Safety supporting structure and method for special-shaped intersection point of inclined shaft of TBM (Tunnel Boring Machine) construction coal mine

Abstract

The invention discloses a TBM construction coal mine inclined shaft special-shaped intersection point safety supporting structure and method, and belongs to the technical field of roadway supporting. The safety supporting structure comprises an umbrella-shaped supporting structure and a concentric-square-shaped supporting structure. The umbrella-shaped supporting structure is arranged in an inclined shaft of the intersection point, and the concentric-square-shaped supporting structure is arranged in a branch roadway fork wall body of the intersection point; in the construction process, the inclined shaft duct piece is firstly supported, then fork outer layer supporting and fork wall body supporting are conducted, the fork wall body is poured, and after a pouring body is stabilized, the umbrella-shaped supporting structure is dismantled; the umbrella-shaped supporting structure and the concentric-square-shaped supporting structure are organically integrated into the special-shaped intersection point, the total-factor supporting requirement of the special-shaped intersection point can be met, and the problems that at present, the supporting structure of the special-shaped intersection point in the TBM construction coal mine inclined shaft is poor in stability, low in adaptability and insufficient in barrier property are solved.

Description

Technical Field

[0001] This invention belongs to the field of shaft and tunnel support technology, and relates to the safety support structure of inclined shafts, specifically a safety support structure and method for irregular intersection points of inclined shafts in TBM-constructed coal mines. Background Technology

[0002] As a key component of the mine development and ventilation system, the construction safety and efficiency of inclined shafts directly impact the mine's operational benefits. In recent years, with the introduction of TBM (Tunnel Boring Machine) technology, the construction efficiency and roadway quality of inclined shafts have significantly improved. However, the design of support structures at irregular intersections (such as intersections between inclined shafts and roadways, entrances, and slope change sections) still faces severe challenges. TBM construction uses arc-shaped segment lining support, which differs from conventional mine roadway support. The openings at intersections severely disrupt the integrity of the segments, resulting in complex stress mechanisms at the intersections. Improper operation can easily lead to accidents such as surrounding rock instability and roof collapse, becoming a technical bottleneck restricting the efficient tunneling of coal mine TBMs.

[0003] For TBM construction in coal mines, there is currently a lack of mature and reliable design and construction standards in the domestic coal mining industry, and existing technologies lack systematic solutions. Construction at irregular intersections in coal mines often references tunnel junction construction techniques, with support structures mainly relying on segment lining or temporary supports. However, conventional methods have significant limitations for the special working conditions of irregular intersections in coal mines. For example, in weak surrounding rock or fractured zones, traditional segment structures struggle to adapt to dynamic load changes, easily leading to local deformation and instability at the intersection; in gas-bearing or aquifer sections, insufficient sealing and impermeability of the support structure may induce secondary disasters.

[0004] Existing technologies for irregular junctions in coal mines mostly employ simple junction support structures or masonry arch junction support structures. Simple junctions are supported by canopy-type supports or riprap walls with steel beams, offering simple structures and convenient construction, but are only suitable for situations with good surrounding rock conditions and a short service life. Masonry arch junctions use concrete or reinforced concrete arches for support, providing robust structures and high load-bearing capacity, but are only suitable for junction widths not exceeding 6 meters. Furthermore, these technologies tend to focus on optimizing single functions and fail to integrate the comprehensive support requirements of irregular junctions, particularly in structural connections and load transfer, lacking innovative technologies that combine stability, adaptability, and safety. Summary of the Invention

[0005] This invention overcomes the shortcomings of existing technologies and proposes a safety support structure and method for irregular intersection points in TBM-constructed coal mine inclined shafts. It solves the problems of poor stability, low adaptability, and insufficient barrier properties of current support structures at irregular intersection points in TBM-constructed coal mine inclined shafts. This invention is achieved through the following technical solution: A safety support structure for irregular intersection points in a TBM-constructed coal mine inclined shaft includes an umbrella-shaped support structure and a U-shaped support structure. The umbrella-shaped support structure is installed inside the inclined shaft at the intersection point and includes an arc-shaped top beam, a horizontal bracing beam, and a single column. The arc-shaped top beam is suspended from the inner side of the top segment of the inclined shaft by anchor cables. The horizontal bracing beam is horizontally installed at both ends of the arc-shaped top beam, and the single column is vertically installed below both ends of the horizontal bracing beam. The U-shaped support structure is installed in the wall of the branch roadway at the intersection point and includes a gantry device and longitudinal and transverse steel reinforcement mesh. The gantry device and longitudinal and transverse steel reinforcement mesh are cast into the wall of the branch roadway by concrete.

[0006] Furthermore, an anti-tipping chain is installed on the upper part of the single column, and the anti-tipping chain is connected to the cross brace beam.

[0007] Furthermore, the two ends of the cross brace beam are welded with lining plates, which contact and support the arched top beam.

[0008] Furthermore, the upper and lower ends of the single column are respectively equipped with U-shaped top pads and bottom pads. The U-shaped top pads face upwards to support the cross bracing beams, and the bottom pads are placed on the bottom plate of the inclined shaft.

[0009] Furthermore, the gantry device includes a gantry top beam and gantry column beams; the gantry top beam is located on the top of the wall at the branch roadway junction, and the gantry column beams are vertically located below both ends of the gantry top beam.

[0010] Furthermore, the gantry assembly also includes a temporary column, which is vertically positioned below the middle of the top beam of the gantry.

[0011] Furthermore, gantry pads are provided at the bottom of both the gantry beams and temporary columns.

[0012] Furthermore, the top slab and two sides of the fork wall are supported by grouting anchors and metal mesh, the surrounding rock of the fork is reinforced by grouting anchors, and the metal mesh on the top beam of the gantry is arranged close to the top of the wall.

[0013] Furthermore, pre-embedded bolts are installed on the cut surfaces of the pipe segments around the junction wall, and the longitudinal and transverse steel meshes are tied together with the pre-embedded bolts.

[0014] A method for safety support at irregular intersection points in inclined shafts of coal mines constructed using TBMs, based on the aforementioned safety support structure for irregular intersection points in inclined shafts of coal mines constructed using TBMs, includes the following steps: Step 1, Inclined shaft segment support: First, suspend the arc top beam over the exposed section of the anchor cable of the top segment, then horizontally install the cross brace beam, and then install the single column support below both ends of the cross brace beam; Step 2, outer support of the junction: According to the design dimensions of the junction, cut the pipe segments at the junction of the branch roadway, then excavate the surrounding rock of the junction wall, and then support the top plate and both sides of the wall. Step 3, Forkway wall support: After the outer layer of support for the forkway is completed, a U-shaped support structure is installed in the forkway wall; Step 4, Intersection Point Casting and Removal: Set up formwork at the intersection point and cast concrete into the intersection wall, including the gantry device and longitudinal and transverse steel mesh; after the cast body is stable, remove the umbrella-shaped support structure installed in the inclined shaft and continue construction of the branch tunnel according to the design requirements.

[0015] The beneficial effects of this invention compared to the prior art are as follows: 1. This invention innovatively proposes an umbrella-shaped support structure, installed within the inclined shaft at the intersection point. It consists of an arc-shaped top beam, a crossbeam, and individual columns, and is suspended from the inner side of the top segments of the inclined shaft by anchor cables. Under stress, the mine pressure at the top of the inclined shaft is distributed to the top segments through the anchor cable support ring, then transferred to the arc-shaped top beam (the outer side of the arc-shaped top beam is in contact with the inner side of the top segments, resulting in more even stress distribution), then to the crossbeam (where stress is concentrated), and finally transferred to the bottom plate of the inclined shaft through the individual columns supporting both ends of the crossbeam. The bottom plate then transfers the stress to the bottom segments, thus achieving stress closure between the top and bottom segments of the inclined shaft. This ensures reliable load transfer, strong structural support capacity, and guarantees the stability of the inclined shaft segments after the intersection point opens.

[0016] 2. This invention innovatively proposes a U-shaped support structure, consisting of a gantry device and longitudinal and transverse steel mesh, installed at the junction of branch roadways. During construction, grouting anchors and metal mesh are first used for outer support in the junction wall, then the U-shaped support structure is installed, and finally, concrete is poured to enclose the junction wall. This composite support structure, consisting of an outer anchor mesh, a middle layer of steel beams, and an inner layer of concrete, effectively supports the top mine pressure at the junction of branch roadways, exhibiting high stability and good barrier properties. The concrete wall pouring and grouting reinforcement of the anchors improve the sealing and impermeability of the junction wall and the surrounding rock, making it applicable to irregular junctions in gas-bearing or water-bearing sections, solving the technical problem of secondary disasters that may be induced at coal seam openings in inclined shafts of coal mines.

[0017] 3. This invention organically integrates umbrella-shaped support structure and loop-shaped support structure into irregular intersection points, which can meet the full-element support requirements of irregular intersection points. Compared with the simple intersection point or masonry arch intersection point support structure in the prior art, it has stronger adaptability. It is not only suitable for conventional coal mine inclined shaft irregular intersection point support, but also applicable to situations with poor surrounding rock conditions, long service life, and large intersection span. Its structural connection is stable, load transfer is smooth, and it has the characteristics of high stability, strong adaptability, good barrier properties, and safety and reliability.

[0018] 4. This invention utilizes both umbrella-shaped and loop-shaped support structures to jointly support the top of the intersection point under mine pressure, providing strong support capacity and ensuring the stability and safety of the intersection point after segment cutting. Pre-embedded bolts are installed on the segment cutting surfaces around the intersection wall, and the longitudinal and transverse steel meshes are tied together with the pre-embedded bolts. Finally, concrete is used to pour the gantry top beam, gantry column beam, longitudinal and transverse steel meshes, and pre-embedded bolts into the intersection wall, connecting the inclined shaft segments and the branch roadway into a unified support system, further improving the overall stability of the irregular intersection point.

[0019] 5. The umbrella-shaped support structure provided by this invention has lining plates welded to both ends of the crossbeam, which increases the contact area between the two ends of the crossbeam and the top beam, making the force transmission between the two components more uniform and stable; the upper and lower ends of the single column are respectively provided with U-shaped top pads and bottom pads, and are connected to the crossbeam with anti-tipping chains, which not only increases the contact area of ​​the force-bearing structure, but also prevents the single column from becoming unstable and collapsing; at the same time, this structure is easy to install and disassemble, and can be recycled and reused. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the planar arrangement of the irregular intersection points described in this invention; Figure 2 This is a cross-sectional layout diagram of the middle section of the irregular intersection point described in this invention; Figure 3 This is a cross-sectional layout diagram of the two ends of the irregular intersection point described in this invention; Figure 4 This is a schematic diagram of the umbrella-shaped support structure arrangement described in this invention; Figure 5 This is a cross-sectional layout diagram of the fork wall at the irregular intersection point described in this invention; Figure 6 This is a schematic diagram of the arrangement of the gantry device described in this invention.

[0021] In the diagram: 1—Inclined shaft; 2—Branch tunnel; 3—Anchor cable; 4—Arch top beam; 5—Horizontal bracing beam; 6—Single column; 7—Liner plate; 8—U-shaped top pad block; 9—Bottom pad block; 10—Anti-chainlock; 11—Grouting anchor rod; 12—Metal mesh; 13—Gantry top beam; 14—Gantry column beam; 15—Temporary column; 16—Gantry pad block; 17—Embedded bolt; 18—Longitudinal and transverse steel mesh; 19—Concrete. Detailed Implementation

[0022] To make the technical problems to be solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solutions of this invention are described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0023] This embodiment describes the intersection of the No. 4 coal seam in the auxiliary inclined shaft of a coal mine. The auxiliary inclined shaft is constructed using a TBM (tunnel boring machine), with arc-shaped segment lining support. The shaft has an inclination angle of 6°, an inner diameter of 6.6m, a segment thickness of 0.35m, and a segment width of 1.5m. The No. 4 coal seam branch roadway has a net width of 4.0m and a net height of 3.2m, with an angle of 30° between the branch roadway and the shaft. The designed intersection point has a net width of approximately 9.3m. Due to the poor stability of the surrounding rock at this intersection point and the risk of gas outburst, the proposed non-standard intersection point safety support structure and method are used during construction to ensure the stability and safety of the intersection point. Figures 1-6 As shown in the figure, this embodiment provides a safety support structure and method for irregular intersection points in TBM-constructed coal mine inclined shafts, including the following steps: Step 1, Inclined Shaft Segment Support: First, install anchor cables 3 to suspend and reinforce the top segments of inclined shaft 1 at the intersection point and the upper segments on the non-intersection side, and then install an umbrella-shaped support structure to support the top segments.

[0024] During on-site construction, if there is a risk of gas outburst or aquifer at the intersection point, measures should be taken in advance and detection should be strengthened to ensure construction safety.

[0025] Furthermore, such as Figure 2 , Figure 3 As shown, anchor cables 3 are installed at the transverse centerline of each group of tunnel segments within inclined shaft 1. The spacing between anchor cables 3 is 1.0m to 1.5m, and the row spacing is equal to the width of the tunnel segment. The number of rows of anchor cables 3 should be 2 to 4 more than the number of tunnel segments within the designed net width range of the branch roadway 2; simultaneously, combined with Figure 1 As shown, each row of anchor cables 3 below the top segment is equipped with an umbrella-shaped support structure inside the shaft, meaning the number of umbrella-shaped support structures equals the number of rows of anchor cables 3. During on-site construction, the drilling of anchor cables 3 can utilize the segment hoisting holes to reduce segment drilling work, but the spacing of anchor cables 3 must be considered. The spacing of anchor cables 3 should be reasonably determined based on factors such as the shaft inner diameter, surrounding rock pressure, and bifurcation size. The length of anchor cables 3 should allow the anchoring agent to be anchored into stable rock strata. If the pull-out resistance of anchor cables 3 cannot meet the design requirements, grouting reinforcement measures must be taken for the surrounding rock. Anchor cables 3 installed to the top segment should have an exposed section of 300mm to 500mm.

[0026] Furthermore, the umbrella-shaped support structure is installed within the inclined shaft 1 at the intersection point, including an arc-shaped top beam 4, a horizontal bracing beam 5, and a single column 6, as shown below. Figure 4As shown, during installation, the arc-shaped top beam 4 is first suspended from the exposed section of the anchor cable 3 of the top segment, then the horizontal bracing beam 5 is installed horizontally (the horizontal bracing beam 5 lies horizontally across both ends of the arc-shaped top beam 4), and finally, the individual column 6 is installed to support the ends of the horizontal bracing beam 5. For material processing, it is recommended that the arc-shaped top beam 4 be made of channel steel, and the outer radius of the arc-shaped top beam 4 should match the inner radius of the top segment. The pre-drilled holes in the arc-shaped top beam 4 should match the spacing of the anchor cables 3 used to anchor the top segment. It is recommended that the horizontal bracing beam 5 be made of I-beams, with a length slightly less than the straight-line distance between the two ends of the arc-shaped top beam 4. The ends of the horizontal bracing beam 5 should be machined into a wedge shape. When selecting materials, the specifications and dimensions of the arc-shaped top beam 4, horizontal bracing beam 5, and individual column 6 should be reasonably determined based on factors such as the inner diameter of the shaft, the surrounding rock pressure, the size of the branch, and the maximum transport height of the equipment.

[0027] Furthermore, such as Figure 4 As shown, the cross bracing beam 5 has lining plates 7 welded to both ends, which contact and support the arc-shaped top beam 4. The upper and lower ends of the single column 6 are respectively equipped with U-shaped top pads 8 and bottom pads 9. The U-shaped top pads 8 have their U-shaped openings facing upwards to support the cross bracing beam 5, and the bottom pads 9 rest on the bottom plate of the inclined shaft 1. An anti-tipping chain 10 is installed on the upper part of the single column 6, and the anti-tipping chain 10 is connected to the cross bracing beam 5. During material processing, the lining plates 7 should be pre-welded to the wedge-shaped parts at both ends of the cross bracing beam 5, and the dimensions of the lining plates 7 should be such that they fit snugly and support the arc-shaped top beam 4. The U-shaped top pads 8 can be made of U-shaped steel and steel plates, and the U-shaped opening dimensions should match the specifications of the cross bracing beam 5. During on-site construction, an additional layer of rubber pads can be reasonably added between the U-shaped top pad 8 and the single column 6 and the cross bracing beam 5 to increase the friction between the materials; the material of the anti-tipping chain 10 is not limited, as long as it can prevent the single column 6 from becoming unstable and collapsing; the lateral spacing between the single columns 6 on both sides should meet the safety of equipment and personnel passage during the construction of the intersection point, and the lateral spacing between the single columns 6 on both sides is usually not less than 2.5m.

[0028] Specifically, in this embodiment, the anchor cable 3 is made of Φ21.8×11300mm steel strand, and is set at the transverse centerline of each group of segments in the inclined shaft 1, with a spacing of 1.2m and a row spacing of 1.5m (equal to the segment width), for a total of 8 rows (2 more rows than the number of segments within the net width of the fork). Each group of top segments has three sets of anchor cables 3, with an exposed section length of approximately 450mm. The umbrella-shaped support structure has a total of 8 rows, with a row spacing of 1.5m (equal to the segment width). The arc top beam 4 is made of 20b channel steel, with an arc length of 4.3m and an outer radius of 3.3m. The cross brace beam 5 is made of 20a I-beam, with a length of 3.8m and a wedge angle of 35° at both ends. The single column 6 is of specification DW35-180 / 100X, and the transverse net spacing between the two single columns 6 is 3.2m.

[0029] Step 2, Outer Support of the Fork: According to the design dimensions of the intersection point, cut the pipe segments at the fork of branch roadway 2, then excavate the surrounding rock of the fork wall, and then use grouting anchor bolts 11 and metal mesh 12 for support on the top slab and both sides of the wall, and use grouting anchor bolts 11 to reinforce the surrounding rock of the fork. Figures 1-3 , Figure 5 As shown.

[0030] During on-site construction, the number of segments to be cut should be 2-4 more than the number of segments within the designed net width of the branch roadway 2 intersection. It is recommended to cut the entire segment group and avoid cutting segments vertically. During construction, first cut the segments along the transverse outline according to the design dimensions of the intersection using a water drill, and then remove the segments group by group. The spacing of the grouting anchor bolts 11 should be reasonably determined based on factors such as the surrounding rock pressure and intersection dimensions.

[0031] Specifically, in this embodiment, a total of 8 sets of pipe segments were cut and removed (2 more sets than the number of pipe segments within the net width of the fork, and the number of sets is equal to the number of 3 rows of anchor cables). The grouting anchor rod 11 is a hollow grouting anchor rod with a diameter of 20×2000mm. The metal mesh 12 is a φ6mm steel mesh with a mesh spacing of 100×100mm. The surrounding rock of the fork is reinforced with cement mortar with a water-cement ratio of 0.45.

[0032] Step 3, Forkway Wall Support: After the outer layer of forkway support is completed, immediately install a U-shaped support structure in the forkway wall. The U-shaped support structure includes a gantry assembly and longitudinal and transverse steel mesh 18. The gantry assembly includes a gantry top beam 13, a gantry column beam 14, and temporary columns 15. Figure 5 , Figure 6 As shown; during installation, first set the gantry top beam 13 at the top of the fork wall, then vertically install the gantry column beam 14 in the fork wall below both ends of the gantry top beam 13, and vertically install the temporary column 15 below the middle of the gantry top beam 13 for support; then install the pre-embedded bolts 17 on the segment cutting surface around the fork wall, and then tie the longitudinal and transverse steel mesh 18 inside the bottom plate, side wall and top plate of the fork.

[0033] During on-site construction, the specifications and models of the gantry top beam 13, gantry column beam 14, and temporary column 15 should be reasonably determined based on factors such as the surrounding rock pressure and the dimensions of the fork. It is recommended that the gantry top beam 13 be made of I-beams, and its length should be at least 2.0m longer than the designed net width of the fork (i.e., each end should extend into the wall at least 1.0m). The gantry top beam 13 should be arranged close to the metal mesh 12 at the top of the wall. In order to facilitate transportation and installation, the gantry top beam 13 can be divided into 2 to 4 sections and connected into a whole beam by means of joint locking and riveting. It is recommended that the gantry column beam 14 be made of I-beams, and the upper end can be equipped with corresponding top pads and rubber pads in the manner of the aforementioned single column 6.

[0034] Furthermore, such as Figure 1 , Figure 5 , Figure 6 As shown, in the U-shaped support structure, 2 to 3 groups of gantry devices are set. Each group of gantry devices includes one gantry top beam 13, four gantry column beams 14, and one temporary column 15. Two gantry column beams 14 are set below each end of the gantry top beam 13. The bottom of the gantry column beams 14 and the temporary column 15 are provided with gantry pads 16. The temporary column 15 should be removed before the concrete 19 is poured. Two embedded bolts 17 are arranged in each group for the segment cutting surface. The spacing between the embedded bolts 17 in each group is 1.0m to 1.5m. The longitudinal and transverse steel mesh 18 should be tied together with the embedded bolts 17. The spacing between the steel bars in the longitudinal and transverse steel mesh 18 is 150mm to 300mm.

[0035] During on-site construction, the number of gantry devices should be reasonably determined based on factors such as the surrounding rock pressure at the junction, the junction size, and the junction wall thickness. Usually, there are two sets, one set on each side along the junction wall thickness direction. When the junction wall thickness is relatively thick (greater than or equal to 1.5m), an additional set can be added in the middle, i.e., three sets can be arranged. In one set of gantry devices, the two gantry beams 14 at each end can be arranged side by side to increase the overall stability of the gantry beams 14. When the junction wall width is large, the number and position of temporary columns 15 can be reasonably adjusted. The exposed length of the pre-embedded bolts 17 shall not be less than 300mm, so as to facilitate binding with the longitudinal and transverse steel mesh 18. When binding the longitudinal and transverse steel mesh 18, the pre-installed gantry device and metal mesh 12 in the bifurcation wall should be taken into account, and they can be bound together. It is recommended that the longitudinal and transverse steel mesh 18 be constructed in the following order: first the bottom slab, then the side walls, and finally the top slab. The spacing between the steel bars in the longitudinal and transverse steel mesh 18 should be reasonably adjusted to facilitate the pouring of concrete 19 and to meet the strength requirements of the wall after pouring.

[0036] Specifically, in this embodiment, two sets of gantry devices are installed in the fork wall. The gantry top beam 13 and the gantry column beam 14 are both made of 20a I-beams. The length of the gantry top beam 13 is 11.5m (2.2m more than the net width of the fork 9.3m), and the length of the gantry column beam 14 is 4.6m. The temporary column 15 is the existing hydraulic support of the mine. The embedded bolts 17 are made of Φ20×800mm threaded steel with an exposed length of 400mm. The longitudinal and transverse steel mesh 18 is made of Φ20 HRB335 steel bars with a spacing of about 250mm between the bars.

[0037] Step 4, Intersection Point Casting and Removal: After the longitudinal and transverse steel mesh 18 is tied, the formwork is erected according to the design dimensions of the intersection point, the temporary column 15 is removed, and concrete 19 is used to cast the intersection wall, including the metal mesh 12, the portal frame top beam 13, the portal frame column beam 14, the longitudinal and transverse steel mesh 18, etc. After the cast body is basically stable, the umbrella-shaped support structure installed in the inclined shaft 1 is removed, and the branch tunnel 2 is constructed according to the design requirements.

[0038] During on-site construction, the strength grade of concrete 19 shall not be lower than C35. A certain amount of early strength agent, waterproofing agent and other additives shall be added to concrete 19 to ensure the stability of the reinforced concrete fork wall. After the concrete 19 pouring body reaches the design strength, the formwork shall be removed first, and then the umbrella support structure shall be removed.

[0039] Specifically, in this embodiment, the strength grade of concrete 19 is C40, and the thickness of the concrete 19 wall at the fork is as follows: 1.2m~1.5m on both sides, 0.8m on the top, and 0.6m on the bottom.

[0040] Finally, the No. 4 coal seam intersection point of the auxiliary inclined shaft in this embodiment was successfully completed. The auxiliary inclined shaft project successfully passed the acceptance of the superior unit and the quality inspection station. Since the completion of this irregular intersection point, no adverse phenomena such as instability, shaft wall cracking, water leakage, or gas outburst have occurred, which proves the feasibility and safety of the TBM construction safety support structure and method for irregular intersection points of coal mine inclined shafts proposed in this invention.

[0041] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0042] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A TBM construction coal mine inclined shaft special-shaped intersection point safety support structure, characterized in that, It includes an umbrella-shaped support structure and a loop-shaped support structure; the umbrella-shaped support structure is set in the inclined shaft (1) at the intersection point, and the umbrella-shaped support structure includes an arc top beam (4), a horizontal support beam (5), and a single column (6); the arc top beam (4) is suspended on the inner side of the top segment of the inclined shaft (1) by anchor cables (3), the horizontal support beam (5) is set horizontally at both ends of the arc top beam (4), and the single column (6) is set vertically below both ends of the horizontal support beam (5); the loop-shaped support structure is set in the wall of the branch roadway (2) at the intersection point, and the loop-shaped support structure includes a gantry device and longitudinal and transverse steel mesh (18); the gantry device and longitudinal and transverse steel mesh (18) are poured into the wall of the branch roadway (2) by concrete (19).

2. The safety support structure for irregular intersection points in TBM-constructed coal mine inclined shafts according to claim 1, characterized in that, An anti-tipping chain (10) is provided on the upper part of the single column (6), and the anti-tipping chain (10) is connected to the cross brace (5).

3. A safety support structure for irregular intersection points in a TBM-constructed coal mine inclined shaft according to claim 2, characterized in that, The cross bracing beam (5) has lining plates (7) welded to both ends, and the arch top beam (4) is supported by the lining plates (7).

4. A safety support structure for irregular intersection points in TBM-constructed coal mine inclined shafts according to claim 2, characterized in that, The top and bottom ends of the single column (6) are respectively provided with U-shaped top pad (8) and bottom pad (9). The U-shaped top pad (8) faces upward to support the cross bracing beam (5), and the bottom pad (9) rests on the bottom plate of the inclined shaft (1).

5. A safety support structure for irregular intersection points in a TBM-constructed coal mine inclined shaft according to claim 1, characterized in that, The gantry device includes a gantry top beam (13) and a gantry column beam (14); the gantry top beam (13) is located on the top of the wall at the junction of the branch roadway (2), and the gantry column beam (14) is vertically located below both ends of the gantry top beam (13).

6. A safety support structure for irregular intersection points in TBM-constructed coal mine inclined shafts according to claim 5, characterized in that, The gantry assembly also includes a temporary column (15), which is vertically positioned below the middle of the top beam (13) of the gantry.

7. A safety support structure for irregular intersection points in TBM-constructed coal mine inclined shafts according to claim 6, characterized in that, Both the bottom of the portal frame beam (14) and the temporary column (15) are provided with portal frame pads (16).

8. A safety support structure for irregular intersection points in a TBM-constructed coal mine inclined shaft according to claim 5, characterized in that, The top slab and two sides of the wall at the fork are supported by grouting anchors (11) and metal mesh (12). The surrounding rock at the fork is reinforced by grouting anchors (11). The top beam (13) of the portal frame is arranged close to the metal mesh (12) on the top of the wall.

9. A safety support structure for irregular intersection points in TBM-constructed coal mine inclined shafts according to claim 1, characterized in that, Pre-embedded bolts (17) are installed on the cut surfaces of the pipe segments around the junction wall, and longitudinal and transverse steel mesh (18) are tied together with the pre-embedded bolts (17).

10. A method for safety support at irregular intersection points in inclined shafts of coal mines constructed using TBMs, characterized in that, The safety support structure for irregular intersection points of TBM-constructed coal mine inclined shafts according to any one of claims 1-9 includes the following steps: Step 1, Inclined shaft segment support: First, suspend the top arc beam (4) on the exposed section of the anchor cable (3) of the top segment, then horizontally install the cross brace beam (5), and then install the single column (6) to support the bottom of both ends of the cross brace beam (5); Step 2, outer support of the fork: cut the pipe segments at the fork of the branch roadway (2) according to the design dimensions of the intersection, then excavate the surrounding rock of the wall at the fork, and then support the top plate and two sides of the wall. Step 3, Forkway wall support: After the outer layer of support for the forkway is completed, a U-shaped support structure is installed in the forkway wall; Step 4, Intersection Point Casting and Demolition: Set up formwork at the intersection point and cast concrete (19) to the intersection wall, including the portal frame device and longitudinal and transverse steel mesh (18); after the cast body is stable, remove the umbrella-shaped support structure installed in the inclined shaft (1) and continue to construct the branch tunnel (2) according to the design requirements.

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