Shield structure of shield tunneling machine and supporting method of shield structure

Abstract

The invention provides a shield structure of a shield tunneling machine and a supporting method of the shield structure, and belongs to the technical field of open type rock tunnel boring machines. Comprising a shield supporting structure, a main drive, a shield 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 spray head assembly in the spraying and mixing system is arranged between a cutter head in the shield tunneling machine and the front end face of the shield main body. The spray head assembly in the spraying and mixing system is arranged on the front end face of the shield in front, the shield is designed to be of a double-layer telescopic structure, and therefore the problems that in a traditional concrete spraying operation mode, the dust concentration is large, the operation environment is severe, equipment in a main machine area is polluted, spraying and mixing supporting are not timely, and the construction safety risk is high can be solved in the operation process.

Description

Technical Field

[0001] The invention belongs to the technical field of open rock tunnel boring machines and relates to a shield structure of a shield machine and a supporting method thereof. Background Art

[0002] During the construction of an open rock tunnel boring machine (TBM), the L1 area (the tail of the shield) tunnel shotcrete support usually uses a concrete shotcrete machine to spray directly onto the rock wall through manual or manipulators to seal the surrounding rock in time, and spray in layers and in batches to the designed thickness. However, this technology currently has problems such as high concentration of spray-mixed dust, poor working environment, high rebound rate, untimely support, and pollution of the main machine area equipment, and it cannot achieve the timely support purpose of implementing spray-mixed support after excavation.

[0003] In order to give full play to the construction performance of open rock tunnel boring machines, improve their advance spraying and mixing support efficiency, enhance the timeliness of advance spraying and mixing support, and improve the working environment, it is of great significance to carry out research and application of shield support structures. As early as 1993, during the concrete lining construction of the Jiulishan water diversion tunnel of the Beijing-Miyun water diversion project, the Beijing Water Conservancy Engineering Office and Tsinghua University developed a set of traveling tunnel sliding templates, which achieved initial success. China Hydropower Corporation used this as a prototype and combined with the continuous innovation and development of sliding form technology to apply for the patent "Circumferential Sliding Formwork for Concrete Lining of Full-Circular Tunnel". This technology is mainly used for full-circular tunnels, using track walking mode, the sliding membrane and the gantry structure share the track, and the support operation is realized through the sliding membrane circular track and the template system. At the same time, the patent "Tunnel Shotcrete Support Technology" applied by China Hydropower Corporation uses a steel support structure and a template for spraying concrete forming to form a support system, which improves the working environment, reduces the rebound force, and improves the work efficiency.

[0004] Open TBMs have always had the significant disadvantage of mismatching excavation speed with support efficiency and support timeliness. When encountering weak, broken, and severely falling geology, there is an urgent need for a timely concrete support technology that can effectively solve the problems of traditional shotcrete support, high concentration of sprayed concrete dust, harsh working environment, high rebound rate, pollution of host area equipment, and high construction safety risks.

[0005] As an important support method in open TBM models, the L1 area advance spraying system plays a role in geological reinforcement during the excavation process. The most widely used tunnel shotcrete support is the direct spraying concrete support operation method, which is located at the tail of the shield. This method has problems such as high concentration of spraying dust, poor working environment, high rebound rate, low work efficiency, and pollution of the main equipment area. It cannot meet the construction requirements of timely spraying support after excavation, which seriously affects the excavation efficiency of the equipment. Therefore, in view of the shortcomings of the L1 area advance spraying system of the open TBM model, it is particularly important to study and develop a shield support structure technology that can effectively improve the problems brought by traditional shotcrete operations, such as high dust concentration, poor working environment, poor support effect, untimely support, and high construction safety risks. Summary of the invention

[0006] The present invention provides a shield structure for a shield machine, including 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 overlapping shield and the side shield in the open-type tunnel boring machine respectively; the single-group shield support structure includes a shield inner shell, a shield outer shell, a support rib and an auxiliary thrust cylinder, the shield inner shell is fixedly connected to the shield main body, the shield outer shell and the shield inner shell are arranged at intervals from each other, one end of the support rib is fixedly connected to the shield inner shell, the other end of the support rib is connected to the shield outer shell, one end of the auxiliary thrust cylinder is connected to the shield outer shell, and the other end of the auxiliary thrust cylinder is connected to the shield main body;

[0008] The top shield is connected to the main drive and the shield body;

[0009] The overlapping shield connects the main drive and the shield body;

[0010] The side shield is connected to the main drive and the shield body;

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

[0012] Optionally, the shield inner shell is configured as an arc structure, and the inner arc surface of the shield inner shell and the outer arc surface of the shield body in the open-type tunnel boring machine are mutually abutted and fixedly connected;

[0013] The shield shell is configured as an arc structure, and the inner diameter of the shield shell is greater than the outer diameter of the shield inner shell;

[0014] The support ribs are provided with a plurality of pieces spaced apart from each other along the circumference, one end of a single support rib is fixedly connected to the inner shell of the shield, and the other end of the single support rib is connected to the outer shell of the shield in a mutually overlapping manner.

[0015] Optionally, the arc radians of the inner shield shell and the outer shield shell are equal, and the arc angle between the inner shield shell and the outer shield shell is set to 90°-260°.

[0016] Optionally, the spray-mixing system includes a rotating ring, a rotating bracket and a rotating driving member;

[0017] An outer gear ring is provided on the outer arc end surface of the rotating ring, an inner gear ring for meshing with the outer gear ring is provided on the rotating bracket, a fixed end of the rotating driving member is fixedly connected to the rotating bracket, and a driving end of the rotating driving member is fixed to the rotating ring;

[0018] The rotating ring is fixedly connected to the nozzle assembly and is used to drive the nozzle assembly to rotate circumferentially.

[0019] Optionally, the nozzle assembly includes a nozzle and a rotary motor for driving the nozzle to rotate, wherein a driving end of the rotary motor is connected to the nozzle, and a fixed end of the rotary motor is connected to a rotating ring.

[0020] Optionally, the nozzle assembly is provided in plurality, and the plurality of nozzle assemblies are arranged along the circumference of the shield.

[0021] The present invention also provides a method for supporting a shield structure of a shield machine, and the specific process of supporting the top shield is as follows:

[0022] In the initial state, the auxiliary thrust cylinder is in a retracted state;

[0023] When an open-type roadheader encounters a soft, broken, or severely falling geological environment and needs to support the spray-mix system, the shield support structure is activated;

[0024] After the cutterhead has advanced a certain distance, the auxiliary thrust cylinder is extended, the shield housing is opened, and the spray-mix system is started. The spray-mix system supports the tunnel wall within a 260° circumference through the axial swing and circumferential rotation of the nozzle assembly.

[0025] After the spray-mix support is completed, the reset begins, the spray-mix system is turned off, the top shield cylinder descends, the auxiliary push cylinder retracts, driving the shield shell to reset, and finally the top shield cylinder rises to press against the tunnel wall.

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

[0027] In order to solve the problems existing in the support operation of the advanced spraying and mixing system in the L1 area of ​​an open TBM model, the present invention proposes a shield structure of a shield machine, whose functions mainly include: a retractable double-shell structure shield, a main drive, an auxiliary thrust cylinder, a top shield cylinder, a side shield cylinder, a spraying and mixing system, etc. The structure has the advantages of simple and reliable principle, low cost, flexible application, strong controllability, and timely support. In the present invention, the nozzle assembly in the spraying and mixing system is placed in front of the front end face of the shield, and the shield is designed as a double-layer retractable structure. Therefore, during the operation process, the problems of high dust concentration, harsh working environment, pollution of the main machine area equipment, untimely spraying and mixing support, and high construction safety risks in the traditional spraying concrete operation method can be improved.

[0028] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 It is a structural schematic diagram of a shield structure of a shield machine in 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 partial enlarged schematic diagram of the middle double-hull structure shield;

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

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

[0035] Figure 6 It is a schematic diagram of the reset state after a shield structure of a shield machine in an embodiment of the present invention is used to support a top shield.

[0036] in:

[0037] 1. Double-shell structure shield, 1.1. Shield inner shell, 1.2. Shield outer 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. Overlap shield, 9. Side shield. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the present invention more clear and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. It should be noted that the drawings of the present invention are all simplified and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the implementation of the present invention; the "number" mentioned in the present invention is not limited to the specific number in the examples in the accompanying drawings; the directions or positional relationships indicated by "front", "middle", "back", "left", "right", "up", "down", "top", "bottom", "middle", etc. mentioned in the present invention are based on the directions or positional relationships shown in the drawings of the present invention, and do not indicate or imply that the devices or components referred to must have a specific direction, nor can they be understood as limitations on the present invention.

[0039] Example:

[0040] See also Figure 1 , Figure 3 and Figure 4 As shown, the present invention also provides a shield structure of a shield machine, including a shield support structure 1, a main drive 2, a top shield cylinder 3, a side shield cylinder 4, a shield body 5 and a spray mixing system 6;

[0041] The nozzle assembly in the spray-mixing system 6 is arranged at the middle position between the cutter disc and the front end face of the shield body 5, so as to realize the rapid spray-mixing reinforcement treatment of the broken surrounding rock after excavation; preferably, the nozzle assembly can rotate circumferentially (specifically, the circumferential rotation of the nozzle assembly is realized by a rotating ring with a gear ring and a rotating bracket; that is, the spray-mixing system 6 also includes a rotating ring, a rotating bracket and a rotating driving member, an outer gear ring is provided on the outer arc end face of the rotating ring, an inner gear ring for meshing with the outer gear ring is provided on the rotating bracket, the fixed end of the rotating driving member is fixedly connected to the rotating bracket, the driving end of the rotating driving member is fixed to the rotating ring, and the rotating ring and the nozzle assembly are fixedly connected to each other, so that the rotating The nozzle assembly is driven by a rotating driving member to perform circumferential rotation) and axial swing (specifically, the axial swing of the nozzle assembly is achieved by a rotary motor; that is, the nozzle assembly includes a nozzle and a rotary motor for driving the nozzle to rotate, the driving end of the rotary motor is connected to the nozzle, and the fixed end of the rotary motor is connected to the rotating ring, so that the nozzle can swing axially relative to the rotating ring), the nozzle assembly can be adjusted from 30 to 90 degrees to the wall of the tunnel, and the distance between the nozzle assembly and the wall of the tunnel can be adjusted within a range of 450-1050mm; further preferably, according to specific needs, the nozzle assembly is provided with a plurality of nozzle assemblies, and the plurality of nozzle assemblies are arranged along the circumference of the shield.

[0042] The shield support structure 1 is used to support the spray-mixing system 6, the top shield 7, the overlapping shield 8 and the side shield 9 in the open tunnel boring machine respectively; and the shield support structure 1 includes a shield inner shell 1.1, a shield outer shell 1.2, support ribs 1.3 and an auxiliary thrust cylinder 1.4; the shield inner shell 1.1 is set as an arc structure, and the inner arc surface of the shield inner shell 1.1 is mutually attached and fixedly connected with the outer arc surface of the shield body 5 in the open tunnel boring machine; the shield outer shell 1.2 is set as an arc structure, And the inner diameter of the shield outer shell 1.2 is larger than the outer diameter of the shield inner shell 1.1; the support rib 1.3 is provided with a plurality of pieces spaced apart from each other along the circumference, one end of a single support rib 1.3 is fixedly connected to the shield inner shell 1.1, and the other end of the single support rib 1.3 is connected to the shield outer shell 1.2 in a overlapping manner; one end of the auxiliary thrust cylinder 1.4 is fixedly connected to the shield outer shell 1.2, and the other end of the auxiliary thrust cylinder 1.4 is fixedly connected to the shield body 5, so as to push the shield outer shell 1.2 to move in the axial direction.

[0043] Preferably, the arc radians of the shield inner shell 1.1 and the shield outer shell 1.2 are equal, and the arc angle between the shield inner shell 1.1 and the shield outer shell 1.2 is preferably set to 90°-260°.

[0044] One end of the top shield cylinder 3 is fixedly connected to the main drive 2, and the other end of the top shield cylinder 3 is fixedly connected to the main body of the top shield 7, so that the top shield 7 is displaced as a whole in the vertical direction; one end of the side shield cylinder 4 is fixedly connected to the main drive 2, and the other end of the side shield cylinder 4 is connected to the main body of the side shield 9, so that the side shield 9 is displaced as a whole in the horizontal direction.

[0045] As a further embodiment of the present invention, the present invention also provides a shield support method. Taking the top shield as an example, the support process is as follows:

[0046] See also Figure 3 and Figure 4 As shown, in the initial state, the auxiliary thrust cylinder is in a retracted state, and when the open TBM is excavating under the condition that the tunnel surrounding rock is in good condition, there is no need to start the shield support structure;

[0047] When encountering a weak, broken, or severely falling geological environment that requires timely spray-mix support after excavation, the shield support structure is activated;

[0048] See also Figure 5 As shown, after the cutterhead has advanced a certain distance, the auxiliary thrust cylinder is extended, the shield housing is opened, and the spray-mix system is started. The spray-mix system supports the tunnel wall within a 260° circumferential range through the axial swing and circumferential rotation of the nozzle assembly.

[0049] After the spray-mix support is completed, reset is started. Figure 6As shown, the spray mixing system is turned off, the top shield cylinder descends, the auxiliary thrust cylinder retracts, driving the shield shell to reset, and finally the top shield cylinder rises to press against the cave wall.

[0050] Furthermore, in the working state and the reset state stages, the working principle of the overlap shield and the side shield is the same as that of the top shield.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A shield structure for a shield machine, characterized in that: It comprises a shield support structure (1), a main drive (2), a shield body (5), a spray mixing system (6), a top shield (7), a lap shield (8), and a side shield (9); The shield support structure (1) is provided with four groups for supporting a top shield (7), a lap shield (8) and a side shield (9) in an open-type tunnel boring machine respectively; a single group of shield support structures (1) comprises a shield inner shell (1.1), a shield outer shell (1.2), support ribs (1.3) and an auxiliary thrust cylinder (1.4); the shield inner shell (1.1) is fixedly connected to a shield body (5); the shield outer shell (1.2) and the shield inner shell (1.1) are arranged at intervals from each other; one end of the support rib (1.3) is fixedly connected to the shield inner shell (1.1); the other end of the support rib (1.3) is connected to the shield outer shell (1.2); one end of the auxiliary thrust cylinder (1.4) is connected to the shield outer shell (1.2); and the other end of the auxiliary thrust cylinder (1.4) is connected to the shield body (5); The top shield (7) is connected to the main drive (2) and the shield body (5); The overlapping shield (8) connects the main drive (2) and the shield body (5); The side shield (9) is connected to the main drive (2) and the shield body (5); The spray head assembly in the spray mixing system (6) is arranged in the middle position between the cutter head and the front end surface of the shield body (5) in the shield machine.

2. The shield structure of the shield machine according to claim 1, characterized in that: The shield inner shell (1.1) is configured as an arc structure, and the inner arc surface of the shield inner shell (1.1) and the outer arc surface of the shield main body (5) in the open-type tunnel boring machine are mutually abutted and fixedly connected; The shield outer shell (1.2) is configured as an 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 ribs (1.3) are provided with a plurality of pieces spaced apart from each other along the circumference, one end of a single support rib (1.3) is fixedly connected to the shield inner shell (1.1), and the other end of the single support rib (1.3) is connected to the shield outer shell (1.2) in a mutually overlapping manner.

3. The shield structure of the shield machine according to claim 2, characterized in that: The arc radians of the shield inner shell (1.1) and the shield outer shell (1.2) are equal, and the arc angles of the shield inner shell (1.1) and the shield outer shell (1.2) are set to be 90°-260°.

4. The shield structure of a shield machine according to any one of claims 1 to 3, characterized in that: The spray mixing system (6) comprises a rotating ring, a rotating bracket and a rotating driving member; An outer gear ring is provided on the outer arc end surface of the rotating ring, an inner gear ring for meshing with the outer gear ring is provided on the rotating bracket, a fixed end of the rotating driving member is fixedly connected to the rotating bracket, and a driving end of the rotating driving member is fixed to the rotating ring; The rotating ring is fixedly connected to the nozzle assembly and is used to drive the nozzle assembly to rotate circumferentially.

5. The shield structure of the shield machine according to claim 4, characterized in that: The nozzle assembly comprises a nozzle and a rotary motor for driving the nozzle to rotate, the driving end of the rotary motor is connected to the nozzle, and the fixed end of the rotary motor is connected to the rotating ring.

6. The shield structure of the shield machine according to claim 4, characterized in that: The nozzle assembly is provided in plurality, and the plurality of nozzle assemblies are arranged along the circumference of the shield.

7. A method for supporting a shield structure of a shield machine, characterized in that: The specific process of supporting the top shield is as follows: In the initial state, the auxiliary thrust cylinder is in a retracted state; When an open-type roadheader encounters a soft, broken, or severely falling geological environment and needs to support the spray-mix system, the shield support structure is activated; After the cutterhead has advanced a certain distance, the auxiliary thrust cylinder is extended, the shield housing is opened, and the spray-mix system is started. The spray-mix system supports the tunnel wall within a 260° circumference through the axial swing and circumferential rotation of the nozzle assembly. After the spray-mix support is completed, the reset begins, the spray-mix system is turned off, the top shield cylinder descends, the auxiliary push cylinder retracts, driving the shield shell to reset, and finally the top shield cylinder rises to press against the tunnel wall.

Images