Support device and method for construction of open TBM through gas tunnel

Abstract

The present invention relates to a support device and method for construction of an open TBM passing through a gas tunnel, wherein the support device comprises: an assembled arch frame and an assembled locking foot anchor rod, wherein the assembled arch frame and the assembled locking foot anchor rod are staggered and connected to form the support device; the construction method of the open TBM passing through a gas tunnel: first, the support device is arranged on the rock wall of the gas tunnel; then, the support device is reinforced; then, chemical grouting is used to consolidate the TBM cutter head and shield; then, loose bodies in front of and around the TBM cutter head are consolidated; then, the collapsed cavity on the top of the TBM cutter head and shield is backfilled; then, an advanced pipe shed is arranged along the arch at the rear of the TBM shield; finally, a secondary lining isolation layer is laid on the gas tunnel body. The present invention can ensure that the open TBM can pass through the gas tunnel safely and efficiently, thereby improving the construction efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of TBM construction of underground tunnels in water conservancy projects, and particularly relates to a support device and a construction method for construction of an open TBM passing through a gas tunnel. Background Art

[0002] my country's coal mine, railway and highway tunnel gas treatment construction technology has become increasingly mature, and has formed gas tunnel construction specifications and regulations. However, in water conservancy projects, the tunnel line is considered to avoid coal seams as much as possible during design. Therefore, when designing and manufacturing open TBM equipment (full-section hard rock tunnel boring machine), it is considered as non-explosion-proof equipment. Related supporting equipment and facilities are all non-explosion-proof equipment, and there are no relevant construction specifications. When designing water conservancy tunnels, the primary support type mostly adopts the type of anchor rod + mesh + steel bar row + steel support + shotcrete combined support. A large number of hot welding operations are required at the construction site. However, when the TBM construction tunnel encounters high-gas coal-bearing strata and continuous weak and broken poor geological sections, due to the influence of the characteristics of the TBM equipment itself, the conventional support method does not meet the construction safety management requirements. Summary of the invention

[0003] The technical problem to be solved by the present invention is that when a TBM tunnel is constructed and encounters high-gas coal-bearing strata and continuous soft and broken poor geological sections, the TBM equipment itself has no explosion-proof design and conventional support methods require a large amount of hot fire welding operations, which cannot guarantee the safe operation of the TBM in the gas tunnel.

[0004] In order to solve the above technical problems, the present invention provides a support device and a construction method for an open TBM to cross a gas tunnel. The support device for an open TBM to cross a gas tunnel comprises: an assembled arch frame and an assembled locking foot anchor rod; the assembled arch frame comprises: a steel support, a steel bar ring, short steel bars, a steel bar row, a steel wire, and a connecting steel; the two ends of the connecting steel are respectively fixedly connected to the wing plates at one end of the two steel supports by bolts, the wing plates at the other end of the steel support are fixedly connected to the short steel bars, and the steel bar ring is divided into The steel bar row is fixedly connected to the wing plate of the adjacent steel support by steel wire, and the ends of the steel bar rows are fixedly connected by steel wire; the assembled locking foot anchor rod comprises: a steel support, an anchor rod, an anchor rod pad, and an L-shaped pad. Anchor rods are arranged on the left and right sides of the steel support, one end of the anchor rod is inserted into the rock wall, and the other end passes through the anchor rod pad and the L-shaped pad in turn, and then is connected with a nut. The upper surface of the anchor rod pad is fixedly connected to one end of the steel support, and the lower surface of the anchor rod pad is fixedly connected to both ends of the L-shaped pad.

[0005] Furthermore, the anchor rod is a hollow structure, and a threading end is provided at one end of the anchor rod. The threading end is a straight thread structure, and the diameter of the threading end is smaller than that of the anchor rod.

[0006] Furthermore, two kidney holes are provided on the anchor rod pad.

[0007] Furthermore, the steel support is an arc-shaped structure.

[0008] A construction method of a support device for an open TBM passing through a gas tunnel construction of the present invention comprises the following steps: firstly, arranging assembled arch frames on a rock wall at intervals of 1m in a circumferential direction, arranging assembled locking foot anchor rods on the left and right sides of a steel support of the assembled arch frame, staggeringly arranging the connection steel of the assembled arch frame and the assembled locking foot anchor rods along the steel support, and then grouting and reinforcing the connection between the assembled arch frame and the rock wall by using the anchor rods of the assembled locking foot anchor rods; then, consolidating and wrapping the TBM shield and the cutter head by using a chemical grouting combination of polyether polyol; Then, mortar is used to consolidate the loose bodies in front of and around the TBM cutterhead; then, the collapsed cavity on the top of the TBM shield and the cutterhead is backfilled; then, a number of advanced pipe sheds are constructed within 120° of the top arch, and the advanced pipe sheds are evenly arranged within 120° of the outer contour of the arch at the rear of the TBM shield, with a spacing of 50 cm between the advanced pipe sheds; then, airtight concrete is used for secondary lining of the tunnel section in the high-gas coal-bearing strata; finally, closed-cell plastic panels are added between the lining concrete and the sprayed concrete of the tunnel section in the high-gas coal-bearing strata.

[0009] Beneficial effects of the present invention: A support device for the construction of an open TBM passing through a gas tunnel of the present invention is composed of an assembled arch frame, a steel bar row combination, and assembled locking anchor rods that are connected to each other by bolts. No open flame welding is required, which fully meets the safety requirements for gas tunnel construction. At the same time, it has a simple structure and is easy to install, which can effectively improve construction efficiency. In addition, after the installation of the support device is completed, the weak parts of the TBM equipment structure are uniquely reinforced, and the gas tunnel body is uniquely isolated, which further improves the safety of the open TBM construction passing through the gas tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 The present invention is a structural schematic diagram of an assembled arch frame of a support device used for construction of an open TBM passing through a gas tunnel.

[0012] Figure 2 The present invention is a schematic structural diagram of a steel bar row of a support device for an open TBM passing through a gas tunnel.

[0013] Figure 3 It is a structural schematic diagram (front view) of an assembled locking foot anchor rod of a support device for an open TBM passing through a gas tunnel construction according to the present invention.

[0014] Figure 4 It is a structural schematic diagram (side view) of an assembled locking foot anchor rod of a support device for an open TBM passing through a gas tunnel construction according to the present invention.

[0015] Figure 5 The present invention is a schematic diagram of the use status of a support device used for construction of an open TBM passing through a gas tunnel.

[0016] In the figure: 1-steel support, 2-anchor rod, 3-anchor rod pad, 4-nut, 5-L-shaped pad, 6-threading end, 7-rock wall, 8-rebar ring, 9-short rebar, 10-rebar row, 11-steel wire, 12-bolt, 13-connecting steel. DETAILED DESCRIPTION

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] like Figure 1 - As shown, a support device for open TBM crossing gas tunnel construction includes: assembled arch frame, assembled locking anchor rod; the assembled arch frame includes: steel support 1 (HW150 steel), steel ring 8, short steel bar 9, steel bar row 10 (adopted according to the surrounding rock conditions ), steel wire 11, connecting steel 13, both ends of the connecting steel 13 (HW125 steel) are fixedly connected to the wing plates at one end of the two steel supports 1 by bolts 12, the wing plates at the other end of the steel support 1 are fixedly connected to the short steel bars 9, the steel bar rings 8 are fixedly connected to the steel bar rows 10 and the short steel bars 9 respectively, the steel bar rows 10 are fixedly connected to the wing plates of the adjacent steel supports 1 by steel wires 11, and the ends of the steel bar rows 10 are fixedly connected by steel wires 11; the assembled locking foot anchor comprises: a steel support 1, an anchor rod 2, an anchor rod pad 3, and an L-shaped pad 5, the left and right sides of the steel support 1 are provided with anchor rods 2, one end of the anchor rod 2 is inserted into the rock wall 7, and the other end passes through the anchor rod pad 3 and the L-shaped pad 5 in turn, and then is connected with the nut 4, the upper surface of the anchor rod pad 3 is fixedly connected to one end of the steel support 1, and the lower surface of the anchor rod pad 3 is fixedly connected to both ends of the L-shaped pad 5.

[0019] Preferably, the anchor rod 2 is a hollow structure, and a threading end 6 is provided at one end of the anchor rod 2 . The threading end 6 is a straight thread structure, and the threading end 6 has a diameter smaller than that of the anchor rod 2 .

[0020] Preferably, the anchor rod pad 3 is provided with two kidney holes.

[0021] A construction method of a support device for an open TBM passing through a gas tunnel of the present invention comprises the following steps:

[0022] (1) Arrange the assembled arch frame on the rock wall 7 at intervals of 1m in a circular manner, lay the assembled locking foot anchor rods on the left and right sides of the steel support 1 of the assembled arch frame, and arrange the connecting steel 13 of the assembled arch frame and the assembled locking foot anchor rods alternately along the steel support 1. Then, grouting reinforcement is performed on the connection between the assembled arch frame and the rock wall 7 by using the anchor rod 2 of the assembled locking foot anchor rod. At the same time, C30W10F50 shotcrete is used for the bottom paving with a thickness of 35cm.

[0023] (2) Use chemical grouting combined with polyether polyol to consolidate and wrap the TBM shield and cutterhead: Use a YT28 hand drill to insert a special chemical grouting DN15ABS catheter through the cutterhead slag collection port or the visible cavity of the shield. The catheter is inserted 5 to 10 cm above the top of the shield. After the two grouts are mixed in a special mixer and injected into the cracks or loose bodies, they will quickly diffuse, emulsify, foam, expand, and consolidate, filling the cavity between the shield and the rock mass to form a gel. Use chemical grouting (filling foaming consolidation type) combined with polyether polyol to chemically grout the installed catheter. The grouting construction is carried out from bottom to top and in a spaced-apart manner. The grouting pressure is not more than 0.3Mpa to ensure that the grout does not leak or leaks less when grouting the large-scale cavities in front of and on the top of the cutterhead;

[0024] (3) Use mortar to consolidate the loose bodies in front of and around the TBM cutterhead: ZLJ-700 drilling rigs and YQ100B light down-the-hole drilling rigs are used for pre-drilling around the cutterhead. The drilling rig positions are adjusted according to the TBM equipment space. ZLJ-700 drilling rigs are arranged on the upper part of the TBM main beam, and YQ100B light down-the-hole drilling rigs are arranged at the anchor drilling positions on both sides of the main beam. The hole opening position is 0.5m to 1m away from the edge of the shield, and the hole is drilled in front of the face of the head. Drill holes along the tail of the shield within a range of 180°, with a hole spacing of 50cm. Drilling can only be done in an inclined manner, with the outward inclination angle controlled at about 20°. After drilling, install the grouting pipe. The steel pipe is a seamless steel pipe of φ89mm and 6mm thick. M25 mortar is used for backfill grouting through the conduit. If the grouting effect is not ideal, the mortar consistency can be appropriately reduced or 0.5:1 cement slurry can be used for auxiliary grouting. The grouting construction is carried out from bottom to top, and every other hole is applied.

[0025] (4) Backfill the collapsed cavity on the top of the TBM shield and cutterhead: The large collapsed cavity on the top is backfilled in layers. The backfilling material is selected according to the depth of the collapsed cavity. C30 sprayed concrete, M25 mortar or lightweight concrete is used. When the depth of the collapsed cavity is less than 30 cm, C30 sprayed concrete is directly sprayed to the designed structure. When the depth of the collapsed cavity is greater than 30 cm and less than 1 m, M25 mortar is used for backfilling. When the depth of the collapsed cavity is greater than 1 m, lightweight concrete is used for backfilling and compaction. When backfilling lightweight concrete, if lightweight concrete flows out from the gap between the cutterhead and the shield, chemical grouting (filling foaming consolidation type) combined with polyether polyol is first used to fill and seal the gap. In addition, when backfilling lightweight concrete for the first time, grouting is started from the first layer of backfill pipe. When slurry flows out between the first layer of exhaust pipe and the rock wall, the backfilling is completed at one time. Use the air duct to blow away the remaining material in the second layer backfill pipe; after the strength of the lightweight concrete of the first backfill reaches the standard, seal the first layer backfill pipe opening and carry out the second backfill; during the second backfill, grouting is carried out from the second layer backfill pipe. When slurry flows out of the second layer exhaust pipe, the second backfill is completed and the second layer backfill pipe opening is sealed. After the second layer backfill is completed, determine whether to carry out the third backfill according to the situation;

[0026] (5) Several advanced pipe sheds are constructed within 120° of the top arch (using ZLJ-700 drilling rig for drilling, the pipe shed length is 30m, and the steel pipe is φ89mm, 6mm thick seamless steel pipe). The advanced pipe sheds are evenly arranged within 120° along the outer contour of the arch at the rear of the TBM shield, and the distance between the advanced pipe sheds is 50cm, arranged in a plum blossom shape (no holes are set in the 8m section between the shield and the upper part of the cutterhead, and grouting holes are set in the section from 8m to 30m, with a hole diameter of 6mm, and 2 holes are set in each ring);

[0027] (6) For tunnel sections in high-gas coal-bearing strata, use airtight concrete (concrete mixed with airtight agent, with a permeability coefficient not greater than 10). -11 cm / s) for secondary lining;

[0028] (7) For tunnel sections in high-gas coal-bearing strata, closed-cell plastic panels are added between the lining concrete and the shotcrete (the closed-cell plastic panels are 5 mm thick and the structural joints of the closed-cell plastic panels are connected by bonding).

[0029] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments and various changes can be made thereto within the knowledge scope of those skilled in the art.

Claims

1. A support device for open TBM construction through a gas tunnel, characterized in that: include: An assembled arch frame, an assembled foot locking anchor rod; the assembled arch frame comprises: a steel support (1), a steel bar ring (8), a short steel bar (9), a steel bar row (10), a steel wire (11), and a connecting steel (13); the two ends of the connecting steel (13) are respectively fixedly connected to the wing plates at one end of two steel supports (1) by bolts (12); the wing plates at the other ends of the steel supports (1) are fixedly connected to the short steel bars (9); the steel bar ring (8) is respectively fixedly connected to the steel bar row (10) and the short steel bars (9); the steel bar row (10) is fixedly connected to the wing plates of adjacent steel supports (1) by steel wires (11). The ends of the steel bar rows (10) are fixedly connected by steel wires (11); the assembled locking anchor comprises: a steel support (1), an anchor rod (2), an anchor rod pad (3), and an L-shaped pad (5); the steel support (1) is provided with anchor rods (2) on the left and right sides; one end of the anchor rod (2) is inserted into the rock wall (7), and the other end passes through the anchor rod pad (3) and the L-shaped pad (5) in sequence, and then is connected with the nut (4); the upper surface of the anchor rod pad (3) is fixedly connected to one end of the steel support (1), and the lower surface of the anchor rod pad (3) is fixedly connected to both ends of the L-shaped pad (5).

2. The support device for open TBM construction through a gas tunnel according to claim 1, characterized in that: A threading end (6) is provided at one end of the anchor rod (2); the threading end (6) is a straight thread structure; and the threading end (6) has a smaller diameter than the anchor rod (2).

3. The support device for open TBM construction through gas tunnel according to claim 1, characterized in that: The anchor rod pad (3) is provided with two kidney holes.

4. A support device for open TBM construction through a gas tunnel according to claim 1, characterized in that: The steel support (1) is in an arc-shaped structure.

5. A construction method using the support device for open TBM crossing a gas tunnel construction according to claim 1, comprising the following steps: 1) Arrange the assembled arch frame on the rock wall (7) at intervals of 1 m in a circular manner, arrange the assembled locking foot anchor rods on the left and right sides of the steel support (1) of the assembled arch frame, arrange the connecting steel (13) of the assembled arch frame and the assembled locking foot anchor rods alternately along the steel support (1), and then use the anchor rods (2) of the assembled locking foot anchor rods to grout the connection between the assembled arch frame and the rock wall (7); 2) Use chemical grouting combined with polyether polyol to consolidate and wrap the TBM shield and cutterhead; 3) Use mortar to consolidate the loose bodies in front of and around the TBM cutterhead; 4) Use lightweight concrete or mortar to backfill the collapsed cavity on the TBM shield and cutterhead top in layers; 5) Several advance pipe sheds are constructed within 120° of the top arch. The advance pipe sheds are evenly arranged within 120° of the outer contour of the arch at the rear of the TBM shield, and the distance between the advance pipe sheds is 50 cm; 6) Use airtight concrete for secondary lining in tunnel sections with high gas coal-bearing strata; 7) Add closed-cell plastic panels between the lining concrete and shotcrete of tunnel sections in high-gas coal-bearing strata.

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