drive, a shield main body, a spraying and mixing system, a top shield, a lap joint shield and a side shield; the shield supporting structure comprises a shield inner shell, a shield outer shell, a supporting rib and an auxiliary pushing oil cylinder; the top shield is connected with the main drive and the shield main body; the lap joint shield is connected with the main drive and the shield main body; the side shield is connected with the main drive and the shield main body; a nozzle assembly in the spraying and mixing system is arranged at the intermediate position between a cutter head in the shield tunneling machine and the front end surface of the shield main body. In the application, the nozzle assembly in the spraying and mixing system is arranged in front of the front end surface of the shield, and the shield is designed as a double-layer telescopic structure, so that the problems of high dust concentration, poor working environment, pollution of main machine area equipment, untimely spraying and mixing supporting, high construction safety risk and the like in the traditional spraying and mixing concrete operation mode can be improved in the operation process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of open rock tunnel boring machine, and relates to a shield structure of a shield tunneling machine and a supporting method thereof. BACKGROUND

[0002] In the construction process of an open rock tunnel boring machine (TBM), the concrete spraying support in the L1 area (the tail part of the shield) of the tunnel is usually achieved by spraying concrete on the rock wall by a concrete spraying machine through manual or mechanical spraying, timely sealing the surrounding rock, and spraying in layers and batches to the designed thickness. However, the current technology has the problems of high concentration of sprayed concrete dust, poor working environment, high rebound rate, untimely support, pollution of the main machine area equipment, and the like, and cannot achieve the purpose of timely support after excavation.

[0003] In order to fully exert the construction performance of the open rock tunnel boring machine, improve the efficiency of the advanced sprayed concrete support, enhance the timeliness of the advanced sprayed concrete support, and improve the working environment, it is of great significance to carry out research and application of the shield support structure. As early as 1993, in the concrete lining construction of the Jiulishan water diversion tunnel of the Beijing-Miyun Water Diversion Project, the Beijing Water Conservancy Engineering Office jointly with Tsinghua University developed a set of tunnel sliding form, which achieved preliminary success. Based on this, the China Water Conservancy Company filed a patent for a "circumferential sliding form for full-circle tunnel concrete lining", which is mainly used for full-circle tunnels, adopts a track walking mode, and the sliding film and the rack structure share the track. The support operation is realized through the sliding film annular track and the formwork system. At the same time, the China Water Conservancy Company applied for a patent for "tunnel formwork sprayed concrete support technology", which uses a steel support structure and a formwork for forming the sprayed concrete to form a support system, improves the working environment, reduces the rebound force, and improves the working efficiency.

[0004] For a long time, the open TBM has the significant disadvantage that the excavation speed does not match the support efficiency and timeliness. When encountering soft, broken, and seriously falling block geology, there is an urgent need for a concrete timely support technology that can effectively solve the problems of untimely traditional sprayed concrete support, high concentration of sprayed concrete dust, poor working environment, high rebound rate, pollution of the main machine area equipment, and high construction safety risk.

[0005] The L1 area advanced spray mixing system is an important supporting method in the open type TBM machine type, and plays a role in geological reinforcement in the tunneling process. The tunnel spray concrete support currently widely used is a straight spray concrete support operation mode, which is located at the tail of the shield. When the operation is performed, there are problems such as high dust concentration, poor operation environment, high rebound rate, low work efficiency, pollution of main machine area equipment, and the like, and the construction requirements of timely spray support after excavation cannot be met, which seriously affects the equipment tunneling efficiency. Therefore, in view of the deficiencies of the L1 area advanced spray mixing system of the open type TBM machine type, it is particularly important to develop a shield support structure technology capable of effectively improving the problems such as high dust concentration, poor operation environment, poor support effect, untimely support, high construction safety risk, and the like caused by the traditional spray concrete operation. SUMMARY

[0006] The shield structure of the shield tunneling machine comprises a shield support structure, a main drive, a shield body, a spray mixing system, a top shield, a lap shield and a side shield.

[0007] The shield support structure is provided with four groups for supporting the top shield, the lap shield and the side shield in the open type tunneling machine respectively; a single shield support structure comprises a shield inner shell, a shield outer shell, a support rib and an auxiliary push oil cylinder, the shield inner shell is fixedly connected with the shield body, the shield outer shell is arranged in spaced relation with the shield inner shell, one end of the support rib is fixedly connected with the shield inner shell, the other end of the support rib is connected with the shield outer shell, one end of the auxiliary push oil cylinder is connected with the shield outer shell, and the other end of the auxiliary push oil cylinder is connected with the shield body.

[0008] The top shield is connected with the main drive and the shield body.

[0009] The lap shield is connected with the main drive and the shield body.

[0010] The side shield is connected with the main drive and the shield body.

[0011] The spray head assembly in the spray mixing system is arranged at a position between the cutter head in the shield tunneling machine and the front end face of the shield body.

[0012] Optionally, the shield inner shell is arranged in a circular arc structure, and the inner circular arc surface of the shield inner shell is in mutual abutment and fixed connection with the outer circular arc surface of the shield body in the open type tunneling machine.

[0013] The shield outer shell is arranged in a circular arc structure, and the inner diameter of the shield outer shell is greater than the outer diameter of the shield inner shell.

[0014] The support rib is provided with a plurality of pieces arranged in spaced relation along the circumference, one end of a single piece of the support rib is fixedly connected with the shield inner shell, and the other end of the single piece of the support rib is connected with the shield outer shell in a mutually overlapping manner.

[0015] Optionally, the arc radian of the shield inner shell and the shield outer shell is equal, and the arc angle of the shield inner shell and the shield outer shell is set as 90-260 degrees.

[0016] Optionally, the spray mixing system comprises a rotating ring, a rotating support and a rotating driving member.

[0017] The outer circular arc end surface of the rotating ring is provided with an outer gear ring, the rotating support is provided with an inner gear ring for intermeshing with the outer gear ring, the fixed end of the rotating driving member is fixedly connected with the rotating support, and the driving end of the rotating driving member is fixed with the rotating ring.

[0018] The rotating ring is fixedly connected with the spray head assembly, and is used for driving the spray head assembly to rotate circumferentially.

[0019] Optionally, the spray head assembly comprises a spray head and a rotating motor for driving the spray head to rotate, the driving end of the rotating motor is connected with the spray head, and the fixed end of the rotating motor is connected with the rotating ring.

[0020] Optionally, a plurality of spray head assemblies are arranged along the circumference of the shield.

[0021] The application further provides a supporting method of the shield structure of the shield tunneling machine.

[0022] In the initial state, the auxiliary pushing oil cylinder is in the retracted state.

[0023] When the open type tunneling machine needs to support the spray mixing system after excavation in the soft, broken and seriously blocky geological environment, the shield supporting structure is started.

[0024] After the cutter head tunnels for a certain distance, the auxiliary pushing oil cylinder is extended, the shield outer shell is opened, the spray mixing system is started, and the spray head assembly is axially swung and circumferentially rotated to spray and support the tunnel wall in the circumferential 260 degree range.

[0025] After the spray mixing support is completed, the reset is started, the spray mixing system is closed, the top shield oil cylinder is lowered, the auxiliary pushing oil cylinder is retracted, the shield outer shell is reset, and finally the top shield oil cylinder is lifted to tightly abut against the tunnel wall.

[0026] Compared with the prior art, the application has the following beneficial effects:

[0027] To address the problems encountered during the L1 zone advanced shotcrete system support operation in open-type TBM models, this invention proposes a shield structure for tunnel boring machines. Its main functions include: a retractable double-shell shield, a main drive system, auxiliary thrust cylinders, a top shield cylinder, side shield cylinders, and a shotcrete system. This structure boasts advantages such as simple and reliable principle, low cost, flexible application, strong controllability, and timely support. Furthermore, by placing the nozzle assembly of the shotcrete system at the front end of the shield, and designing the shield as a double-layer retractable structure, this invention can improve upon the problems of high dust concentration, harsh working environment, pollution of main equipment areas, untimely shotcrete support, and high construction safety risks associated with traditional shotcrete operations.

[0028] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0029] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0030] Figure 1 This is a schematic diagram of a shield structure for a tunnel boring machine according to an embodiment of the present invention;

[0031] Figure 2 yes Figure 1 Schematic diagram of the AA section;

[0032] Figure 3 yes Figure 1 A partially enlarged schematic diagram of the double-shell structure shield;

[0033] Figure 4 yes Figure 3 Schematic diagram of the BB cross section;

[0034] Figure 5 This is a schematic diagram of the working state when a shield structure of a tunnel boring machine is used to support the top shield in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the reset state after the shield structure of a tunnel boring machine in an embodiment of the present invention supports the top shield.

[0036] in:

[0037] 1. Double-shell structure shield; 1.1. Inner shield shell; 1.2. Outer shield shell; 1.3. Support ribs; 1.4. Auxiliary thrust cylinder; 2. Main drive; 3. Top shield cylinder; 4. Side shield cylinder; 5. Shield body; 6. Spray mixing system; 7. Top shield; 8. Overlapping shield; 9. Side shield. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more clear and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings. It should be noted that the drawings of the present application are all simplified and use non-accurate proportions, only to facilitate and clearly assist in explaining the implementation of the present application; the number of several mentioned in the present application is not limited to the specific number in the example of the drawings; the directions or position relationships mentioned in the present application, such as 'front','middle','rear', 'left', 'right', 'top', 'bottom', 'top', 'bottom','middle', are all based on the directions or position relationships shown in the drawings of the present application, and do not indicate or imply that the devices or parts referred to must have a specific direction, nor can it be understood as a limitation on the present application.

[0039] Embodiment:

[0040] Referring to Figure 1 , Figure 3 and Figure 4 , the present application also provides a shield structure of a shield tunneling machine, which comprises a shield support structure 1, a main drive 2, a top shield oil cylinder 3, a side shield oil cylinder 4, a shield main body 5 and a spray mixing system 6.

[0041] The spray head assembly in the spray mixing system 6 is arranged at the intermediate position of the cutter head and the front end face of the shield main body 5, so as to realize the rapid crushing and surrounding rock spray mixing reinforcement treatment after excavation; preferably, the spray head assembly can rotate circumferentially (specifically, the circumferential rotation of the spray head assembly is realized by relying on the rotating ring with a gear ring and the rotating support; that is, the spray mixing system 6 further comprises a rotating ring, a rotating support and a rotating drive, the outer circular arc end face of the rotating ring is provided with an outer gear ring, the rotating support is provided with an inner gear ring for intermeshing with the outer gear ring, the fixed end of the rotating drive is fixedly connected with the rotating support, and the driving end of the rotating drive is fixed with the rotating ring, the rotating ring and the spray head assembly are fixedly connected with each other, so as to rotate circumferentially by driving of the rotating drive) and axial swing (specifically, the axial swing of the spray head assembly is realized by relying on a rotating motor; that is, the spray head assembly comprises a spray head and a rotating motor for driving the spray head to rotate, the driving end of the rotating motor is connected with the spray head, and the fixed end of the rotating motor is connected with the rotating ring, so as to realize the axial swing of the spray head relative to the rotating ring), the distance between the spray head assembly and the tunnel wall can be adjusted within the range of 30 to 90 degrees, and the distance between the spray head assembly and the tunnel wall can be adjusted within the range of 450-1050mm; further preferably, according to specific requirements, the spray head assembly is provided with a plurality of spray head assemblies, and the plurality of spray head assemblies are arranged along the circumference of the shield.

[0042] The shield support structure 1 is used for supporting the spray mixing system 6, the top shield 7, the lap shield 8 and the side shield 9 in the open type tunneling machine respectively, and the shield support structure 1 comprises a shield inner shell 1.1, a shield outer shell 1.2, a support rib 1.3 and an auxiliary push oil cylinder 1.4; the shield inner shell 1.1 is arranged as a circular arc structure, and the inner circular arc surface of the shield inner shell 1.1 is mutually attached and fixedly connected with the outer circular arc surface of the shield body 5 in the open type tunneling machine; the shield outer shell 1.2 is arranged as a circular arc structure, and the inner diameter of the shield outer shell 1.2 is greater than the outer diameter of the shield inner shell 1.1; the support rib 1.3 is provided with a plurality of pieces which are arranged at intervals along the circumference, one end of a single piece of the support rib 1.3 is fixedly connected with the shield inner shell 1.1, and the other end of the single piece of the support rib 1.3 is connected with the shield outer shell 1.2 in a mutually overlapping manner; one end of the auxiliary push oil cylinder 1.4 is fixedly connected with the shield outer shell 1.2, and the other end of the auxiliary push oil cylinder 1.4 is fixedly connected with the shield body 5, and is used for pushing the shield outer shell 1.2 to displace along the axial direction.

[0043] Preferably, the circular arc radian of the shield inner shell 1.1 and the shield outer shell 1.2 is equal, and the circular arc included angle of the shield inner shell 1.1 and the shield outer shell 1.2 is preferably arranged as 90°-260°.

[0044] One end of the top shield oil cylinder 3 is fixedly connected with the main drive 2, and the other end of the top shield oil cylinder 3 is fixedly connected with the top shield 7 body, so as to realize the displacement of the whole top shield 7 along the vertical direction; one end of the side shield oil cylinder 4 is fixedly connected with the main drive 2, and the other end of the side shield oil cylinder 4 is connected with the side shield 9 body, so as to realize the displacement of the whole side shield 9 along the horizontal direction.

[0045] As a further embodiment of the present application, the present application further provides a shield support method, taking the top shield as an example, and the support process is as follows:

[0046] Referring to FIGS. 1-8, Figure 3 and Figure 4 shown, in the initial state, the auxiliary push oil cylinder is in the retracted state, and when the open type TBM is excavated under the condition that the tunnel surrounding rock is in good condition, the shield support structure does not need to be started;

[0047] When the soft, broken and seriously falling geological environment needs to be excavated and sprayed and mixed for support in time, the shield support structure is started;

[0048] Referring to FIGS. 1-8, Figure 5 shown, after the cutter head is excavated for a certain distance, the auxiliary push oil cylinder is extended, the shield outer shell is opened, the spray mixing system is started, and the spray head assembly is axially swung and circumferentially rotated to spray and mix the tunnel wall in the circumferential 260° range;

[0049] After the spray mixing support is completed, the reset is started, referring to FIGS. 1-8, Figure 6As shown, the spray mixing system is closed, the top shield oil cylinder is lowered, the auxiliary push oil cylinder is retracted, the shield shell is reset, and finally the top shield oil cylinder is raised to tightly abut the hole wall.

[0050] Further, in the working state and the reset state stage, the working principle of the lap shield and the side shield is same as the top shield.

[0051] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A shield structure for a tunneling machine, characterized in that, The shield support structure (1), the main drive (2), the shield body (5), the spray mixing system (6), the top shield (7), the lap shield (8), and the side shield (9); The shield support structure (1) is provided with four groups of shield support structures respectively used for supporting the top shield (7), the lap shield (8) and the side shield (9) in the open tunneling machine. The top shield (7) is connected with the main drive (2) and the shield body (5). The lap shield (8) is connected with the main drive (2) and the shield body (5). The side shield (9) is connected with the main drive (2) and the shield body (5). The spray head assembly in the spray mixing system (6) is arranged at a middle position between the cutter head and the front end surface of the shield body (5) in the shield tunneling machine. The specific process for supporting the top shield is as follows: In the initial state, the auxiliary pushing oil cylinder is in the retracted state. When the open tunneling machine needs to be sprayed and mixed for support after excavation in a soft, broken and seriously blocky geological environment, the shield support structure is started. After the cutter head tunnels for a certain distance, the auxiliary pushing oil cylinder is extended, the shield outer shell is opened, the spray mixing system is started, and the spray head assembly is axially swung and circumferentially rotated to spray and support the tunnel wall within a 260° range around the tunnel. After the spray mixing support is completed, the spray mixing system is closed, the top shield oil cylinder is lowered, the auxiliary pushing oil cylinder is retracted, the shield outer shell is reset, and finally the top shield oil cylinder is raised to tightly press against the tunnel wall.

2. The shield structure for a tunneling machine according to claim 1, characterized in that, The shield inner shell (1.1) is arranged in a circular arc structure, and the inner circular arc surface of the shield inner shell (1.1) is mutually attached and fixedly connected with the outer circular arc surface of the shield body (5) in the open tunneling machine. The shield outer shell (1.2) is arranged in a circular arc structure, and the inner diameter of the shield outer shell (1.2) is greater than the outer diameter of the shield inner shell (1.1). The support rib (1.3) is provided with a plurality of pieces arranged at intervals along the circumference, one end of each piece of the support rib (1.3) is fixedly connected with the shield inner shell (1.1), and the other end of each piece of the support rib (1.3) is connected with the shield outer shell (1.2) in a mutually overlapping manner.

3. The shield structure for a tunneling machine according to claim 2, characterized in that, The circular arc radians of the shield inner shell (1.1) and the shield outer shell (1.2) are equal.

4. A shield structure for a tunneling machine according to any one of claims 1-3, characterized in that The spray mixing system (6) comprises a rotating ring, a rotating support and a rotating drive. An outer gear ring is arranged on the outer circular arc end surface of the rotating ring, an inner gear ring for mutually engaging with the outer gear ring is arranged on the rotating support, the fixed end of the rotating drive is fixedly connected with the rotating support, and the driving end of the rotating drive is fixed with the rotating ring. The rotating ring is fixedly connected with the spray head assembly for driving the spray head assembly to rotate circumferentially.

5. The shield structure for a tunneling machine according to claim 4, wherein The spray head assembly comprises a spray head and a rotating motor for driving the spray head to rotate, a driving end of the rotating motor is connected with the spray head, and a fixed end of the rotating motor is connected with a rotating ring.

6. The shield structure for a tunneling machine according to claim 4, wherein The spray head assembly is provided in plurality, and the plurality of spray head assemblies are arranged along the circumference of the shield.

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